Solar ultraviolet-induced erythema in human skin and nuclear factor-kappa-B-dependent gene expression in keratinocytes are modulated by a French maritime pine bark extract

Diterpenes of Pinus pinaster aiton with anti-inflammatory, analgesic, and antibacterial activities

ETHNO-PHARMACOLOGICAL RELEVANCE

The P. pinaster species, known as 'Pino nigral or rodeno', is used in the treatment of colds, asthma, flu, and tuberculosis.

AIM OF THE STUDY

This study determined the anti-inflammatory, analgesic, and antibacterial activities of the P. pinaster resin, identifying the compounds with higher biological activity.

MATERIALS AND METHODS

A bio-guided isolation of the compounds of P. pinaster was carried out by selecting the most active extracts with anti-inflammatory and analgesic effects in the HBEC3-KT, MRC-5, and THP-1 cell lines. The antibacterial activity was determined against the S. aureus, S. pneumoniae, K. pneumoniae and P. aeruginosa strains.

RESULTS

The following compounds were identified by NMR: dehydroabietic acid (1), ( + )-cis-abienol (2), pimaric acid (3), isopimaric acid (4), 7α-hydroxy-dehydroabietic acid (5), 7-oxo-dehydroabietic acid (6), 15-hydroxy-abietic acid (7), 7-oxo-15-hydroxy-dehydroabietic acid (8), 13-oxo-8 (14)-podocarpen-18-oic acid (9), and pinyunin A (10). Regarding their anti-inflammatory activity, all compounds inhibited NF-κB. Compound 9 was the most active (IC50 = 3.90-12.06 μM). Concerning the analgesic activity, all the compounds inhibited NK-1, yet compound 9 was the most active (IC50 = 0.28-0.33 μM). Finally, compounds 6 (MIC = 12.80-25.55 μM) and 9 (MIC = 9.80-24.31 μM) were the most promising antibacterial compounds in all strains.

CONCLUSION

This study managed to identify, for the first time, six diterpenes from the resin of P. pinaster, with anti-inflammatory, analgesic, and antibacterial activity. Among the identified compounds, compound 9 was the most active, being considered a promising candidate as an antagonist of the tachykinin NK-1 receptor and as an analgesic agent against inflammation and neuropathic pain. It also had an antibacterial effect against Gram negative bacteria.

The Impact of Antioxidants on Vitiligo and Melasma: A Scoping Review and Meta-Analysis

Reactive oxygen species (ROS) generated during melanogenesis make melanocytes particularly vulnerable to oxidative stress, influencing their survival and melanin synthesis. Oxidative stress, significantly present in vitiligo and recently also detected in melasma, triggers inflammatory cascades and melanogenesis, making antioxidants a promising therapeutic avenue. A systematic search was conducted on Embase and Pubmed to study the efficacy of antioxidants for treating vitiligo and/or melasma. Meta-analysis was performed to assess the difference in Melasma Severity Index (MASI) scores between baseline and follow-up. Various antioxidants like polypodium leucotomos, ginkgo biloba, catalase/superoxide dismutase, and vitamin E have potential in vitiligo. For melasma, vitamin C, silymarin, and niacinamide were among those showing promise in reducing pigmentation, with vitamin C displaying significant effects in meta-analysis. Different antioxidants improve both vitiligo and melasma, with an increased minimal erythema dose (MED) following UV exposure being significant for vitiligo and tyrosinase inhibition being crucial for melasma. However, the efficacy of individual antioxidants varies, and their exact mechanisms, especially in stimulating melanocyte proliferation and anti-inflammatory pathways, require further investigation to understand better and optimize their use.

Topical and Systemic Therapies in Melasma: A Systematic Review

Introduction

Melasma is an acquired disorder, which presents with well-demarcated, brown-colored hyperpigmented macules, commonly involving the sun-exposed areas such as the face. It is a chronic and distressing condition, affecting the patients' quality of life, and has been conventionally treated with "first-line" agents including hydroquinone (HQ) alone or as a part of a triple combination cream (TCC), while "second-line" options include chemical peels, and third line options include laser therapy.

Materials and Methods

A systematic search was performed for all topical and systemic treatments for melasma up till May 4, 2021, using the PubMed and EMBASE databases, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. The search terms "melasma" and "treatment" were used to search for the relevant articles on both these databases, and a total of 4020 articles were identified. After removing the duplicate entries and screening the titles, abstracts, and full-text articles, we identified 174 randomized controlled trials (RCTs) or controlled clinical trials.

Results

Based on our review, HQ, TCCs, sunscreens, kojic acid (KA), and azelaic acid receive grade A recommendation. Further large-scale studies are required to clearly establish the efficacy of topical vitamin C, resorcinol, and topical tranexamic acid (TXA). Several newer topical agents may play a role only as an add-on or second-line drugs or as maintenance therapy. Oral TXA has a strong recommendation, provided there are no contraindications. Procyanidins, Polypodium leucotomos (PL), and even synbiotics may be taken as adjuncts.

Discussion

Several newer topical and systemic agents with multimodal mechanisms of action have now become available, and the balance seems to be tipping in favor of these innovative modalities. However, it is worth mentioning that the choice of agent should be individualized and subject to availability in a particular country.

Effects of Plant-Derived Dietary Supplements on Skin Health: A Review

Dietary supplements have become increasingly popular to improve facial appearance and optimize skin health. With countless supplements available online and in stores, there are unlimited options for patients to choose from. Federal law does not require the Food and Drug Administration to assess each product's efficacy before its appearance on the market. Therefore, evidence-based medicine is vital for dermatologists to provide adequate recommendations regarding the safety and efficacy of various dietary supplements. The goal of this review is to evaluate plant-derived, antioxidant oral supplements and their effects on wrinkle appearance, skin hydration, skin elasticity, and photoprotection.

