Antioxidant and skin-whitening effects of aerial part of Euphorbia supina Raf. Extract

Molecular understanding of the therapeutic potential of melanin inhibiting natural products

With the development of society and the improvement of people's living standards, there is an increasing demand for melanin-inhibiting products that prioritize health, safety, and efficacy. Therefore, the development of natural products that can safely and efficiently inhibit melanin synthesis is of great social significance and has significant market potential. In this paper, by reviewing the literature reported in recent years, we summarized the natural products with inhibition of melanin synthesis effects that have been put into or not yet put into the market, and classified them according to the chemical groups of their compounds or the extraction methods of the natural products. Through the summary analysis, we found that these compounds mainly include terpenoids, phenylpropanoids, flavonoids and so on, while the natural product extracts mainly include methanol extracts, ethanol extracts, and aqueous extracts. Their main inhibition of melanin synthesis mechanisms include: (1) direct inhibition of tyrosinase activity; (2) down-regulation of the α-MSH-MC1R, Wnt, NO, PI3K/Akt and MAPK pathways through the expression of MITF and its downstream genes TYR, TRP-1, and TRP-2; (3) antioxidant; (4) inhibition of melanocyte growth through cytotoxicity; (5) inhibition of melanosome production and transport. This paper provides an in-depth discussion on the research progress of whitening natural products and their market value. The aim is to offer guidance for future research and development of natural skin whitening products.

Preclinical studies on melanogenesis proteins using a resveratrol-nanoformula as a skin whitener

A naturally occurring polyphenol called trans-resveratrol has received a lot of attention due to its possible health advantages for humans. The low solubility of trans-resveratrol and its isomerization upon UV exposure strongly limit its application as a skin-whitening agent. In the present study, to increase trans-resveratrol solubility, a new nanoformula was created by combining hydrophilic surfactants and oils. Trans-Resveratrol nanoformula has been prepared, characterized, and applied as a skin-whitening agent on the dorsal skin of Guinea pigs. The optimized trans-resveratrol nanoformula with a particle size of 63.49 nm displayed a single peak and a polydispersity index [0.36 ± 0.02]. In addition, the zeta potential of the optimized formula was -30.4 mV, confirming the high stability of this nanoformula. The melanin contents in the trans-resveratrol nanoformula-treated group were substantially lower than those of the control and the blank nanoformula-treated groups after staining of the dorsal skins [black areas] of guinea pigs with Fontana Mountain dye. The pigmentation index in the control, blank nanoformula, and optimized trans-resveratrol nanoformula were 329.4 ± 36.9, 335.8 ± 71.4, and 124.8 ± 19.6 respectively. Confirming this finding, immunohistochemistry analysis of skin tissues revealed that the expressions of melanogenesis-regulating proteins such as tyrosinase and microphthalmia-associated transcription factor were down-regulated. The safety of topical application of trans-resveratrol nanoformula was validated by no changes in free radical levels and oxidative stress markers proteins in the livers and kidneys of guinea pigs at the end of the experiment. Conclusions: A novel trans-resveratrol nanoformula as well as the mechanism whereby it promotes skin whitening effects were presented. Furthermore, the study illustrated that trans-resveratrol nanoformula is safe, non-toxic, and can be applied for skin whitening, although more research on human skin is needed.

Echinochrome A Inhibits Melanogenesis in B16F10 Cells by Downregulating CREB Signaling

Excessive increase in melanin pigment in the skin can be caused by a variety of environmental factors, including UV radiation, and can result in spots, freckles, and skin cancer. Therefore, it is important to develop functional whitening cosmetic reagents that regulate melanogenesis. In this study, we investigated the effects of echinochrome A (Ech A) on melanogenesis in the B16F10 murine melanoma cell line. We triggered B16F10 cells using α-MSH under Ech A treatment to observe melanin synthesis and analyze expression changes in melanogenesis-related enzymes (tyrosinase, tyrosinase-related protein 1 (TYRP1), and tyrosinase-related protein 2 (TYRP2)) at the mRNA and protein levels. Furthermore, we measured expression changes in the microphthalmia-associated transcription factor (MITF), CREB, and pCREB proteins. Melanin synthesis in the cells stimulated by α-MSH was significantly reduced by Ech A. The expression of the tyrosinase, TYRP1, and TYRP2 mRNA and proteins was significantly decreased by Ech A, as was that of the MITF, CREB, and pCREB proteins. These results show that Ech A suppresses melanin synthesis by regulating melanogenesis-related enzymes through the CREB signaling pathway and suggest the potential of Ech A as a functional agent to prevent pigmentation and promote skin whitening.

