Investigation of bioactivities of methanolic and ethyl acetate extracts of Dioscorea pentaphylla leaf along with its phenolic composition

TLDR: In this article, the authors investigated the in-vivo antioxidant properties, brine shrimp lethality bioassay, and antimicrobial activity and invivo analgesic, anti-inflammatory, and antidiarrheal potentiality of methanolic and ethyl acetate extracts of Dioscorea pentaphylla.

Abstract: The present study was performed to investigate the in-vitro antioxidant properties, brine shrimp lethality bioassay, and antimicrobial activity and in-vivo analgesic, anti-inflammatory, and antidiarrheal potentiality of methanolic and ethyl acetate extracts of Dioscorea pentaphylla (D. pentaphylla) leaf along with determining the bioactive phenolic compounds by HPLC analysis. Standard methods were used to investigate the aforementioned bioactivities. Methanol extract showed higher total phenolic activity, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and Nitric oxide (NO) radical scavenging activities, whereas ethyl acetate extract showed better activities in total flavonoid and total antioxidant capacity assays. Dose-dependent moderate reducing capacity was observed for both extracts in cupric reducing and reducing power capacity assays. The methanol extract was found to be more potent than ethyl acetate extract according to brine shrimp lethality bioactivity test. Both extracts exhibited broad-spectrum antimicrobial activity in the disk diffusion method. In tail immersion test, at 1000 mg/kg dose, both extracts of D. pentaphylla showed a significant (p < 0.05) reduction in pain sensation. Ethyl acetate extract has significantly (p < 0.05) decreased writhing of the tested mice which were induced by acetic acid. The number of licks in formalin-induced paw licking test was markedly (p < 0.05) lessened in both extracts administration. Ethyl acetate extract revealed better anti-inflammatory activities than methanol extract in two well-known anti-inflammatory models (Xylene-induced ear edema, Cotton pellet-induced granuloma formation). Methanol extract displayed potent anti-diarrheal activity. HPLC analysis confirmed the existence of phenolic compounds (gallic acid, rutin, and quercetin) in the leaf extract of D. pentaphylla. These phytochemical constituents might have the role in the observed activities.