Life Extension Magazine®

Issue: May 2017

Arterial protect, Oral probiotics, Glycation, and Cognitive decline

Arterial protect, Oral probiotics, Glycation, and Cognitive decline

Arterial protect

Atherosclerosis as an inflammatory disease.

In many ways, atherosclerosis is a chronic inflammatory disorder and this issue is confirmed by recent investigations that have focused on inflammation, providing new insight into mechanisms of disease. Several recent studies have addressed the role of chemokines in leukocyte accumulation in atherosclerosis, extending our knowledge and understanding of the complex and cell type-specific functions of chemokines in atherosclerosis. Activated T-lymphocytes within the atherosclerotic vessel wall express the CD40 ligand surface molecule, known to play a major role in several immunological pathways. In addition to activated T-lymphocytes, functional CD40 and CD40L are coexpressed by human vascular endothelial cells, smooth muscle cells and human macrophages in vitro as well as in situ in human atherosclerotic lesions. Recent studies indicate that CD40L activates atheroma-associated cells by promoting the expression of molecules thought to be involved in atherosclerosis, such as adhesion molecules, cytokines, matrix metalloproteinases, and tissue factor. Atherosclerosis starts with an innate immune response involving the recruitment and activation of monocytes macrophages that respond to an excessive accumulation of modified lipids within the arterial wall, followed by an adaptive immune response involving antigen-specific T lymphocytes. Effector T cells recognize modified auto-antigens such as oxidized LDL and heat shock proteins (i.e. HSP-60) that are presented by antigen-presenting cells such as macrophages or dendritic cells. The accumulation of inflammatory cells within the arterial wall leads to local production of chemokines, interleukins and proteases that enhance the influx of monocytes and lymphocytes, thereby promoting the progression of atherosclerotic lesions Recent reports have helped explain some of these questions by pointing to a role of contact dependent interaction between CD40 and CD40 ligand (CD40L, renamed CD154) as a stimulus for atheroma-associated cells. Also Macrophages play important roles in the progression of atherosclerosis by exhibiting unique characteristics under the various stimuli, evolving the plaque instability, thrombus formation and remodeling. Macrophage recruitment by abnormal endothelium over developing atherosclerotic plaques, is aided by endothelial expression of adhesion molecules (ICAM-1, VCAM, ELAM). The knowledge of atherosclerosis as an inflammatory disease offers the opportunity to develop novel therapeutic strategies targeting the inflammatory component of the disease.

Curr Pharm Des. 2012;18(28):4266-8

Pathophysiology of coronary artery disease.

During the past decade, our understanding of the pathophysiology of coronary artery disease (CAD) has undergone a remarkable evolution. We review here how these advances have altered our concepts of and clinical approaches to both the chronic and acute phases of CAD. Previously considered a cholesterol storage disease, we currently view atherosclerosis as an inflammatory disorder. The appreciation of arterial remodeling (compensatory enlargement) has expanded attention beyond stenoses evident by angiography to encompass the biology of nonstenotic plaques. Revascularization effectively relieves ischemia, but we now recognize the need to attend to nonobstructive lesions as well. Aggressive management of modifiable risk factors reduces cardiovascular events and should accompany appropriate revascularization. We now recognize that disruption of plaques that may not produce critical stenoses causes many acute coronary syndromes (ACS). The disrupted plaque represents a "solid-state" stimulus to thrombosis. Alterations in circulating prothrombotic or antifibrinolytic mediators in the "fluid phase" of the blood can also predispose toward ACS. Recent results have established the multiplicity of "high-risk" plaques and the widespread nature of inflammation in patients prone to develop ACS. These findings challenge our traditional view of coronary atherosclerosis as a segmental or localized disease. Thus, treatment of ACS should involve 2 overlapping phases: first, addressing the culprit lesion, and second, aiming at rapid "stabilization" of other plaques that may produce recurrent events. The concept of "interventional cardiology" must expand beyond mechanical revascularization to embrace preventive interventions that forestall future events.

Circulation. 2005 Jun 28;111(25):3481-8

Modification of the echogenicity of femoral plaques after treatment with total triterpenic fraction of Centella asiatica: a prospective, randomized, placebo-controlled trial.

The aim of this study was to evaluate whether TTFCA (total triterpenic fraction of Centella asiatica), was effective, by modulating collagen production, in a period of 12 months, increasing the echogenicity of echolucent plaques at the femoral bifurcation. Hypoechoic atherosclerotic plaques have been found to be associated with an increased evidence of cerebrovascular events. In this type of plaques stromal composition is limited as the collagen component is generally very low; the plaque composition is mainly due to lipid accumulation or thrombosis. The aim of this study was the evaluation of echogenicity of hyperechoic plaques and how it could be modified by a drug acting on the modulation of collagen synthesis. Antiplatelet agents were used in all patients; cholesterol-lowering agents were used in 34% of patients in the treatment group and in 36% in the placebo group. TTFCA was used at the dose of 60 mg thrice daily (oral tablets). Of the 60 included subjects 26 completed the study in the treatment group and 24 in the placebo group. At inclusion the average GSM in the treatment group was 14 (SD 3) and 14.3 (SD 3) in controls. At 12 months GSM was increased up to 22.8 (SD 4) in the treatment group and it was 15 (SD 3) in controls. Considering texture no significant changes were observed in controls while a qualitative increase in homogenicity was observed in the TTFCA group. Plaque size measured at the beginning and at the end of the study showed a median increase in size, in controls (23%; range 0%-44%); it was unchanged in the TTFCA group (variation 7%; 4%-26%). In conclusion in the treatment group plaques increased in echogenicity and in homogenicity; size and stenosis remained unchanged. Modulating the scarring process within echolucent plaques (low echogenicity, high echolucency, with a very low collagen/stromal component), possibly by collagen modulation, makes plaques more stable. This has been achieved and documented in the present study by an increase in the gray-scale median (plaques become more echogenic, more 'white'). The variation in GSM is generally associated with a lower risk of wall thrombosis, rupture and embolization. These observations indicate a positive action of TTFCA on the stabilization of hypoechoic, low-density femoral plaques.

Angiology. 2001 Oct;52 Suppl 2:S69-73

Total triterpenic fraction of Centella asiatica in chronic venous insufficiency and in high-perfusion microangiopathy.

