Chemical composition, antioxidant and antimicrobial activities of the edible medicinal Ononis natrix growing wild in Tunisia.

Results showed that leaf methanolic extract of Ononis natrix has important total phenol (51 mg GAE/g DW) and flavonoid (14.76 CE/g DW) contents. The chemical composition of O. natrix leaf revealed the presence of quercitine (24.5%), amentoflavone (14.1%), flavones (11.3%) and kaempferol (10.5%). The leaf extract showed a high total antioxidant activity with 60.94 mg of GAE/g DW, displayed a high 2,2-diphenyl-1-picrylhydrazyl scavenging ability with low IC50 value (29 μg/mL) and a great reducing power (EC50 = 100 μg/mL). O. natrix leaf extract exhibited a significant broad spectrum activity against all tested microorganisms with bacterial inhibition zone sizes ranging from 8.5 to 17 mm in diameter.