Antioxidative and Antimicrobial Evaluation of Bark Extracts from Common European Trees in Light of Dermal Applications

Plant species have developed effective defense strategies for colonizing diverse habitats and protecting themselves from numerous attacks from a wide range of organisms, including insects, vertebrates, fungi, and bacteria. The bark of trees in particular constitutes a number of components that protect against unwanted intruders. This review focuses on the antioxidative, dermal immunomodulatory, and antimicrobial properties of bark extracts from European common temperate trees in light of various skin pathogens, wound healing, and the maintenance of skin health. The sustainability aspect, achieved by utilizing the bark, which is considered a byproduct in the forest industry, is addressed, as are various extraction methods applied to retrieve extracts from bark.

Discovery of SARS-CoV-2-E channel inhibitors as antiviral candidates

Lack of efficiency has been a major problem shared by all currently developed anti-SARS-CoV-2 therapies. Our previous study shows that SARS-CoV-2 structural envelope (2-E) protein forms a type of cation channel, and heterogeneously expression of 2-E channels causes host cell death. In this study we developed a cell-based high throughput screening (HTS) assay and used it to discover inhibitors against 2-E channels. Among 4376 compounds tested, 34 hits with cell protection activity were found. Followed by an anti-viral analysis, 15 compounds which could inhibit SARS-CoV-2 replication were identified. In electrophysiological experiments, three representatives showing inhibitory effect on 2-E channels were chosen for further characterization. Among them, proanthocyanidins directly bound to 2-E channel with binding affinity (K_D) of 22.14 μM in surface plasmon resonance assay. Molecular modeling and docking analysis revealed that proanthocyanidins inserted into the pore of 2-E N-terminal vestibule acting as a channel blocker. Consistently, mutations of Glu 8 and Asn 15, two residues lining the proposed binding pocket, abolished the inhibitory effects of proanthocyanidins. The natural product proanthocyanidins are widely used as cosmetic, suggesting a potential of proanthocyanidins as disinfectant for external use. This study further demonstrates that 2-E channel is an effective antiviral drug target and provides a potential antiviral candidate against SARS-CoV-2.

Nutrition and youthful skin

Nutrition and dietary supplements have been used to promote a youthful appearance for millennia. Despite high public demand for these products, evidence supporting their efficacy is limited and often inconsistent. We discuss the structural and functional changes that occur in the skin during the aging process. We also review evidence supporting the use of nutritional supplements commonly used to promote a youthful appearance, including essential fatty acids, coenzyme Q, collagen peptides, curcumin, polyphenols, flavonoids, probiotics, silymarin, and vitamins A, C, D, and E. We also consider the role of advanced glycosylated end products, antiinflammatory diets, and caloric restriction in delaying premature skin aging. Although evidence supporting the use of some dietary interventions is promising, further long-term studies in humans are required to fully understand their effects on the promotion of a youthful appearance.

Biomarkers of geroprotection and cardiovascular health: An overview of omics studies and established clinical biomarkers in the context of diet

The slowdown, inhibition, or reversal of age-related decline (as a composite of disease, dysfunction, and, ultimately, death) by diet or natural compounds can be defined as dietary geroprotection. While there is no single reliable biomarker to judge the effects of dietary geroprotection, biomarker signatures based on omics (epigenetics, gene expression, microbiome composition) are promising candidates. Recently, omic biomarkers started to supplement established clinical ones such as lipid profiles and inflammatory cytokines. In this review, we focus on human data. We first summarize the current take on genetic biomarkers based on epidemiological studies. However, most of the remaining biomarkers that we describe, whether omics-based or clinical, are related to intervention studies. Then, because of their promising potential in the context of dietary geroprotection, we focus on the effects of berry-based interventions, which up to now have been mostly described employing clinical markers. We provide an aggregation and tabulation of all the recent systematic reviews and meta-analyses that we could find related to this topic. Finally, we present evidence for the importance of the "nutribiography," that is, the influence that an individual's history of diet and natural compound consumption can have on the effects of dietary geroprotection.

Pinus Species as Prospective Reserves of Bioactive Compounds with Potential Use in Functional Food-Current State of Knowledge

The pine (Pinus L.) is the largest and most heteromorphic plant genus of the pine family (Pinaceae Lindl.), which grows almost exclusively in the northern hemisphere. The demand for plant-based remedies, supplements and functional food is growing worldwide. Although pine-based products are widely available in many parts of the world, they are almost absent as food ingredients. The literature shows the beneficial effects of pine preparations on human health. Despite the wide geographical distribution of pine trees in the natural environment, there are very few data in the literature on the widespread use of pine in food technology. This study aims to present, characterise and evaluate the content of phytochemicals in pine trees, including shoots, bark and conifer needles, as well as to summarise the available data on their health-promoting and functional properties, and the potential of their use in food and the pharmaceutical industry to support health. Various species of pine tree contain different compositions of bioactive compounds. Regardless of the solvent, method, pine species and plant part used, all pine extracts contain a high number of polyphenols. Pine tree extracts exhibit several described biological activities that may be beneficial to human health. The available examples of the application of pine elements in food are promising. The reuse of residual pine elements is still limited compared to its potential. In this case, it is necessary to conduct more research to find and develop new products and applications of pine residues and by-products.

Management of hyperpigmentation: Current treatments and emerging therapies

Hyperpigmentation of the skin refers to a dermatological condition which alters the color of the skin, making it discolored or darkened. The treatments for hyperpigmentation disorders often take very long to show results and have poor patient compliance. The first-line treatment for hyperpigmentation involves topical formulations of conventional agents such as hydroquinone, kojic acid, and glycolic acid followed by oral formulations of therapeutic agents such as tranexamic acid, melatonin, and cysteamine hydrochloride. The second-line approaches include chemical peels and laser therapy given under the observation of expert professionals. However, these therapies pose certain limitations and adverse effects such as erythema, skin peeling, and drying and require long treatment duration to show visible effects. These shortcomings of the conventional treatments provided scope for further research on newer alternatives for managing hyperpigmentation. Some of these therapies include novel formulations such as solid lipid nanocarriers, liposomes, phytochemicals, platelet-rich plasma, microneedling. This review focuses on elaborating on several hyperpigmentation disorders and their mechanisms, the current, novel and emerging treatment options for management of hyperpigmentation.

Pine Bark Phenolic Extracts, Current Uses, and Potential Food Applications: A Review

PURPOSE

To summarize the main findings from research on food uses of Pine Bark Phenolic Extracts (PBPE), their origin, methods of extraction, composition, health effects, and incorporation into food products.