Total triterpenic fraction of Centella asiatica (TTFCA) is effective in improving venous wall alterations in chronic venous hypertension and in protecting the venous endothelium. TTFCA is active on connective tissue modulation, improves the synthesis of collagen and other tissue proteins by modulating the action of fibroblasts in the vein wall, and stimulates collagen remodeling in and around the venous wall. This is due to the modulating action of TTFCA on fibroblasts as shown by experiments on the growth of human embryonal fibroblasts. TTFCA has a moderate in-vitro and in-vivo stimulating effect on collagen synthesis and, at higher dosages, an inhibition on the synthesis of collagen and acid mucopolysaccharides. Studies have indicated the role of TTFCA on the synthesis of specific venous wall elements by cell cultures of human embryonal fibroblasts. The tissue-stimulating action is shown by the increased collagen production independent from the stimulation of cell proliferation (this differentiates the action of TTFCA from cell growth factors). TTFCA is active on the microcirculation in venous and diabetic microangiopathy. Signs and symptoms of venous hypertension and edema are improved by treatment. The remodeling on collagen synthesis could be one of the possible mechanisms of actions of TTFCA in the remodeling of echolucent (soft; therefore, with risk of thrombosis and embolization) plaques at the carotid and femoral bifurcation. This compound is safe and well tolerated. In conclusion, several actions of TTFCA in vascular diseases makes the use of this compound very interesting in venous and arterial problems.

Angiology. 2001 Oct;52 Suppl 2:S9-13

Pycnogenol® and Centella Asiatica for asymptomatic atherosclerosis progression.

METHODS: This was an observational pilot substudy of the San Valentino epidemiological cardiovascular study. The study included 1363 subjects aged 45-60 without any conventional risk factors who had non stenosing atherosclerotic plaques (<50%) in at least one carotid or common femoral bifurcation, allocated into 6 groups: Group 1 (CONTROLS): management was based on education, exercise, diet and lifestyle changes. This same management plan was used in all groups; Group 2 Pycnogenol 50 mg/day; Group 3 Pycnogenol 100 mg/day; Group 4 Aspirin 100 mg/day or Ticlopidine 250 mg/day if intolerant to aspirin; Group 5 Aspirin 100 mg/day and Pycnogenol 100 mg/day; Group 6 Pycnogenol 100 mg/day plus TECA (total triterpenic fraction of Centella Asiatica) 100 mg/day. There was a six monthly follow-up up to 30 months. Plaque progression was assessed using the ultrasonic arterial score based on the arterial wall morphology and the number of plaques that progressed from the non-stenotic to the stenotic group. A secondary endpoint was to evaluate the changes in oxidative stress at baseline and at 30 months. RESULTS: The ultrasonic score increased significantly in groups 1, 2 and 4 but not in groups 3, 5 and 6 suggesting a beneficial effect of Pycnogenol 100 mg. The percentage of plaques that progressed from class IV to class V was 8.4% in group 2, 5.3% in group 3, 4% in group 5 and 1.1% in group 6 (P<0.0001) compared with 16.6% in group 4 (aspirin) and 21.3% in the control group suggesting a beneficial effect of Pycnogenol. The lowest rate of progression was in group 6 (Pycnogenol plus TECA). At 30 months, the oxidative stress in all the Pycnogenol groups was less than in the control group. The oxidative stress was lower in the Pycnogenol 100 mg group than the Pycnogenol 50 mg group (P<0.0001). In the combined group of Pycnogenol and TECA the oxidative stress was less than the Pycnogenol alone (P<0.001). CONCLUSION: Pycnogenol and the combination of Pycnogenol+TECA appear to reduce the progression of subclinical arterial lesions in low-risk asymptomatic subjects. The reduction in plaque progression was associated with a reduction in oxidative stress. The results justify a large randomized controlled study to demonstrate the efficacy of the combined Pycnogenol and TECA prophylactic therapy in subclinical atherosclerosis.

Int Angiol. 2014 Feb;33(1):20-6M

Pycnogenol® and Centella asiatica in the management of asymptomatic atherosclerosis progression.

AIM: The aim of the study was to evaluate the effect of the nutritional supplements Pycnogenol® and total triterpenic fraction of Centella asiatica (TTFCA) on atherosclerosis progression in low-risk asymptomatic subjects with carotid or femoral stenosing plaques. METHODS: This was an observational pilot, substudy of the San Valentino epidemiological cardiovascular study. The study included 824 subjects aged 45-60 without any conventional risk factors who had a stenosing atherosclerotic plaque (>50-60%) in at least one carotid or common femoral bifurcation, allocated into 6 groups: Group 1 (Controls): management was based on education, exercise, diet and lifestyle changes. This same management plan was used in all other groups; group 2: Pycnogenol® 50 mg/day; group 3: Pycnogenol® 100 mg/day; group 4: Aspirin® 100 mg/day or ticlopidine 250 mg/day if intolerant to aspirin; group 5: Aspirin® 100 mg/day and Pycnogenol® 100 mg/day; group 6: Pycnogenol® 100 mg/day plus TTFCA 100 mg/day. The follow-up lasted 42 months. Plaque progression was assessed using the ultrasonic arterial score based on the arterial wall morphology and the number of plaques that progressed and on the number of subjects that had cardiovascular events. A secondary endpoint was to evaluate the changes in oxidative stress at baseline and at 42 months. RESULTS: The ultrasonic score increased significantly in groups 1, 2, and 4 (>1%) but not in groups 3, 5 and 6 (<1%) suggesting a beneficial effect of Pycnogenol® 100 mg. Considering the percent of patients that progressed from class V (asymptomatic) to VI (symptomatic) there was a progression of plaques in 48.09% of controls. In the Pycnogenol ® 100 (group 3, 10.4%) and in the Aspirin®+ Pycnogenol® (group 5, 10.68%) progression was half of what observed with antiplatelet agent (group 4, 20.93%); in the TTFCA+ Pycnogenol® group (group 6) progression was 7.4 times lower than in controls; 3.22 times lower than in the antiplatelet agents group (4). Events (hospital admission, specialized care) were observed in 16.03% of controls; there were 8.83% of subjects with events with Pycnogenol® 50 mg and 8% in group 3 (Pycnogenol® 100 mg). In group 4 (antiplatelets), 8.52% of subjects had events; in group 5, 6.87% of subjects had events and in group 6 (TTFCA+ Pycnogenol®) only 4.41% had events (this was the lowest event rate; P<0.05). All treatment groups had a significantly lower event rate (P<0.05) in comparison with controls. Considering treatments groups 2, 3, 5, 6 had a lower number (P<0.05) of subjects in need of cardiovascular management in comparison with controls. The need for risk factor management was higher in controls and lower in group 6 (P<0.05). In groups 2 to 6 the need for risk factor management was lower than in controls (P<0.05). Including all events (hospital admission, need for treatment or for risk management) 51.9% of controls were involved. In the other groups there was a reduction (from a -9.28% reduction in group 2 to a -26% in group 6) (P<0.002). The most important reduction (higher that in all groups; P<0.05) was in group 6. At 42 months, oxidative stress in all the Pycnogenol® groups was less than in the control group. In the combined group of Pycnogenol® and TTFCA the oxidative stress was less than with Pycnogenol® alone (P<0.001). CONCLUSION: Pycnogenol® and the combination of Pycnogenol® +TTFCA appear to reduce the progression of subclinical arterial plaques and the progression to clinical stages. The reduction in plaque and clinical progression was associated with a reduction in oxidative stress. The results justify a large, randomized, controlled study to demonstrate the efficacy of the combined Pycnogenol® and TTFCA prophylactic therapy in preclinical atherosclerosis.

