Dietary polyphenols as photoprotective agents against UV radiation

Computer-aided drug design supporting sunscreen research: a showcase study using previously synthesized hybrid UV filter-antioxidant compounds

CONTEXT

Although quantum mechanical calculations have proven effective in accurately predicting UV absorption and assessing the antioxidant potential of compounds, the utilization of computer-aided drug design (CADD) to support sustainable synthesis research of new sunscreen active ingredients remains an area with limited exploration. Furthermore, there are ongoing concerns about the safety and effectiveness of existing sunscreens. Therefore, it remains crucial to investigate photoprotection mechanisms and develop enhanced strategies for mitigating the harmful effects of UVR exposure, improving both the safety and efficacy of sunscreen products. A previous study conducted synthesis research on eight novel hybrid compounds (I-VIII) for use in sunscreen products by molecular hybridization of trans-resveratrol (RESV), avobenzone (AVO), and octinoxate (OMC). Herein, time-dependent density functional theory (TD-DFT) calculations performed in the gas phase on the isolated hybrid compounds (I-VIII) proved to reproduce the experimental UV absorption. Resveratrol-avobenzone structure-based hybrids (I-IV) present absorption maxima in the UVB range with slight differences between them, while resveratrol-OMC structure-based hybrids (V-VIII) showed main absorption in the UVA range. Among RESV-OMC hybrids, compounds V and VI exhibited higher UV absorption intensity, and compound VIII stood out for its broad-spectrum coverage in our simulations. Furthermore, both in silico and in vitro analyses revealed that compounds VII and VIII exhibited the highest antioxidant activity, with compound I emerging as the most reactive antioxidant within RESV-AVO hybrids. The study suggests a preference for the hydrogen atom transfer (HAT) mechanism over single-electron transfer followed by proton transfer (SET-PT) in the gas phase. With a strong focus on sustainability, this approach reduces costs and minimizes effluent production in synthesis research, promoting the eco-friendly development of new sunscreen active ingredients.

METHODS

The SPARTAN'20 program was utilized for the geometry optimization and energy calculations of all compounds. Conformer distribution analysis was performed using the Merck molecular force field 94 (MMFF94), and geometry optimization was carried out using the parametric method 6 (PM6) followed by density functional theory (DFT/B3LYP/6-31G(d)). The antioxidant behavior of the hybrid compounds (I-VIII) was determined using the highest occupied molecular orbital (εHOMO) and the lowest unoccupied molecular orbital (εLUMO) energies, as well as the bond dissociation enthalpy (BDE), ionization potential (IP), and proton dissociation enthalpy (PDE) values, all calculated at the same level of structural optimization. TD-DFT study is carried out to calculate the excitation energy using the B3LYP functional with the 6-31G(d) basis set. The calculated transitions were convoluted with a Gaussian profile using the Gabedit program.

Industrial and culinary treatments applied to Piquillo pepper (Capsicum annuum cv. Piquillo) impact positively on (poly)phenols' bioaccessibility and gut microbiota catabolism

Thermal treatments applied to plant-based foods prior to consumption might influence (poly)phenols' bioaccessibility and the metabolization of these compounds by the gut microbiota. In the present research, the impact of industrial (grilling and canning) and culinary (microwaving and frying) treatments on the bioaccessibility and colonic biotransformations of (poly)phenols from Piquillo pepper (Capsicum annum cv. Piquillo) were evaluated by in vitro gastrointestinal digestion and colonic fermentation models and HPLC-ESI-MS/MS. The application of industrial treatments impacted positively on (poly)phenols' bioaccessibility compared to raw pepper. Microwaving also exerted a positive effect on (poly)phenols' bioaccessibility compared to canning whereas the addition of oil for frying seemed to negatively affect (poly)phenols' release from the food matrix. Throughout the 48 hours of the colonic fermentation process (poly)phenolic compounds were catabolized into different (poly)phenol derivatives whose formation was also positively affected by industrial and culinary treatments. Based on the concentration and time of appearance of these derivatives, catabolic pathways of (poly)phenols from Piquillo pepper were proposed. The major (poly)phenol derivatives identified (3-(3'-hydroxyphenyl)propanoic acid, 4-hydroxy-3-methoxyphenylacetic acid and benzene-1,2-diol) are considered of great interest for the study of their bioactivity and the potential effect on human health.

