Fernblock, a nutriceutical with photoprotective properties and potential preventive agent for skin photoaging and photoinduced skin cancers

Sunproofing from within: A deep dive into oral photoprotection strategies in dermatology

BACKGROUND

Photoprotection is the first measure in the prevention and treatment of the deleterious effects that sunlight can cause on the skin. It is well known that prolonged exposure to solar radiation leads to acute and chronic complications, such as erythema, accelerated skin aging, proinflammatory and procarcinogenic effects, and eye damage, among others.

METHODS

A better understanding of the molecules that can protect against ultraviolet radiation and their effects will lead to improvements in skin health.

RESULTS

Most of these effects of the sunlight are modulated by oxidative stress and proinflammatory mechanisms, therefore, the supplementation of substances that can regulate and neutralize reactive oxygen species would be beneficial for skin protection. Current evidence indicates that systemic photoprotection should be used as an adjunctive measure to topical photoprotection.

CONCLUSION

Oral photoprotectors are a promising option in improving protection against damage induced by UVR, as they contain active ingredients that increase the antioxidant effects of the body, complementing other photoprotection measures. We present a review of oral photoprotectors and their effects.

Clinical Applications of Polypodium leucotomos (Fernblock®): An Update

Exposure to sun radiation leads to higher risk of sunburn, pigmentation, immunosuppression, photoaging and skin cancer. In addition to ultraviolet radiation (UVR), recent research indicates that infrared radiation (IR) and visible light (VIS) can play an important role in the pathogenesis of some of these processes. Detrimental effects associated with sun exposure are well known, but new studies have shown that DNA damage continues to occur long after exposure to solar radiation has ended. Regarding photoprotection strategies, natural substances are emerging for topical and oral photoprotection. In this sense, Fernblock^®, a standardized aqueous extract of the fern Polypodium Leucotomos (PLE), has been widely administered both topically and orally with a strong safety profile. Thus, this extract has been used extensively in clinical practice, including as a complement to photodynamic therapy (PDT) for treating actinic keratoses (AKs) and field cancerization. It has also been used to treat skin diseases such as photodermatoses, photoaggravated inflammatory conditions and pigmentary disorders. This review examines the most recent developments in the clinical application of Fernblock^® and assesses how newly investigated action mechanisms may influence its clinical use.

Antioxidant and photoprotective potential of Polypodium leucotomos

In recent years, Polypodium leucotomos has emerged with a great interest for having medicinal and therapeutic potential. It is producing very promising results due to the presence of antioxidant and photoprotective properties. Electronic libraries and databases, including Scopus, PubMed, Google Scholar, Science Direct, and Web of Science were searched to identify relevant studies; 79 publications contributed to this review regarding Polypodium leucotomos botanical aspects, chemical composition, antioxidant and photoprotective activity. It is used in complementary and alternative therapies with various pharmaceutical dosage forms (systemic or topical). Thanks to the composition of phytochemical constituents present in the leaves and rhizomes which confer antioxidant and photoprotective activity that has clinical therapeutic potential to be used as systemic and topical sunscreen of natural origin for the prevention of different types of skin diseases caused by harmful ultraviolet A and ultraviolet B radiations. However, more studies are needed in the future to test the ability and enhance the capacity of sunscreen and sunblock in cosmetic formulations. To conclude, it is recommended to carry out scientific studies based on different analytical methods to evaluate the phytoconstituents potential and to develop stable pharmaceutical formulations according to the skin phototype.

Protective Effect of the Hydrophilic Extract of Polypodium leucotomos, Fernblock®, against the Synergistic Action of UVA Radiation and Benzo[a]pyrene Pollutant

Oxidative stress is a harmful effect induced on the skin by polycyclic aromatic hydrocarbons (PAH), including benzo[a]pyrene (BaP) air pollutants. This effect is amplified by the additive damaging effect of the sun, especially through the UVA light component. Besides being one of the main compounds that make up air pollution, BaP can also be found in tar, tobacco smoke, and various foods. In addition to its direct carcinogenic potential, BaP can act as a photosensitizer absorbing sunlight in the UVA range and thus generating ROS and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Fernblock^® (FB) is an aqueous extract from the leaves of Polypodium leucotomos that has been proven to exert photoprotective and antioxidant effects on skin cells. In this study, we evaluate the potential of FB to prevent the damage induced by a combination of BaP and UVA light on human keratinocyte and mouse melanocyte cell lines (HaCaT and B16-F10, respectively). In particular, we have analyzed the capacity of FB to counteract the alterations caused on cellular morphology, viability, oxidative stress and melanogenic signaling pathway activation. Our data indicate that FB prevented cell damage and reduced oxidative stress and melanogenic signaling pathway activation caused by a combination of BaP and UVA light irradiation. Altogether, our findings support the fact that FB is able to prevent skin damage caused by the exposure to a combination of UVA and the air pollutant BaP.

