Antioxidant and α-Glucosidase inhibition of Pyrrosia longifolia extracts

Abstract

Background: Pyrrosia longifolia is a fern species belonging to the Polypodiaceae family. Three Pyrrosia species, P. lingua, P. sheareri, and P. petiolosa, are included in the Chinese Pharmacopeia as sources of traditional medicine for ailments such as for patients with diabetes mellitus. Objectives: This study examined the inhibitory activity of α-glucosidase in different P. longifolia extracts, as well as their antioxidant activity and toxicity levels. Methods: This species was extracted via maceration in methanol and partitioning according to polarity levels (n-hexane, dichloromethane, ethyl acetate, and water). Antioxidant activity was measured by scavenging free radicals against the DPPH radical, antidiabetic activity was determined using an in vitro α-glucosidase inhibitory test, and toxicity was determined using the Brine Shrimp Lethality Test (BSLT). Results: Antioxidant activity using radical DPPH showed ethyl acetate extract had the highest inhibitory activity with IC50 28.22 ppm and α-glucosidase inhibitory activity showed that all the extracts showed very weak activity at concentrations of 500 ppm. Additional toxicity analysis revealed that none of the extracts was harmful to Artemia salina. Conclusion: This study demonstrates that this species has strong antioxidant activity, and that additional analysis is required. It also identifies the chemicals that are responsible for the antioxidant activity.