Int Angiol. 2015 Apr;34(2):150-7

Effects of Pycnogenol® on endothelial dysfunction in borderline hypertensive, hyperlipidemic, and hyperglycemic individuals: the borderline study.

AIM: This registry study aimed to evaluate the effects of supplementation with pycnogenol on altered endothelial function (EF) in borderline hypertensive, hyperlipidemic and hyperglycemic subjects without atherosclerotic changes in their main arteries and no coronary artery disease. METHODS: Flow mediated dilatation (FMD) and endothelium-independent (EID) dilatation were measured with brachial ultrasound after occlusion. Also, after occlusion, laser Doppler (LDF) flux and distal straingauge flow were measured. Oxidative stress (oxstress) was evaluated at 8 and 12 weeks. 93 subjects with borderline symptoms were enrolled into the study: 32 hypertensives, 31 hyperlipidemics, 30 hyperglycemics. All participants were instructed to follow the best available management to control their symptoms. In addition to best management, half of the subjects in each group used 150 mg/day Pycnogenol®. 31 normal subjects were included as control. RESULTS: After 12 weeks metabolic values and blood pressure were back to normal in all subjects. Values were slightly better under Pycnogenol®. FMD increased after 8 weeks from an average 5.3;3.4% to 8.2;2.2% with a further increase to 8.8;3.1% (P<0.05) at 12 weeks. No effects were found in controls and normal subjects. EID of normal subjects was consistently higher with 26%. LDF skin flux increased with Pycnogenol® at 8 weeks and 12 weeks. The final flux increase was not different from normal values. In controls flux after occlusion was not improved at 8 weeks; there was a significant but minor increase at 12 weeks. Flux increases were superior in all Pycnogenol® subjects. In Pycnogenol® subjects, limb flow after occlusion increased at 8 weeks with a further increase at 12 weeks. In controls inclusion flow after occlusion was comparable at 8 and 12 weeks. Oxidative stress was significantly decreased in Pycnogenol® subjects at 8 and 12 weeks. Minor differences were observed in controls. CONCLUSION: This open registry study indicates that Pycnogenol® improves EF in preclinical, borderline subjects in a macro-microcirculatory model. This observation may suggest an important preventive possibility for borderline hypertensive, hyperglycemic and hyperlipidemic subjects.

Int Angiol. 2015 Feb;34(1):43-52

Increase in echogenicity of echolucent carotid plaques after treatment with total triterpenic fraction of Centella asiatica: a prospective, placebo-controlled, randomized trial.

The aim of this study was to evaluate whether total triterpenic fraction of Centella asiatica (TTFCA), was effective in modulating collagen production over 12 months, by producing an increase in echogenicity in echolucent carotid plaques. Part I was a pilot study aimed at evaluating the effects of TTFCA on different types of plaques. Part II was a prospective, randomized, placebo-controlled trial aimed at evaluating the effects of TTFCA on hypoechoic-echolucent plaques. The sonographic examination of carotid plaques was made with high-resolution ultrasound. Capturing, digital image processing, and normalization were standardized, interobserver, intrascanner, gain-level variability were standardized using as reference blood (black) for the most echolucent parts of the plaque and the adventitia (white) as the most echogenic part. Normalization of echo texture was obtained and plaque characterization differentiated echo-texture of plaque associated with events and those that did not cause embolization, thrombosis, or cardiovascular events. After identifying plaques at higher risk, patients were treated with TTFCA (oral tablets, 60 mg, thrice daily for 12 months) to evaluate whether this compound, by modulating collagen synthesis, could increase the echogenicity and therefore the stability of echolucent plaques. Part II was aimed at evaluating the effects of TTFCA on hypoechoic-echolucent plaques. Asymptomatic patients with echolucent plaques (GSM<18) were treated with TTFCA (60 mg, oral tablets three times daily for 12 months) or with comparable placebo after informed consent. All patients were also treated with antiplatelet agents. In part 1, at inclusion the GSC in the hypoechoic group was 15 (range, 12-18) while in the hyperechoic group it was 26 (range, 24-31); at 6 months it was increased in the hypoechoic group and at 12 months the increase was significant (19.5; p<0.05). There was a minor increase in GSM in the hyperechoic group (30; ns). In part II in the treatment group there was a significant difference in GSM (increase) at 12 months (p<0.05), improvement in texture (p<0.05) and a nonsignificant decrease in stenosis. No changes were observed in the placebo group. Events were observed in 6.5% of patients in the TTFCA group and in 11% in the control group (p<0.05). In conclusion these observations suggest a positive action of TTFCA on the stabilization of hypoechoic, low-density carotid plaques.

