Screening of Natural Bioactive Metabolites and Investigation of Antioxidant, Antimicrobial, Antihyperglycemic, Neuropharmacological, and Cytotoxicity Potentials of Litsea polyantha Juss. Ethanolic Root Extract

This study was designed to identify some bioactive phytochemicals from ethanolic extract of roots of Litsea polyantha and to evaluate some of its pharmacological activities. Phytochemical tests indicated the presence of reducing sugar, combined reducing sugar, tannins, flavonoids, alkaloids, terpenoids, and phenol. In the antioxidant assay using 2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging method, the IC50 value was found to be 82.31 μg/mL. Total content of phenolic compounds, flavonoid, and tannin was found to be 152.69 mg GAE/gm, 85.60 mg QE/gm, and 77.22 mg GAE/gm of dry extract, respectively. In disc diffusion antibacterial assay, the extract exhibited highest zone of inhibition up to 12.25 mm against Escherichia coli at the concentration of 500 μg/disc. For brine shrimp lethality bioassay, the extract exhibited LC50 56.082 μg/mL. In in vivo antihyperglycemic activity test by oral glucose tolerance test using Swiss Albino mice at the oral dose of 250 and 500 mg/kg, the extract showed statistically significant antihyperglycemic effect. Finally, in vivo, the extract exhibited the dose dependent CNS depressant effects by reducing the locomotors of Swiss Albino mice which was confirmed through three different neuropharmacological activity tests such as open field, hole cross, and hole board test.