arbutin and ethyl-acetate

Melanin plays an important role in protecting human skin, while excessive synthesis of melanin can cause abnormal pigmentation and induce skin diseases. Long-term use of commercial whitening agents in managing skin melanin such as kojic acid and arbutin can lead to some negative effects such as dermatitis and liver cancer. Although past studies have researched the melanin inhibitory effect of plant extracts, the effective dose and mechanisms are not well summarized and discussed. This study aims to explore the melanin inhibitory property of phytochemicals and tries to answer the following research questions: (1) Which plant extracts and phytochemicals could inhibit melanin biosynthesis in the skin? what is the mechanism of action? (2) Have human trials been conducted to confirm their melanin inhibitory effect? (3) If not, which phytochemicals are recommended for further human trials? This article would provide information for future research to develop natural and safe skin whitening products.. A preferred reporting items for systematic reviews and meta-analyses (PRISMA) systematic review method and OHAT risk-of-bias tool were applied to screen literature from 2000 to 2021 and 50 research articles met the selection criteria.. Flavonoids, phenolic acids, stilbenes and terpenes are main classes of phytochemicals responsible for the melanin inhibitory effects. The in vitro/in vivo melanin inhibitory effects of these plant extracts/phytochemicals are achieved via three main mechanisms: (1) the ethyl acetate extract of Oryza sativa Indica cv., and phytochemicals such as galangin and origanoside could manage melanin biosynthesis through competitive inhibition, non-competitive inhibition or mixed-type inhibition of tyrosinase; (2) phytochemicals such as ginsenoside F1, ginsenoside Rb1 and 4‑hydroxy-3-methoxycinnamaldehyde could inhibit melanogenesis through down-regulating microphthalmia-related transcription factor (MITF) gene expression via different signalling pathways; (3) the ethanolic extracts of Dimorphandra gardneriana, Dimorphandra gardneriana, Lippia microphylla and Schinus terebinthifolius have a good ultraviolet absorption ability and high sun protective factor (SPF) values, thereby inhibiting UV induced melanogenesis in the skin.. Although many plant extracts and phytochemicals have been found to inhibit melanin production, most of the results were only proved in cellular and/or animal models. Only the ethyl acetate extract of Oryza sativa Indica cv. panicle, and ginsenoside F1 were proved effective in human trials. Animal studies proved the effectiveness of galangin, origanoside, ginsenoside Rb1 and 4‑hydroxy-3-methoxycinnamaldehyde with effective dose below 3 mM, and therefore recommended for future human trial. In addition, cellular studies have demonstrated the effectiveness of oxyresveratrol, mulberroside A, kurarinol, kuraridinol, plumbagin, (6aR,11aR)-3,8-dihydroxy-9‑methoxy pterocarpan, ginsenoside Rh4, cardamonin, nobiletin, curcumin, β-mangostin and emodin in inhibiting melanin synthesis at low concentrations of 20 µM and proved the low SPF values of Dimorphandra gardneriana, Dimorphandra gardneriana, Lippia microphylla and Schinus terebinthifolius extracts, and therefore recommended for further animal and human trials.

Topics: Acetates; Acrolein; Animals; Arbutin; Bleaching Agents; Cell Line, Tumor; Curcumin; Emodin; Flavonoids; Ginsenosides; Glucosides; Humans; Hydroxybenzoates; Melanins; Microphthalmia-Associated Transcription Factor; Monophenol Monooxygenase; Phytochemicals; Plant Extracts; Pterocarpans; Stilbenes; Transcription Factors

In this study, extracts were obtained from leaves of Pyrus communis L., Pyrus elaeagrifolia Pall., and Pyrus pyrifolia (Bum.) Nak. These extracts were tested for antiradical and antibacterial activity, as well as for the amount of total phenolic compounds, hydroquinone and arbutin. The antiradical activity was measured using 2,2-diphenyl-1-picrylhydrazyl radical and antibacterial activity with the disk diffusion method. The amount of phenolic compounds was determined using Folin Ciocalteu's phenol reagent, but the amount of hydroquinone and arbutin was measured with high performance liquid chromatography. The strongest antiradical activity was observed for ethyl acetate extract from leaves of P. communis L., and the lowest for the poorly soluble fraction (precipitate) from leaves of P. elaeagrifolia Pall. The highest number of antiradical units per gram of raw materials was noted for leaves of P. communis. The strongest antibacterial activity was measured for ethyl acetate extracts. The calculation of Spearman rank correlation coefficients indicated the existence of a positive correlation between contents of hydroquinone in extracts and their antibacterial activity for almost all investigated bacterial strains. The strains of fungi such as Candida albicans and Saccharomyces cerevisiae were completely resistant to the action of extracts.

Topics: Acetates; Anti-Bacterial Agents; Antioxidants; Arbutin; Bacillus subtilis; Biphenyl Compounds; Disk Diffusion Antimicrobial Tests; Escherichia coli; Helicobacter pylori; Hydroquinones; Picrates; Plant Extracts; Plant Leaves; Pseudomonas aeruginosa; Pyrus; Solvents; Species Specificity; Staphylococcus aureus

A methanolic extract and its ethyl acetate-soluble fraction from Sri Lankan curry-leaf, the leaves of Murraya koenigii, inhibited melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. Two new carbazole alkaloids, karapinchamines A and B, were isolated from the ethyl acetate-soluble fraction together with 12 known carbazole alkaloids. The structures of karapinchamines A and B were determined by physicochemical analyses. The principal alkaloid constituents were found to display potent melanogenesis inhibitory activity. The structural requirements of the carbazole alkaloids for melanogenesis inhibitory activity were discussed.

Topics: Acetates; Alkaloids; Animals; Carbazoles; Cell Differentiation; Cell Line, Tumor; Chemical Fractionation; Gene Expression Regulation; Magnetic Resonance Spectroscopy; Melanins; Mice; Molecular Conformation; Murraya; Plant Extracts; Plant Leaves

To study the inhibition of extracts from Synotis erythropappa on tyrosinase.. The 70% ethanol extracts were extracted by petroleum benzine, ethyl acetate and n-butanol, and the inhibitory activities against tyrosinase of every fraction were determined in vitro and the inhibitory kinetics of ethyl acetate and n-butanol fractions were investigated.. The four fractions extracted all had inhibitory activities on tyrosinase, inhibitory activities of ethyl acetate and n-butanol fraction were higher. Their IC50 were 57.8, 140 microg/ml for monophenol oxidase activity and 41.2, 59.6 microg/ml for diphenol oxidase activity, respectively. The inhibition kinetics analyzed by Hnewaver-Burk plots showed that ethyl acetate fraction was a competitive type inhibitor, and its Ki was determined to be 19.7 microg/ml. n-butanol fraction was an uncompetitive type inhibitor, and its Ki was determined to be 60.7 microg/ml.. Ethyl acetate and n-butanol fractions of extracts from Synotis erythropappa show potential inhibitory activity on tyrosinase.

Topics: Acetates; Arbutin; Asteraceae; China; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Enzyme Inhibitors; Ethanol; Inhibitory Concentration 50; Monophenol Monooxygenase; Plants, Medicinal; Time Factors