Evaluation of in Vitro and in Vivo Depigmenting Activity of Raspberry Ketone from Rheum officinale

Abstract

Melanogenesis inhibition by raspberry ketone (RK) from Rheum officinale was investigated both in vitro in cultivated murine B16 melanoma cells and in vivo in zebrafish and mice. In B16 cells, RK inhibited melanogenesis through a post-transcriptional regulation of tyrosinase gene expression, which resulted in down regulation of both cellular tyrosinase activity and the amount of tyrosinase protein, while the level of tyrosinase mRNA transcription was not affected. In zebrafish, RK also inhibited melanogenesis by reduction of tyrosinase activity. In mice, application of a 0.2% or 2% gel preparation of RK applied to mouse skin significantly increased the degree of skin whitening within one week of treatment. In contrast to the widely used flavoring properties of RK in perfumery and cosmetics, the skin-whitening potency of RK has been demonstrated in the present study. Based on our findings reported here, RK would appear to have high potential for use in the cosmetics industry.

Lipase-Catalyzed Synthesis of Kojic Acid Derivative in Bioreactors and the Analysis of Its Depigmenting and Antioxidant Activities

“…Lysate with total protein of 250 µg was added in 100 µL of lysis buffer in 96-well plate. Then, 100 µL of L-DOPA (1 mM) was added and further incubated for 60 min at 37 • C. The absorbance was measured at 490 nm using the microplate reader where the final activity was expressed in percentage (%) [9]. KA was used as a positive control.…”

Methanol Partition Fraction of Ethanol Extract of Discorea nipponica Makino Inhibits Melanogenesis

“…Antioxidants can interfere with oxidation processes by acting as free radical scavengers or ROS scavengers, and then down-regulate melanin production [12,[16][17]. For instance, vitamin C or vitamin E can reduce the photooxidation of preexisting melanin particles [18].…”

“…L-DOPA staining assay was performed as previously reported [12]. The cells were washed 3 times in ice-cold PBS, and lysed in cold lysis buffer (20 mM sodium phosphate (pH 6.8), 1 % Triton X-100, 1 mM PMSF) containing a protease inhibitor cocktail (Abcam, Cambridge).…”

MicroRNA-218 inhibits melanogenesis by directly suppressing microphthalmia-associated transcription factor expression

“…The melanin evaluation was assayed as described by Lin, et al 35 Briefly, the pigmented pellet was dissolved in 1 M of NaOH at 60 °C for 1 h, and the color of the melanin solution was captured using a camera (Nikon). The intensity was further read at 490 nm using a microplate reader.…”