Abstract
Introduction: Medicinal plants have important roles in the treatment of infections. This study aimed to investigate the relationship among the amount of phenol, flavonoid, and antioxidant properties, as well as the effect of antimicrobial properties of methanolic extracts of nine medicinal plants against standard bacteria.
Materials and Methods: Nine plants were collected from Zabol, located in the south-eastern of Iran and identified in the botanical laboratory of the University of Zabol, Iran. The soaking process prepared extracts including Althaea officinalis, Calotropis procera, Eryngium caucasicum, Malva Sylvestris, Nerium oleander, Saponaria officinali, Satureja hortensis, Sinapis alba, and Urtica dioica, and total phenol and flavonoid content were measured by folin-ciocaltio reagent and aluminum chloride by colorimetric methods, antioxidant activity by 2, 2-diphenyl-1-picrylhydrazyl method, and antibacterial activity of extracts against standard bacteria (Pseudomonas aeruginosa, Streptococcus pneumoniae, Proteus mirabilis, Escherichia coli, Bacillus cereus, Streptococcus mutans, Hafnia elevi, Enterococcus fecalis) were evaluated.
Results: The results showed that the methanol extract of N. oleander with an average of 3.36 mg/g and C. procera with an average of 0.48 mg/g of dry weight have the highest and lowest amounts of phenolic compounds, respectively. C. procera extract (ith an average of 85.54 mg/ml was the most effective and M. sylvestris extract with an average of 21.80 mg/ml had the least role in inhibiting free radicals. The results of the antimicrobial activity of different extracts showed that the largest non-growth zone diameter in bacteria P. mirabilis, E. coli, and H. alevi is related to the extract of N. oleander.
Conclusion: The results of this study showed the differences in the number of effective compounds of the studied plants and their antioxidant properties. Also, after carefully examining the effects of these extracts in vitro and in vivo, it is suggested that these extracts be studied as a substitute for chemical drugs to treat infections.