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Sun Protection

July 2013

Increasing incidence of melanoma among young adults: an epidemiological study in Olmsted County, Minnesota.

OBJECTIVE: To identify the change in the incidence of cutaneous melanoma over time among young adults. PATIENTS AND METHODS: Using Rochester Epidemiology Project data, we identified patients aged 18 to 39 years who had a first lifetime diagnosis of melanoma from January 1, 1970, through December 31, 2009, in Olmsted County, Minnesota. Demographic and clinical information, including survival, was abstracted, and estimates of the incidence of melanoma and overall and disease-specific survival were generated. RESULTS: From 1970 to 2009, the incidence of melanoma increased by 8-fold among young women and 4-fold among young men. Overall and disease-specific survival seemed to improve over time; hazard ratios comparing year of diagnosis with mortality were 0.92 and 0.91, respectively. CONCLUSION: The incidence of cutaneous melanoma among young adults is rapidly increasing, especially among women. Continued close monitoring of this high-risk population is necessary.

Mayo Clin Proc. 2012 Apr;87(4):328-34

Mechanistic insights in the use of a Polypodium leucotomos extract as an oral and topical photoprotective agent.

Photoprotection is essential to prevent the deleterious effects of ultraviolet (UV) light, including skin cancer, photoaging and immunosuppression. Photoprotective agents can be classified according to their main mechanism of action. Some of them absorb or deflect UV photons (sunscreens), whereas others prevent or fix the deleterious effects of UV exposure. Here, we review recent evidence on the cellular and molecular mechanisms underlying the photoprotective effect of a Polypodium leucotomos fern extract (PL). PL is a natural mixture of phytochemicals endowed with powerful antioxidant properties. Its short-term effects include inhibition of reactive oxygen species production induced by UV radiation, DNA damage, isomerization and decomposition of trans-urocanic acid, prevention of UV-mediated apoptosis and necrosis, as well as degradative matrix remodeling, which is the main cause of photoaging. These short-term effects translate into long-term prevention of photoaging and photocarcinogenesis. A striking property is that PL can exert its effect when administered orally. Together, these effects postulate PL as a natural photoprotective agent and a potential adjuvant to phototherapy for various skin diseases.

Photochem Photobiol Sci. 2010 Apr;9(4):559-63

Polypodium leucotomos decreases UV-induced epidermal cell proliferation and enhances p53 expression and plasma antioxidant capacity in hairless mice.

A single dose of ultraviolet radiation (UVR) induces significant changes in blood and skin of hairless mice. Oral administration of a hydrophilic extract of the fern Polypodium leucotomos (PL, 300 mg/kg during 5 days before UVR and for two additional days after irradiation) modulates some of the effects of UVR. Most significantly, PL administration reduced the number of proliferating cells by 13%, increased the number of p53(+) cells by 63%, enhanced the antioxidant plasma capacity (ORAC) by 30% and reinforced the network of dermal elastic fibres. Western blot analysis of skin antioxidant-related enzymes failed to demonstrate significant changes caused by PL. Thus, the beneficial effect of PL likely owes to its antioxidant and anti-ROS properties rather than its modulation of the expression of endogenous antioxidant systems. These data provide mechanistic clues for its efficacy as a systemic photoprotective agent with antioxidant and anti-photo-ageing properties.

Exp Dermatol. 2012 Aug;21(8):638-40

Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin—a case-control study.

BACKGROUND: Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. METHODS: A case-control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. RESULTS: A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥ 3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. CONCLUSIONS: Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

BMC Cancer. 2012 Sep 20;12:417

Oral polypodium leucotomos extract photoprotective activity in 57 patients with idiopathic photodermatoses.

