Effect of extraction solvent on total phenol content, total flavonoids content, antioxidant and antimicrobial activities against phytopathogenic and foodborne pathogens bacteria of Ruta montana extracts

In this study, water and various concentrations of methanol and ethanol in water were used as solvent in the extraction of aerial part of Ruta montana. The aims were to investigate the effects of solvents on the extraction of polyphenol from Ruta montana, from Taza region, and evaluate in vitro the antioxidant and antimicrobial activities against phytopathogenic and foodborne pathogens bacteria of the extracts. The results showed that the Ruta montana extract obtained by 80% methanol exhibited the highest phenolic (117.70 ± 2.82 mg GAE/g Ext) and flavonoid (77 ± 6.55 mg ER/g Ext) contents. The antioxidant potential was examined by Diphenyl picryl hydrazinyl radical (DPPH) and ferric reducing power assays (FRAP). The 80% methanol extract presented the greatest capacity to reduce the DPPH (IC50=10.66 ± 1.52 µg/mL), and the highest ferric reducing power (66.66 ± 5.67 mg AAE/g of extract). The antimicrobial activity of extracts from Ruta montana against phytopathogenic and foodborne pathogens bacteria was qualitatively and quantitatively tested by the development of inhibition zones (ZID) and MTT-assay. The ZID ranged between 10.66 mm and 19.33 mm. Proteus mirabilis, Clavibacter michiganensis subsp. michiganensis 1616-3, Bacillus subtilis DSM 6633, Listeria innocua CECT 4030 were the most sensitive bacteria with MIC varied from 1.56 to 12.5 mg/mL. These finding suggest that Ruta montana may be considered as a potential sources of phenol contents with antioxidant and antibacterial potentials against phytopathogenic and foodborne pathogens bacteria