Evaluation of biological activities depending on different part and harvesting time of Reynoutria sachalinensis

Abstract

Reynoutria sachalinensis is traditionally used for medicinal purposes in Asia and holds significant research value as a functional ingredient. However, despite its potential, the industrial utilization of R. sachalinensis is limited by a lack of comprehensive information about its biological activity. Consequently, this study was conducted to assess the utilization potential of R. sachalinensis, which is native to Korea, by analyzing variations in its pharmacological activity based on different plant parts and harvest times. The extraction yield of R. sachalinensis leaves was found to be remarkably higher than that of the stem and rhizomes, with a significantly higher yield observed in leaves harvested in June compared to all other treatments. The phenol contents and antioxidant activities revealed an increase in the antioxidant content and activities in the leaves and stem depending on the harvest time, and R. sachalinensis leaves harvested in July demonstrated strong antioxidant activity and proved to be a rich source of flavonoids. Skin-whitening, anti-inflammatory, and anticancer activity analyses showed that leaves exhibited stronger pharmacological activity than the stem and rhizomes. Quercetin 3-O-glucoside and quercetin 3-O-(6 ''-acetyl-glucoside) were identified as the major flavonoid compounds in the leaves, suggesting their potential contribution to these activities. Based on these research results, the physiological activity of R. sachalinensis leaves was evaluated according to harvest time, confirming their potential for new use as a functional ingredient.