The study was aimed at investigating the antimelanogenic and antioxidant properties of essential oil when extracted from the leaves of Artemisia argyi, then analyzing the chemical composition of the essential oil. The inhibitory effect of the essential oil on melanogenesis was evaluated by a mushroom tyrosinase activity assay and B16F10 melanoma cell model. The antioxidant capacity of the essential oil was assayed by spectrophotometric analysis, and the volatile chemical composition of the essential oil was analyzed with gas chromatography-mass spectrometry (GC/MS). The results revealed that the essential oil significantly inhibits mushroom tyrosinase activity (IC₅₀ = 19.16 mg/mL), down-regulates B16F10 intracellular tyrosinase activity and decreases the amount of melanin content in a dose-dependent pattern. Furthermore, the essential oil significantly scavenged 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) ABTS radicals, showed an apparent reduction power as compared with metal-ion chelating activities. The chemicals constituents in the essential oil are ether (23.66%), alcohols (16.72%), sesquiterpenes (15.21%), esters (11.78%), monoterpenes (11.63%), ketones (6.09%), aromatic compounds (5.01%), and account for a 90.10% analysis of its chemical composition. It is predicted that eucalyptol and the other constituents, except for alcohols, in the essential oil may contribute to its antioxidant activities. The results indicated that essential oil extracted from A. argyi leaves decreased melanin production in B16F10 cells and showed potent antioxidant activity. The essential oil can thereby be applied as an inhibitor of melanogenesis and could also act as a natural antioxidant in skin care products.

The effects of essential oil from Eucalyptus camaldulensis flowers oil on melanogenesis and the oil’s antioxidant characteristics were investigated. Assays of mushroom and cellular tyrosinase activities and melanin content of mouse melanoma cells were performed spectrophotometrically, and the expression of melanogenesis-related proteins was determined by Western blotting. The possible signaling pathways involved in essential oil-mediated depigmentation were also investigated using specific protein kinase inhibitors. The results revealed that E. camaldulensis flower essential oil effectively suppresses intracellular tyrosinase activity and decreases melanin amount in B16F10 mouse melanoma cells. The essential oil also exhibits antioxidant properties and effectively decreases intracellular reactive oxygen species (ROS) levels. The volatile chemical composition of the essential oil was analyzed with gas chromatography–mass spectrometry (GC/MS). The chemical constituents in the essential oil are predominately oxygenated monoterpenes (34.9%), followed by oxygenated sesquiterpenes (31.8%), monoterpene hydrocarbons (29.0%) and sesquiterpene hydrocarbons (4.3%). Our results indicated that E. camaldulensis flower essential oil inhibits melanogenesis through its antioxidant properties and by down-regulating both mitogen-activated protein kinases (MAPK) and protein kinase A (PKA) signaling pathways. The present study indicates that the essential oil has the potential to be developed into a skin care product.

Lactic acid bacteria are beneficial to human health. Lactic acid bacteria have wide applications in food, cosmetic and medicine industries due to being Generally Recognized As Safe (GRAS) and a multitude of therapeutic and functional properties. Previous studies have reported the beneficial effects of lactic acid bacteria, their extracts or ferments on skin health, including improvements in skin conditions and the prevention of skin diseases. Lipoteichoic acid isolated from Lactobacillus plantarum was reported to inhibit melanogenesis in B16F10 melanoma cells. In particular, lipoteichoic acid also exerted anti-photoaging effects on human skin cells by regulating the expression of matrix metalloproteinase- 1. The oral administration of Lactobacillus delbrueckii and other lactic acid bacteria has been reported to inhibit the development of atopic diseases. Additionally, the clinical and histologic evidence indicates that the topical application of lactic acid is effective for depigmentation and improving the surface roughness and mild wrinkling of the skin caused by environmental photo-damage. This review discusses recent findings on the effects of lactic acid bacteria on skin health and their specific applications in skin-whitening cosmetics.

This study was aimed at investigating the antimelanogenic and antioxidative properties of the essential oil extracted from leaves of V. negundo Linn and the analysis of the chemical composition of this essential oil. The efficacy of the essential oil was evaluated spectrophotometrically, whereas the volatile chemical compounds in the essential oil were analyzed by gas chromatography-mass spectrometry (GC-MS). The results revealed that the essential oil effectively suppresses murine B16F10 tyrosinase activity and decreases the amount of melanin in a dose-dependent manner. Additionally, the essential oil significantly scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals, and showed potent reducing power versus metal-ion chelating properties in a dose-dependent pattern. The chemical constituents in the essential oil are sesquiterpenes (44.41%), monoterpenes (19.25%), esters (14.77%), alcohols (8.53%), aromatic compound (5.90%), ketone (4.96%), ethers (0.4%) that together account for 98.22% of its chemical composition. It is predicted that the aromatic compound in the essential oil may contribute to its antioxidant activities. The results indicated that essential oil extracted from V. negundo Linn leaves decreased melanin production in B16F10 melanoma cells and showed potent antioxidant activities. The essential oil can thereby serve as an inhibitor of melanin synthesis and could also act as a natural antioxidant.

[8]-Gingerol is an active component of Zinger and shows several pharmacological activities, such as antipyretic and anti-inflammation characteristics. To identify a potential skin-whitening agent, the inhibitory effects of [8]-gingerol on melanogenesis and its mechanism of action were investigated. In the present study, the effects of [8]-gingerol on mushroom tyrosinase, tyrosinase activity and melanin content were determined spectrophotometrically; the expression of melanogenesis-related proteins in B16F10 and B16F1 melanoma cells were determined by Western blotting. Furthermore, the possible signaling pathways involved in [8]-gingerol-mediated depigmentation were also investigated using specific inhibitors. The results revealed that [8]-gingerol (5-100μM) effectively suppressed intracellular tyrosinase activity and decreased the amount of melanin in B16F10 and B16F1 cells. In addition, [8]-gingerol also effectively decreased intracellular reactive species (RS) and reactive oxygen species (ROS) levels at the same dose range. Our results indicated that [8]-gingerol inhibited melanogenesis in B16F10 and B16F1 cells by down-regulation of both mitogen-activated protein kinases (MAPK) and protein kinase A (PKA) signaling pathways or through its antioxidant properties. Hence, [8]-gingerol could be used as an effective skin-whitening agent.