Euphorbia characias Extract: Inhibition of Skin Aging-Related Enzymes and Nanoformulation

Plant extracts have long served as important sources of bioactive compounds, and they are currently the focus of extensive research in the development of novel preventive and therapeutic strategies. However, their health benefits are often limited by low bioavailability. Nanoparticle delivery systems can represent a solution to such limitations. Euphorbia characias is a Mediterranean shrub known to have biological activities, such as inhibiting tyrosinase and showing a potential role as a skin-whitening agent. In this study, an ethanolic extract from E. characias leaves was tested for its inhibitory activity on skin-related enzymes, such as elastase, collagenase, and hyaluronidase, and for sun protection factors. Moreover, the extract was formulated in phospholipid vesicles to improve its local bioavailability and applicability. The vesicles were characterized by size, surface charge, storage stability, and entrapment efficiency. The nanoformulation was also evaluated for antioxidant activity and assayed for cytocompatibility and anti-tyrosinase activity in melanoma cells. Our findings demonstrated that the extract has a photo-protective effect and enzyme-inhibitory properties. E. characias nanoformulation was also cytocompatible and improved the extract’s activity in the cells, suggesting a potential skin application for antimelanogenic treatments and confirming the key role of nanotechnological approaches to maximize plant extract’s potentialities.

Euphorbia supina Extracts Block NADPH Oxidase-Mediated, Ceramide-Induced Apoptosis Initiated by Diesel Particulate Matter

Air pollutants contribute to the development of diseases such as asthma, chronic obstructive pulmonary disease (COPD), pulmonary cancer, cardiovascular problems, and some skin diseases. We recently found that a major air pollutant, diesel particulate matter (DPM), induces apoptosis in human keratinocytes by increasing a proapoptotic lipid mediator, ceramide. DPM activates nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), which stimulates sphingomyelinase, leading to an increased conversion of sphingomyelin to ceramide. Interestingly, we characterized that although NOX is a reactive oxygen species (ROS) generator, the activation of sphingomyelinases by NOX is an ROS-independent mechanism. A Korean weed, prostrate spurge Euphorbia supina Rafin (ESR), has been used for centuries as a folk medicine to treat bronchitis, hepatitis, hemorrhage, and skin inflammation. Flavonoids, terpenes and tannins are enriched in ESR, and although ESR has proven antioxidative activity, its biological activities are largely unknown. Here, we investigate whether and how ESR protects keratinocytes against DPM-mediated apoptosis. We found that ESR-extracts (ESR-Ex) protect keratinocytes from DPM-induced apoptosis by inhibiting NOX activation in keratinocytes in response to DPM. We also demonstrated that ESR-Ex suppresses NOX activation via a blockage of the aryl hydrocarbon receptor (AhR) activation-mediated transcription of neutrophil cytosolic factor 1 (NCF1)/p47phox, a subunit of NOX. Our study reveals previously uncharacterized biological activity of ESR-Ex; i.e., its inhibition of Ahr and NOX activation. Thus, because the inhibition of NOX has already been developed to treat NOX-mediated diseases, including various types of cardiovascular diseases and cancers, initiated by air pollutants and because AhR activation contributes to the development of chronic inflammatory diseases, our study provides further advantages for the medical use of ESR.

Natural Sources of Melanogenic Inhibitors: A Systematic Review

OBJECTIVE

Melanin gives some natural protection against the harmful effects of UV radiation, however, excessive production of melanin causes skin hyperpigmentation. Depigmenting cosmetics can be used to control this process, however, depigmenting agents commonly used have some disadvantages, such as low bioavailability, photosensitization, cellular toxicity, and insolubility. Natural sources of melanogenic inhibitors have become important alternatives to synthetic ones. The objective of this review was to summarise the results of studies on natural extracts that have been reported in the literature to inhibit the process of melanogenesis, giving a view on their suitability for potential use in new cosmetic formulations for skin-lightening.

DATA SOURCES

A systematic literature search was carried out using the descriptors: "melanogenesis", "tyrosinase", "tyrosinase inhibition", and "natural agents".

STUDY SELECTION

Publications were selected based on our designated inclusion and exclusion criteria and a total of fifteen studies were found which met these criteria.

DATA EXTRACTION

The following were used in the review of each paper which met the criteria: the name of the plant (all of the natural extracts turned out to be from plants), the method used to obtain the plant extract, the method for evaluating anti-tyrosinase activity, the main results and the conclusions.