Anti-inflammatory, antioxidant and photoprotective activity of standardised Gaultheria procumbens L. leaf, stem, and fruit extracts in UVA-irradiated human dermal fibroblasts

ETHNOPHARMACOLOGICAL RELEVANCE

Gaultheria procumbens L. is a polyphenolic-rich medicinal and food plant. Its leaves, stems, and fruits are traditional anti-inflammatory, antipyretic, antioxidant, and antimicrobial herbal medicines used to treat internal and external inflammation-related ailments, including rheumatic diseases, influenza, the common cold, fever, and skin and periodontal problems. Moreover, G. procumbens leaf extract is used for skin care as an anti-ageing and anti-wrinkle ingredient.

AIM OF THE STUDY

Various environmental factors, especially solar ultraviolet radiation, accelerate skin ageing by promoting oxidative stress and inflammation. Despite the dermoprotective and anti-ageing applications, the impact of G. procumbens on human dermal fibroblasts is unknown. Therefore, the study aimed to evaluate the anti-inflammatory, antioxidant, and photoprotective activity of G. procumbens standardised leaf, stem, and fruit extracts in cellular models, including human dermal fibroblasts (Hs68 cells) under UVA-irradiation, the primary pro-ageing skin stressor.

MATERIALS AND METHODS

Hs68 fibroblasts were pre-treated (24h) with G. procumbens extracts (0.5-100 μg/mL) or reference compounds followed by UVA-irradiation (8 J/cm2). Cell viability and metabolic activity were measured by CCK-8 and MTT assays in human Hs68 and mouse L929 fibroblasts, respectively. The ROS level, SOD, and GST activities were estimated by fluorescence and spectrophotometric techniques. The pro-inflammatory potential (NF-κB transcription factor activation) was checked using THP1-Blue™ NF-κB cells, and the anti-inflammatory activity was studied by measuring IL-8, ICAM-1, and NF-κB levels and phosphorylation of Erk kinase in LPS-stimulated Hs68 cells by spectrophotometry and confocal microscopy. The UVA-induced DNA damage and cell migration were evaluated by comet and scratch assays, respectively.

RESULTS

The extracts did not affect the metabolic activity of mouse L929 fibroblasts and the viability of unirradiated human Hs68 cells. Additionally, the extracts noticeably enhanced the viability of UVA-irradiated Hs68 cells up to 115-120% (p < 0.001) for stem and leaf extract at 25 μg/mL. All extracts in a wide concentration range (0.5-100 μg/mL) did not activate monocytes or induce the NF-κB transcription factor in LPS-stimulated Hs68 fibroblasts. On the other hand, the extracts (5-25 μg/mL) restored the activity of endogenous antioxidant enzymes, i.e., SOD and GST, up to 120-140% (p < 0.001) in the UVA-irradiated Hs68 cells. Moreover, a statistically significant reduction of ROS, IL-8, ICAM-1, and NF-κB levels by up to 48%, 88%, 43%, and 39%, respectively (p < 0.001) and strong suppression of Erk kinase activation was observed for the extracts (25-50 μg/mL) in LPS-stimulated human fibroblasts. The total DNA damage (% tail DNA) in irradiated Hs68 cells was also strongly decreased by up to 66-69% (p < 0.001) at 50 μg/mL. However, the treatment with the extracts did not relevantly enhance the cell migration of Hs68 fibroblasts.

CONCLUSIONS

The results suggest that G. procumbens may effectively protect human skin fibroblast from UVA irradiation. The leaf and stem extracts were the most potent antioxidants, while fruit and stem extracts revealed the strongest anti-inflammatory activity. The observed effects support the traditional use of aerial plant parts (leaves, stems, and fruits) in treating inflammation-related skin disorders cross-linked with oxidative stress and the topical application of Gaultheria extracts as anti-ageing agents intended for skin care.

Multicolor Hair Dyeing with Biocompatible Dark Polyphenol Complex-Integrated Shampoo with Reactive Oxygen Species Scavenging Activity

