There is a growing demand and use of herbal cosmetics for skin purposes due to their perceived safety when applied to the skin. Three Cassipourea species commonly known as \"ummemezi\" are used interchangeably by women in rural areas of Eastern Cape and KwaZulu-Natal provinces to treat hypermelanosis as well as sun protection. We conducted a phytochemical comparison of three Cassipourea species; Cassipourea flanaganii (Schinz) Alston, Cassipourea gummiflua Tul. verticillata (N.E.Br.) J. Lewis and Cassipourea malosana (Baker) Alston by Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis in negative mode. The results obtained from the LC-MS/MS yielded a total number of twenty-four compounds of different chemical classes, including fatty acids, steroids, di- and tri-terpenoids, flavonoids, phenolic acids, and eighteen among them were tentatively identified. The LC-MS /MS analysis showed that the three studied Cassipourea extracts contain compounds that have anti-tyrosinase activity and consequently. The presence of these compounds, either in synergy or individually, can be attributed to the anti-tyrosinase effect. Although the traditional names of the species are used interchangeably, they are different, however, they possess similar skin-lightening properties. Despite the recent popularity of modern cosmetic products, plants continue to play an important role in the local cosmetics industry in South Africa\'s Eastern Cape and KwaZulu-Natal community provinces.

Inhibition of melanogenesis by quercetin and vitamin E is extensively reported in the literature, independently, with limitations in antioxidant potential owing to less permeation, solubility, decreased bioavailability, and reduced stability. Thus, the aim of the present study was to synthesize a novel complex of metal ions (copper and zinc) with quercetin to enhance antioxidant properties which were confirmed by docking studies. Polycaprolactone-based nanoparticles of the synthesized complex (PCL-NPs, Q-PCL-NPs, Zn-Q-PCL-NPs, Cu-Q-PCL-NPs) were made later loaded with vitamin E which made the study more interesting in enhancing antioxidant profile. Nanoparticles were characterized for zeta size, charge, and polydispersity index, while physiochemical analysis of nanoparticles was strengthened by FTIR. Cu-Q-PCL-NPs-E showed maximum in vitro release of vitamin E, i.e., 80 ± 0.54%. Non-cellular antioxidant effect by 2,2-diphenyl-1-picrylhydrazyl was observed at 93 ± 0.23% in Cu-Q-PCL-NPs-E which was twofold as compared to Zn-Q-PCL-NPs-E. Michigan Cancer Foundation-7 (MCF-7) cancer cell lines were used to investigate the anticancer and cellular antioxidant profile of loaded and unloaded nanoparticles. Results revealed reactive oxygen species activity of 90 ± 0.32% with the addition of 89 ± 0.64% of its anticancer behavior shown by Cu-Q-PCL-NPs-E after 6 and 24h. Similarly, 80 ± 0.53% inhibition of melanocyte cells and 95 ± 0.54% increase of keratinocyte cells were also shown by Cu-Q-PCL-NPs-E that confirmed the tyrosinase enzyme inhibitory effect. Conclusively, the use of zinc and copper complex in unloaded and vitamin E-loaded nanoparticles can provide enhanced antioxidant properties with inhibition of melanin, which can be used for treating diseases of melanogenesis.

This study targets the evaluation of melanin synthesis inhibition activity of the bamboo shoot skin as agro-waste. The total methanolic extract of bamboo peel extract was evaluated for its skin protective effects via measuring its melanin inhibitory activity and its suppression activity on the expression of tyrosinase mRNA levels. Results showed that bamboo peel extract has a good ability for the inhibition of melanin synthesis so further studies were performed for the isolation of its constituents. Twelve compounds have been isolated from the shoot skin of Phyllostachys pubescens. Their structures were elucidated based on extensive spectroscopic methods. The melanin inhibition potential of the isolates was tested with their collagen-production-promoting activity for the determination of active principles. Results showed that Betulinic acid, tachioside, and 1,2-dilinolenin significantly suppressed melanin production per cell compared to control. Triacontanol, tricin, and (+)-lyoniresinol 9\'-O-glucoside also tended to decrease melanin production per cell. These findings indicated that the skin of bamboo shoots, a significant agricultural waste, is a useful natural source for further research on its potential for aging problems such hyperpigmentation and cognitive function impairment.

