Vernonia amygdalina Delile (Asteraceae) as a Candidate Antimalarial Agent: Phytochemical Composition, Ethnopharmacological Use, and Heme Polymerization Inhibition Potential – A Literature Review
Benjamin Anja Orngu, Edema Enogiomwan Imalele
Abstract
Vernonia amygdalina Delile (Asteraceae), commonly called bitter leaf, is widely used in sub-Saharan African traditional medicine to manage malaria and febrile illness. This literature review consolidates current knowledge on the phytochemistry of V. amygdalina and evaluates the evidence for its antimalarial activity, with emphasis on inhibition of heme polymerization (hemozoin formation) as a mechanistic hypothesis. PubMed, Scopus, Web of Science, and Google Scholar were searched using combinations of the terms V. amygdalina, bitter leaf, antimalarial, heme polymerization, hemozoin, beta-hematin, phytochemistry, and Plasmodium falciparum. Primary research articles, reviews, and authoritative reports were considered, with emphasis on publications from 2015 to 2026. Of 53 records identified, 33 were included. The plant contains sesquiterpene lactones (notably vernodalol and vernolide), flavonoids (including luteolin and apigenin), alkaloids, saponins, tannins, and phenolic compounds. Leaf extracts show in vitro antiplasmodial activity at low microgram-per-milliliter concentrations, suppress Plasmodium berghei in mice, and reduce mosquito-stage parasite development, although vernolide and vernodalol showed considerable cytotoxicity. Direct evidence of heme polymerization inhibition is limited to a single-concentration beta-hematin screen of one methanol leaf extract, which gave a positive signal lower than chloroquine’s; no IC50 values for solvent fractions or isolated constituents were identified. Heme binding by V. amygdalina constituents therefore remains a hypothesis. Standardized beta-hematin inhibition assays on defined fractions, combined with parasite-based confirmation and cytotoxicity testing, are needed.