DATA SYNTHESIS

All evaluated natural agents demonstrated anti-tyrosinase effect. The species Leathesia difformis, Morus alba, Orostachys japonicus, Heracleum moellendorffii, Coix lacryma-jobi (adlay), Inula brittanica, and Gailardia aristata stood out from the others due to their application as potential inhibitors of more than three proteins related to melanogenesis, including the cyclic adenosine monophosphate response element-binding protein (CREB), microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), and dopachrome tautomerase (DCT).

CONCLUSION

The plants present an anti-tyrosinase effect that must be better explored in the new cosmetic formulations. The anti-melanogenic effects of the plant are mainly related to presence of phenolic and antioxidant compounds.

Skin hyperpigmentation and its treatment with herbs: an alternative method

Background

With an increasing number of patients, those who are facing a lot of skin-related complaints, often referred to as skin of pigmentation patients, are on the rise. Among all the most common complaints in patients with skin of color is hyperpigmentation. So, there is need of herbal formulation for treatment of hyperpigmentation.

Main body

This review article addresses the different types of hyperpigmentation, causes, and its treatment with herbs for the management of the skin hyperpigmentation. As uneven pigmentation of skin or hyperpigmentation is a common skin condition, which occurs when the skin produces more melanin. This can make spots or patches of skin appear darker than surrounding areas. Some forms of hyperpigmentation with post-inflammatory, melasma, and sun spots are more likely to affect areas of face, arms, and legs due to sun exposure and injury. Although the availability of multiple treatments for the condition which leads to some adverse effects, hyperpigmentation continues to present skin care management challenges for dermatologists.

Conclusion

Some plants and phytoconstituents, e.g., Azadirachta indica, Glycyrrhiza glabra, Panax ginseng and genistein, ellagic acids, quercetin, are very useful in herbal cosmetic as anti-hyperpigmentry agents in cosmetic industries. Some of flavonoids and triterpenoids present in plants also show their effect as antioxidant and skin whitening agents. It is expected that this review will compile and improve the existing knowledge on the potential utilization of herbs for the treatment of skin hyperpigmentation.

Oenothera laciniata Hill Extracts Exhibits Antioxidant Effects and Attenuates Melanogenesis in B16-F10 Cells via Downregulating CREB/MITF/Tyrosinase and Upregulating p-ERK and p-JNK

Oenothera laciniata Hill is a perennial herb traditionally used to alleviate inflammatory complications. This study investigated the antioxidant and anti-melanogenic activities of O. laciniata. The methanolic extract (OLM) of O. laciniata and its different fractions, including ethyl acetate (OLEF), n-butanol (OLBF), and water (OLWF) fractions, were prepared. Antioxidant activities were evaluated by total phenolic content, the radical-scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH^•), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^+•), and superoxide anion (O2^−•), reducing capacity, and metal chelating ability. OLM and its fractions exhibited potent antioxidant activity in these in vitro assays, with a correlation between radical-scavenging activity and total phenolic content. OLM and its fractions inhibited the mushroom tyrosinase activity superior to the reference control, ascorbic acid. In B16-F10 melanoma cells, OLM and its fractions significantly decreased melanin production and tyrosinase activity. Mechanistic investigations revealed that OLM and its fractions inhibited tyrosinase and TRP-2 expressions via downregulating MITF and phosphorylated CREB and differentially inducing ERK or JNK phosphorylation. Additionally, OLM and its fractions caused no significant cytotoxicity towards B16-F10 or skin fibroblast cells at concentrations used in these cellular assays. These findings demonstrated the potential of O. laciniata extracts as the ideal skin protective agent with dual antioxidant and anti-melanogenic activities.

Platycodon grandiflorum extract: chemical composition and whitening, antioxidant, and anti-inflammatory effects

Whitening cosmetics have a large market scale and broad development prospects, while whitening products of traditional Chinese medicine have always been a research hotspot. In this study, the whitening active extract of Platycodon grandiflorum (PGE) was isolated and purified for the first time, and the whitening activity mechanism and chemical composition of PGE were elucidated. A total of 45 components were identified via high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis, including arbutin, syringin, chlorogenic acid, platycoside E, platycodin D₃, baicalin, platycodin D, and luteolin. The scavenging rates of PGE toward DPPH and ABTS free radicals were 98.03% and 84.30%, respectively. The inhibition rate of PGE toward tyrosinase was up to 97.71%. The PGE had significant anti-inflammatory effects on RAW264.7 macrophages stimulated by lipopolysaccharide (LPS) and had significant inhibition effects on tyrosinase and melanin generation of B16F10 cells stimulated by α-MSH. The results showed that the PGE achieved a synergistic whitening effect by inhibiting the activation of oxygen free radicals on tyrosinase, antioxidation, anti-inflammatory effect, enzyme activity, and melanin generation. As a whitening agent extracted from natural plants, PGE has great potential in the research and development of plant whitening cosmetics, which lays a foundation for the further development and utilization of Platycodon grandiflorum resources and also provides a theoretical basis for the development of green and organic whitening cosmetics.

