BackgroundUltraviolet radiation from sunlight induces overproduction of reactive oxygen species (ROS) resulting in skin photoaging and hyperpigmentation disorders. Novel whitening and anti-wrinkle compounds from natural products have recently become of increasing interest. The purpose of this study was to find products that reduce ROS in 14 Thai plant extracts.MethodsTo determine total phenolic and flavonoid content, antioxidant activity, anti-tyrosinase activity and anti-collagenase activity, we compared extracts of 14 Thai plants prepared using different solvents (petroleum ether, dichloromethane and ethanol). Antioxidant activities were determined by DPPH and ABTS assays.ResultsTotal phenolic content of the 14 Thai plants extracts was found at the highest levels in ethanol followed by dichloromethane and petroleum ether extracts, respectively, while flavonoid content was normally found in the dichloromethane fraction. Scavenging activity ranged from 7 to 99% scavenging as assessed by DPPH and ABTS assays. The ethanol leaf extract of Ardisia elliptica Thunb. had the highest phenolic content, antioxidant activity and collagenase inhibition, while Cassia alata (L.) Roxb. extract had the richest flavonoid content. Interestingly, three plants extracts, which were the ethanolic fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb., had high antioxidant content and activity, and significantly inhibited both tyrosinase and collagenase.ConclusionOur finding show that the ethanol fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb. show promise as potential ingredients for cosmetic products such as anti-wrinkle agents and skin whitening products.

Background: Ultraviolet radiation (UVR) is the major cause for hyperpigmentation, and to prevent this natural products are increasingly being explored as potential skin whitening agents. The aim of this study was to determine the total phenolic and flavonoid content, free radical scavenging activity, anti-tyrosinase activity and the inhibition of melanin content in α-melanocyte stimulating hormone-induced B16F10 melanoma cells of an aqueous extract of Garcinia atroviridis Griff. ex. T. Anderson fruit pericarps. Methods: The aqueous extract was prepared by extraction with distilled water at 105 o C for 60 min. Total phenolic and flavonoid content were determined using the Folin-Ciocalteau and aluminium chloride methods, respectively. Scavenging activity was assessed using 2,2-Diphennyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS). Tyrosinase activity and melanin content were determined spectrophotometrically. Results: The results showed that the aqueous extract of Garcinia atroviridis fruit pericarps had a phenolic (26.33 ± 0.77 mg GAE/g plant extract) and flavonoid content (9.31 ± 0.40 mg QE/g plant extract). The aqueous extract of Garcinia atroviridis significantly inhibited mushroom tyrosinase activity (IC 50 of 40.72 ± 1.83 µg/mL) and cellular tyrosinase activity (at a concentration of 125 µg/mL) in α-melanocyte stimulating hormone-induced B16F10 melanoma cells. The Garcinia atroviridis extract also suppressed melanin content at concentrations of 31.25-125 µg/mL. Correlations of mushroom tyrosinase inhibition with DPPH and ABTS scavenging activities were 0.8673 and 0.9468, respectively. Conclusion: Our findings show that an aqueous extract of Garcinia atroviridis fruit pericarps is a source of natural compounds and antioxidant capacity which can inhibit tyrosinase activity and melanin content. Thus, aqueous extracts of Garcinia atroviridis may be a potential source of skin whitening agents for hyperpigmentation.

Croton roxburghii and Croton sublyratus have been used as skin treatments in traditional medicine. The objective of the present study was to investigate the antimelanogenic effect of ethanol extracts of Croton roxburghii (CRE) and Croton sublyratus (CSE) leaves on cellular melanin content and cellular tyrosinase activity as mediated by the action of microthalmia transcription factor (MITF) and melanogenic enzymes. Croton roxburghii and Croton sublyratus leaves were extracted by petroleum ether, dichloromethane and absolute ethanol, sequentially. The ethanolic crude extracts were examined for antimelanogenic activity by their ability to decrease melanin content and cellular tyrosinase activity in alpha-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells. In addition, the extracts were evaluated to determine a plausible mechanism of melanogenesis suppression through determining the activation of MITF transcription factor and melanogenic proteins (tyrosinase, tyrosinase-related protein 1 or TRP-1 and tyrosinase-related protein 2 or TRP-2) at the transcriptional and translation levels in α-MSH-induced B16F10 cells. Upon treatment with CRE and CSE, the cells showed significant decreases in melanin content and cellular tyrosinase activity. CRE and CSE also suppressed MITF, tyrosinase, TRP-1 and TRP-2 at the transcription and translation levels in α-MSH-stimulated melanin biosynthesis in B16F10 cells. Our finding shows that CRE and CSE inhibit melanin content and cellular tyrosinase activity through suppressing MITF and melanogenic enzymes. CRE and CSE may be useful to combine with skin whitening agents for cosmetic uses.

Background Probiotics can release bioactive substances known as postbiotics, which can inhibit pathogenic microorganisms, improve immunomodulation, reduce antioxidant production, and modulate the gut microbiota. Methods In this study, we evaluated the in vitro antimicrobial effects, antioxidant activity, and anti-inflammatory potential of 10 lyophilized cell-free supernatants (LCFS) of Lactobacillus isolates. LCFS was obtained via centrifugation and subsequent lyophilization of the supernatant collected from the culture medium ofeach isolate. The antibacterial and antibiofilm activities of the LCFS were determined using broth microdilution. The antioxidant potential was evaluated by measuring the total phenolic and flavonoid contents and 2,2-Diphennyl-1-picrylhydrazyl (DPPH) and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS+) radical scavenging activities. Results All the isolates were able to inhibit the four tested pathogens. The isolates exhibited strong antibiofilm activity and eradicated the biofilms formed by Acinetobacter buamannii and Escherichia coli. All the prepared Lactobacillus LCFS contained phenols and flavonoids and exhibited antioxidant activities in the DPPH and ABTS+ radical scavenging assays. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay revealed that LCFS was not cytotoxic to RAW 264.7 cells. In addition, the ten Lactobacillus LCFS decreased the production of nitric oxide. Conclusions All the isolates have beneficial properties. This research sheds light on the role of postbiotics in functional fermented foods and pharmaceutical products. Further research to elucidate the precise molecular mechanisms of action of probiotics is warranted.