Plant Secondary Metabolites against Skin Photodamage: Mexican Plants, a Potential Source of UV-Radiation Protectant Molecules

Human skin works as a barrier against the adverse effects of environmental agents, including ultraviolet radiation (UVR). Exposure to UVR is associated with a variety of harmful effects on the skin, and it is one of the most common health concerns. Solar UVR constitutes the major etiological factor in the development of cutaneous malignancy. However, more than 90% of skin cancer cases could be avoided with appropriate preventive measures such as regular sunscreen use. Plants, constantly irradiated by sunlight, are able to synthesize specialized molecules to fight against UVR damage. Phenolic compounds, alkaloids and carotenoids constitute the major plant secondary metabolism compounds with relevant UVR protection activities. Hence, plants are an important source of molecules used to avoid UVR damage, reduce photoaging and prevent skin cancers and related illnesses. Due to its significance, we reviewed the main plant secondary metabolites related to UVR protection and its reported mechanisms. In addition, we summarized the research in Mexican plants related to UV protection. We presented the most studied Mexican plants and the photoprotective molecules found in them. Additionally, we analyzed the studies conducted to elucidate the mechanism of photoprotection of those molecules and their potential use as ingredients in sunscreen formulas.

Cryptomphalus aspersa Eggs Extract Potentiates Human Epidermal Stem Cell Regeneration and Amplification

Modern life and extended life expectancy have prompted the search for natural compounds alleviating skin aging. Evidence supports the beneficial effects on skin integrity and health from the topical administration of preparations of the mollusc Cryptomphalus aspersa eggs extract (IFC-CAF®) and suggests these effects are partly derived from an impact on skin renewal and repair mechanisms. The objective was to dissect in vitro the specific impact of IFC-CAF® on different parameters related to the regenerative potential, differentiation phenotype and exhaustion of skin stem cells. A prominent impact of IFC-CAF® was the induction of stratification and differentiated phenotypes from skin stem cells. IFC-CAF® slowed down the cell cycle at the keratinocyte DNA repair phase and, decelerated proliferation. However, it preserved the proliferative potential of the stem cells. IFC-CAF® reduced the DNA damage marker, γH2AX, and induced the expression of the transcription factor p53. These features correlated with significant protection in telomere shortening upon replicative exhaustion. Thus, IFC-CAF® helps maintain orderly cell cycling and differentiation, thus potentiating DNA repair and integrity. Our observations support the regenerative and repair capacity of IFC-CAF® on skin, through the improved mobilization and ordered differentiation of keratinocyte precursors and the enhancement of genome surveillance and repair mechanisms that counteract aging.

Formation of Cyclobutane Pyrimidine Dimers after UVA Exposure (Dark-CPDs) Is Inhibited by an Hydrophilic Extract of Polypodium leucotomos

Exposure to sun and especially to ultraviolet radiation (UVR) exerts well known detrimental effects on skin which are implicated in malignancy. UVR induces production of cyclobutane pyrimidine dimers (CPDs), immediately during exposure and even hours after the exposure, these latter being called dark-CPDs, as consequence of the effects of different reactive species that are formed. Fernblock^® (FB), an aqueous extract of Polypodium leucotomos, has proven to have photoprotective and antioxidant effects on skin. The aim of our work was to investigate the potential photoprotective effect of FB against dark-CPD formation. Murine melanocytes (B16-F10) were exposed to UVA radiation and the production of dark-CPDs and different reactive oxygen and nitrogen species (ROS and RNS) was measured. Significant dark-CPD formation could be seen at 3 h after UVA irradiation, which was inhibited by the pre-treatment of cells with FB. Formation of nitric oxide, superoxide and peroxynitrite was increased after irradiation, consistent with the increased CPD formation. FB successfully reduced the production of these reactive species. Hence, these results show how dark-CPDs are formed in UVA irradiated melanocytes, and that FB acts as a potential antioxidant and ROS scavenger, preventing the DNA damage induced by sun exposure.

