Background & Objectives: Traditionally use of the medicinal plants for treating of diseases. This present study is carried out to evaluate the antimicrobial and antioxidant activities and determination of total phenolic and flavonoid contents of three extracts (Methanolic, Ethanolic and Aqueous) of five different species of medicinal plants such as Withania somnifera L. Dunal., Salvia rhytidea Bent, Levisticum officinale L, Seidlitzia rosmarinus L., and Achillea wilhelmsii L.
Material & Methods: After preparing the extracts with maceration method, antioxidant activities were determined by two methods (DPPH and FRAP) and antimicrobial activities were estimated by Disk-Diffusion method against bacteria (Staphylococcus aureus, Bacillus cereus, Escherichia coli and fungi (Aspergillus niger and Candida albicans) and phenolic and flavonoid contents were determined by Folin-Ciocaltiu, Aluminum Chloride colorimetric.
Results: The results showed that, the methanolic extract of W. somnifera had maximum total phenolic (41.45±4.64 mgGAE/gExtract) and flavonoid contents (35.21±2.54 mgQUE/gExtract) and antioxidant activity, (IC₅₀=8.12±1.36µg/ml, 58.19±1.68 mM Fe²⁺/mgExtract) and antimicrobial activity against Staphylococcus aureus and Candida albicans with the diameter of inhibition zone (29±1.06 and (27±1.00 mm) respectively. In contrast, the aqueous extract of L. officinale had minimum value of total phenolic (17.12±1.93 mgGAE/gExtract) and flavonoid contents (12.61±2.06 mgQUE/gExtract) and antioxidant activity (IC₅₀=121.43±3.36µg/ml, 13.74±2.52 mM Fe²⁺/mgExtract) and antimicrobial activity against Bacillus cereus and Aspergillus niger with the diameter of inhibition zone (4±0.57 and 5±1.00 mm) respectively.
Conclusion: Overall, based on the results, the studied plants can be a good candidate for the treatment of diseases caused by oxidative stress, and diseases are caused by pathogenic microbes.