METHODS

A narrative review of all the relevant papers known to the authors was conducted.

RESULTS

PBPE are mainly extracted from the bark Pinus pinaster. They are generally rich in procyanidins and their effects on health in the form of nutritional supplements include effect on some forms of cancer, on diabetes, on eye and skin health. Their method of extraction influences greatly their composition and yield, and commercially suitable methods are still to be developed. Incorporation into food products raises challenges related to bioavailability and subsequent bioactivity and sensory properties of the final products.

CONCLUSION

PBPE represent an opportunity for the development of functional foods with phenolic-rich bioactive compounds.

Administration of Apple Polyphenol Supplements for Skin Conditions in Healthy Women: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

This clinical study was performed to evaluate the effects of continuous apple polyphenol (AP) administration on facial skin conditions and pigmentation induced by ultraviolet (UV) irradiation in healthy women participants. Participants (n = 65, age 20–39 years) were randomized to receive tablets containing AP (300 or 600 mg/day) or placebo in a double-blinded, placebo-controlled clinical trial. Continuous administration of AP for 12 weeks significantly prevented UV irradiation induced skin pigmentation (erythema value, melanin value, L value), although a dose-dependent relationship was not clearly observed. In contrast, no significant differences were detected between the groups with regard to water content and trans-epidermal water loss. Our study demonstrated that APs and their major active compounds, procyanidins, have several health benefits. Here, we report that continuous administration of AP for 12 weeks alleviated UV irradiation induced skin pigmentation, when compared with placebo, in healthy women.

Skin Health from the Inside Out

The skin is the main interface between the body and the environment, providing a biological barrier against an array of chemical and physical pollutants (e.g., ultraviolet light, ozone, etc.). Exposure of the skin to these outdoor stressors generates reactive oxygen species (ROS), which can overwhelm the skin's endogenous defense systems (e.g., catalase, vitamins C and E, etc.), resulting in premature skin aging due to the induction of DNA damage, mitochondrial damage, lipid peroxidation, activation of inflammatory signaling pathways, and formation of protein adducts. In this review, we discuss how topical application of antioxidants, including vitamins C and E, carotenoids, resveratrol, and pycnogenol, can be combined with dietary supplementation of these antioxidant compounds in addition to probiotics and essential minerals to protect against outdoor stressor-induced skin damage, including the damage associated with aging.

Unravelling the insulin-like growth factor I-mediated photoprotection of the skin

Chronic exposure of human skin to solar ultraviolet radiation (UVR) induces a range of biological reactions which may directly or indirectly lead to the development of skin cancer. In order to overcome these damaging effects of UVR and to reduce photodamage, the skin's endogenous defence system functions in concert with the various exogenous photoprotectors. Growth factors, particularly insulin-like growth factor-I (IGF-I), produced within the body as a result of cellular interaction in response to UVR demonstrates photoprotective properties in human skin. This review summarises the impact of UVR-induced photolesions on human skin, discusses various endogenous as well as exogenous approaches of photoprotection described to date and explains how IGF-I mediates UVR photoprotective responses at the cellular and mitochondrial level. Further, we describe the current interventions using growth factors and propose how the knowledge of the IGF-I photoprotection signalling cascades may direct the development of improved UVR protection and remedial strategies.

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.

Effects of Ultraviolet Irradiation on Cellular Senescence in Keratinocytes Versus Fibroblasts

Aging is a biologic process characterized by time-dependent functional declines that are influenced by oxidative stress-induced inflammatory reactions. In particular, ultraviolet (UV) irradiation plays a key role in cellular senescence in photo-aged skin. However, the cellular senescence of epidermal keratinocytes and dermal fibroblasts by UV irradiation may differ depending on the exposure time and dosage of UV irradiation. Therefore, the purpose of the study was to evaluate and compare the effects of UV irradiation on cellular senescence in human epidermal keratinocytes (HaCaT) and human dermal fibroblasts (HDFs). After cell viability test, 200 mJ/cm UV irradiation was used in this study. To evaluate the reactive oxygen species and reactive nitrogen species production, the levels of glutathione (GSH) and nitrite (NO2) were measured. We also performed reverse transcription-polymerase chain reaction, Western blot analysis, and senescence-associated beta-galactosidase assay. An overall decrease in GSH and an increase in NO2 were observed in the HaCaT and HDF cells. However, the time-line and dose-dependent effects varied. Higher expressions of tumor necrosis factor-α, inducible nitric oxide synthase, and interleukin-1β than that of the control group were observed in both cells. The HDF cells showed high levels of matrix metallopeptidase 9 and neutral endopeptidase protein but low levels of SIRT1 and procollagen I. The expression of nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) was increased in the HaCaT cells, but not in the HDF cells. The NF-κB peaked at 1 hour after UV irradiation in the HaCaT cells. The "turning-on" signal was faster in the irradiated HaCaT cells.

Toll-Like Receptor-Dependent Immunomodulatory Activity of Pycnogenol®

BACKGROUND

Pycnogenol® (PYC), an extract of French maritime pine bark, is widely used as a dietary supplement. PYC has been shown to exert anti-inflammatory actions via inhibiting the Toll-like receptor 4 (TLR4) pathway. However, the role of the other receptors from the TLR family in the immunomodulatory activity of PYC has not been described so far.

AIM

The aim of this study was to investigate whether PYC might exert its immunomodulatory properties through cell membrane TLRs (TLR1/2, TLR5, and TLR2/6) other than TLR4. Moreover, the effect of gastrointestinal metabolism on the immunomodulatory effects of PYC was investigated.

FINDINGS

We showed that intact non-metabolized PYC dose-dependently acts as an agonist of TLR1/2 and TLR2/6 and as a partial agonist of TLR5. PYC on its own does not agonize or antagonize TLR4. However, after the formation of complexes with lipopolysaccharides (LPS), it is a potent activator of TLR4 signaling. Gastrointestinal metabolism of PYC revealed the immunosuppressive potential of the retentate fraction against TLR1/2 and TLR2/6 when compared to the control fraction containing microbiota and enzymes only. The dialyzed fraction containing PYC metabolites revealed the capacity to induce anti-inflammatory IL-10 secretion. Finally, microbially metabolized PYC affected the colonic microbiota composition during in vitro gastrointestinal digestion.

