Antioxidant activity, total phenolic and flavonoid content, and antibacterial effects of Stachys lavandulifolia Vahl. flowering shoots

Plants are a rich source of phenolic compounds and one of the most important nature-based antioxidants. The compounds derived from plant-based extracts are an important pharmaceutical resource. This study was conducted to investigate the antioxidant activity and total phenolic and flavonoid content, and to investigate the antibacterial effects of Stachys lavandulifolia flowering shoots extract. In this study, S. lavandulifolia was gathered from Isfahan and extracted by maceration using ethanol 70%. Total phenol content was measured by FolinCiocalcteu reagent and gallic acid standard, and antioxidant activity was investigated by DPPH with reference to butylated hydroxytoluene (BHT). Antibacterial effects were investigated by Broth Microdilution and minimum inhibitory concentration and minimum bactericidal concentration were determined.The effects of different concentrations of S. lavandulifolia were investigated on Staphylococcus aureus and Enterococcus faecalis by disk diffusion with reference to vancomycin and nitrofurantoin. The findings demonstrated that the inhibition of DPPH free radicals was greater by hydroalcoholic S. aureus extract than BHT, and therefore the IC50 of this extract was lower than BHT. Total phenolic content was obtained 18.61 (mg gallic acid) and the flavonol and flavonoid content was obtained 2.42 and 8.93 mg/g, respectively. In this study, investigating the effects of different concentrations of hydroalcoholic S. lavandulifolia extract on pathogenic bacteria by disk diffusion and Broth Microdilution demonstrated that this extract exerted great inhibitory effects on both bacteria. S. aureus was more susceptible to S. lavandulifolia extract than E. faecalis.