Antioxidant and skin health-enhancing activities of wild indigo (Baptisia tinctoria) root extracts

This study aimed to investigate the effects of wild indigo (Baptisia tinctoria) root extract as a functional food material, in terms of antioxidant and skin health-related activities. Both water and ethanol (50/50, v/v) extracts showed high phenol content. They were evaluated for antioxidant activity, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), antioxidant protection factor (PF), and thiobarbituric acid reactive substances (TBARS). While the DPPH radical scavenging activities of water and ethanol extracts were 84.23% and 89.30%, respectively, at 200 μg/mL total phenol content (TPC), the ABTS radical cation scavenging activities were 51.39% and 48.10%, respectively. The water and ethanol extracts also showed desirable antioxidant PF levels of 1.18 and 1.16, respectively. Furthermore, the antioxidant effects on TBARS significantly increased by 37.31% and 51.43%, respectively, in 200 μg/mL of water and ethanol extracts. Both the extracts showed high dose-dependent collagenase inhibitory activities, up to 27.60% and 77.39%, respectively. The ethanol extract showed an elastase inhibitory activity of 37.21%; the tyrosinase inhibitory effect (which facilitates natural skin-whitening) was 59.26% at 200 μg/mL TPC. The hyaluronidase activity inhibition, related to anti-inflammatory activity, was 20.02% for the water extract and 14.30% for the ethanol extract, at 200 μg/mL TPC. Therefore, B. tinctoria extract has potential applications in cosmetics and food supplements due to its antioxidant and skin health promoting activities.