Whitening cosmetics have a large market scale and broad development prospects, while whitening products of traditional Chinese medicine have always been a research hotspot.

HPLC-DAD analysis of Hyssopus Cuspidatus Boriss extract and mensuration of its antioxygenation property

BACKGROUND

Hyssopus cuspidatus Boriss has been used as an important ethnomedicinal plant for long to eliminate phlegm, relieve cough and as well as having antibacterial, antioxygenation, and antitumor activities. In this study, the polyphenol contents, flavonoid contents, free radical scavenging assay and animal antioxygenation property assay of ethanol extract of H. cuspidatus were measured.

METHODS

This study determined the total polyphenol and flavonoid contents in H. cuspidatus by UV-VIS. Caffeic, ferulic, and rosmarinic acids were measured using HPLC-DAD. Free radical scavenging assay of H. cuspidatus was studied by colorimetric method. Animal antioxygenation property assay of H. cuspidatus was studied with mice by biochemical assay kits.

RESULTS

The total polyphenol and flavonoid contents of H. cuspidatus in 2017, 2018, 2019 were determined and the contents of H. cuspidatus in 2019 was the highest. In addition, rosmarinic acid was the phenolic acid with the highest content in H. cuspidatus. Compared with those of DPPH free radical, hydroxyl free radical, and superoxide anion free radical, the scavenging ability of H. cuspidatus of ABTS free radical was stronger, the average IC50 value was 0.0245 mg/mL. In animal antioxygenation property experiment, the model group was successfully established with decreased activities of SOD, CAT, and GSH-px and increased content of MDA. The ethanol extract of H. cuspidatus increased the activities of SOD, CAT, and GSH-px and reduced the content of MDA. Each group of samples and the ascorbic acid positive control group showed significant differences in the results of free radical scavenging and animal antioxygenation property experiments (P < 0.05).

CONCLUSIONS

These results suggest that H. cuspidatus exerts an antioxygenation property, which can be attributed to the contents of total polyphenol and flavonoid. Given its strong antioxygenation property, H. cuspidatus can be used as a new natural antioxidant in food preservation and disease treatment.

Traditional Chinese Herbal Medicine for Whitening

Melanin is the chief pigment responsible for the pigmentation of human skin. Increasing evidence indicates that traditional Chinese drugs with skin-whitening effects are attracting the attention of consumers and researchers because they are perceived to be milder, safer, and healthier than synthetic alternatives. This commentary summarizes the current research on Chinese herbal medicines that inhibit melanin and their biological activities. The findings presented in this study suggest that these traditional Chinese herbal medicines might be potential candidates for novel skin-whitening agents.

Development of aqueous-based multi-herbal combination using principal component analysis and its functional significance in HepG2 cells

Background

The present study was carried out to prepare multi-herbal combination via comparing antioxidant activity and polyphenolic composition of five medicinal plant extracts of Punica granatum L., Putranjiva roxburghii Wall., Swertia chirata Buch.-Ham., Tinospora cordifolia (Willd.) Miers and Trigonella corniculata L.

Methods

The herbs were individually evaluated using in vitro antioxidant assays and analyzed by HPLC-PDA. The resultant data was examined using principal component analysis (PCA). Further, herbal combination was prepared on the basis of PCA.

Results

The PCA divided the plants into three groups. The leading or primary group contained P. granatum and P. roxburghii with the highest antioxidant activity strongly correlated with high amount of kaempferol. S. chirata was acknowledged as nourisher herb in one and T. cordifolia and T. corniculata were identified as stimulator herbs in other group. The herbal combination exhibited high antioxidant activity as compared to the individual plants. The combination revealed good antiproliferative efficacy against hepatocellular carcinoma (HepG2) cells with IC₅₀ of 75.864 μg/ml.

Conclusions

The activity observed in vitro with HepG2 cells suggests that the herbal combination can provide therapeutic activity in vivo in future. The study may provide information regarding precise preparation of multi-herbal formulations using PCA as a tool in pharmaceutical industries.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2432-9) contains supplementary material, which is available to authorized users.