Dermatologic Applications of Polypodium leucotomos: A Literature Review

BACKGROUND: Polypodium leucotomos (PL) is a natural extract from tropical fern leaves with antioxidant and anti-inflammatory properties. It has been implicated as a potential treatment agent in multiple dermatologic conditions. OBJECTIVE: Here, we review the mechanism of action and current dermatologic applications of PL and extrapolate potential future dermatologic applications of PL. DESIGN: An extensive literature review on Pubmed was conducted in search of relevant background information and human studies utilizing PL for the treatment of dermatologic conditions. METHODS: Using the PubMed database, a literature search was conducted to identify relevant publications. "Polypodium leucotomos" was input as the key search criterion. The results were filtered by species (human) and language (English). Only papers with dermatologic applications were selected. Additionally, relevant publications found in the reference sections of selected articles were manually searched and selected. Included articles explore the origin, basic science mechanism, and various dermatologic applications of PL studied in humans. Each article was thoroughly studied by all authors and applicable data from each was used for the compilation of this review article. RESULTS: See Table 1 for a summary of dermatologic applications of PL based on available human clinical studies. LIMITATIONS: There was a limited number of human studies concerning the use of PL for treatment of dermatologic conditions and, of the available studies, many were of a small sample size. CONCLUSION: PL has a clinically significant role for the treatment and prevention of certain dermatologic conditions including: photoprotection, photocarcinogenesis, photoaging, vitiligo, melasma, and polymorphic light eruption. There is supporting evidence for its use in malignant melanoma high-risk patients, for enhanced actinic keratosis clearance following photodynamic therapy, and for symptomatic relief in atopic dermatitis. Potential clinical uses that require additional human clinical studies include solar urticaria, post-inflammatory hyperpigmentation, cutaneous lupus erythematosus, and other photosensitive cutaneous disorders.

The role of the aqueous extract Polypodium leucotomos in photoprotection

Solar radiation in the ultraviolet (UV), visible (VIS), and infrared (IR) ranges produces different biological effects in humans. Most of these, particularly those derived from ultraviolet radiation (UVR) are harmful to the skin, and include cutaneous aging and increased risk of cutaneous diseases, particularly skin cancer. Pharmacological photoprotection is mostly topical, but it can also be systemic. Oral photoprotectives constitute a new generation of drugs to combat the deleterious effects of solar radiation. Among these, an extract of Polypodium leucotomos (PL/Fernblock®, IFC Group, Spain) contains a high content of phenolic compounds that endow it with antioxidant activity. PL can administered orally or topically and is completely safe. PL complements and enhances endogenous antioxidant systems by neutralizing superoxide anions, hydroxyl radicals, and lipoperoxides. In addition to its antioxidant activity, PL also improves DNA repair and modulates immune and inflammatory responses. These activities are likely due to its ability to inhibit the generation and release of reactive oxygen species (ROS) by UVR, VIS, and IR radiation. PL also prevents direct DNA damage by accelerating the removal of induced photoproducts and decreasing UV-induced mutations. Oral PL increases the expression of active p53, decreases cell proliferation, and inhibits UV-induced COX-2 enzyme levels. PL has been used to treat skin diseases such as photodermatoses and pigmentary disorders and recently as a complement of photodynamic phototherapy in actinic keratoses. The photoprotective capability of PL has been proven in a multitude of in vitro and in vivo studies, which include animal models and clinical trials with human subjects. Based on this evidence, PL is a new generation photoprotector with antioxidant and anti-inflammatory properties that also protects DNA integrity and enhances the immune response.

The Combination of Sulforaphane and Fernblock® XP Improves Individual Beneficial Effects in Normal and Neoplastic Human Skin Cell Lines

Plenty of evidence supports the health effects exerted by dietary supplements containing phytochemicals, but the actual efficacy and safety of their combinations have been seldom experimentally evaluated. On this basis, we investigated in vitro the antioxidant/antineoplastic efficacy and anti-aging activity of a dietary supplement containing sulforaphane (SFN), a sulfur-isothiocyanate present in broccoli, combined with the patented extract Fernblock^® XP (FB), obtained from the tropical fern Polypodium leucotomos. We evaluated the effect of SFN and FB, alone or in combination, on migration ability, matrix metalloproteinases (MMP) production, neoangiogenic potential and inflammasome activation in human WM115 and WM266-4 melanoma cells. Moreover, the effects on MMPs and reactive oxygen species production, and IL-1β secretion were studied in human normal keratinocytes. The SFN/FB combination inhibited melanoma cell migration in vitro, MMP-1, -2, -3, and -9 production, inflammasome activation and IL-1β secretion more efficiently than each individual compound did. In normal keratinocytes, SFN/FB was more efficient than SFN or FB alone in inhibiting MMP-1 and -3 production and IL-1β secretion in the presence of a pro-inflammatory stimulus such as TNF-α. The potential use of SFN/FB based supplements for the prevention of skin aging and as adjuvants in the treatment of advanced melanoma is suggested.

Fernblock® Upregulates NRF2 Antioxidant Pathway and Protects Keratinocytes from PM2.5-Induced Xenotoxic Stress

Humans in modern industrial and postindustrial societies face sustained challenges from environmental pollutants, which can trigger tissue damage from xenotoxic stress through different mechanisms. Thus, the identification and characterization of compounds capable of conferring antioxidant effects and protection against these xenotoxins are warranted. Here, we report that the natural extract of Polypodium leucotomos named Fernblock®, known to reduce aging and oxidative stress induced by solar radiations, upregulates the NRF2 transcription factor and its downstream antioxidant targets, and this correlates with its ability to reduce inflammation, melanogenesis, and general cell damage in cultured keratinocytes upon exposure to an experimental model of fine pollutant particles (PM_2.5). Our results provide evidence for a specific molecular mechanism underpinning the protective activity of Fernblock® against environmental pollutants and potentially other sources of oxidative stress and damage-induced aging.

