Integrated In Vivo and In Silico Evaluation of Antimalarial Compounds from Vernonia ambigua Leaves Identified by GC-MS Profiling

Amina Jega Yusuf^1*Abdul-Rahman Abdullahi Alpha¹Mustapha Salihu¹Jamila Aminu²Naz Mina Mert Sahin³Kemal Yelekci³Abdullahi Ibrahim Uba⁴Mustapha Umar Imam⁵

• ¹Department of Pharmaceutical and medicinal chemistry, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria, Sokoto, Nigeria
• ²Gombe State University, Gombe, Nigeria
• ³Kadir Has Universitesi, Istanbul, Türkiye
• ⁴Istanbul Arel Universitesi, Istanbul, Türkiye
• ⁵Usmanu Danfodiyo University, Sokoto, Nigeria

Background: Malaria remains a global health challenge, and the emergence of drug-resistant Plasmodium strains has necessitated the search for new antimalarial agents. Vernonia ambigua is used traditionally to treat malaria in parts of Africa, but its pharmacological potential remains underexplored. The aim of this study was to evaluate the antimalarial activity and chemical constituents of the chloroform leaf extract (CLE) of V. ambigua using in vivo and in silico approaches. Methods: Acute toxicity was evaluated using Lorke's method, and antimalarial activity was assessed via Ryley and Peter's 4-day curative test in Plasmodium berghei–infected Swiss albino mice, followed by GC–MS profiling and in silico analyses (molecular docking and dynamics simulations) of the identified compounds. Results: The CLE showed a 73.8% parasite cure rate at 500 mg/kg, with no observed toxicity up to 5000 mg/kg. GC-MS profiling revealed thirteen compounds, of which 9H-fluorene-4-carboxylic acid and Tolnaftate showed strong PfLDH binding (docking scores of –7.7 and –7.6 kcal/mol, respectively). Tolnaftate demonstrated potentially modest stability in the active site of PfLDH during MD simulation. ADME/toxicity profiling identified 9H-fluorene-4-carboxylic acid as the most promising compound, combining favorable bioavailability, low predicted toxicity, and good synthetic accessibility. Conclusion: V. ambigua possesses potent antimalarial properties, with 9H-fluorene-4-carboxylic acid and Tolnaftate emerging as promising PfLDH inhibitors. These findings support further investigation and development of its bioactive constituents as antimalarial drug leads.