CONCLUSIONS

This study showed that gastrointestinal metabolism of PYC reveals its biological activity as a potential inhibitor of TLRs signaling. The results suggest that metabolized PYC acts as a partial agonist of TLR1/2 and TLR2/6 in the presence of the microbiota-derived TLR agonists (retentate fraction) and that it possesses anti-inflammatory potential reflected by the induction of IL-10 from THP-1 macrophages (dialysate fraction).

Nutraceuticals for Skin Care: A Comprehensive Review of Human Clinical Studies

The skin is the body’s largest organ, it participates in sensitivity and offers protection against microorganisms, chemicals and ultraviolet (UV) radiation. Consequently, the skin may suffer alterations such as photo-ageing, immune dysfunction and inflammation which may significantly affect human health. Nutraceuticals represent a promising strategy for preventing, delaying, or minimising premature ageing of the skin and also to alleviate certain skin disorders. Among them, bioactive peptides and oligosaccharides, plant polyphenols, carotenoids, vitamins and polyunsaturated fatty acids are the most widely used ingredients. Supplementation with these products has shown evidence of having an effect on the signs of ageing and protection against UV radiation ageing in several human trials. In this review, the most relevant human studies on skin nutraceuticals are evaluated and the statistical resolution, biological relevance of their results, and, the trial protocols are discussed. In conclusion, quality and rigorousness of the trials must be improved to build credible scientific evidence for skin nutraceuticals and to establish a cause-effect relationship between the ingredients the beneficial effects for the skin.

Pinus densiflora bark extract ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice by regulating Th1/Th2 balance and skin barrier function

Korean red pine (Pinus densiflora) bark has been traditionally used in Korea and other parts of East Asia to relieve inflammatory diseases. Although many studies using P. densiflora bark have been reported, its effect on atopic dermatitis (AD) has not been elucidated. Thus, we investigated whether the P. densiflora bark extract (PBE) has potential to attenuate AD symptoms and elucidated the molecular mechanism. Oral administration of PBE to mice with 2,4-dinitrochlorobenzene (DNCB)-induced AD lessened dermatitis scores and scratching behavior and significantly reduced measures of epidermal thickness, infiltration of mast cells and eosinophils, levels of immunoglobulin E (IgE), and IgG₁ /IgG_2a ratio in serum. PBE not only inhibited IL-4, IL-5, and IL-13 but also increased IFN-γ in splenic production. Furthermore, PBE significantly suppressed mRNA expression of thymic stromal lymphopoietin and further downregulated the mRNA expression of Th2 and Th17 cytokines such as IL-4, IL-13, IL-17, IL-31, and TNF-α. In addition, the protein expressions of filaggrin, involucrin, and loricrin in lesional skin were recovered by PBE. These results suggest that PBE attenuates DNCB-induced AD via regulating Th1/Th2 balance and skin barrier function.

Research on the antioxidant, wound healing, and anti-inflammatory activities and the phytochemical composition of maritime pine (Pinus pinaster Ait)

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnobotanical investigations have shown that the Pinus species have been used against rheumatic pain and for wound healing in Turkish folk medicine.

MATERIAL AND METHODS

In this study, phytochemical composition, antioxidant, anti-inflammatory, and wound healing activities of Maritime Pine (Pinus pinaster Ait.) that is collected in Turkey are investigated. Essential oil composition and the amount of extracts (lipophilic and hydrophilic) of maritime pine wood and fresh cone samples had been tested.

RESULTS

The essential oil from cones of P. pinaster revealed the highest activities, whereas other parts of the plant did not display any appreciable wound healing, anti-inflammatory, or antioxidant effects. α-Pinene was the main constituent of the essential oil obtained from the cones of P. pinaster.

CONCLUSION

Experimental studies shown that P. pinaster's remarkable anti-inflammatory and wound healing activities support the traditional use of the plant, and suggest it could have a place in modern medicine.

Recent development of signaling pathways inhibitors of melanogenesis

Human skin, eye and hair color rely on the production of melanin, depending on its quantity, quality, and distribution, Melanin plays a monumental role in protecting the skin against the harmful effect of ultraviolet radiation and oxidative stress from various environmental pollutants. However, an excessive production of melanin causes serious dermatological problems such as freckles, solar lentigo (age spots), melasma, as well as cancer. Hence, the regulation of melanin production is important for controlling the hyper-pigmentation. Melanogenesis, a biosynthetic pathway to produce melanin pigment in melanocyte, involves a series of intricate enzymatic and chemical catalyzed reactions. Several extrinsic factors include ultraviolet radiation and chemical drugs, and intrinsic factors include molecules secreted by surrounding keratinocytes or melanocytes, and fibroblasts, all of which regulate melanogenesis. This article reviews recent advances in the development of melanogenesis inhibitors that directly/indirectly target melanogenesis-related signaling pathways. Efforts have been made to provide a description of the mechanism of action of inhibitors on various melanogenesis signaling pathways.

Pycnogenol Attenuates the Release of Proinflammatory Cytokines and Expression of Perilipin 2 in Lipopolysaccharide-Stimulated Microglia in Part via Inhibition of NF-κB and AP-1 Activation

Over activation of microglia results in the production of proinflammatory agents that have been implicated in various brain diseases. Pycnogenol is a patented extract from French maritime pine bark (Pinus pinaster Aiton) with strong antioxidant and anti-inflammatory potency. The present study investigated whether pycnogenol may be associated with the production of proinflammatory mediators in lipopolysaccharide-stimulated BV2 (mouse-derived) microglia. It was found that pycnogenol treatment was dose-dependently associated with significantly less release of nitricoxide (NO), TNF-α, IL-6 and IL-1β, and lower levels of intercellular adhesion molecule1 (ICAM-1) and perilipin 2 (PLIN2). Furthermore, this effect was replicated in primary brain microglia. Levels of inducible NO synthase mRNA and protein were attenuated, whereas there was no change in the production of the anti-inflammatory cytokine IL-10. Further evidence indicated that pycnogenol treatment led to the suppression of NF-κB activation through inhibition of p65 translocation into the nucleus and inhibited DNA binding of AP-1, suggesting that these proinflammatory factors are associated with NF-κB and AP-1. We conclude that pycnogenol exerts anti-inflammatory effects through inhibition of the NF-κB and AP-1pathway, and may be useful as a therapeutic agent in the prevention of diseases caused by over activation of microglia.