Hair dyeing has become a prevalent lifestyle trend, especially within the fashion industry. However, it possesses disadvantages, such as containing carcinogenic and toxic materials. In this study, we developed a biocompatible hair-dyeing technology using a shampoo with a dark polyphenol complex (DPC), referred to as S-DPC. The DPC was formed from a mixture of gallic acid and [1,1'-biphenyl]-2,2',4,4',5,5'-hexol and used to enhance both the stability of the hair coating and its ability to scavenge reactive oxygen species (ROS). Colloidal DPC particles play a pivotal role in the coating process of various hair dyes, ensuring the uniform coloring of human hair through intermolecular interactions such as hydrogen bonding. Owing to the effect of a polyphenol complex on hair coating, we observed improved antistatic performance and enhanced mechanical strength, resulting in a substantial increase in elongation at the breaking point from 33.74% to 48.85%. The multicolor S-DPC exhibited antioxidant properties, as indicated by its ROS-scavenging ability, including 2,2-diphenyl-1-picrylhydrazyl inhibition (87-89%), superoxide radical scavenging (84-87%), and hydroxyl radical scavenging (95-98%). Moreover, the in vitro analysis of the DPC revealed nearly 100% cell viability in live and dead assays, highlighting the remarkable biocompatibility of the DPC. Therefore, considering its effectiveness and safety, this biomaterial has considerable potential for applications in hair dyeing.

Kinkéliba (Combretum micranthum) Leaf Extract Alleviates Skin Inflammation: In Vitro and In Vivo Study

Kinkéliba (Combretum micranthum, Seh-Haw in Wolof) is a popular bush tea in West African countries. Although the kinkéliba plant's leaves have been widely consumed for its nutritional and medicinal properties, its benefits on skin health potential have been practically untouched. In human epidermal primary keratinocytes, vitexin and isovitexin-rich kinkéliba extract treatment significantly (p < 0.001) enhanced up to 39.6% of the cell survival rate decreased by UV radiation irritation. The treatment of kinkéliba leaf extracts also reduced the production of UV-induced pro-inflammatory cytokines IL-6 and IL-8 by 57.6% and 42.5%, respectively (p < 0.001), which cause skin redness and skin barrier dysfunction, as well as wrinkles and collagen degradation. The anti-inflammation efficacy of kinkéliba leaf extracts might involve significant inhibition on the levels of cellular reactive oxygen species (ROS) (-70.8%, p < 0.001) and nitrotyrosine (-56.9%, p < 0.05). Further topical applications of kinkéliba leaf extract gel were found to reduce sodium lauryl sulfate (SLS)-induced skin inflammation: at D7, the skin trans-epidermal water loss (TEWL) and skin redness (a* value) were both reduced by 59.81% (p < 0.001) and 22.4% (p < 0.001), compared with D0. In vitro and in vivo data support a new topical application of the kinkéliba leaf as an effective active ingredient for the treatment of skin inflammation, as well as subsequent barrier dysfunction and inflammaging.

Non-denatured yak type I collagen accelerates sunburned skin healing by stimulating and replenishing dermal collagen

Sunburn is one of the most common skin lesions caused by excessive UV exposure, and its incidence is highly correlated with the risks of skin cancer. A variety of drugs including corticosteroids and NSAIDs have been developed to treat acute sunburn, however, they have raised severe concerns such as poor healing efficacy and long recovery time. We have for the first time extracted non-denatured type I collagen from yak hide, which displays a canonical triple helical structure with melting temperature of 42.7 °C. The highly pure yak collagen type I (YCI) self-assembles to form well-ordered nanofibers with periodic d-bands. YCI is highly biocompatible, and it significantly promotes the proliferation and adhesion of HFF-1 cells. The sunburn healing effects of YCI has been investigated using acute skin injury mouse model. Histological analysis shows that 4 days' treatment of YCI has resulted in the recovery of sunburned mice skin to a healthy state, indicated by pronounced acceleration of epithelization and collagen deposition. The collagen volume fraction as well as the hydroxyproline (Hyp) content of YCI-treated sunburned skin have been found to be greatly increased, confirming the enhanced regeneration of collagen. YCI creams and dressings have also shown superior healing capacity of sunburn by remarkably shortening the recovery time. Notably, the denatured collagen-targeted staining results indicated a large quantity of denatured collagen in sunburned mice, which became substantially reduced after the YCI treatment. FITC-labeled YCI has been further found to penetrate into the dermis of sunburned mice. The highly biocompatible and bioactive non-denatured YCI provides an improved treatment of sunburn, indicating very promising applications of YCI in cosmetics and dermatology.

