PHARMACOGNOSTICAL OVERVIEW ON TERMINALIA ARJUNA: A JUSTIFICATION OF FOLKLORIC BELIEF

The application of medicinal plants such as Terminalia arjuna to maintain health and treat disease started since time immemorial and still is a part of medical practice. The phytochemical analysis of bark of T. arjuna in methanolic, hydromethanolic (1:1), aqueous and petroleum ether extracts revealed the presence of carbohydrates, amino acid, alkaloids, saponins, tannins, flavonoids, terpenoids, glycosides, xanthoproteins and phenols. In-vitro antioxidant capacity by linear regression analysis was measured by assaying DPPH radical and H₂O₂ scavenging capacities. Their respective IC₅₀ values were found to be 336.89 μg/ml and 253.01 μg/ml. The hydromethanolic extract gave total phenolic, total flavonoids and FRAP values of 754.16 ± 16.26 mg GAE/g, 247.02 ± 8.81 mg/g QE/g and 1.36 ± 0.03 mM FeSO₄ respectively. The IC₅₀ values for in-vitro anti-inflammatory activities were evaluated by the following assays: lipoxygenase inhibition (IC₅₀ = 480.5 μg/ml), heat induced protein denaturation (IC₅₀ = 282.32 μg/ml), proteinase inhibition (IC₅₀ = 1339.3 μg/ml) and RBC membrane stabilization (IC₅₀ = 192.81 μg/ml) at different concentrations using aspirin as control. Studies were also carried out to assess the hypoglycemic potential by assaying the ability of the plant to inhibit alpha amylase (IC₅₀ = 210.91 μg/ml) and pancreatic lipase (IC₅₀ = 51.52 μg/ml) activities. In addition, glucose binding capacity and glucose diffusion was also monitored). Antimicrobial activity of the extracts was studied against common pathogens. The zone of inhibition was observed using well diffusion method.