The melanogenesis-inhibitory effect and the percutaneous formulation of ginsenoside Rb1.

Ginsenoside Rb1 (Rb1) is the most predominant ginsenoside isolated from the roots of ginseng (Panax ginseng C. A. Meyer). This compound is active in various human biological pathways that are involved in human collagen synthesis and inhibition of cell apoptosis. In this study, the skin-whitening effects of Rb1 were investigated in B16 melanoma cells. Our results showed that Rb1 inhibited melanogenesis in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16 cells in a dose-dependent manner, which collectively indicated that Rb1 may have skin-whitening effects and may be formulated into skin-whitening products for skin care. Accordingly, a ginsenoside collagen transdermal patch was developed as a vehicle to topically deliver Rb1 into pig skin. The percutaneous permeation, retention within skin, and release in vitro of Rb1 from seven transdermal patch formulas were studied. It was determined that the best formula for ginsenoside collagen transdermal patch is made of protein collagen hydrolysate powder (PCHP) 2.0% (w/w), methyl cellulose (MC) 0.5% (w/w), polyethyleneglycol 6000 (PEG6000) 0.5% (w/w), ginsenoside 0.036% (w/w), azone 0.4% (v/w), menthol 0.20% (w/w), and water.