Amoebicidal, antimicrobial and in vitro ROS scavenging activities of Tunisian Rubus ulmifolius Schott, methanolic extract.

The present study aimed to evaluate the activity of methanolic extract of Rubus ulmifolius Schott against the Acanthamoeba castellani Neff Strain as well as its antioxidant and antimicrobial effects. The tested extract has a good amoebicidal activity with low IC50 (61.785 ± 1.322 μg/ml) and also has significant activity against both Gram-positive (S. aureus, S. agalactiae) and Gram-negative bacteria (E. coli, S. typhimurium) and against C. albicans. The inhibition zones diameters (IZD) and minimal inhibitory concentration (MIC) values were in the range of 22.5-50 mm and 02.29-4.76 mg ml-1, respectively. In the other hand, the in vitro ROS scavenging activity was evaluated, the tested extract exhibited a good effect on the ·OH radical (89.99% at a concentration of 100 μg/ml) when compared to the ascorbic acid (68.81%). Moreover, the inhibition percentage of superoxide generation by R. ulmifolius extract at 100 μg/ml was greater than ascorbic acid (79.55; 64.79%, respectively). Also, the tested extract showed a high percentage of H2O2 scavenging activity (99.95% at 100 μg/ml). Our findings suggest that R. ulmifolius could be a potential source of natural antioxidant in preventing many diseases associated with oxidative stress, amoebic and bacterial infections.