Prospective Evaluation of the Efficacy of a Food Supplement in Increasing Photoprotection and Improving Selective Markers Related to Skin Photo-Ageing

INTRODUCTION

Skin exposure to ultraviolet radiation (UVR) can cause oxidative stress, particularly in the absence of adequate protective measures or in individuals with a sensitive skin type. Most commonly, protection from UVR entails the use of topical sunscreens. Sunscreens, however, have various limitations. The objective of this study was to evaluate the efficacy and tolerability of an oral food supplement containing a combination of actives with mainly antioxidative properties (vitamins A, C, D3, E, selenium, lycopene, lutein, as well as green tea, polypodium and grape extracts) in the context of photoprotection.

METHODS

Photoprotective efficacy was assessed in a 12-week-long, open, prospective and monocentric clinical study with 30 subjects (27 women and 3 men) having a Fitzpatrick skin type I-III and manifesting clinical ageing signs. The study included several visits (14, 28, 56, and 84 days after starting supplement intake), in which photoprotection was evaluated by the measurement of the minimal erythema dose (MED), while the antioxidant capacity of the skin was assessed through ferric reducing antioxidant power (FRAP) and malondialdehyde (MDA) assays. Additionally, several skin parameters (including radiance, elasticity, and moisture) were evaluated. Product evaluation was performed throughout the length of the study by means of a self-assessment questionnaire, and safety was monitored through a self-recording of all observed adverse reactions.

RESULTS

The MED levels increased significantly compared to baseline throughout the study visits, reaching an increase of + 8.1% at T84, p < 0.001. FRAP results also indicated a significant increase in the antioxidant capacity of the skin compared to baseline (+ 22.7% at T84, p < 0.001), while the MDA assay showed a significant decrease in MDA concentration compared to baseline (- 6.4% at T84, p < 0.001) which, in line with the FRAP results, indicated enhanced antioxidative protection of the skin. All assessed skin parameters, including radiance (+ 36.1% at T84, p < 0.001), gross elasticity (+ 13.2% at T84, p < 0.001), net elasticity (+ 28.0% at T84, p < 0.001), and moisture (+ 13.8% at T84, p < 0.001) were also significantly improved. The product was well tolerated as no adverse events were attributed by the investigators to the use of the product. Additionally, the global score obtained from the self-assessment questionnaires provided overwhelmingly positive feedback from the study subjects.

CONCLUSIONS

The food supplement evaluated in this study was effective and well-tolerated by the subjects, demonstrating a beneficial effect in terms of photoprotection, enhancing the antioxidative status of the skin and improving general skin condition.

TRIAL REGISTRATION

Retrospectively registered 3rd October 2019, ISRCTN18121679.

Polypodium Leucotomos Extract (PLE): New Study Gives Evidence-based Insight into "Ain't Nothing Like the Real Thing"

Polypodium leucotomos is widely available as an oral supplement and has been shown to exhibit photoprotective properties which might provide adjunctive benefit when used along with topically applied suncreens. However, data are lacking with the majority of Polypodium leucotomos formulations (including extracts) related to their quantitative and qualitative polyphenol content and specific photoprotective properties. This article reviews results from a study of six different Polypodium leucotomos extract formulations, comparing their polyphenol and excipient contents and specific photoprotective properties. Consistency was observed primarily with one specific brand of Polypodium leucotomos extract oral capsules, which is also supported by a large body of published evidence.

Cutaneous Photoprotective Activity of a Short-term Ingestion of High-Flavanol Cocoa: A Nutritional Intervention Study

In vivo and in vitro studies have shown that prolonged oral administration of flavanol-rich cocoas extracts have photoprotective effects. The aim of the present study was to assess the photoprotective activity of short-time administration of a new variety of naturally selected cocoa extract rich in bioactive compounds. We selected a cocoa powder particularly rich in polyphenols, flavanols, caffeine, theobromine and theophylline. We then investigated, in 10 healthy subjects, the photoprotective effects of one week of daily oral administration of two doses of such powder. Phototesting with solar simulated radiation was performed at baseline and after cocoa supplementation. Visual assessment of the minimal erythema dose and spectrophotometric measurement of the "a" parameter were done after 24 h from the irradiation. Oral daily supplementation of 1 g of high-flavanol cocoa was not effective but a one-week administration of 4-6 g of cocoa induced a statistically significant increase in the visual erythema threshold and a significant reduction in the "a" parameter. We demonstrated that a new variety of naturally selected cocoa extract, even when administered for a short time, retains a dose-dependent photoprotective effect. These results are also indicative of the fact that topical sunscreens could be supplemented by a specific diet.

