A Comparison of the Components and Biological Activities of the Ethanol Extracts of Achyranthes japonica Nakai and Achyranthes bidentata Blume

In the course of a study for the development of functional foods utilizing Woosul (Achyranthis radix), the components and various biological activities of Korean Woosul (AJN: Achyranthes japonica Nakai) and Chinese Woosul (ABB: Achyranthes bidentata Blume) were compared. Woosul in Korea, including AJN and ABB, are regulated and part of the Korean Pharmacopoeia. From AJN and ABB, ethanol extracts and their subsequent organic solvent fractions were prepared and their in-vitro antimicrobial, antioxidant and anti-diabetes activities were evaluated. Although AJN and ABB have no clear distinction in terms of usage in Korea, our results suggest that AJN has higher quantities of lipid-soluble components and lower amounts of water-soluble sugars than does ABB. ABB also appears to possess greater amounts of flavonoid and polyphenol substances than AJN. Analyses of biological activities showed that the fractions of AJN were more active as antibacterial agents, and possessed more pronounced α-glucosidase inhibitory activities than those of the ABB fractions. However, the antioxidant activities of the ABB fractions, as determined by DPPH anion-, ABTS cation-, nitrite-scavenging activity and reducing power, were higher than those of the AJN fractions. Our results suggest that the components and bioactivity of the extracts and subsequent fractions of AJN and ABB are different. Therefore, usage of either AJN or ABB should be carefully considered, as regards their individual properties, when the active fractions of Woosul are employed in the development of functional foods or novel plant-derived medicines.