Pharmacological and Phytochemical Insights into Methanol and Hexane Bark Extracts of Terminalia arjuna: A Comprehensive Review

Abstract

Terminalia arjuna, a member of the family Combretaceae, is a widely recognized medicinal tree native to the Indian subcontinent. Its bark has long been employed in traditional medicine systems, especially Ayurveda, for the treatment of cardiovascular ailments, inflammation, microbial infections, and oxidative stress-related conditions. Recent advances in phytochemical and pharmacological research have highlighted the significance of solvent-based extractions, particularly using methanol (polar) and hexane (non-polar), to isolate diverse classes of bioactive constituents. Methanol extracts are rich in phenolic compounds, flavonoids, tannins, and glycosides, whereas hexane extracts predominantly contain non-polar molecules such as sterols, terpenoids, and long-chain hydrocarbons. This review systematically explores the physicochemical properties, phytoconstituents, pharmacological activities, and therapeutic implications of T. arjuna bark extracts, with emphasis on methanol and hexane fractions. Extraction methodologies, yield variations, bioassay results, antioxidant and antimicrobial potential, and comparative advantages of solvent polarity are critically discussed. Data are synthesized from multiple studies to highlight the molecular diversity and therapeutic versatility of T. arjuna. Emerging evidence suggests that solvent polarity dictates not only the phytochemical profile but also the biological efficacy of the extracts. The review further identifies gaps in current literature and proposes future research directions, including standardization, formulation, and clinical translation.