Fernblock Prevents Dermal Cell Damage Induced by Visible and Infrared A Radiation

Sun overexposure leads to higher risk of photoaging and skin cancer. The contribution of infrared (IR) and visible light (VIS) radiation is currently being taken into account in their pathogenesis. Erythema, hyperpigmentation, genotoxicity or the increase of matrix metalloproteinases (MMPs) expression are some of the effects induced by these types of radiation. Extracts of various botanicals endowed with antioxidant activity are emerging as new photoprotective compounds. A natural extract from Polypodium leucotomos (Fernblock^®, FB) has antioxidant and photoprotective properties and exhibits a strong anti-aging effect. In this study, we evaluated the protective capacity of FB against the detrimental effects of infrared A (IRA) and VIS radiation in human dermal fibroblasts. We analyzed the effects of FB on the morphology, viability, cell cycle and expression of extracellular matrix components of fibroblasts subjected to VIS and IRA. Our results indicate that FB prevents cell damage caused by VIS and IRA. Moreover, it reduces the increase in MMP-1 and cathepsin K expression induced by both VIS and IRA radiation, and curbs alterations in fibrillin 1, fibrillin 2 and elastin expression. All these findings support FB as a feasible approach to prevent or treat skin damage caused by IRA or VIS exposure.

Oral Photoprotection: Effective Agents and Potential Candidates

Electromagnetic radiation in the ultraviolet, visible, and infrared ranges produces biologic effects in humans. Where some of these effects are beneficial, others are harmful to the skin, particularly those stemming from ultraviolet radiation (UVR). Pharmacological photoprotection can be topical or systemic. Systemic photoprotection is often administered orally, complementing topical protection. New and classic oral agents (e.g., essential micronutrients as vitamins, minerals, polyphenols, carotenoids) are endowed with photoprotective and anti-photocarcinogenic properties. These substances bear the potential to increase systemic protection against the effects of electromagnetic radiation in the UV, visible, and infrared ranges. Protective mechanisms vary and include anti-oxidant, anti-inflammatory, and immunomodulatory effects. As such, they provide protection against UVR and prevent photo-induced carcinogenesis and aging. In this review, we present state of the art approaches regarding the photoprotective effects of vitamins and vitamin derivatives, dietary botanical, and non-botanical agents. A growing body of data supports the beneficial effects of oral photoprotection on the health of the skin. More studies will likely confirm and expand the positive impact of oral dietary botanicals as complementary measures for photoprotection.

Double-blind, Placebo-controlled Trial to Evaluate the Effectiveness of Polypodium Leucotomos Extract in the Treatment of Melasma in Asian Skin: A Pilot Study

Introduction: Melasma is a common pigmentary disorder with a multifactorial etiology that can hinder its management. The aqueous extract of the fern Polypodium leucotomos (PLE), Fernblock^® (IFC, Madrid, Spain), has demonstrated antioxidant and photoprotective activities and has been used for the treatment of several pigmentary disorders. The aim of this study was to evaluate the efficacy and safety of oral PLE in the treatment of melasma in Asian patients. Methods: Forty healthy adult patients with clinical diagnoses of melasma who were receiving treatment with topical 4% hydroquinone cream and sunscreen with a sun protection factor (SPF) of 50+ were recruited for inclusion in this study from the National Skin Centre in Singapore. They were randomized to receive either oral PLE supplementation or placebo for 12 weeks. Patients were assessed at baseline, Day 28, Day 56, and Day 84 using the modified Melasma Area and Severity Index (mMASI); melanin and erythema indexes; VISIA^® photography (Canfield Scientific, Parsippany, New Jersey, USA); and the Melasma Quality of Life (MelasQoL) questionnaire. Adverse events were recorded. Results: Following four, eight, and 12 weeks of treatment, there were statistically significant differences between the mMASI scores of both groups as compared with the baseline scores (p≤0.01). mMASI scores of the PLE group at eight and 12 weeks were also significantly lower than those of the placebo group (p≤0.05). At the end of the study, a significant improvement was reached in both groups (both p≤0.01), with no significant differences between them. The scores of the melanin and erythema indices displayed a slight improvement in both groups, without significant differences among them. MelasQoL score showed an improvement in the PLE group versus the placebo group. Our results demonstrate that the PLE aqueous extract product significantly improves and accelerates the outcome reached with hydroquinone and sunscreen almost from the first month of treatment in comparison with the placebo. There were no significant side effects reported. Conclusions: The oral PLE aqueous extract product appears to be a safe and effective adjunctive treatment for melasma in combination with topical hydroquinone and sunscreen.