Evaluation of Chemical Composition, Sun Protection Factor and Antioxidant Activity of Lithuanian Propolis and Its Plant Precursors

The growing interest in polyphenols of natural origin and their plant sources encourages the study of their chemical composition and biological activity. Propolis is widely used as a source of phenolic compounds. The aim of this study is to evaluate and compare the chemical composition, antioxidant activity and sun protection factor (SPF) of the ethanolic extracts of the poplar buds, birch buds and pine buds of propolis plant precursors collected in Lithuania. The IC50 concentration of the extracts was evaluated using DPPH and ABTS methods. Extracts of poplar buds, birch buds and propolis showed a lower IC50 concentration by ABTS and DPPH methods compared with pine buds extracts. Poplar buds and propolis extracts showed the highest SPF value, while birch and pine buds extracts showed a lower SPF value. High-performance liquid chromatography (HPLC) analysis results showed that phenolic acids, such as p-coumaric acid and cinnamic acid, and flavonoids, such as pinobanksin and pinocembrin, were identified in all the tested extracts. Salicin has been identified only in poplar buds extracts. The results of antioxidant activity showed that propolis poplar and birch buds are a promising source of biologically active polyphenols.

Process Optimization of Phytoantioxidant and Photoprotective Compounds from Carob Pods (Ceratonia siliqua L.) Using Ultrasonic Assisted Extraction Method

The current study first describes the extraction of phytoantioxidant polyphenols from Carob byproducts (pods) using maceration and heating-assisted extraction as traditional methods and ultrasonic-assisted extraction (UAE) as an innovative method to determine the most efficient extraction process in terms of four targeted responses: total phenolic content (TPC), antioxidant activities (TAC and DPPH), and photoprotective properties as measured by the sun protection factor (SPF). Second, we used response surface methodology (RSM) with a central composite rotatable design (CCDR) approach to investigate the influence of process variables (extraction time, extraction temperature, and solvent concentration) on UAE, which was found to be the most effective extraction technique in our study. Carob byproduct extracts had a TPC ranging from 6.21 to 21.92 mg GAE/g dw, a TAC ranging from 22.00 to 49.30 mg AAE/g dw, DPPH scavenging activity ranging from 56.35 to 90.50%, and SPF values ranging from 8.62 to 22.37. The optimal UAE conditions for maximum TPC, TAC, DPPH, and SPF responses were determined to be 38.90% ethanol, 53.90 °C, and 50.92 min. Using Carob as a source for sustainable and bioactive products in conjunction with optimized UAE is a promising contribution to the cosmetic industry that will help to strengthen the concept of environmentally-friendly "green chemistry". Given that Carob pulp or seeds are considered food byproducts, the research presented here encourages the use of these agri-food waste materials in cosmetics.

Protective Effect of Bifidobacterium animalis subs. lactis MG741 as Probiotics against UVB-Exposed Fibroblasts and Hairless Mice

Skin photoaging, which causes wrinkles, increased epidermal thickness, and rough skin texture, is induced by ultraviolet B (UVB) exposure. These symptoms by skin photoaging have been reported to be involved in the reduction of collagen by the expression of matrix metalloproteinases (MMPs) and activator protein-1 (AP-1). This study investigated the protective effects of Bifidobacterium animalis subsp. lactis MG741 (Bi. lactis MG741) in Hs-68 fibroblasts and hairless mice (HR-1) following UVB exposure. We demonstrated that the Bi. lactis MG741 reduces wrinkles and skin thickness by downregulating MMP-1 and MMP-3, phosphorylation of extracellular signal-regulated kinase (ERK), and c-FOS in fibroblasts and HR-1. Additionally, in UVB-irradiated dorsal skin of HR-1, Bi. lactis MG741 inhibits the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), an inflammation-related factor. Thus, Bi. lactis MG741 has the potential to prevent wrinkles and skin inflammation by modulating skin photoaging markers.

Photochemoprevention of ultraviolet Beam Radiation-induced DNA damage in keratinocytes by topical delivery of nanoformulated Epigallocatechin-3-gallate

Ultraviolet Beam (UVB) radiation is the main cause of skin cancer worldwide. Besides biocompatibility, the instability and limited skin permeability are the most challenging features of many effective photochemopreventive agents. (-)-Epigallocatechin-3-gallate (EGCG) is a natural polyphenolic compound extracted from Camellia sinensis that has been demonstrated to have antioxidant, anti-inflammatory, and anti-cancer properties. We evaluated the efficacy of three innovative EGCG nanoformulations in chemoprevention of UVB-induced DNA damage in keratinocytes. Results indicated that the EGCG nanoformulations reduced UVB-induced oxidative stress elevation and DNA damage. The nanoformulations also reduced the UVB-induced formation of pyrimidine and pyrimidone photoproducts in 2D human immortalized HaCaT keratinocytes and SKH-1 hairless mice through antioxidant effects and possibly through absorption of UVB radiation. In addition, EGCG nanoformulations inhibited UVB-induced chemokine/cytokine activation and promoted EGCG skin permeability and stability. Taken together, the results suggest the use of EGCG nanoformulations as potential natural chemopreventive agents during exposure to UVB radiation.