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.

Pycnogenol prevents peritoneal adhesions

PURPOSE

This study tested the ability of pycnogenol, an extract from the bark of the French maritime pine (Pinus pinaster), to prevent intra-abdominal adhesions.

METHODS

Thirty female Wistar albino rats were separated randomly into three equal groups: Group (1) the control group, which underwent surgery, but was given no drug; Group (2) given 10 mg/kg of pycnogenol dissolved in normal saline intraperitoneally for 10 days after surgery; and Group (3) given 0.1 mL of normal saline for 10 days intraperitoneally after surgery. On post-operative day 10, all of the animals were killed and any adhesions were evaluated macroscopically and histopathologically.

RESULTS

The macroscopic adhesion scores (mean ± SD) for Groups 1, 2, and 3 were 2.5 ± 0.53, 0.60 ± 0.70, and 2.0 ± 0.82, respectively. The macroscopic adhesion score was significantly lower in Group 2 than in Groups 1 and 3 (p < 0.001). All three components of the histopathological evaluation (inflammation, fibrosis, and neovascularization) were significantly lower in Group 2 than in Groups 1 or 3 (p < 0.001, p < 0.001, and p = 0.004, respectively).

CONCLUSIONS

Pycnogenol was found to be effective at preventing surgery-related adhesions in an animal model.

UVB Stimulates the Expression of Endothelin B Receptor in Human Melanocytes via a Sequential Activation of the p38/MSK1/CREB/MITF Pathway Which Can Be Interrupted by a French Maritime Pine Bark Extract through a Direct Inactivation of MSK1

Melanogenesis is the physiological process by which melanin is synthesized to protect the skin from UV damage. While paracrine interactions between keratinocytes and melanocytes are crucial for regulating epidermal pigmentation, the endothelin (EDN)-endothelin B-receptor (EDNRB) interaction is one of the key linkages. In this study, we found that a single exposure of normal human melanocytes (NHMs) with UVB stimulates the expression of EDNRB and its upstream transcription factor microphthalmia-associated transcription factor (MITF) at the transcriptional and translational levels. That stimulation can be abrogated by post-irradiation treatment with a French maritime pine bark extract (PBE). UVB stimulated the phosphorylation of p38 and c-jun N-terminal kinase (JNK), but not ERK, followed by the increased phosphorylation of MSK1 and CREB. The post-irradiation treatment with PBE did not affect the increased phosphorylation of p38 and JNK, but distinctly abrogated the phosphorylation of MSK1 and CREB. Post-irradiation treatment with the MSK1 inhibitor H89 significantly down-regulated the increased gene expression of MITF and EDNRB in UVB-exposed NHMs. Our findings indicate for the first time that the increased expression of MITF that leads to the up-regulation of melanocyte-specific proteins in UVB-exposed NHMs is mediated via activation of the p38/MSK1/CREB pathway but not the ERK/RSK/CREB pathway. The mode of action by PBE demonstrates that interrupting MSK1 activation is a new target for antioxidants including PBE which can serve as anti-pigmenting agents in a reactive oxygen species-depletion-independent manner.

Pycnogenol® in Metabolic Syndrome and Related Disorders

The present review provides an update of the biological actions of Pycnogenol® in the treatment of metabolic syndrome and related disorders such as obesity, dyslipidaemia, diabetes and hypertension. Pycnogenol® is a French maritime pine bark extract produced from the outer bark of Pinus pinaster Ait. Subsp. atlantica. Its strong antioxidant, antiinflammatory, endothelium-dependent vasodilator activity, and also its anti-thrombotic effects make it appropriate for targeting the multifaceted pathophysiology of metabolic syndrome. Clinical studies have shown that it can reduce blood glucose levels in people with diabetes, blood pressure in mild to moderate hypertensive patients, and waist circumference, and improve lipid profile, renal and endothelial functions in metabolic syndrome. This review highlights the pathophysiology of metabolic syndrome and related clinical research findings on the safety and efficacy of Pycnogenol®. The results of clinical research studies performed with Pycnogenol® are discussed using an evidence-based, target-oriented approach following the pathophysiology of individual components as well as in metabolic syndrome overall.

Photoprotective effect of botanicals and vitamins: A systematic review of clinical trials

BACKGROUND

Overexposure to solar radiation is a major contributor to skin cancer development and premature skin aging. Botanical extracts and vitamins may represent novel photoprotective agents.

OBJECTIVE

We sought to systemically review clinical evidence for the use of botanically derived agents and vitamins as photoprotective agents.

METHODS

We systematically searched Embase and PubMed databases. Two independent reviewers reviewed abstracts for inclusion. Additional relevant studies were identified by a manual review of reference lists. Data from eligible studies were extracted independently and discrepancies were resolved by consensus.

RESULTS

A total of 51 studies met inclusion criteria. Limited available evidence indicates that several botanical agents and vitamins in topical or oral forms may have promising photoprotective effects. However, generalizability of results is limited by small sample sizes.

CONCLUSION AND RELEVANCE

Botanical extracts and vitamins may add to the armamentarium of sun-protective agents. Additional high-quality trials are needed to strengthen support for their use.

The effect of pycnogenol on patients with dysmenorrhea using low-dose oral contraceptives

Objective

Menstrual symptoms such as dysmenorrhea usually occur during the hormone-free interval in oral contraceptive users. Progestin withdrawal activates NF-κB transcription factor, which upregulates both vascular endothelial growth factor (VEGF) and Cox-2 expression in the endometrium. The use of natural NF-κB inhibitors such as pycnogenol may block this response, improving dysmenorrhea.