Antioxidants in dermatology

The skin cells continuously produce, through cellular respiration, metabolic processes or under external aggressions, highly reactive molecules oxidation products, generally called free radicals. These molecules are immediately neutralized by enzymatic and non-enzymatic systems in a physiological and dynamic balance. In situations where this balance is broken, various cellular structures, such as the cell membrane, nuclear or mitochondrial DNA may suffer structural modifications, triggering or worsening skin diseases. several substances with alleged antioxidant effects has been offered for topical or oral use, but little is known about their safety, possible associations and especially their mechanism of action. The management of topical and oral antioxidants can help dermatologist to intervene in the oxidative processes safely and effectively, since they know the mechanisms, limitations and potential risks of using these molecules as well as the potential benefits of available associations.

A 28-day oral toxicology study of an aqueous extract of Polypodium leucotomos (Fernblock®)

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The NOAEL study was 5000 mg/kg bw/d—the highest dose tested.

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No target organs or treatment-related toxicological effects were identified.

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Our results are relevant to the evaluation of the safety of human ingestion of Fernblock^®.

Fernblock^® is a standardized commercial aqueous extraction of the leaves of the tropical fern Polypodium leucotomos promoted as an orally active photoprotective substance. In a previous battery of toxicological tests on Fernblock^®, no genotoxicy was observed and no oral toxicity was observed up to 1200 mg/kg bw/day. The current study was conducted in Hsd.Han Wistar rats using doses of 0, 2000, 3500, and 5000 mg/kg bw/day Fernblock^® by gavage for 28 consecutive days. No mortality or toxic effects were observed and no target organs were identified. The no observed adverse effect level was determined to be 5000 mg/kg bw/day, the highest dose tested.

Phytochemicals from fern species: potential for medicine applications

Ferns are an important phytogenetic bridge between lower and higher plants. Historically they have been used in many ways by humans, including as ornamental plants, domestic utensils, foods, and in handicrafts. In addition, they have found uses as medicinal herbs. Ferns produce a wide array of secondary metabolites endowed with different bioactivities that could potentially be useful in the treatment of many diseases. However, there is currently relatively little information in the literature on the phytochemicals present in ferns and their pharmacological applications, and the most recent review of the literature on the occurrence, chemotaxonomy and physiological activity of fern secondary metabolites was published over 20 years ago, by Soeder (Bot Rev 51:442-536, 1985). Here, we provide an updated review of this field, covering recent findings concerning the bioactive phytochemicals and pharmacology of fern species.

Fernblock (Polypodium leucotomos Extract): Molecular Mechanisms and Pleiotropic Effects in Light-Related Skin Conditions, Photoaging and Skin Cancers, a Review

Healthier life styles include increased outdoors time practicing sports and walking. This means increased exposure to the sun, leading to higher risk of sunburn, photoaging and skin cancer. In addition to topical barrier products, oral supplementations of various botanicals endowed with antioxidant activity are emerging as novel method of photoprotection. Polypodium leucotomos extract (PL, commercial name Fernblock^®, IFC Group, Spain) is a powerful antioxidant due to its high content of phenolic compounds. PL is administered orally, with proven safety, and it can also be used topically. Its mechanisms include inhibition of the generation and release of reactive oxygen species (ROS) by ultraviolet (UV) light. It also prevents UV- and ROS-induced DNA damage with inhibition of AP1 and NF-κB and protection of natural antioxidant enzyme systems. At the cellular level, PL decreases cellular apoptosis and necrosis mediated UV and inhibits abnormal extracellular matrix remodeling. PL reduces inflammation, prevents immunosuppression, activates tumor suppressor p53 and inhibits UV-induced cyclooxygenase-2 (COX-2) enzyme expression. In agreement with increased p53 activity, PL decreased UV radiation-induced cell proliferation. PL also prevents common deletions mitochondrial DNA damage induced by UVA, and MMP-1 expression induced Visible Light and Infrared Radiation. These cellular and molecular effects are reflected in inhibitions of carcinogenesis and photoaging.

Use of Polypodium leucotomas Extract in Clinical Practice: A Primer for the Clinician

Polypodium leucotomas extract is a natural product derived from a tropical fern that is available as an over-the-counter product in the United States and several other countries. A designated brand of oral Polypodium leucotomas extract has been shown in several research studies to exhibit a variety of antioxidant and photoprotective properties. Clinical research with this same formulation of Polypodium leucotomas extract has demonstrated multiple potential therapeutic applications. This article provides a thorough overview of research completed with Polypodium leucotomas extract and outlines suggested approaches for clinical use.

