PHYTOCHEMICAL STUDIES AND ANTISNAKE VENOM ACTIVITY OF THE CRUDE METHANOL EXTRACT OF INDIGOFERA NUMMULARIIFOLIA

Abstract

Abstract
Medicinal plants remain an important source of therapeutic agents, especially in communities where traditional medicine continues to play a central role in healthcare. Indigofera nummulariifolia (Fabaceae), widely used in ethnomedicine for the management of snakebites, has received limited scientific evaluation despite its notable traditional relevance. This study examined the phytochemical constituents of the aerial parts of I. nummulariifolia and assessed the antisnake venom potential of its crude methanol extract (CME) against Naja nigricollis venom.
The plant material was extracted with methanol and successively fractionated using standard solvent partitioning techniques. Purification of the hexane fraction through repeated gel filtration yielded a white crystalline compound (AH). Spectroscopic analyses (IR, UV, ¹H- and ¹³C-NMR, including 2D NMR) identified AH as stigmasterol. Acute toxicity assessment in Swiss albino mice, following OECD guideline 425, indicated that the extract is relatively safe with an oral LD₅₀ greater than 2000 mg/kg. Meanwhile, the LD₉₉ of N. nigricollis venom was determined to be 6.53 mg/kg. In prophylactic studies, preincubation of CME (100–400 mg/kg) with venom conferred complete protection, resulting in 100% survival and significantly prolonged survival times (p < 0.05) compared with untreated controls. Curative administration after envenomation also extended survival time, though eventual mortality occurred in all groups.
These findings provide scientific validation for the traditional use of I. nummulariifolia in snakebite management. The crude extract’s antisnake venom effects, highlights the plant as a potential source of promising lead compounds for further drug development.