Patients and methods

Twenty-four patients with severe dysmenorrhea were allocated to one of two treatment groups. In Group A (n=13), women were treated with an oral contraceptive containing 15 μg of ethinyl estradiol and 60 mg of gestodene (Adoless^®) in a 24/4 regimen for three consecutive cycles. Women in Group B (n=11) used the same contraceptive regimen together with 100 mg of pycnogenol (Flebon^®) continuously for 3 months. Pain scores were graded using a visual analog scale (VAS) before and during the hormone-free interval at the end of the third treatment cycle.

Results

Before treatment, VAS pain scores for dysmenorrhea were 8 and 9 in Groups A and B, respectively. However, by the end of the third treatment cycle, pain scores had decreased significantly (P<0.05) both in groups A and B. The final pain scores were 6 in Group A and 2 in Group B, a difference that was statistically significant (P<0.0001). In Group B, 27% of the patients became pain-free, while in Group A, none of the women reported complete disappearance of this symptom. The number of bleeding days was also lower in Group B.

Discussion

Pycnogenol effectively decreased pain scores and the number of bleeding days when administered concomitantly with a low-dose 24/4 oral contraceptive containing gestodene.

The protective role of antioxidants in the defence against ROS/RNS-mediated environmental pollution

Overproduction of reactive oxygen and nitrogen species can result from exposure to environmental pollutants, such as ionising and nonionising radiation, ultraviolet radiation, elevated concentrations of ozone, nitrogen oxides, sulphur dioxide, cigarette smoke, asbestos, particulate matter, pesticides, dioxins and furans, polycyclic aromatic hydrocarbons, and many other compounds present in the environment. It appears that increased oxidative/nitrosative stress is often neglected mechanism by which environmental pollutants affect human health. Oxidation of and oxidative damage to cellular components and biomolecules have been suggested to be involved in the aetiology of several chronic diseases, including cancer, cardiovascular disease, cataracts, age-related macular degeneration, and aging. Several studies have demonstrated that the human body can alleviate oxidative stress using exogenous antioxidants. However, not all dietary antioxidant supplements display protective effects, for example, β-carotene for lung cancer prevention in smokers or tocopherols for photooxidative stress. In this review, we explore the increases in oxidative stress caused by exposure to environmental pollutants and the protective effects of antioxidants.

Combining oral contraceptives with a natural nuclear factor-kappa B inhibitor for the treatment of endometriosis-related pain

Endometriosis is a chronic disease in which a persistent state of heightened inflammation is maintained by nuclear factor-kappa B (NF-κB) activation. The progestins present in oral contraceptives are potent inhibitors of NF-κB translocation to cell nuclei, while Pycnogenol® (Pinus pinaster) acts by blocking post-translational events. In this study, the effects of Pycnogenol on pain scores were investigated in patients with endometriosis using oral contraceptives containing either gestodene or drospirenone in extended regimens. Pain scores were determined using a visual analog scale before and after 3 months of treatment. Oral contraceptives, used alone (groups 1 and 3) or in association with Pycnogenol (groups 2 and 4), resulted in significant decreases in pain scores after 3 months of treatment; however, this reduction was significantly greater in the groups using oral contraceptives + Pycnogenol (groups 2 and 4) compared with those using oral contraceptives alone (groups 1 and 3). In the groups using oral contraceptives alone, 50% of patients became pain-free by the end of the third month of treatment. These results suggest that Pycnogenol increases the efficacy of oral contraceptives for the treatment of endometriosis-related pain.

Pycnogenol® in chronic venous insufficiency and related venous disorders

The present review provides an update of the biological profile of Pycnogenol in the light of its use in the treatment of chronic venous insufficiency (CVI) and related venous disorders such as deep vein thrombosis (DVT), post-thrombotic syndrome, long haul air-travel-related leg oedema, venous ulcers and acute haemorrhoids. Pycnogenol is a French maritime pine bark extract produced from the outer bark of Pinus pinaster Ait. subsp. atlantica. Its strong antioxidant, anti-inflammatory and vasodilator activities, antithrombotic effects and collagen stabilizing properties make it uniquely able to target the multi facet pathophysiology of CVI and related venous disorders. Clinical studies have shown that it can reduce oedema of the legs in CVI, reduce the incidence of deep venous thrombosis during long haul flights and enhance the healing of venous ulcers and haemorrhoidal episodes by topical application and/or oral administration. This review highlights clinical research findings on the safety, compliance and efficacy of Pycnogenol, including its use in combination products.

The effects of pycnogenol on antioxidant enzymes in a mouse model of ozone exposure

BACKGROUND/AIMS

Ozone is an environmentally reactive oxidant, and pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark that have antioxidant activity. We investigated the effects of pycnogenol on reactive nitrogen species, antioxidant responses, and airway responsiveness in BALB/c mice exposed to ozone.

METHODS

Antioxidant levels were determined using high performance liquid chromatography with electrochemical detection. Nitric oxide (NO) metabolites in bronchoalveolar lavage (BAL) fluid from BALB/c mice in filtered air and 2 ppm ozone with pycnogenol pretreatment before ozone exposure (n = 6) were quantified colorimetrically using the Griess reaction.

RESULTS

Uric acid and ascorbic acid concentrations were significantly higher in BAL fluid following pretreatment with pycnogenol, whereas γ-tocopherol concentrations were higher in the ozone exposed group but were similar in the ozone and pycnogenol pretreatment groups. Retinol and γ-tocopherol concentrations tended to increase in the ozone exposure group but were similar in the ozone and pycnogenol pretreatment groups following ozone exposure. Malonylaldehyde concentrations increased in the ozone exposure group but were similar in the ozone and pycnogenol plus ozone groups. The nitrite and total NO metabolite concentrations in BAL fluid, which parallel the in vivo generation of NO in the airways, were significantly greater in the ozone exposed group than the group exposed to filtered air, but decreased with pycnogenol pretreatment.

CONCLUSIONS

Pycnogenol may increase levels of antioxidant enzymes and decrease levels of nitrogen species, suggesting that antioxidants minimize the effects of acute ozone exposure via a protective mechanism.

