Antioxidant and antibacterial properties of Aloe Vera (Aloe Barbadensismiller)

This research was carried out to study the antioxidant and antibacterial properties of Aloe barbadensis Miller that was planted locally. Through the determination by using Folin-Ciocalteu method, the total extractable phenolic contents of hexane extracts obtained from fresh and dried samples were 0.05::t 0.58 mg GAE/g and 3.03 ::t 1.73 mg GAE/g respectively. On the other hand, the total extractable phenolic contents of acetone extracts obtained from fresh and dried samples were 0.91 ::t 0.00 mg GAE/g and 74.58::t 1. 67 mg GAE/g respectively while the total extractable phenolic contents of methanol extracts obtained from fresh and dried samples were 2.23 ::t 0.92 mg GAE/g and 164.87::t 0.46 mg GAE/g respectively. The antioxidant activity, measured by the DPPH' method at ECso was 12.89 mg/ml and 3.05 mg/ml for the methanol extracts obtained from fresh and dried samples. In the p-carotene/linoleic acid test system, the acetone extract obtained from dried sample was superior with 95.38% inhibition rate. All the extracts were evaluated for their antibacterial activity against the four selected pathogens (Bacillus cereus, Staphylococcus aureu~ Escherichia coli 0157: H7 and Salmonella typhimurium) by using the paper disc diffusion method All the extracts showed positive results in this test except the hexane extracts of A. barbadensis Miller. The methanol extracts showed the strongest antibacterial activity in which zone inhibitions of more than 10 mm were observed against both Gram-poSitive and Gramnegative bacteria.