PHYTOCHEMICAL, TOXICOLOGICAL, AND PHARMACOLOGICAL INVESTIGATION OF INDIGENOUS MEDICINAL PLANTS FROM ONDO/OGUN STATES FOR ANTI‑MALARIA DRUG DISCOVERY

Abstract

Malaria remains a major public health challenge in sub-Saharan Africa, compounded by increasing
resistance of Plasmodium falciparum to existing anti-malarial therapies. This study investigated
the phytochemical composition, toxicological safety, and pharmacological efficacy of selected
indigenous medicinal plants from Ondo and Ogun States, Southwest Nigeria, traditionally used for
malaria treatment. An ethnobotanical survey guided plant selection, followed by solvent
extraction, phytochemical screening, chromatographic isolation, and spectroscopic
characterisation of bioactive compounds. In-vitro anti-plasmodial activity was evaluated against
chloroquine-resistant P. falciparum strains, while in-vivo efficacy was assessed using Plasmodium
berghei-infected albino mice. Acute toxicity studies were conducted in accordance with OECD
guidelines. Results revealed that several plant extracts, particularly Morinda lucida, Enantia
chlorantha, and Vernonia amygdalina, exhibited strong anti-plasmodial activity with IC₅₀ values
below 12 μg/mL and significant parasite suppression in vivo. Toxicological findings indicated
wide safety margins with no severe adverse effects at therapeutic doses. The study validates
indigenous anti-malarial knowledge and identifies promising plant-derived candidates for further
drug development. These findings highlight the potential of locally sourced medicinal plants as
affordable and culturally acceptable leads in the search for new anti-malarial drugs.