Angiology. 2001 Oct;52 Suppl 2:S19-25

Oral probiotics

Influence of the probiotic Streptococcus salivarius strain M18 on indices of dental health in children: a randomized double-blind, placebo-controlled trial.

The prevalence of dental caries continues to increase, and novel strategies to reverse this trend appear necessary. The probiotic Streptococcus salivarius strain M18 offers the potential to confer oral health benefits as it produces bacteriocins targeting the important cariogenic species Streptococcus mutans, as well as the enzymes dextranase and urease, which could help reduce dental plaque accumulation and acidification, respectively. In a randomized double-blind, placebo-controlled study of 100 dental caries-active children, treatment with M18 was administered for 3 months and the participants were assessed for changes to their plaque score and gingival and soft-tissue health and to their salivary levels of S. salivarius, S. mutans, lactobacilli, β-haemolytic streptococci and Candida species. At treatment end, the plaque scores were significantly (P = 0.05) lower for children in the M18-treated group, especially in subjects having high initial plaque scores. The absence of any significant adverse events supported the safety of the probiotic treatment. Cell-culture analyses of sequential saliva samples showed no differences between the probiotic and placebo groups in counts of the specifically enumerated oral micro-organisms, with the exception of the subgroup of the M18-treated children who appeared to have been colonized most effectively with M18. This subgroup exhibited reduced S. mutans counts, indicating that the anti-caries activity of M18 probiotic treatments may be enhanced if the efficiency of colonization is increased. It was concluded that S. salivarius M18 can provide oral health benefits when taken regularly.

J Med Microbiol. 2013 Jun;62(Pt 6):875-84

Persistence of the oral probiotic Streptococcus salivarius M18 is dose dependent and megaplasmid transfer can augment their bacteriocin production and adhesion characteristics

Bacteriocin-producing probiotic Streptococcus salivarius M18 offers beneficial modulatory capabilities within the oral microbiome, apparently through potent inhibitory activity against potentially deleterious bacteria, such as Streptococcus pyogenes. The oral cavity persistence of S. salivarius M18 was investigated in 75 subjects receiving four different doses for 28 days. Sixty per cent of the subjects already had some inhibitor-producing S. salivarius in their saliva prior to probiotic intervention. Strain M18's persistence was dependent upon the dose, but not the period of administration. Culture analysis indicated that in some individuals the introduced strain had almost entirely replaced the indigenous S. salivarius, though the total numbers of the species did not increase. Selected subjects showing either high or low probiotic persistence had their salivary populations profiled using Illumina sequencing of the V6 region of the 16S rRNA gene. Analysis indicated that while certain bacterial phenotypes were markedly modulated, the overall composition of the oral microbiome was not modified by the probiotic treatment. Megaplasmids encoding bacteriocins and adhesion factors were transferred in vitro to generate a transconjugant S. salivarius exhibiting enhanced antimicrobial production and binding capabilities to HEp-2 cells. Since no widespread perturbation of the existing indigenous microbiota was associated with oral instillation and given its antimicrobial activity against potentially pathogenic streptococci, it appears that application of probiotic strain M18 offers potential low impact alternative to classical antibiotic prophylaxis. For candidate probiotic strains having relatively poor antimicrobial or adhesive properties, unique derivatives displaying improved probiotic performance may be engineered in vitro by megaplasmid transfer.

PLoS One. 2013 Jun 13;8(6):e65991

Megaplasmids encode differing combinations of lantibiotics in Streptococcus salivarius.

Streptococcus salivarius strains commonly produce bacteriocins as putative anti-competitor or signalling molecules. Here we report that bacteriocin production by the oral probiotic strain S. salivarius K12 is encoded by a large (ca. 190 kb) plasmid. Oral cavity transmission of the plasmid from strain K12 to a plasmid-negative variant of this bacterium was demonstrated in two subjects. Tests of additional S. salivarius strains showed large (up to ca. 220 kb) plasmids present in bacteriocin-producing isolates. Various combinations (up to 3 per plasmid) of loci encoding the known streptococcal lantibiotics salivaricin A, salivaricin B, streptin and SA-FF22 were localised to these plasmids. Since all bacteriocin-producing strains of S. salivarius tested to date appear to harbour plasmids, it appears that they may function as mobile repositories for bacteriocin loci, especially those of the lantibiotic class.

Antonie Van Leeuwenhoek. 2006 Oct;90(3): 269-80

Identification of serum biomarkers for aging and anabolic response.

OBJECTIVE: With the progressive aging of the human population, there is an inexorable decline in muscle mass, strength and function. Anabolic supplementation with testosterone has been shown to effectively restore muscle mass in both young and elderly men. In this study, we were interested in identifying serum factors that change with age in two distinct age groups of healthy men, and whether these factors were affected by testosterone supplementation. METHODS: We measured the protein levels of a number of serum biomarkers using a combination of banked serum samples from older men (60 to 75 years) and younger men (ages 18 to 35), as well as new serum specimens obtained through collaboration. We compared baseline levels of all biomarkers between young and older men. In addition, we evaluated potential changes in these biomarker levels in association with testosterone dose (low dose defined as 125 mg per week or below compared to high dose defined as 300 mg per week or above) in our banked specimens. RESULTS: We identified nine serum biomarkers that differed between the young and older subjects. These age-associated biomarkers included: insulin-like growth factor (IGF1), N-terminal propeptide of type III collagen (PIIINP), monokine induced by gamma interferon (MIG), epithelial-derived neutrophil-activating peptide 78 (ENA78), interleukin 7 (IL-7), p40 subunit of interleukin 12 (IL-12p40), macrophage inflammatory protein 1b (MIP-1b), platelet derived growth factor b (PDGFb) and interferon-inducible protein 10 (IP-10). We further observed testosterone dose-associated changes in some but not all age related markers: IGF1, PIIINP, leptin, MIG and ENA78. Gains in lean mass were confirmed by dual energy X-ray absorptiometry (DEXA). CONCLUSIONS: Results from this study suggest that there are potential phenotypic biomarkers in serum that can be associated with healthy aging and that some but not all of these biomarkers reflect gains in muscle mass upon testosterone administration.

Immun Ageing. 2011 Jun 20;8(1):5

The C5a receptor impairs IL-12-dependent clearance of Porphyromonas gingivalis and is required for induction of periodontal bone loss.