AIM: Idiopathic photodermatoses (IP) are a recurrent, acquired sunlight-induced rash of delayed onset, appearing after exposure to ultraviolet radiation in susceptible individuals. The aim of this study was to assess the photoprotective activity of polypodium leucotomos (PL) in IP. METHODS: Fifty-seven patients affected by IP were recruited for the study (53 with polymorphic light eruption and 4 with solar urticaria). The use of UV protection filters or other drugs that could in some way interfere with exposure to light were excluded. All patients exposed themselves to sunlight while consuming 480 mg/day of PL extract orally. A statistical evaluation of the basal clinical conditions compared to those after sunlight exposure with PL was performed. RESULTS: About 73.68% of the patients had a benefit from the administered PL, with a significant reduction of skin reaction and subjective symptoms. No side effects were observed. Results were statistically significant (P<0.05). CONCLUSION: PL complete absence of toxicity combined with its multifactorial protection, makes it an effective and safe treatment for photoprotection in IP.

G Ital Dermatol Venereol. 2011 Apr;146(2):85-7

Beneficial regulation of matrixmetalloproteinases and their inhibitors, fibrillar collagens and transforming growth factor-beta by Polypodium leucotomos, directly or in dermal fibroblasts, ultraviolet radiated fibroblasts, and melanoma cells.

The extracellular matrix (ECM) that gives tissue its structural integrity is remodeled in skin aging/photoaging and cancer via the increased expression/activities of matrixmetalloproteinases (MMP), inhibition of the tissue inhibitors of matrix metalloproteinases (TIMP), or inhibition of collagen synthesis. Transforming growth factor-beta (TGF-beta), a predominant regulator of the ECM, is inhibited in aging/photoaging and stimulated in carcinogenesis. P. leucotomos (fern) extract has potential to counteract these alterations via its antioxidant, anti-inflammatory and photoprotective properties. The goal of this research was to determine the efficacy of P. leucotomos to (a) directly inhibit MMP-1, 2, 3, and 9 activities, (b) inhibit MMP-2, and stimulate TIMPs, fibrillar collagens and TGF-beta in non-irradiated or ultraviolet (UV) radiated fibroblasts, and (c) inhibit MMPs and TGF-beta, and stimulate TIMPs in melanoma cells. To this purpose, we examined the direct effect of P. leucotomos (0-1%) on MMPs’ activities, and its effects on the expression (protein and/or transcription levels) of (1) MMPs and TIMPs in dermal fibroblasts, and melanoma cells, (2) TGF-beta in non-irradiated, UVA (2.5 J/cm2) or UVB (2.5 mJ/cm2) irradiated fibroblasts, and melanoma cells, and (3) types I, III, and V collagen in non-irradiated or UV irradiated fibroblasts. P. leucotomos directly inhibited the activities of MMPs as well as the expression of MMPs in fibroblasts, and melanoma cells while stimulating the expression of TIMPs in these cells. P. leucotomos stimulated types I, III, and V collagen in non-irradiated fibroblasts, and types I and V collagen in UV radiated fibroblasts. P. leucotomos had predominant stimulatory effects on TGF-beta expression in non-irradiated or UV radiated fibroblasts, and inhibited TGF-beta expression in melanoma cells. The effects of P. leucotomos were largely similar to that of ascorbic acid. P. leucotomos demonstrated dual protective effects on the ECM via its inhibition of the ECM proteolytic enzymes and the stimulation of the structural ECM collagens. The effects of P. leucotomos on fibroblasts and melanoma cells may be partly via its cell-specific regulation of TGF-beta expression and partly via its antioxidant property. The intake or topical application of P. leucotomos may be beneficial to skin health, in aging and cancer prevention or treatment.

Arch Dermatol Res. 2009 Aug;301(7):487-95

Polypodium leucotomos extract inhibits glutathione oxidation and prevents Langerhans cell depletion induced by UVB/UVA radiation in a hairless rat model.

In this report, we have addressed the effect of oral administration of a hydrophilic extract of the fern Polypodium leucotomos (PL) on the deleterious effects of ultraviolet radiation (UVR) on the levels of epidermal and plasmatic antioxidants in hairless rats. We have found that pretreatment with PL effectively reduced glutathione oxidation in both blood and epidermis, suggesting a potent systemic antioxidant effect. In addition, PL inhibited UVR-mediated Langerhans cell (LC) depletion. Our results demonstrate the efficacy of PL as an oral antioxidant and photoimmunoprotective agent and support its employment as a complement to topical sunscreens.