A comprehensive toxicological safety assessment of an aqueous extract of Polypodium leucotomos (Fernblock(®))

A battery of toxicological studies was conducted in accordance with internationally accepted standards to investigate the genotoxicity and repeated-dose oral toxicity of Fernblock(®), a commercial aqueous extraction of the leaves of the tropical fern Polypodium leucotomos used for its oral and topical photoprotective properties. No evidence of mutagenicity was observed in a bacterial reverse mutation test or in vitro mammalian chromosomal aberration test nor was any genotoxic activity observed in an in vivo mouse micronucleus test. Two repeated-dose oral toxicity studies were conducted in male and female Wistar rats. In the first study, no mortality or toxic effects were observed and no target organs were identified at doses administered for 14 days by gavage up to the maximum dose of 5000 mg/kg bw/day. Based on these results, a 90-day study was conducted at 0, 300, 600, and 1200 mg/kg bw/day. No mortality or treatment-related adverse effects were observed and no target organs were identified. The NOAEL from the 90-day study was determined to be 1200 mg/kg bw/day, the highest dose tested.

Oral Polypodium leucomotos increases the anti-inflammatory and melanogenic responses of the skin to different modalities of sun exposures: a pilot study

BACKGROUND

The effects on the inflammatory and tanning responses of sunlight/UVR of several oral antioxidants are still unknown.

OBJECTIVE

Assess intensity, time course of the inflammatory, and tanning responses to increasing dosages of solar-simulated radiation (SSR) at baseline and after oral supplementation of an extract of Polypodium leucotomos (PLE).

METHODS

Ten healthy subjects underwent phototesting with SSR with a visual and spectrophotometrical assessment of the responses with or without daily oral supplementation of two tablets containing 240 mg of PLE for a total of 15 days.

RESULTS

Polypodium leucotomos supplementation induced a significant increase of the minimal erythema dose (MED), a faster recovery of the inflammation following the delivery of super-erythemal doses, and no significant changes of the minimal melanogenic dose (MMD). Spectrophotometric assessment of the Δa* in test areas exposed to equally doses of SSR did not show differences.

CONCLUSIONS

Polypodium leucotomos supplementation increased the MED and induced a faster recovery of the inflammation and a stronger tanning response with no changes in the melanogenic threshold.

Brazilian consensus on photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection.

Sports Dermatology: Part 1 of 2 Traumatic or Mechanical Injuries, Inflammatory Conditions, and Exacerbations of Pre-existing Conditions

Competitive athletes endure extreme bodily stress when participating in sports-related activities. An athlete's skin is particularly susceptible to a wide array of repetitive physical and environmental stressors that challenge the skin's protective function. Many unique dermatoses are well-known to the serious athlete due to countless hours of intense physical training, but are frequently unrecognized by many healthcare professionals. Sports dermatology is a distinctive, budding field of dermatology that focuses on dermatoses frequently encountered in athletes. Athletic skin problems are notoriously infectious in nature due to the inherent environment of close-contact physical activity. Nonetheless, other skin conditions can manifest or worsen with recurring mechanical or traumatic injury or exposure to environmental hazards. Additionally, sports-related activities may exacerbate other pre-existing dermatological conditions that may possibly be unknown to the athlete or clinician. The objective of this two-part review is to arm the astute physician with the fundamental knowledge of the range of dermatological conditions distinct to the competitive athlete. Knowledge of these cutaneous conditions in the context of specific sporting events will permit the clinician to manage these unique patients most effectively. Part one will focus on traumatic or mechanical injuries, inflammatory conditions, and exacerbations of pre-existing conditions frequently seen in athletes.

Mechanisms of Photoaging and Cutaneous Photocarcinogenesis, and Photoprotective Strategies with Phytochemicals

Photoaging and photocarcinogenesis are primarily due to solar ultraviolet (UV) radiation, which alters DNA, cellular antioxidant balance, signal transduction pathways, immunology, and the extracellular matrix (ECM). The DNA alterations include UV radiation induced thymine-thymine dimers and loss of tumor suppressor gene p53. UV radiation reduces cellular antioxidant status by generating reactive oxygen species (ROS), and the resultant oxidative stress alters signal transduction pathways such as the mitogen-activated protein kinase (MAPK), the nuclear factor-kappa beta (NF-κB)/p65, the janus kinase (JAK), signal transduction and activation of transcription (STAT) and the nuclear factor erythroid 2-related factor 2 (Nrf2). UV radiation induces pro-inflammatory genes and causes immunosuppression by depleting the number and activity of the epidermal Langerhans cells. Further, UV radiation remodels the ECM by increasing matrixmetalloproteinases (MMP) and reducing structural collagen and elastin. The photoprotective strategies to prevent/treat photoaging and photocarcinogenesis include oral or topical agents that act as sunscreens or counteract the effects of UV radiation on DNA, cellular antioxidant balance, signal transduction pathways, immunology and the ECM. Many of these agents are phytochemical derivatives and include polyphenols and non-polyphenols. The flavonoids are polyphenols and include catechins, isoflavones, proanthocyanidins, and anthocyanins, whereas the non-flavonoids comprise mono phenolic acids and stilbenes. The natural sources of polyphenols include tea, cocoa, grape/wine, soy, pomegranate, and Polypodium leucotomos. The non-phenolic phytochemicals include carotenoids, caffeine and sulphoraphance (SFN). In addition, there are other phytochemical derivatives or whole extracts such as baicalin, flavangenol, raspberry extract, and Photomorphe umbellata with photoprotective activity against UVB radiation, and thereby carcinogenesis.