Novel, biocatalytically produced hydroxytyrosol dimer protects against ultraviolet-induced cell death in human immortalized keratinocytes

Compounds derived from botanicals, such as olive trees, have been shown to possess various qualities that make them function as ideal antioxidants and, in doing so, protect them against the damaging effect of ultraviolet (UV)-derived oxidative stress. The aim of this study was to biocatalytically synthesize a dimeric product (compound II) from a known botanical, 3-hydroxytyrosol, and test it for its antioxidant ability using a human immortalized keratinocyte cell line (HaCaT). 2,2-Diphenyl-picryhydrazyl (DPPH) antioxidant assays showed 33 and 86.7% radical scavenging activity for 3-hydroxytyrosol and its dimer, respectively. The ferric-reducing antioxidant power (FRAP) assay corroborated this by showing a 3-fold higher antioxidant activity for the dimer than 3-hydroxytyrosol. Western blot analyses, showing cells exposed to 500 μM of the dimeric product when ultraviolet A (UVA)-irradiated, increased the anti-apoptotic protein Bcl-2 expression by 16% and reduced the pro-apoptotic protein Bax by 87.5%. Collectively, the data show that the dimeric product of 3-hydroxytyrosol is a more effective antioxidant and could be considered for use in skin-care products, health, and nutraceuticals.

New horizons in treating disorders of hyperpigmentation in skin of color

Pigmentary abnormalities are among the most common reasons why patients with skin of color visit a dermatologist. Hydroquinone has been a cornerstone for the treatment of hyperpigmentation; however, concerns regarding adverse effects have prompted a search for alternative agents. Some promising topical treatments include soy, licorice, rucinol, mulberry, niacinamide, ellagic acid, resveratrol, and dioic acid. Oral agents, primarily used for the prevention of postprocedural hyperpigmentation, include procyanidins, tranexamic acid, and Polypodium leucotomos. Advances in Q-switched lasers, intense pulse light, fractional photothermolysis, and the advent of tretinoin peeling add to the clinician's armamentarium for treating hyperpigmentation.

Identification and characterization of proanthocyanidins of 16 members of the Rhododendron genus (Ericaceae) by tandem LC-MS

The proanthocyanidins of the leaves of 16 taxa of the Rhododendron genus (Ericaceae) [Rhododendron 'Catawbiense Grandiflorum', Rhododendron 'Cunningham's White', Rhododendron smirnowii Trautv., Rhododendron calophytum Franch., Rhododendron dichroanthum ssp. scyphocalyx (Balf. f. & Forrest ) Cowan, Rhododendron micranthum Turcz., Rhododendron praevernum Hutch., Rhododendron ungernii Trautv., Rhododendron kaempferi Planch., Rhododendron degronianum ssp. heptamerum var. hondoense (Nakai ) H. Hara, Rhododendron fortunei Lindl., Rhododendron ponticum L., Rhododendron galactinum Balf. f. ex Tagg., Rhododendron oreotrephes W. W. Sm., Rhododendron brachycarpum ssp. brachycarpum D. Don ex G. Don, and Rhododendron insigne Hemsl. & E. H. Wilson ] were investigated qualitatively by liquid chromatography-mass spectrometry in series. Twenty-nine dimeric proanthocyanidins based on (epi)catechin and (epi)gallocatechin were detected and characterized on the basis of their unique fragmentation pattern in the negative ion mode tandem mass spectrometry spectra. All of them were extracted for the first time from these sources, and ten of them were not reported previously in nature. The position of the galloyl residue was assigned on the basis of the retro-Diels-Alder fragmentation and the dehydrated retro-Diels-Alder fragmentation; it resulted from the loss of gallic acid as a neutral loss in the negative ion mode. Furthermore, four caffeoylquinic acids, six p-coumaroylquinic acids, epigallocatechin, gallocatechin, catechin, epicatechin, epigallocatechin gallate, catechin gallate, epicatechin gallate, gallocatechin gallate, two quercetin-O-hexosides, quercetin-O-galloyl-hexoside, quercetin-O-pentoside, quercetin-O-rhamnoside, quercetin-O-pentoside-O-hexoside, quercetin-O-rhamnoside-O-hexoside, quercetin-O-feruloyl-hexoside, quercetin-O-(p-hydroxy)benzoyl-hexoside, taxifolin-O-pentoside, myricetin-O-rhamnoside, two myricetin-O-pentosides, three myricetin-O-hexosides, and two myricetin-O-galloyl-hexosides were detected and shown to possess characteristic tandem mass spectrometry spectra and were tentatively assigned on the basis of their retention time.

The antioxidant and antigenotoxic effects of pycnogenol(®) on rats treated with cisplatin

Oxidative stress and inflammation are implicated in the pathogenesis of cisplatin-induced toxicity. Pycnogenol® is known for its strong antioxidant and anti-inflammatory effects. In this study, the possible protective effects of pycnogenol on kidney, bone marrow, and red blood cells in rats treated with cisplatin were investigated. The rats were divided into four groups. Group 1 was the control and groups 2, 3, and 4 were orally treated with pycnogenol (200 mg/kg bw, o.p) for 5 days, treated with cisplatin (7 mg/kg bw, i.p.) on the fifth day and treated with cisplatin plus pycnogenol, respectively. Antioxidative parameters in kidney and red blood cells were measured. Chromosome anomalies in bone marrow and renal histopathology were also investigated. Activities of pro-oxidant enzymes (myeloperoxidase and xanthine oxidase), malondialdehyde, and nitric oxide levels significantly increased but antioxidant enzymes activities decreased in the kidneys and red blood cells after cisplatin treatment. Pycnogenol treatment prior to the administration of cisplatin significantly decreased cisplatin-induced injury, as evidenced by its normalizing these parameters. Chromosomal aberrations decreased and mitotic index frequencies increased in bone marrow treated with cisplatin plus pycnogenol. These findings suggest that pycnogenol may be a useful protective agent against the toxicity associated with cisplatin therapy.