Exp Dermatol. 2008 Aug;17(8):653-8

Antiinflammatory effects of a red orange extract in human keratinocytes treated with interferon-gamma and histamine.

Red oranges are an important component of the so-called Mediterranean diet and they have been used by traditional medicine for their health protective properties, particularly to heal sore throat and cough, suggesting an interesting antiinflammatory activity. The purpose of this study was to evaluate the antiinflammatory activity of a red orange (Citrus sinensis varieties: Moro, Tarocco, Sanguinello) complex (ROC), characterized by high levels of anthocyanins, flavanones, hydroxycinnamic acids and ascorbic acid, on the human keratinocyte line NCTC 2544 exposed to interferon-gamma (IFN-gamma) and histamine. The expression of immunomodulatory membrane molecules such as inter-cellular adhesion molecule-1 (ICAM-1) by Western blot analysis, and the release of chemokines such as monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) through ELISA kits, were determined. ICAM-1 modulates the permanence and activation of T lymphocytes in the epidermis. MCP-1 is a specific chemoattractant for monocytes and dendritic cells. IL-8 is important for the recruitment of both neutrophils and T lymphocytes. Addition of ROC at different concentrations together with IFN-gamma and histamine induced a dose-dependent inhibition of ICAM-1 expression and MCP-1 and IL-8 release. ROC shows interesting antiinflammatory properties in human keratinocyte cells NCTC 2544. This natural complex could have a topical employment and mitigate the consequences of some skin pathologies.

Phytother Res. 2010 Mar;24(3):414-8

Involvement of inducible nitric oxide synthase and cyclooxygenase-2 in the anti-inflammatory effects of a red orange extract in human chondrocytes.

In the present study, a complex of compounds (red orange complex, ROC), obtained from three red orange varieties (Citrus sinensis varieties: Moro, Tarocco and Sanguinello), containing cyanidin glycosides, hydroxycinnamic acids, flavanone glycosides and ascorbic acid, was screened to discover new lead compounds in the suppression of the production of key molecules released during inflammatory events in interleukin-1beta (IL-beta) stimulated human primary chondrocytes. The expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX)-2 and intercellular adhesion molecule-1 (ICAM-1), and the release of nitric oxide, prostaglandin (PG)E(2) and interleukin-8 (IL-8) were determined. Indomethacin was used as an anti-inflammatory drug reference. ROC acts as a potent inhibitor of iNOS and COX-2 gene expression while also suppressing the production of PGE(2) and nitrite in human chondrocytes. In addition, ROC induces a significant decrease in ICAM expression and IL-8 release. These findings suggest that ROC exerts anti-inflammatory effects probably through the suppression of COX-2 and iNOS expression.

Nat Prod Res. 2010 Sep;24(15):1469-80

Protective effects of a red orange extract on UVB-induced damage in human keratinocytes.

UV light is considered one of the major etiological factor in skin aging, cancer and also to systemic impairment such as immunosuppression. Increased production of reactive oxygen species (ROS) and oxidative stress condition are known to play a central role in initiating and driving the signalling events that lead to cellular response following UV irradiation. In the present study we have investigated the photoprotective activity of a standardized extract from red orange (ROE), obtained from three red orange varieties and containing as main active principles phenolic compounds (anthocyanins, flavanones and hydroxycinnamic acids) and ascorbic acid. The aim of this study was to evaluate the efficacy of ROE in modulating cellular responses to UVB in human keratinocytes (HaCaT). Our data indicate that ROE is potentially able to efficiently counteract UVB-induced response, and in particular some events associated to inflammation and apoptosis, such as NF-kB and AP-1 translocation and procaspase-3 cleavage. This activity is probably due to a block of cellular oxidative stress-related events. Thus we can propose ROE as a useful natural standardised extract in skin photoprotection with promising applications in the field of dermatology.

Biofactors. 2007;30(2):129-38