A study on the antioxidant and antimicrobial activities in the chloroformic and methanolic extracts of 6 important medicinal plants collected from North of Iran.

As possible sources of natural bioactive molecules, the plant essential oils and extracts have been used globally in new antimicrobial compounds, food preservatives, and alternatives to treat infectious disease.

In this research, the antimicrobial activities of chloroformic and methanolic extracts of Sophora flavescens, Rhaponticum repens, Alhagi maurorum, Melia azedarach, Peganum harmala, and Juncus conglomeratus were evaluated against 8 bacteria (S. aureus, B. subtilis, R. toxicus, P. aeruginosa, E. coli, P. syringae, X. campestris, P. viridiflava) and 3 fungi (Pyricularia oryzae, Fusarium oxysporum and Botrytis cinerea), through disc diffusion method. Furthermore, the essential oils of plants with the highest antibacterial activity were analyzed utilizing GC/MS. Moreover, the tested plants were exposed to screening for possible antioxidant effect utilizing DPPH test, guaiacol peroxidas, and catalase enzymes. Besides, the amount of total phenol and flavonoid of these plants was measured.

Among the tested plants, methanolic and chloroformic extracts of P. harmala fruits showed the highest antibacterial activity against the tested bacteria. Besides, the investigation of free radical scavenging effects of the tested plants indicated the highest DPPH, protein, guaiacol peroxidase, and catalase in P. harmala, M. azedarach, J. conglomeratus fruits, and J. conglomeratus fruits, respectively. In addition, the phytochemical analysis demonstrated the greatest amounts of total phenolic and flavonoid compositions in J. conglomeratus and P. harmala, respectively.

The results indicated that these plants could act as a promising antimicrobial agent, due to their short killing time.