Photoprotective effects of sweet potato leaf polyphenols and caffeic acid against UV-induced skin-damage in BALB/C nude mice

This study aimed at clarifying the mechanism by which sweet potato leaf polyphenols (SPLPs) ameliorate ultraviolet (UV) radiation damage, using the BALB/c hairless female mouse model. The moisture and hydroxyproline (HYP) contents of the model mouse skin and the thickness of the epidermis and dermis were determined by staining and histological examination. Anti-oxidative enzyme activities, malondialdehyde (MDA) content, and protein carbonyl content in skin tissue and serum were investigated. Expression of inflammatory markers and mitogen-activated protein kinase signaling pathways were evaluated. Topical caffeic acid at 30 mg kg^-1 most strongly inhibited the decrease in skin moisture, HYP content, and the thickening of the epidermis. Topical SPLP at 100 mg kg^-1 most significantly inhibited the dermal thickening, increased the activities of the superoxide dismutase, catalase as well as glutathione peroxidase, and decreased the content of serum MDA and protein carbonyls markedly. Furthermore, the topical SPLP suppressed the UV-induced rise in the inflammatory markers MMP-1, TNF-α, and NF-κB, and alleviated phosphorylation levels of the stress-signaling proteins JNK and p38. Thus, topical SPLP provided the best overall protection for mouse skin from UV-induced damage.

Black Bean (Phaseolus vulgaris L.) Polyphenolic Extract Exerts Antioxidant and Antiaging Potential

Phenolic compounds present in common beans (Phaseolus vulgaris L.) have been reported to possess antimicrobial, anti-inflammatory and ultraviolet radiation (UVR) protective properties. UVR from sunlight, which consists of UV-B and UV-A radiations, induces reactive oxygen species (ROS) and free radical formation, consequently activating proteinases and enzymes such as elastase and tyrosinase, leading to premature skin aging. The objective of this work was to extract, characterize and evaluate the antioxidant and antiaging potential of polyphenols from a black bean endemic variety. The polyphenolic extract was obtained from black beans by supercritical fluid extraction (SFE) using CO₂ with a mixture of water–ethanol as a cosolvent and conventional leaching with a mixture of water–ethanol as solvent. The polyphenolic extracts were purified and characterized, and antioxidant potential, tyrosinase and elastase inhibitory potentials were measured. The extract obtained using the SFE method using CO₂ and H₂O–Ethanol (50:50 v/v) as a cosolvent showed the highest total phenolic compounds yield, with 66.60 ± 7.41 mg GAE/g coat (p > 0.05) and 7.30 ± 0.64 mg C3GE/g coat (p < 0.05) of anthocyanins compared to conventional leaching. Nineteen tentative phenolic compounds were identified in leaching crude extract using ESI-QTOF. Quercetin-3-D-galactoside was identified in crude and purified extracts. The purified SFC extract showed IC₅₀ 0.05 ± 0.002 and IC₅₀ 0.21 ± 0.008 mg/mL for DPPH and ABTS, respectively. The lowest IC₅₀ value of tyrosinase inhibition was 0.143 ± 0.02 mg/mL and 0.005 ± 0.003 mg/mL of elastase inhibition for leaching purified extract. Phenolic compounds presented theoretical free energy values ranging from −5.3 to −7.8 kcal/mol for tyrosinase and −2.5 to −6.8 kcal/mol for elastase in molecular docking (in silico) studies. The results suggest that the purified extracts obtained by SFE or conventional leaching extraction could act as antioxidant and antiaging ingredients for cosmeceutical applications.

Nutrition and nonmelanoma skin cancers

Nonmelanoma skin cancer (NMSC), the most widely diagnosed cancer in the United States, is rising in incidence despite public health and educational campaigns that highlight the importance of sun avoidance. It is,therefore, important to establish other modifiable risk factors that may be contributing to this increase. There is a growing body of evidence in the literature suggesting certain nutrients may have protective or harmful effects on NMSC. We review the current literature on nutrition and its effect on NMSC with a focus on dietary fat, vitamin A, nicotinamide, folate, vitamin C, vitamin D, vitamin E, polyphenols, and selenium.