The C5a anaphylatoxin receptor (C5aR; CD88) is activated as part of the complement cascade and exerts important inflammatory, antimicrobial, and regulatory functions, at least in part, via crosstalk with TLRs. However, the periodontal pathogen Porphyromonas gingivalis can control C5aR activation by generating C5a through its own C5 convertase-like enzymatic activity. In this paper, we show that P. gingivalis uses this mechanism to proactively and selectively inhibit TLR2-induced IL-12p70, whereas the same pathogen-instigated C5aR-TLR2 crosstalk upregulates other inflammatory and bone-resorptive cytokines (IL-1b, IL-6, and TNF-a). In vivo, the ability of P. gingivalis to manipulate TLR2 activation via the C5a-C5aR axis allowed it to escape IL-12p70-dependent immune clearance and to cause inflammatory bone loss in a murine model of experimental periodontitis. In the latter regard, C5aR-deficient or TLR2-deficient mice were both resistant to periodontal bone loss, in stark contrast with wild-type control mice, which is consistent with the interdependent interactions of C5aR and TLR2 in P. gingivalis immune evasion and induction of bone-resorptive cytokines. In conclusion, P. gingivalis targets C5aR to promote its adaptive fitness and cause periodontal disease. Given the current availability of safe and effective C5aR antagonists, pharmacological blockade of C5aR could act therapeutically in human periodontitis and reduce associated systemic risks.

J Immunol. 2011 Jan 15;186(2):869-77

Inflammation as a potential mediator for the association between periodontal disease and Alzheimer's disease.

Periodontal disease (PDD) is associated with increased risk of cardiovascular disease, cerebrovascular disease, and mortality in many studies, while other studies have begun to suggest an association of PDD with Alzheimer's disease (AD). This paper discusses how infectious pathogens and systemic infection may play a role in AD. The roles of infection and inflammation are addressed specifically with regard to known AD pathologic lesions including senile plaques, neuron death, neurofibrillary tangles, and cerebrovascular changes. A testable model of proposed pathways between periodontal infection and AD is presented including three possible mechanisms: a) direct effects of infectious pathogens, b) inflammatory response to pathogens, and c) the effects on vascular integrity. The role of gene polymorphisms is discussed, including apolipoprotein (APOE) varepsilon4 as a pro-inflammatory and pro-infection genotype.

Neuropsychiatr Dis Treat. 2008 Oct;4(5):865-76


Mitochondrial dysfunction, proteotoxicity, and aging: causes or effects, and the possible impact of NAD+-controlled protein glycation.

Aging is frequently characterized by the accumulation of altered proteins and dysfunctional mitochondria. This review discusses possible causes of these effects, their interdependence and the impact of energy metabolism on proteostasis, especially formation and elimination of altered proteins. It is suggested NAD+ to some degree regulates formation of aberrant proteins and generation of oxygen free-radicals and reactive oxygen species (ROS), because when NAD+ is limiting, glycolytic triose phosphates spontaneously decompose into methylglyoxal (MG), a highly deleterious glycating agent and ROS inducer. That NAD+ has stimulatory effects on stress protein expression and autophagy, while mitochondria regenerate NAD+ from NADH, further integrates energy metabolism into proteostasis. It is suggested that, as altered proteins can deleteriously interact with mitochondria, changes in synthesis, or elimination, of cytosolic error-proteins will affect mitochondrial activity. It is also suggested that functional mitochondria are essentially antiaging agents, while their dysfunction or inactivity accelerate ROS formation and aging. These proposals may also help explain the oxygen paradox that while ROS may be causal to aging, increased mitochondrial activity (i.e., oxygen utilization) suppresses aging and much associated pathology. Increased synthesis of glutathione, humanin, and mitochondrial chaperone proteins are other additional consequences of increased mitogenesis and which would help ensure proteostasis.

Adv Clin Chem. 2010;50:123-50

Aging risk factors and Parkinson's disease: contrasting roles of common dietary constituents.

Aging is a Parkinson's disease (PD) risk factor. It is suggested here that certain dietary components may either contribute to or ameliorate PD risk. There is evidence, which indicates that excessive carbohydrate (glucose or fructose) catabolism is a cause of mitochondrial dysfunction in PD, one consequence is increased production of methylglyoxal (MG). However, other dietary components (carnosine and certain plant extracts) not only scavenge MG but can also influence some of the biochemical events (signal transduction, stress protein synthesis, glycation, and toxin generation) associated with PD pathology. As double blind, placebo-controlled carnosine supplementation studies have revealed beneficial outcomes in humans, it is suggested that MG scavengers such as carnosine be further explored for their therapeutic potential toward PD.

Neurobiol Aging. 2014 Jun;35(6):1469-72.

Would carnosine or a carnivorous diet help suppress aging and associated pathologies?

Carnosine (beta-alanyl-L-histidine) is found exclusively in animal tissues. Carnosine has the potential to suppress many of the biochemical changes (e.g., protein oxidation, glycation, AGE formation, and cross-linking) that accompany aging and associated pathologies. Glycation, generation of advanced glycosylation end-products (AGEs), and formation of protein carbonyl groups play important roles in aging, diabetes, its secondary complications, and neurodegenerative conditions. Due to carnosine's antiglycating activity, reactivity toward deleterious carbonyls, zinc- and copper-chelating activity and low toxicity, carnosine and related structures could be effective against age-related protein carbonyl stress. It is suggested that carnivorous diets could be beneficial because of their carnosine content, as the dipeptide has been shown to suppress some diabetic complications in mice. It is also suggested that carnosine's therapeutic potential should be explored with respect to neurodegeneration. Olfactory tissue is normally enriched in carnosine, but olfactory dysfunction is frequently associated with neurodegeneration. Olfactory administration of carnosine could provide a direct route to compromised tissue, avoiding serum carnosinases.

Ann N Y Acad Sci. 2006 May;1067:369-74

Could carnosine or related structures suppress Alzheimer's disease?

