Abstract
Malaria remains a major global health issue, particularly in endemic regions. Traditional medicine offers promising remedies, such as Melochia umbellata, a plant used in Cameroonian folk medicine for malaria treatment. While its in vitro antiplasmodial activity has been reported, the safety and curative efficacy of M. umbellata aqueous leaf extract (MULAE) in vivo required further investigation. This study evaluated the curative antimalarial and hepato-renal protective effects of MULAE in a Plasmodium berghei-infected rat model, alongside its phytochemical characterization. Qualitative and quantitative analyses confirmed the presence of pharmacologically active secondary metabolites, including alkaloids, phenols, flavonoids, and saponins. In acute toxicity tests (OECD guideline 423), female rats received single oral doses of MULAE (2000, 5000 mg/kg). No mortality or signs of toxicity were observed throughout the 14-day monitoring period, indicating an LD(50) greater than 5000 mg/kg. For the curative assay, P. berghei-infected rats were treated for five days with MULAE (100, 200, 400 mg/kg), chloroquine (10 mg/kg), or distilled water. MULAE significantly suppressed parasitemia dose-dependently; the 400 mg/kg dose achieved 86.20% chemosuppression. The extract also improved hematological markers (restoring hemoglobin levels to 14.9 g/dL at 400 mg/kg), mitigated infection-induced weight loss, and reduced organ damage. This organ protection was evidenced by improved blood serum markers (creatinine, ALAT, ASAT, bilirubin, total protein), restored oxidative status, and ameliorated histopathological changes in the liver, kidneys, and spleen. These findings validate the traditional use of M. umbellata and support its potential as a source for novel antimalarial and organ-protective agents.