In vitro and in vivo Evaluation of Polyherbal Extracts of Selected Medicinal Plants as Remedies against Malaria

Malaria remains a deadly disease that affects many people globally, particularly in the tropical and subtropical regions. The rapid emergence of resistance to currently available antimalarial agents and the limitations of conventional therapies underscore the urgent need for novel therapeutic options. Traditional medicine, which commonly employs medicinal plants either individually or in polyherbal formulations, represents a valuable reservoir of bioactive compounds with potential antimalarial activity. This study investigated the antimalarial efficacy of a polyherbal formulation comprising five medicinal plants: Azadirachta indica, Mangifera indica, Psidium guajava, Dacryodes edulis, and Pennisetum purpureum. Plant materials were extracted using ethanol, and extracts were combined in varying proportions. The individual extracts and their combinations were evaluated for in vitro antiplasmodial activity against the Plasmodium falciparum ATCC strain Welch-30932, while in vivo efficacy was assessed using a curative model in mice. Phytochemical screening was conducted following standard qualitative methods. The results demonstrated that both individual extracts and polyherbal combinations exhibited significant (p < 0.05) antiplasmodial activity in vitro (IC₅₀: 12.2 ± 0.1–110.2 ± 0.3 µg/mL) and in vivo, with parasitemia clearance ranging from 73.02% to 92.76% (standard drug: 90.25%). Among the individual extracts, M. indica exhibited the most pronounced activity. Notably, the polyherbal formulation containing the extracts in a 2:2:1:1:1 ratio produced the highest antimalarial effect. The phytoconstituents identified were alkaloids, terpenes, tannins, steroids, flavonoids, and glycosides. The results provide evidence in support for the ethnomedicinal use of these plants and highlight the therapeutic potential of the polyherbal formulation for antimalarial drug development.