Abstract
Lycium schweinfurthii (L. schweinfurthii) is a shrub belonging to the Solanaceae family which is widely distributed in North Africa and the Mediterranean region. The leaves and fruits have traditionally been used for gastrointestinal diseases. There are currently only a limited number of scientific studies investigating the antibacterial activity of L. schweinfurthii. This study aimed to investigate the antioxidant activity and antibacterial effect of L. schweinfurthii leaves extracts. Extraction was carried out using a cold maceration method by fractionation on different solvents (petroleum ether, ethyl acetate and methanol). The phytochemical screening was performed qualitatively. An in-vitro analysis of antioxidant activity was applied using qualitative and quantitative DPPH scavenging activity test. Lycium schweinfurthii leaves extracts were tested at different concentrations against Gram-positive and Gram-negative bacteria isolated bacteria from Tripoli Medical Center (Staphylococcus aureus & Escherichia coli) zone of inhibition was recorded as the mean value. The phytochemical screening showed the presence of major secondary metabolites. However, the methanol fraction contained (flavonoids, phenolic compounds, alkaloids, tannins, saponins and carbohydrates). The methanolic extract showed good DPPH scavenging activity compared to the ascorbic acid which used as positive control. At 100 mg/ml concentration, petroleum ether fraction had the highest antibacterial activity against Staphylococcus aureus, followed by methanol and ethyl acetate fractions (8.33, 7.33 & 5 mm respectively). Methanol fraction at 100 mg/ml showed the largest zone of inhibition against Escherichia coli followed by ethyl acetate and petroleum ether leaves extract (9, 6.66 and 5.83 mm respectively). It can be concluded that the Lycium schweinfurthii leaves extracts have promising antioxidant and antibacterial activity against bacterial strains