A novel series of twenty-seven cinnamides constituted by cinnamic acid derivatives liked to 1-aryl piperazines were synthesized and evaluated for their potential inhibitory diphenolase activity of mushroom tyrosinase. Among them, the presence of a 3-chloro-4-fluorophenyl moiety at the N-1 position of piperazine ring was essential for a potent tyrosinase inhibitory effect, with the 3-nitrocinnamoyl (19p) and 2-chloro-3-methoxycinnamoyl (19t) derivatives as the most potent compounds of the series, with IC50 of 0.16 and 0.12 μM, respectively, resulting much active than kojic acid, whose IC50 value was 17.76 μM. In general, all compounds characterized by the presence of a 1-(3-chloro-4-fluorophenyl)piperazine moiety showed an excellent potency, and the nature, position and number of the substituents on the aryl of the cinnamic acid did not affect significantly the anti-tyrosinase activity. The molecular docking to the active site of the enzyme has been also performed to investigate the nature of enzyme-inhibitor interactions. Furthermore, for selected highly active compounds, their ability to inhibit melanogenesis in the A375 human melanoma cells and in vivo zebrafish model was also evaluated. One of the most potent compounds of series (19t) significantly reduced the pigmentation of zebrafish at 50 μM, unfortunately showing 100% mortality in the Fish Embryo Acute Toxicity (FET) test at the same concentration, Moreover, the zebrafish assay reveals that also compound 19r (IC50:0.51 μM against mushroom tyrosinase) effectively reduces melanogenesis with no acute toxicity effects and it could be proposed as potential candidate to treat tyrosinase-mediated hyperpigmentation.

Ferula penninervis Regel & Schmalh. is a perennial plant used in Kazakh traditional folk medicine to treat epilepsy, neurosis, rheumatism, gastroduodenal ulcers, dyspepsia, wounds, abscesses or tumors. The aim of this work was to isolate series of sesquiterpene lactones from a crude methanolic root extract and investigate their in vitro cytotoxic potential against androgen-dependent prostate cancer LNCaP and epithelial prostate PNT2 cells, as well as to evaluate their melanin production inhibitory effects in murine melanoma B16F10 cells stimulated with α-melanocyte-stimulating hormone (αMSH). Two new (penninervin P and penninervin Q) and five known (olgin, laferin, olgoferin, oferin and daucoguainolactone F) guaiane-type sesquiterpene lactones were isolated with the use of a simple and fast liquid-liquid chromatography method. Olgin and laferin showed the most promising cytotoxic effects in LNCaP cells (IC50 of 31.03 and 23.26 μg/mL, respectively). Additionally, olgin, laferin, olgoferin, and oferin (10 μg/mL) potently impaired melanin release (40.67-65.48% of αMSH + cells) without influencing the viability of B16F10 cells. In summary, our findings might indicate that guaiane-type sesquiterpene lactones from F. penninervis could be regarded as promising candidates for further research in discovering new therapeutic agents with anti-prostate cancer and skin depigmentation properties.

Sideritis perfoliata L. subsp. perfoliata is an endemic species of the Eastern Mediterranean region with several uses in traditional medicine. The present study aims to explore the unknown properties of S. perfoliata investigating the nutritional content as well as the antioxidant, anticancer, antituberculosis, antiwrinkle, anti-acne, hyper/hypo-pigmentation and antibacterial activities. Mineral content, nutritional value, the composition and antioxidant properties of the essential oil, the antityrosinase, the antibacterial activity and anti-elastase potential of the extract, were evaluated. The antiproliferative activity of S. perfoliata against cervical cancer (HeLa), human melanoma (UCT-Mel-1), human hepatocellular carcinoma (HepG2) and human epidermoid carcinoma (A431) was investigated. Cytotoxic effects on normal human keratinocyte (HaCat) and kidney epithelial (Vero) cell lines were also determined. Sideritis perfoliata exhibited high nutritional value of proteins and minerals (K, P, Mg, Fe, Zn, Cu). The most abundant components of the essential oil were found to be α-pinene, β-phelladrene, valeranone, β-pinene and sabinene. The ethanolic extract of S. perfoliata displayed moderate antioxidant potential and antibacterial activity against Prevotella intermedia. Noteworthy elastase and moderate anticancer potential against the human liver cancer cell line (HepG2) was observed with IC50 values of 57.18 ± 3.22 μg/mL and 64.27 ± 2.04 μg/mL respectively. The noteworthy in vitro activity of S. perfoliata could be due to the presence of flavonoids and phenols in the leaves, having high nutritional value. Sideritis perfoliata could potentially be useful to reduce the appearance of wrinkles and for the treatment of liver cancer. The moderate antibacterial, antioxidant and elastase activity of the plant can be linked to the traditional use of S. perfoliata for the treatment of wounds and inflammation.