Reactive oxygen species, reactive nitrogen species, copper and zinc ions, glycating agents and reactive aldehydes, protein cross-linking and proteolytic dysfunction may all contribute to Alzheimer's disease (AD). Carnosine (beta-alanyl-L-histidine) is a naturally-occurring, pluripotent, homeostatic agent. The olfactory lobe is normally enriched in carnosine and zinc. Loss of olfactory function and oxidative damage to olfactory tissue are early symptoms of AD. Amyloid peptide aggregates in AD brain are enriched in zinc ions. Carnosine can chelate zinc ions. Protein oxidation and glycation are integral components of the AD pathophysiology. Carnosine can suppress amyloid-beta peptide toxicity, inhibit production of oxygen free-radicals, scavenge hydroxyl radicals and reactive aldehydes, and suppresses protein glycation. Glycated protein accumulates in the cerebrospinal fluid (CSF) of AD patients. Homocarnosine levels in human CSF dramatically decline with age. CSF composition and turnover is controlled by the choroid plexus which possesses a specific transporter for carnosine and homocarnosine. Carnosine reacts with protein carbonyls and suppress the reactivity of glycated proteins. Carbonic anhydrase (CA) activity is diminished in AD patient brains. Administration of CA activators improves learning in animals. Carnosine is a CA activator. Protein cross-links (gamma-glutamyl-epsilon-amino) are present in neurofibrillary tangles in AD brain. gamma-Glutamyl-carnosine has been isolated from biological tissue. Carnosine stimulates vimentin expression in cultured human fibroblasts. The protease oxidised-protein-hydrolase is co-expressed with vimentin. Carnosine stimulates proteolysis in cultured myocytes and senescent cultured fibroblasts. These observations suggest that carnosine and related structures should be explored for therapeutic potential towards AD and other neurodegenerative disorders.

J Alzheimers Dis. 2007 May;11(2):229-40

Benfotiamine prevents macro- and microvascular endothelial dysfunction and oxidative stress following a meal rich in advanced glycation end products in individuals with type 2 diabetes.

OBJECTIVE: Diabetes is characterized by marked postprandial endothelial dysfunction induced by hyperglycemia, hypertriglyceridemia, advanced glycation end products (AGEs), and dicarbonyls (e.g., methylglyoxal [MG]). In vitro hyperglycemia-induced MG formation and endothelial dysfunction could be blocked by benfotiamine, but in vivo effects of benfotiamine on postprandial endothelial dysfunction and MG synthesis have not been investigated in humans until now. RESEARCH DESIGN AND METHODS: Thirteen people with type 2 diabetes were given a heat-processed test meal with a high AGE content (HAGE; 15.100 AGE kU, 580 kcal, 54 g protein, 17 g lipids, and 48 g carbohydrates) before and after a 3-day therapy with benfotiamine (1,050 mg/day). Macrovascular flow-mediated dilatation (FMD) and microvascular reactive hyperemia, along with serum markers of endothelial disfunction (E-selectin, vascular cell adhesion molecule-1, and intracellular adhesion molecule-1), oxidative stress, AGE, and MG were measured during both test meal days after an overnight fast and then at 2, 4, and 6 h postprandially. RESULTS: The HAGE induced a maximum reactive hyperemia decrease of -60.0% after 2 h and a maximum FMD impairment of -35.1% after 4 h, without affecting endothelium-independent vasodilatation. The effects of HAGE on both FMD and reactive hyperemia were completely prevented by benfotiamine. Serum markers of endothelial dysfunction and oxidative stress, as well as AGE, increased after HAGE. These effects were significantly reduced by benfotiamine. CONCLUSIONS: Our study confirms micro- and macrovascular endothelial dysfunction accompanied by increased oxidative stress following a real-life, heat-processed, AGE-rich meal in individuals with type 2 diabetes and suggests benfotiamine as a potential treatment.

Diabetes Care. 2006 Sep;29(9):2064-71

Human pericyte-endothelial cell interactions in co-culture models mimicking the diabetic retinal microvascular environment.

Pericytes regulate vascular tone, perfusion pressure and endothelial cell (EC) proliferation in capillaries. Thiamine and benfotiamine counteract high glucose-induced damage in vascular cells. We standardized two human retinal pericyte (HRP)/EC co-culture models to mimic the diabetic retinal microvascular environment. We aimed at evaluating the interactions between co-cultured HRP and EC in terms of proliferation/apoptosis and the possible protective role of thiamine and benfotiamine against high glucose-induced damage. EC and HRP were co-cultured in physiological glucose and stable or intermittent high glucose, with or without thiamine/benfotiamine. No-contact model: EC were plated on a porous membrane suspended into the medium and HRP on the bottom of the same well. Cell-to-cell contact model: EC and HRP were plated on the opposite sides of the same membrane. Proliferation (cell counts and DNA synthesis), apoptosis and tubule formation in Matrigel were assessed. In the no-contact model, stable high glucose reduced proliferation of co-cultured EC/HRP and EC alone and increased co-cultured EC/HRP apoptosis. In the contact model, both stable and intermittent high glucose reduced co-cultured EC/HRP proliferation and increased apoptosis. Stable high glucose had no effects on HRP in separate cultures. Both EC and HRP proliferated better when co-cultured. Thiamine and benfotiamine reversed high glucose-induced damage in all cases. HRP are sensitive to soluble factors released by EC when cultured in high glucose conditions, as suggested by conditioned media assays. In the Matrigel models, addition of thiamine and benfotiamine re-established the high glucose-damaged interactions between EC/HRP and stabilized microtubules.

Acta Diabetol. 2012 Dec;49 Suppl 1:S141-51

Augmentation of blood lipid glycation and lipid oxidation in diabetic patients.