Omega-3 polyunsaturated fatty acids: photoprotective macronutrients

Ultraviolet radiation (UVR) in sunlight has deleterious effects on skin, while behavioural changes have resulted in people gaining more sun exposure. The clinical impact includes a year-on-year increase in skin cancer incidence, and topical sunscreens alone provide an inadequate measure to combat overexposure to UVR. Novel methods of photoprotection are being targeted as additional measures, with growing interest in the potential for systemic photoprotection through naturally sourced nutrients. Omega-3 polyunsaturated fatty acids (n-3 PUFA) are promising candidates, showing potential to protect the skin from UVR injury through a range of mechanisms. In this review, we discuss the biological actions of n-3 PUFA in the context of skin protection from acute and chronic UVR overexposure and describe how emerging new technologies such as nutrigenomics and lipidomics assist our understanding of the contribution of such nutrients to skin health.

Cosmeceuticals: practical applications

Cosmeceuticals are topically applied products that are more than merely cosmetic, yet are not true drugs that have undergone rigorous placebo controlled studies for safety and efficacy. There are many review articles that outline the theoretical biologic and clinical actions of these cosmeceuticals and their various ingredients. This article reviews how to incorporate various cosmeceuticals into the treatment regime of patients, depending on the diagnosis and therapies chosen. The practical application of when, why, and on whom to use different products will enable dermatologists to improve the methodology of product selection and, ultimately, improve patient's clinical results.

A randomized, double-blind, placebo-controlled exploratory study to evaluate the potential of pycnogenol for improving allergic rhinitis symptoms

The potential of Pycnogenol for relieving allergic rhinitis (birch pollen) symptoms was explored in a double-blind, placebo-controlled trial. In 2008 19 subjects started treatment 3 weeks prior to the onset of birch pollen season in Ontario, Canada. While there was an improvement of eye and nasal symptoms with Pycnogenol, there was no significance versus placebo. It was postulated that Pycnogenol may require a lag-time between the start of therapy and the onset of action. Therefore 39 subjects were treated 5-8 weeks prior to the 2009 birch allergy season. The evaluation of subjects in 2009 showed much lower scores for eye (-35%) and nasal (-20.5%) symptoms with Pycnogenol compared with placebo. In succession of the allergy season birch specific IgE increased by 31.9% in the placebo group compared with only 19.4% in the Pycnogenol group. Detailed analysis suggested that symptom-relief was better the longer subjects were on Pycnogenol prior to the allergen exposure. The best results were found with subjects who took Pycnogenol 7-8 weeks ahead of the allergy season. With the limited number of 39 patients statistical predications were unattainable. In conclusion, Pycnogenol improved allergic rhinitis symptoms when supplementation was started at least 5 weeks before the onset of the allergy season.

The cosmetic treatment of wrinkles

Wrinkles now have a greater social impact because people live longer. Science and hedonism overlap in the search for causes, treatments and prevention of wrinkles. The cosmetic approach to wrinkles includes: i Cleansing ii Photoprotection iii Active ingredients Active ingredients go well beyond simple moisturisers and exert a more complex activity in protecting skin from external injuries, nourishing it and removing its superficial layers. Transport systems and excipients are increasingly effective. Functional agents currently include alpha hydroxy acids (AHAs), poly-AHAs, complex poly-AHAs, retinoids, fish polysaccharides, anti-enzymatic agents, antioxidants (including ascorbic acid, pycnogenol, ursolic acid, vegetable isoflavones, vitamin E, coenzyme Q10, lipoic acid, resveratorol, l-carnosine and taurine) as well as agaricic acid and various plant extracts. All are reviewed in this text. Most are topical, some can be given by mouth, even as food supplements. Cosmetics are becoming closer to drugs in preventing and treating wrinkles. Included amongst the cosmeceuticals are the anti-wrinkle agents described herein.

Effects of Pinus brutia bark extract and Pycnogenol in a rat model of carrageenan induced inflammation

The present study was conducted to explore the anti-inflammatory activities of Pinus brutia bark extract and Pycnogenol in a rat model of carrageenan-induced inflammation. Firstly, the compositions of both samples were determined using HPLC. Then, carrageenan-induced paw edema was used to assess anti-inflammatory activity in mice. Paw volume was measured before and 1, 2, 3, 4, 5 and 6h after the injection of carrageenan. Intraperitoneal administration of both the extract and Pycnogenol inhibited paw swelling dose-dependently at 2, 3, 4, 5 and 6h after carrageenan injection. Both samples exhibited significant anti-inflammatory activities at doses of 75 and 100 mg/kg body wt. between 2 and 4 hours after administration (p<0.05), respectively. Additionally, P. brutia bark extract showed significantly better activity at doses of 75 and 100mg/kg body wt. than indomethacine at the dose of 10mg/kg body wt. (p<0.05). No acute toxicity was identified in intraplantar injection of the extract at a dose of 2000 mg/kg body wt.. Therefore, P. brutia bark extract possessing 3.3-fold more total catechins and 9.8-fold more taxifolin than Pycnogenol can be utilized as an anti-inflammatory agent.

Effects of a turmeric extract (Curcuma longa) on chronic ultraviolet B irradiation-induced skin damage in melanin-possessing hairless mice

Turmeric (the rhizomes of Curcuma longa L., Zingiberacease) is widely used as a dietary pigment and spice, and has been traditionally used for the treatment of inflammation, skin wounds and hepatic disorders in Ayurvedic, Unani and Chinese medicine. Although the topical application or oral administration of turmeric is used to improve skin trouble, there is no evidence to support this effect. The aim of this study was to clarify whether turmeric prevents chronic ultraviolet B (UVB)-irradiated skin damage. We examined the effects of a turmeric extract on skin damage including changes in skin thickness and elasticity, pigmentation and wrinkling caused by long-term, low-dose ultraviolet B irradiation in melanin-possessing hairless mice. The extract (at 300 or 1000 mg/kg, twice daily) prevented an increase in skin thickness and a reduction in skin elasticity induced by chronic UVB exposure. It also prevented the formation of wrinkles and melanin (at 1000 mg/kg, twice daily) as well as increases in the diameter and length of skin blood vessels and in the expression of matrix metalloproteinase-2 (MMP-2). Prevention of UVB-induced skin aging by turmeric may be due to the inhibition of increases in MMP-2 expression caused by chronic irradiation.