Background and Aim: Nowadays, the increasing spread of drug resistance among bacteria has led to the use of other methods including herbal medicines to control human infections worldwide. This study was conducted to determine the antibacterial effects of ethanolic extract of flowering plants Calendual officinalis L. against some pathogen microorganisms.
Material and Method: The studied plant was collected from Marand city in East Azerbaijan, Iran and were confirmed as Calendual officinalis L. by botanists of East research center. Ethanolic extract of flowers was prepared in different concentrations (0/19, 0/39, 0/75, 1/56, 3/12, 6/25, 12/5 and 25 mg/ml) by meceration. Antibacterial activity of the extract was conducted with agar well diffusion and micro dilution method on the abovementioned standard strains. Data analysis was performed by one-way ANOVA analysis at P<0.001.
Results: The maximum sensitivity with average diameter of the inhibition zone (13±0/45 mm) was assessed risen from the concentration of 50 mg/ml ethanolic extract of the plant Calendual officinalis L. flowers of Staphylococcus aureus. Also, the minimum inhibitory concentration for Staphylococcus aureus and Enterococcus faecalis was 0.75 mg/ml. Also, the minimum lethal concentration was 0.75 mg/ml against Staphylococcus aureus bacteria.
Conclusion: The ethanolic extract of flowering plants Calendual officinalis L. in springtime under laboratory conditions has inhibitory effect against all four strains tested. Therefore, this extract can be a good alternative for future studies in in vivo to provide antibacterial drugs<span style="font-family: " dir="RTL" b="" roman";"="" new="" "times="" roman";="" major-bidi;="" 12pt;="" zar";="" lang="FA">.