Screening and evaluation of antioxidant, antimicrobial, cytotoxic, thrombolytic and membrane stabilizing properties of the methanolic extract and solvent-solvent partitioning effect of Vitex negundo Bark

Abstract

ObjectiveTo investigate different biological activities of the methanolic extract and solvent-solvent partitioning of Vitex negundo (V. negundo) bark. MethodsIn-vitro anti-oxidant study was determined using total phenolic compound analysis and DPPH radical scavenging assay. In vitro antimicrobial study was measured by observing zone of inhibition. The cytotoxic activity was studied using brine shrimp lethality bioassay and thrombolytic activity by clot disruption method. ResultsIn the evaluation of anti-oxidant activity, the amount of total phenolic content differed in different extractives as from 12.94 mg of GAE/g of extractives to 54.19 mg of GAE/g of extractives of V. negundo. Among all extractives, the highest phenolic content was found in n-hexane fraction (N-HXN) (54.19 mg of GAE/g of extractives). Significant amount of phenolic compounds were present in methanol extract (ME) (35.19 mg of GAE/g of extractives) and aqueous soluble fraction (AQSF) (12.94 mg of GAE/g of extractives). The free radical scavenging activity of ME and its different partitions were assessed using DPPH free radicals assay. The highest free radical scavenging activity was found in AQSF (IC50=7.78 μg/mL). The antimicrobial screening of the bark of V. negundo exhibited mild to moderate activity in test microorganisms. The chloroform soluble fraction demonstrated the highest inhibition against microbial growth having zone of inhibition as 8-12 mm. In the brine shrimp lethality bioassay, The LC50 values of n-hexane and chloroform soluble fractions were found 3.713 6 μg/mL, and 0.910 μg/mL respectively while the LC50 values of standard Vincristine sulphate was 0.408 μg/mL. The methanol extract and their different organic soluble of V. negundo bark inhibited hypotonic solution-induced haemolysis of erythrocytes in In-vitro membrane stabilizing activity test. The AQSF and N-HXN showed inhibition of haemolysis as 55.05% and 29.89% that were lower than 71.9% of aspirin (0.10 mg/mL). Methanol extract of V. negundo and all of its different partitions exhibited moderate thrombolytic activity of 36.95%-22.98%. ConclusionsThese experiments were able to show the several biological activity of methanolic extract and its soluble fractions of V. negundo at a time.