Antioxidant Activity of Fermented Kaempferia parviflora and Inhibitory Action against Tyrosinase and Elastase

In this study, we measured the total phenol and flavonoid contents, radical scavenging activity, and tyrosinase and elastase inhibitory activity of Kaempferia parviflora fermented with various useful microorganisms (BS: Bacillus subtilis, LP: Lactobacillus plantarum, LC: Lactobacillus casei, CU: Candida utilis, Y1: Saccharomyces cerevisiae strain CHY1011, Y2: S. cerevisiae strain ZP541) to investigate the potential for future use of K. parviflora as an industrial raw material in health functional foods and cosmetics. The yield of freeze-dried powder of K. parviflora fermented by BS, LP, LC, CU, Y1, and Y2 was 56.41%, 48.28%, 48.75%, 47.12%, 41.32%, and 39.93%, respectively. The total phenol contents were 13.88∼33.29 gallic acid equivalents mg/g, with the highest content being found in the group fermented by BS. The flavonoid contents showed the highest value in the control group (8.55 catechin hydrate (CE) mg/g), but the group fermented by BS had higher total flavonoid content (7.08 CE mg/g) than those of the other groups. The control group and the group fermented by BS had IC50 values of 0.68 mg/mL and 0.56 mg/mL based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 2,2'-azino-bis(3-ethylbenzothiazoline-6- sulfonic acid) radical scavenging activities of 1.14 mg/mL and 1.46 mg/mL, respectively. The FRAP value (1 mg/mL) was highest in the control group (1.13 mM). Evaluation of the tyrosinase inhibition activity revealed values of 29.29 to 47.00% at 5 mg/mL, with the group fermented by CU having the highest value. At the same concentration, elastase inhibition activity was significantly higher, with the group fermented by BS having the highest value. The total phenol content showed a significant correlation with DPPH radical scavenging activity and elastase inhibition activity. Moreover, the total flavonoid content was highly positively correlated with DPPH and ABTS radical scavenging activity and FRAP. Therefore, fermentation of K. parviflora using various microorganisms increases its antioxidant activity and inhibition of tyrosinase and elastase, so it can be developed for use in functional foods and cosmetics.