Studies on in vitro evaluation of antibacterial and antioxidant activity of Hydrilla verticillata (L.f.) Royle

Abstract

The purpose of the present investigation was to evaluate the therapeutic effect of Hydrilla verticillata (L.f.) Royle by examining its antibacterial and antioxidant properties in in vitro condition. For this study the methanolic and n -hexane extracts of Hydrilla verticillata (L.f.) Royle was tested against 5 pathogenic bacteria such as “Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Shigella flexneri and Vibrio choleriae” by using agar well diffusion method and for antioxidant activity DPPH scavenging assay was carried out. An antibiotic Ciprofloxacin was taken as reference. The result of the study revealed that, the n-hexane extract of H. verticillata showed highest zone of inhibition against Enterococcus faecalis (20±1.41 mm) and least against Vibrio choleriae (12±1.63 mm) at concentration of 15 mg/mL. While, methanolic extract showed highest zone of inhibition against Shigella flexneri (26±0.75 mm) and the least zone of inhibition against Klebsiella pneumoniae (20±1.24 mm). The significant result for anti-oxidant activity was evaluated. The IC50 value of n-hexane and methanolic extracts were 36.26 and 16.84 respectively. The methanolic extract was found to be having better result than n-hexane extract. The n-hexane ex-tract showed the presence of alkaloids, triterpenoids and polyphenolic compounds, tannin, glycoside while phytoconstituents like alkaloids, saponins, tannins, steroids, flavonoid, glycosides, triterpenoids and poly- phenolic compounds were found to be present in methanolic extract of H. verticillata. Further study can be done on the evaluation of secondary metabolites compound analysis for therapeutic effect.