Evaluation of antibacterial and antioxidant activities of Cissus rotundifolia (Forssk.) leaves extract obtained by ultrasonic-assisted extraction conditions

In this study, the antibacterial and antioxidant activities of Cissus rotundifolia leaves extract were evaluated. The active compounds of plant leaves were extracted by using ultrasonic-assisted extraction conditions. Yield, total phenolic compounds and antioxidant activities were determined. In addition to six strains of gram-positive and negative bacteria were used for testing antibacterial activities of the plants’ extracts. The obtained results demonstrated that extraction of active compounds by using ultrasonic-assisted extraction was more efficient. The dry yield and total phenol compounds of extract were 29.97% and 82.87 mg GAE/g DE, respectively. The antibacterial activities of the extracts were tested against two types of bacteria, Gram-positive strains: Bacillus subtilis, Staphylococcus aureus, and Streptococcus agalactiae, and Gram-negative strains: Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. The results showed that leaves extract was more effective against Gram-negative bacterial strains. The concentrations of minimum inhibitory and minimum bactericidal of the leaves extract against S. typhimurium, E. coli and P. aeruginosa (Gram-negative bacteria) were at concentrations of 10, 20 and 20 mg/mL, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothioline-6-sulphonic acid)-diammonium salt (ABTS) scavenging activities at a concentration of 2 mg/mL were 90.94% and 98.20%, respectively, while the IC₅₀ was achieved at concentrations of 0.475 and 0.790 mg/mL, respectively. The leaves extract has high antibacterial and antioxidant activities; therefore, it could be a rich source of natural antibacterial and antioxidants for several food and therapeutic applications.