Rehmannia glutinosa root and Saururus chinensis plant have been widely used in natural traditional medicines. This study was conducted to investigate the effect of the content of the main components of R. glutinosa root and S. chinensis plant by extraction method. The results of comparative analysis of extraction yield, total flavonoid, and polyphenol content by extraction method indicated that extraction yield had the best performance with hot water extraction for R. glutinosa and ultrasound-assisted extraction for S. chinensis. The total flavonoid and polyphenol content had the best performance with maceration extraction for R. glutinosa and ultrasound-assisted extraction for S. chinensis. ABTS and DPPH activity was excellent with maceration extraction for both R. glutinosa and S. chinensis. The analysis of the main components showed that maceration extraction was most effective for both S. chinensis and R. glutinosa. Specifically, maceration extraction of R. glutinosa yielded 1.5 times more than conventional ultrasound-assisted extraction.

Background: In this study, examined the effects of an extract of a mixture of Angelica gigas, Cnidium officinale, Paeonia lactiflora, and Rehmannia glutinosa fermented by Leuconostoc mesenteroides, with enhanced value and functionality. In oriental medicine, a mixture of these herbs is called Samultang. Methods and Results: In this study, we evaluated the effects of a fermented extract of Samultang on oxidative stress, procollagen type I expression, and melanin production. Samultang was extracted with 70% ethanol, followed by inoculation with Leuconostoc mesenteroides to obtain the fermented extract. The evaluation of viability of B16F10 cells and human foreskin fibroblast (HHF) revealed that both ethanol and fermented extracts of Samultang were non-toxic. The results of 1,1-diphenyl-2-picrylhydrazyl (DPPH) test showed that the fermented extract of Samultang (SC50 value = 100 ㎍/㎖) was a more effective DPPH free radical scavenger than its ethanol extract. In addition, procollagen type I expression was higher in cells treated with the fermented extract of Samultang than in cells treated with ethanol. In the non-toxic concentration range, the fermented extract of Samultang showed strong inhibitory effect on melanin production in α-melanocyte stimulatin hormone-stimulated B16F10 cells (IC50 = 37.9 ㎍/㎖). Conclusions: These results suggest that the fermented extract of Samultang has considerable protential as a cosmetic ingredient owing to its antioxidant, anti-wrinkle, and whitening effects.