Recent Advances in Phenolic Metabolites and Skin Cancer

Skin cancer represents any tumor development from the cutaneous structures within the epidermis, dermis or subcutaneous tissue, and is considered to be the most prevalent type of cancer. Compared to other types of cancer, skin cancer is proven to have a positive growth rate of prevalence and mortality. There are available various treatments, including chemotherapy, immunotherapy, radiotherapy and targeted therapy, but because of the multidrug resistance development, a low success has been registered. By this, the importance of studying naturally occurring compounds that are both safe and effective in the chemoprevention of skin cancer is emphasized. This review focuses on melanoma because it is the deadliest form of skin cancer, with a significantly increasing incidence in the last decades. As chemopreventive agents, we present polyphenols and their antioxidant activity, anti-inflammatory effect, their ability to balance the cell cycle and to induce apoptosis and their various other effects on skin melanoma. Besides chemoprevention, studies suggest that polyphenols can have treating abilities in some conditions. The limitations of using polyphenols are also pointed out, which are related to their poor bioavailability and stability, but as the technology is well developed, it is possible to augment the efficacy of polyphenols in the case of melanoma.

Plant Polyphenols: Natural and Potent UV-Protective Agents for the Prevention and Treatment of Skin Disorders

Nowadays, destructive and immunosuppressive effects from long-term exposure to UV radiation have been fully investigated and documented in the literature. UV radiation is known as the main cause of skin aging and carcinogenesis. Hence, skin protection against anti-oxidative and immunosuppressive processes is highly in demand. Now, plant polyphenols have been found as a versatile and natural tool for the prevention and treatment of various skin diseases. The presence of a large number of hydroxyl groups in the cyclic structure of polyphenols has induced valuable biological activities. Among them, their UV protective activity has attracted lots of attention due to promising efficacy and simple instruction to use.

Antioxidant activity of polyphenolic compounds obtained from Euphorbia antisyphilitica by-products

In this study, an alternative extraction technique, ultrasound-assisted extraction, was used to extract the polyphenolic fraction from two different residues of the candelilla plant (Euphorbia antisyphilitica). These metabolites were further analyzed to evaluate their bioactivity as antioxidants. In addition, their functional groups were identified by Fourier transform infrared (FTIR) spectroscopy. The antioxidant assays showed statistically significant differences between the phenolic extracts, with citric acid residues (CAR) exhibiting a higher oxidant effect than sulfuric acid residues (SAR). The CAR from San Jerónimo (SJ) cultivar showed decreased IC50 values (179.441 ± 7.92 μL mL-1, DPPH•), and its polyphenolic fraction was able to inhibit lipid oxidation (70.31 ± 2.50%). FTIR analysis subsequently revealed the presence of functional groups related to polyphenolic compounds, such as hydroxy, carbonyl, carbon double bond, and amine groups. In addition, FTIR spectra showed slight differences in phenolic compounds, due to the strong acid treatment involved in the extraction of wax. The present study demonstrated that candelilla by-products from citric acid-wax extraction have a polyphenolic fraction with strong antioxidant activity, which may be useful in food and pharmaceutical products.

Photochemoprotective Potential of the Ethyl Acetate Fraction from Eugenia hiemalis Leaves and Its 2,6-Di-O-galloylarbutin Isolate Against UVB-Induced Photodamage

Intense and constant exposure to UVB radiation can lead to inflammation and oxidative stress, which are associated with many cutaneous disorders, including photoaging and skin cancer. Antioxidant plant materials that are rich in polyphenols, such as the ethyl acetate fraction (EAF) from Eugenia hiemalis leaves, and phenolic compounds represent a promising approach to protect the skin against UVB-induced damage. The present study evaluated the photochemoprotective potential of the EAF and its 2,6-di-O-galloylarbutin (1) isolate. The EAF and the phenolic antioxidant (1) reduced UVB-induced L929 fibroblast death. The EAF prevented UVB-induced damage in fibroblasts by inhibiting the intracellular production of reactive oxygen species and lipid peroxidation, especially in pretreated cells. Topical treatment with an emulsion with 1% EAF prevented/attenuated UVB-induced inflammation and oxidative stress in the skin in hairless mice by controlling the increase in myeloperoxidase activity, reducing superoxide anion production, maintaining radical-scavenging ability and ferric reducing power, and controlling the depletion of reduced glutathione and catalase levels. The EAF also inhibited the increase in epidermal thickness, mast cell infiltration, the number of sunburn cells and collagen fiber destruction that were triggered by UVB. The in vitro and in vivo results indicated that the EAF is a bioactive agent that is able to protect the skin against the harmful effects of UVB.