The environmental strain Aeromonas salmonicida subsp. pectinolytica 34melT produces abundant melanin through the homogentisate pathway in several culture media, but unexpectedly not when grown in a medium containing glycerol. Using this observation as a starting point, this study investigated the underlying causes of the inhibition of melanin synthesis by glycerol, to shed light on factors that affect melanin production in this microorganism. The effect of different carbon sources on melanin formation was related to the degree of oxidation of their C atoms, as the more reduced substrates delayed melanization more than the more oxidized ones, although only glycerol completely abolished melanin production. Glyphosate, an inhibitor of aromatic amino acid synthesis, did not affect melanization, while bicyclopyrone, an inhibitor of 4-hydroxyphenylpyruvate dioxygenase (Hpd), the enzyme responsible for the synthesis of homogentisate, prevented melanin synthesis. These results showed that melanin production in 34melT depends on the degradation of aromatic amino acids from the growth medium and not on de novo aromatic amino acid synthesis. The presence of glycerol changed the secreted protein profile, but none of the proteins affected could be directly connected with melanin synthesis or transport. Transcription analysis of hpd, encoding the key enzyme for melanin synthesis, showed a clear inhibition caused by glycerol. The results obtained in this work indicate that a significant decrease in the transcription of hpd, together with a more reduced intracellular state, would lead to the abolishment of melanin synthesis observed. The effect of glycerol on melanization can thus be attributed to a combination of metabolic and regulatory effects.

BACKGROUND: We aimed to enhance the solubility, dissolution properties, and skin-whitening ability of ferulic acid (FA) by preparing a ferulic acid-phospholipid complex (FA-PC). The properties and melanogenesis inhibition activities of FA-PC were then elucidated.
METHODS: We characterized the complex via differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, solubility, and oil-water partition coefficient. A Strat-M® membrane, a synthetic membrane possessing diffusion characteristics that are well-correlated with human skin, was used for the diffusion studies of FA-PC.
RESULTS: We found that the lipophilicity of FA improved when complexed with phospholipids, allowing FA-PC to release FA in a controlled pattern. In the same time, complexing with phospholipids also obviously enhanced inhibition of B16F10 cellular melanogenesis.
CONCLUSIONS: FA-PC is a promising material for medicinal and cosmetic usages.

Greyia radlkoferi ethanol extract and its five compounds were tested for their inhibitory activity against the mushroom tyrosinase enzyme and melanin production on melanocytes. The crude extract showed significant tyrosinase inhibition with IC50 of 17.96μg/ml. This is the first report of the isolation of these 5 compounds from Greyia radlkoferi. 2\',4\',6\'-Trihydroxydihydrochalcone showed the highest tyrosinase inhibition at 17.70μg/ml (68.48μM), with low toxicity when compared with crude extract. This compound is therefore, a key component in the crude extract, which is responsible for tyrosinase inhibitory activity. The RT-qPCR indicated that the mechanism of action is most likely post transcriptional. Further, the molecular docking study showed that tyrosinase inhibitory activity depends on interaction of the compound with Cu2+ ions at the active site. This is the first report of the tyrosinase inhibitory activity of the G. radlkoferi extract and molecular insights on interaction of its compounds with Cu2+ ions as the driving factor for tyrosinase inhibition. These results suggest that the extract of G. radlkoferi and the compound 2\',4\',6\'-trihydroxydihydrochalcone have great potential to be further developed as pharmaceutical or cosmetic agents for use against dermatological disorders associated with melanin.