Phytochemical profiles, total flavonoids, total phenolic content and antioxidant activities via free radical scavenging activities (FRSA) of philippine herbal vines

Abstract

Philippines is bestowed with the abundance of plant biodiversity. Many of these plants have not been studied or thoroughly evaluated. Such plants could be a potential source of new molecules with impending therapeutic activities only waiting to be discovered. One of this is the group of vines that are widespread and fast growing including Hiptage benghalensis, Antigonon leptopus, Macroptillium atropurpureum and Dioscorea bulbifera L. These plants that have been used by traditional healers in rural communities in the Philippines as source of food, tea and medicine for a long time. In this study, the basic nutraceutical components of the crude extracted from the four herbal vines and their in vitro antioxidant properties was investigated to provide baseline data for the possible development of these plants as functional food and pharmaceutical products. Qualitative screening of the phytochemical constituents showed that alkaloids, tannins, saponins, steroids and flavonoids were present in their leaf extracts. All four showed varied free radical scavenging activities (FRSA). The greatest DPPH radical scavenging activity was observed in H. begnhalensis (84.64%), followed by A. leptopus (68.21%), M. atropurpureum (26.62%) and D. bulbifera L. (19.04%). The FRAP assay revealed that H. benghalensis had the highest antioxidant activity (8.32 mg/g) while ABTS assay showed that M. atropurpureum had the strongest scavenging ability of free radicals (0.0842 mg Trolox/g). The total flavonoid content (TFC) analysis showed that D. bulbifera L. had the highest TFC (420.35 mg quercetin per gram-dried material). The total phenolic content (TPC) of the four herbal vines showed large variations, between 26.56±0.160 and 55.91 ±0.087 mg GAE/g dried material. The plant leaf extracts arranged in increasing values of TPC are H. benghalensis (26.565)