Assessment of antioxidant and antibacterial activities of crude extracts of verbena officinalis Linn root or Atuch (Amharic)

Verbena officinalis Linn is a traditionally known medicinal plant which is used against a number of diseases including inflammatory conditions. In this study its antioxidant activity (reducing powers, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities), ferric reduction activity potential (FRAP), total flavonoid concentration and antimicrobial activities of 80%, 90%, 100% methanol and chloroform extracts of V. officinalis Linn root and 90% and100% methanol leaf extracts were determined. Its antioxidant activity increases with increase in amount of extract (10% to 40%v/v). Total flavonoid content (TFC) varied from 73.32±0.002 mgQE/100g of dry weight (90% methanol) to 42.39±0.032 mgQE/100g dry weight (chloroform), 2,2-diphenyl-1-picrylhydrazyl (DPPH), radical scavenging activity (%) was varied between 87.39% (90% methanol) to 45.57% (chloroform) while Ferric reducing antioxidant power was observed between 372.93±0.04 mgAAE/100 g extract (90% methanol) to 129.41±0.026 mgAAE/100 g chloroform in the root extract. The methanolic extract of the leaf showed less antioxidant activity than the methanolic extract of the root. Crude extracts of V. officinalis root showed various degree of antimicrobial activity towards drug resistance microbial pathogens. Growth inhibition tests against bacterial pathogens demonstrated concentration dependence. Moreover, gram positive bacteria were more susceptible to V. officinalis root extract when compared to gram negative bacteria. In general V. officinalis root and leave extracts possess strong antioxidant and antimicrobial activities