Cyanobacteria and Red Macroalgae as Potential Sources of Antioxidants and UV Radiation-Absorbing Compounds for Cosmeceutical Applications

In recent years, research on natural products has gained considerable attention, particularly in the cosmetic industry, which is looking for new bio-active and biodegradable molecules. In this study, cosmetic properties of cyanobacteria and red macroalgae were analyzed. The extractions were conducted in different solvents (water, ethanol and two combinations of water:ethanol). The main molecules with antioxidant and photoprotective capacity were mycosporine-like amino acids (MAAs), scytonemin and phenolic compounds. The highest contents of scytonemin (only present in cyanobacteria) were observed in Scytonema sp. (BEA 1603B) and Lyngbya sp. (BEA 1328B). The highest concentrations of MAAs were found in the red macroalgae Porphyra umbilicalis, Gelidium corneum and Osmundea pinnatifida and in the cyanobacterium Lyngbya sp. Scytonema sp. was the unique species that presented an MAA with maximum absorption in the UV-B band, being identified as mycosporine-glutaminol for the first time in this species. The highest content of polyphenols was observed in Scytonema sp. and P. umbilicalis. Water was the best extraction solvent for MAAs and phenols, whereas scytonemin was better extracted in a less polar solvent such as ethanol:_dH₂O (4:1). Cyanobacterium extracts presented higher antioxidant activity than those of red macroalgae. Positive correlations of antioxidant activity with different molecules, especially polyphenols, biliproteins and MAAs, were observed. Hydroethanolic extracts of some species incorporated in creams showed an increase in the photoprotection capacity in comparison with the base cream. Extracts of these organisms could be used as natural photoprotectors improving the diversity of sunscreens. The combination of different extracts enriched in scytonemin and MAAs could be useful to design broad-band natural UV-screen cosmeceutical products.

Valorization of the green waste parts from sweet potato (Impoea batatas L.): Nutritional, phytochemical composition, and bioactivity evaluation

In the present study, leaves from 13 sweet potato cultivars were collected as raw materials. The nutritional and functional composition, antioxidant activity, and sunscreen activity of different sweet potato leaf samples were determined, and the comprehensive nutritional quality was calculated by gray relational analysis. Results showed that the nutritional and functional components are significantly different between different cultivars. Tainong71 showed the highest comprehensive nutritional quality, followed by Fu22, Ningcai, Fu23, Ecai10, Zhecai726, Ecai1, Fu18, Pushu53, Guangcai5, Shulv1, Guangcai2, and Zhecai1. The antioxidant activity varied from 3.94 to 16.75 g Trolox equivalent/100 g dry weight. Pushu53 showed the highest sunscreen activity, with the sun protection factor 24.65. There was a positive correlation between antioxidant activity and sunscreen activity (r = .737, p = .004). In conclusion, sweet potato leaves possess high nutritional and functional properties, and have the huge potential to be used as green leafy vegetables and sunscreen agent.

Anthocyanins from black peanut skin protect against UV-B induced keratinocyte cell and skin oxidative damage through activating Nrf 2 signaling

Excessive Ultraviolet (UV) irradiation induces skin damage. In the present study, the potential protective activity of anthocyanins (cyanidin-3-O-sophoroside and cyanidin-3-O-sambubioside) from black peanut against skin damage induced by UV-B was evaluated in vitro and in vivo. Treatment with anthocyanins significantly reversed UV-B induced oxidative damage and following apoptotic death in human HaCaT cells. Nuclear-factor-E2-related factor 2 (Nrf 2) was activated by anthocyanins through Nrf 2 protein stabilization and nuclear translocation, along with the expressions of antioxidant responsive element (ARE)- related genes (HO1, GCLC and NOQ1). Nrf 2 knockdown in HaCaT cells by targeted-shRNA plasmid markedly abolished the protective activity of anthocyanins against UV-B irradiation. Additionally, topical application of anthocyanins (5 mg cm-2) inhibited UV-B induced oxidative stress and cell apoptosis in BALB/c mouse skin tissues. The protective effect of anthocyanins can be explained by the regulation of oxidative-stress and the suppression of cell apoptosis through the activation of Nrf-2 by interaction with the MAPK and NF-κB signaling pathways. Our results suggested that anthocyanins from black peanut skin might be used as a potential photochemo-protective agent against UV-B induced skin damage.