Lipid oxidation plays a role in the pathophysiology of several diseases, including diabetes. Patients with type 2 diabetes show abnormally high plasma levels of phosphatidylcholine hydroperoxide (PCOOH). However, little is known about the biochemical processes that increase plasma PCOOH in diabetes. We hypothesized that "glycated lipid moieties" may form in diabetic plasma and cause oxidative stress resulting in PCOOH formation. To evaluate this hypothesis, liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were developed to analyze Amadori-glycated phosphatidylethanolamine (Amadori-PE, an early stage Maillard product), as well as the advanced glycation end products (AGE) carboxymethyl-PE (CM-PE) and carboxyethyl-PE (CE-PE). The product ion scan, neutral loss scanning, and multiple reaction monitoring provide useful structural and quantitative information about Amadori-PE, CM-PE, and CE-PE in diabetic plasma and erythrocytes. We found that plasma and erythrocyte Amadori-PE concentrations were significantly higher in diabetic patients (757±377 nM plasma, 2793±989 nM packed cells) than in normal subjects (165±66 nM plasma, 712±52 nM packed cells), and that Amadori-PE concentrations were positively correlated with PCOOH. By contrast, no significant differences were observed in blood AGE-PE concentrations between diabetic patients (CM-PE: 7.7±3.5 nM plasma, 528±83 nM packed cells; CE-PE: 2.5±1.1 nM plasma, 82±24 nM packed cells) and normal subjects (CM-PE: 6.6±3.1 nM plasma, 705±533 nM packed cells; CE-PE: 4.2±1.5 nM plasma, 68±16 nM packed cells). These results suggest that Amadori-PE is more prone to accumulation in the blood with diabetes than CM-PE or CE-PE. This review describes the involvement of blood lipid glycation and lipid oxidation in the development of diabetes.

Clin Chem Lab Med. 2014 Jan 1;52(1):47-52

Glycation of plasma lipoprotein lipid membrane and screening for lipid glycation inhibitor.

We recently reported that phosphatidylethanolamine (PE)-linked Amadori product (Amadori-PE) increased abnormally in diabetic plasma. However, the glycation mechanism of human plasma low-density lipoprotein (LDL) is still unclear. Moreover, lipid glycation inhibitors have yet to be discovered. In this study, we compared the glycation kinetics of LDL lipid and LDL protein in vitro and screened lipid glycation inhibitors. LDL-PE was converted to Amadori-PE followed by LDL protein (apoB) glycation. Pyridoxal 5'-phosphate could easily react with PE before the glucose-PE reaction, and the PE-pyridoxal 5'-phosphate adduct was detected in human red blood cells. Pyridoxal 5'-phosphate can be used in diabetes prevention.

Ann N Y Acad Sci. 2008 Apr;1126:288-90

Cognitive decline

Protein requirement of elderly women: nitrogen balance responses to three levels of protein intake.

BACKGROUND: For elderly women, insufficient data exist to assess the accuracy of the assumed mean protein requirement of 0.6 g of protein x kg(-1) x day(-1), and the adequacy of the current Recommended Dietary Allowance (RDA) of 0.8 g of protein x kg(-1) x day(-1). The aims of this study were to assess the mean protein requirement and suggested safe and adequate protein intake (protein allowance) of elderly women using a shorter-term nitrogen balance protocol. METHODS: During three separate 18-day trials, 11 elderly women (age range, 70-81 years) were randomly fed eucaloric diets designed to provide either 0.50, 0.75, or 1.00 g of protein x kg(-1) x day(-1). Nitrogen balance was determined at Weeks 2 and 3 (Days 7-10 and 14-17, respectively) of each trial using data from total nitrogen analyses of duplicate food composites, 24-hour urine collections, and stool collections. The mean protein requirement was calculated using linear regression of individual women's data from all three trials and inverse prediction. RESULTS: At protein intakes of 0.53 +/- 0.02, 0.76 +/- 0.02, or 1.06 +/- 0.05 g of protein x kg(-1) x day(-1), net nitrogen balances during Week 2 were -14.5 +/- 3.1, 3.8 +/- 2.5 and 23.4 +/- 3.3 mg of nitrogen x kg(-1) x day(-1), respectively, for these body weight- and body composition-stable women. At Week 3, the net nitrogen balances were -0.1 +/- 2.7, 8.5 +/- 3.6 and 42.0 +/- 3.0 mg of nitrogen x kg(-1) x day(-1). From Week 2 to Week 3, shifts to more positive nitrogen balances occurred due to decreases in urinary nitrogen excretion. The mean protein requirement at Week 2 was calculated to be 0.70 +/- 0.09 g of protein. kg(-1) x day(-1) (coefficient of variation [CV] = 13%) and at Week 3 was calculated to be 0.56 +/- 0.09 g of protein x kg(-1) x day(-1) (CV = 17%). From these data, an adequate protein allowance was estimated to be greater than the RDA at Week 2 (0.90 g of protein x kg(-1) x day [d](-1)), and not different than the RDA at Week 3 (0.76 g of protein x kg(-1) x d(-1)). CONCLUSIONS: The decrease over time in urinary nitrogen excretion from Week 2 to Week 3 suggests that these elderly women did not achieve a metabolic steady state during this shorter-term nitrogen balance study. Collectively, these data suggest that the total protein needs of elderly women are at or above the current RDA for protein. However, the results of this study indicate that shorter-term nitrogen balance protocols are insufficient to firmly establish the RDA for protein of elderly women, and further research is required using alternative criteria measures.

J Gerontol A Biol Sci Med Sci. 2001 Nov;56 (11):M724-30

Use of phosphocreatine kinetics to determine the influence of creatine on muscle mitochondrial respiration: an in vivo 1P-MRS study of oral creatine ingestion.

Recent human isolated muscle fiber studies suggest that phosphocreatine (PCr) and creatine (Cr) concentrations play a role in the regulation of mitochondrial respiration rate. To determine whether similar regulatory mechanisms are present in vivo, this study examined the relationship between skeletal muscle mitochondrial respiration rate and end-exercise PCr, Cr, PCr-to-Cr ratio (PCr/Cr), ADP, and pH by using (31)P-magnetic resonance spectroscopy in 16 men and women (36.9 +/- 4.6 yr). The initial PCr resynthesis rate and time constant (T(c)) were used as indicators of mitochondrial respiration after brief (10-12 s) and exhaustive (1-4 min) dynamic knee extension exercise performed in placebo and creatine-supplemented conditions. The results show that the initial PCr resynthesis rate has a strong relationship with end-exercise PCr, Cr, and PCr/Cr (r > 0.80, P < 0.001), a moderate relationship with end-exercise ADP (r = 0.77, P < 0.001), and no relationship with end-exercise pH (r = -0.14, P = 0.34). The PCr T(c) was not as strongly related to PCr, Cr, PCr/Cr, and ADP (r < 0.77, P < 0.001-0.18) and was significantly influenced by end-exercise pH (r = -0.43, P < 0.01). These findings suggest that end-exercise PCr and Cr should be taken into consideration when PCr recovery kinetics is used as an indicator of mitochondrial respiration and that the initial PCr resynthesis rate is a more reliable indicator of mitochondrial respiration compared with the PCr T(c).