Natural products as photoprotection

The rise in solar ultraviolet radiation on the earth's surface has led to a depletion of stratospheric ozone over recent decades, thus accelerating the need to protect human skin against the harmful effects of UV radiation such as erythema, edema, hyperpigmentation, photoaging, and skin cancer. There are many different ways to protect skin against UV radiation's harmful effects. The most popular way to reduce the amount of UV radiation penetrating the skin is topical application of sunscreen products that contain UV absorbing or reflecting active molecules. Based on their protection mechanism, the active molecules in sunscreens are broadly divided into inorganic and organic agents. Inorganic sunscreens reflect and scatter UV and visible radiation, while organic sunscreens absorb UV radiation and then re-emit energy as heat or light. These synthetic molecules have limited concentration according to regulation concern. Several natural compounds with UV absorption property have been used to substitute for or to reduce the quantity of synthetic sunscreen agents. In addition to UV absorption property, most natural compounds were found to act as antioxidants, anti-inflammatory, and immunomodulatory agents, which provide further protection against the damaging effects of UV radiation exposure. Compounds derived from natural sources have gained considerable attention for use in sunscreen products and have bolstered the market trend toward natural cosmetics. This adds to the importance of there being a wide selection of active molecules in sunscreen formulations. This paper summarizes a number of natural products derived from propolis, plants, algae, and lichens that have shown potential photoprotection properties against UV radiation exposure-induced skin damage.

Polypodium leucotomos as an Adjunct Treatment of Pigmentary Disorders

INTRODUCTION

Extracts of the tropical fern Polypodium leucotomos appear to possess beneficial properties for the skin attributed to the presence of numerous compounds within the extract that have antioxidant and photoprotective properties. Orally administered Polypodium leucotomos may provide protection against the detrimental photoaging effects of sunlight and can also help reduce the frequency and severity of polymorphous light eruption. Polypodium leucotomos has also been shown to be beneficial for the prevention and potential treatment of several aesthetically relevant conditions.

OBJECTIVE

The purpose of this review is to investigate the beneficial role of Polypodium leucotomos as an adjunct treatment for vitiligo, melasma, and postinflammatory hyperpigmentation.

RESULTS

Based on a review of relevant literature including the results of a randomized, placebo-controlled study, the oral administration of Polypodium leucotomos significantly improved the severity of melasma in women after 12 weeks. Three randomized, double-blind, placebo-controlled studies have demonstrated significant improvements in vitiligo when oral Polypodium leucotomos therapy was combined with psoralens plus ultraviolet A and narrowband ultraviolet B. No controlled studies have assessed the efficacy of Polypodium leucotomos for the treatment of postinflammatory hyperpigmentation; however, its known antioxidant and anti-inflammatory properties and demonstrated effectiveness for melasma support its use for treating this condition. No adverse events have been associated with the use of Polypodium leucotomos.

CONCLUSION

In addition to preventing many harmful effects associated with sunlight exposure, orally administered Polypodium leucotomos also appears to provide adjunctive benefits in treating vitiligo, melasma, and may have the potential to help with postinflammatory hyperpigmentation.

Oxidative stress and skin cancer: an overview

Skin is the largest body organ that serves as an important environmental interface providing a protective envelope that is crucial for homeostasis. On the other hand, it is a major target for toxic insult by a broad spectrum of physical and chemical agents that are capable of altering its structure and function. There are a large number of dietary contaminants and drugs can manifest their toxicity in skin. These environmental toxicants or their metabolites are inherent oxidants and/or directly or indirectly drive the production of a variety of reactive oxidants also known as reactive oxygen species. These are short-lived entities that are continuously generated at low levels during the course of normal aerobic metabolism. These are believed to activate proliferative and cell survival signaling that can alter apoptotic pathways that may be involved in the pathogenesis of a number of skin disorders. The skin possesses an array of antioxidant defense mechanisms that interact with toxicants to obviate their deleterious effect. The "antioxidant power" of a food is an expression of its capability both to defend the human organism from the action of the free radicals and to prevent degenerative disorders. Plants like olive trees have their own built-in protection against the oxidative damage of the sun, and these built-in protectors function as cell protectors in our own body. Although many antioxidants have shown substantive efficacy in cell culture systems and in animal models of oxidant injury, unequivocal confirmation of their beneficial effects in human populations has proven elusive.