A Comprehensive Insight on the Health Benefits and Phytoconstituents of Camellia sinensis and Recent Approaches for Its Quality Control

Tea, Camellia sinensis, which belongs to the family Theaceae, is a shrub or evergreen tree up to 16 m in height. Green tea is very popular because of its marked health benefits comprising its anticancer, anti-oxidant, and antimicrobial activities, as well as its effectiveness in reducing body weight. Additionally, it was recognized by Chinese people as an effective traditional drink required for the prophylaxis against many health ailments. This is due to the complex chemical composition of green tea, which comprises different classes of chemical compounds, such as polyphenols, alkaloids, proteins, minerals, vitamins, amino acids, and others. The beneficial health effects of green tea ultimately led to its great consumption and increase its liability to be adulterated by either low-quality or non-green tea products with concomitant decrease in activity. Thus, in this review, green tea was selected to highlight its health benefits and phytoconstituents, as well as recent approaches for its quality-control monitoring that guarantee its incorporation in many pharmaceutical industries. More research is needed to find out other more biological activities, active constituents, and other simple and cheap techniques for its quality assurance that ascertain the prevention of its adulteration.

Dietary compounds and cutaneous malignant melanoma: recent advances from a biological perspective

Cutaneous malignant melanoma is a heterogeneous disease, being the consequence of specific genetic alterations along several molecular pathways. Despite the increased knowledge about the biology and pathogenesis of melanoma, the incidence has grown markedly worldwide, making it extremely important to develop preventive measures. The beneficial role of correct nutrition and of some natural dietary compounds in preventing malignant melanoma has been widely demonstrated. This led to numerous studies investigating the role of several dietary attitudes, patterns, and supplements in the prevention of melanoma, and ongoing research investigates their impact in the clinical management and outcomes of patients diagnosed with the disease. This article is an overview of recent scientific advances regarding specific dietary compounds and their impact on melanoma development and treatment.

Protective Effect of Bovine Elastin Peptides against Photoaging in Mice and Identification of Novel Antiphotoaging Peptides

This study aimed to investigate the protective effects of bovine elastin hydrolysates on UV-induced skin photoaging in mice and to identify the potent antiphotoaging peptides. Results showed that the ingestion of elastin peptides could obviously ameliorate epidermis hyperplasia and fibroblast apoptosis, and increase the content of hydroxyproline and water in photoaging skin in vivo ( p < 0.05). Furthermore, four peptides with elastase inhibitory activity were purified and identified, including GLPY, PY, GLGPGVG, and GPGGVGAL. Interestingly, GLPY and GPGGVGAL exhibited the highest inhibition activity with 58.77% and 42.91% at 10 mΜ, respectively. This might be attributed to the N-terminal Gly, C-terminal Leu, and Pro at the third position of the N-terminus, which showed stronger affinity and interaction with elastase. Moreover, GLPY and GPGGVGAL could also inhibit the apoptosis of fibroblasts effectively at 50 μΜ ( p < 0.01). It suggested that elastin peptides had great potential to prevent and regulate skin photoaging.

Agro-Industrial By-Products and Their Bioactive Compounds—An Ally against Oxidative Stress and Skin Aging

The increased consumer awareness towards hazards related with sun exposure has given a boost in the cosmetics industry and particularly the sun care market. Human skin is continually being threatened by the UV irradiation present in sunlight and acute UV exposure leads to skin photoaging. Cosmetic and/or dermatological applications include several bioactive compounds that contribute to the regulation of epidermal homeostasis by providing protection against solar radiation and improving the antioxidant activity of epidermis. Plant extracts are sources of active ingredients with intense therapeutic properties, and the topical application or oral intake of these compounds could ameliorate skin condition. Nowadays, there is a growing demand for the application of the bioactive agents contained in agro-industrial byproducts in sun care products, since many of them have shown promising properties as skin photoprotectants. However, well-conducted clinical studies are required to prove their safety and efficacy before they could be regularly used. Environmentally friendly extraction and sustainable techniques are therefore under examination for recovering such compounds from agro-industrial byproducts and converting them into innovative high-value natural ingredients used in cosmetic formulations.