J Appl Physiol (1985). 2004 Jun;96(6):2288-92

Creatine metabolism and psychiatric disorders: Does creatine supplementation have therapeutic value?

Athletes, body builders, and military personnel use dietary creatine as an ergogenic aid to boost physical performance in sports involving short bursts of high-intensity muscle activity. Lesser known is the essential role creatine, a natural regulator of energy homeostasis, plays in brain function and development. Creatine supplementation has shown promise as a safe, effective, and tolerable adjunct to medication for the treatment of brain-related disorders linked with dysfunctional energy metabolism, such as Huntington's Disease and Parkinson's Disease. Impairments in creatine metabolism have also been implicated in the pathogenesis of psychiatric disorders, leaving clinicians, researchers and patients alike wondering if dietary creatine has therapeutic value for treating mental illness. The present review summarizes the neurobiology of the creatine-phosphocreatine circuit and its relation to psychological stress, schizophrenia, mood and anxiety disorders. While present knowledge of the role of creatine in cognitive and emotional processing is in its infancy, further research on this endogenous metabolite has the potential to advance our understanding of the biological bases of psychopathology and improve current therapeutic strategies.

Neurosci Biobehav Rev. 2012 May;36(5):1442-62

The effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength.

Our purpose was to assess muscular adaptations during 6 weeks of resistance training in 36 males randomly assigned to supplementation with whey protein (W; 1.2 g/kg/day), whey protein and creatine monohydrate (WC; 0.1 g/kg/day), or placebo (P; 1.2 g/kg/day maltodextrin). Measures included lean tissue mass by dual energy x-ray absorptiometry, bench press and squat strength (1-repetition maximum), and knee extension/flexion peak torque. Lean tissue mass increased to a greater extent with training in WC compared to the other groups, and in the W compared to the P group (p < .05). Bench press strength increased to a greater extent for WC compared to W and P (p < .05). Knee extension peak torque increased with training for WC and W (p < .05), but not for P. All other measures increased to a similar extent across groups. Continued training without supplementation for an additional 6 weeks resulted in maintenance of strength and lean tissue mass in all groups. Males that supplemented with whey protein while resistance training demonstrated greater improvement in knee extension peak torque and lean tissue mass than males engaged in training alone. Males that supplemented with a combination of whey protein and creatine had greater increases in lean tissue mass and bench press than those who supplemented with only whey protein or placebo. However, not all strength measures were improved with supplementation, since subjects who supplemented with creatine and/or whey protein had similar increases in squat strength and knee flexion peak torque compared to subjects who received placebo.

Int J Sport Nutr Exerc Metab. 2001 Sep;11 (3): 349-64M

Influence of the protein digestion rate on protein turnover in young and elderly subjects.

It has long been recognized that numerous dietary parameters, such as the amount and type of protein and nonprotein energy sources, affect protein metabolism. More recently, we demonstrated that the protein digestion rate is an independent factor regulating postprandial protein gain. Indeed, in young men, using a non-steady-state approach and intrinsically labeled milk protein fractions [whey protein (WP) and casein (CAS)] we showed that a slow digested dietary protein (CAS) induced a greater protein gain than a fast one (WP). The mechanisms of this gain also differed according to the protein rate of digestion. WP stimulated amino acid oxidation and protein synthesis without modifying proteolysis, whereas CAS increased amino acid oxidation and protein synthesis to a lesser extent and strongly inhibited proteolysis. These results led to the concept of "slow" and "fast" protein and were confirmed by further experiments during which the meals tested presented different digestion rates but were otherwise identical in terms of amino acid profile. We also analyzed the effects of fat and carbohydrates added to CAS and WP. Our preliminary results suggest that added nonprotein energy sources to CAS and WP attenuated the differences in both the protein digestion rate and protein gain. Finally, and in contrast to young subjects, a "fast" protein may be more beneficial than a "slow" one in elderly subjects, to limit body protein loss. However, long-term studies are needed to confirm this age-related effect.

J Nutr. 2002 Oct;132(10):3228S-33S

Co-ingestion of protein and leucine stimulates muscle protein synthesis rates to the same extent in young and elderly lean men.

BACKGROUND: The progressive loss of skeletal muscle mass with aging is attributed to a disruption in the regulation of skeletal muscle protein turnover. OBJECTIVE: We investigated the effects on whole-body protein balance and mixed-muscle protein synthesis rates of the ingestion of carbohydrate with or without protein and free leucine after simulated activities of daily living. DESIGN: Eight elderly (75 +/- 1 y) and 8 young (20 +/- 1 y) lean men were randomly assigned to 2 crossover experiments in which they consumed either carbohydrate (CHO) or carbohydrate plus protein and free leucine (CHO+Pro+Leu) after performing 30 min of standardized activities of daily living. Primed, continuous infusions with L-[ring-13C6]phenylalanine and L-[ring-2H2]tyrosine were applied, and blood and muscle samples were collected to assess whole-body protein turnover and the protein fractional synthetic rate in the vastus lateralis muscle over a 6-h period. RESULTS: Whole-body phenylalanine and tyrosine flux were significantly higher in the young than in the elderly men (P < 0.01). Protein balance was negative in the CHO experiment but positive in the CHO+Pro+Leu experiment in both groups. Mixed-muscle protein synthesis rates were significantly greater in the CHO+Pro+Leu than in the CHO experiment in both the young (0.082 +/- 0.005%/h and 0.060 +/- 0.005%/h, respectively; P < 0.01) and the elderly (0.072 +/- 0.006%/h and 0.043 +/- 0.003%/h, respectively; P < 0.01) subjects, with no significant differences between groups. CONCLUSIONS: Co-ingestion of protein and leucine with carbohydrate after activities of daily living improves whole-body protein balance, and the increase in muscle protein synthesis rates is not significantly different between lean young and elderly men.

Am J Clin Nutr. 2006 Sep;84(3):623-32