"Evaluation of the Phenolic Contents, Antioxidant and Antimicrobial Activities of Leaves Extracts of Ruta Graveolens"

Abstract

Ruta graveolens, better known as rue, is a polyvalent herb rich in secondary metabolites that has demonstrated different biological properties and its various medicinal properties. Ruta belongs to the Rutaceae family and is native to the Mediterranean region. We choose same species plant, from two origin, North Africa (Tunisia) and South Europe (France). Different extracts were obtained from dried leaves by using five solvents with increasing polarity, petroleum ether, chloroform, ethyl acetate, ethanol, methanol, and water. Different extracts from both plants, demonstrated in most of tests the same profile. Starting with yield extraction evaluation, a high yields were obtained with ethanol, methanol and aqueous plant extracts. Phenols content assessment reveals an important amount in ethanolic and methanolic extracts of polyphenols, flavonoids and in petroleum ether, chloroform and ethyl acetate of tannins. The antioxidant power was evaluated by using four methods, mainly DPPH, ABTS, β-Carotene and FRAP. Results are expressed as Inhibitory Concentration 50 and the best performance was noted with ethanolic and methanolic extracts.Effect of five organic and aqueous extracts of both plants on growth of two Gramnegative and two Gram-positive bacteria and Candida albicans was evaluated by MIC and MBC determination. Ethanol and methanol extracts of both Ruta exerts a bactericidal effect on different bacterial strain. While, a selective antifungal activity was noted only with methanolic extracts. Results were confirmed with MBC/MIC ratio (less than or equal to 4). Phenols content, especially polyphenols and flavonoids, showed good correlation with antioxidant and antimicrobial activities, which confirm its significant contribution to those activities of Ruta graveolens extracts.