Analysis of phytochemical constituents, antibacterial, antioxidant, photoprotective activities and cytotoxic effect of leaves extracts and fractions of Aloe vera

The aim of the study was to investigate the Aloe vera phytochemical compounds using HPLC–mass spectrometry and to evaluate their antibacterial, antioxidant, photoprotective and cytotoxic activities. The acetone extract, methanol extract and its four fractions: chloroform, ethyl acetate, n- butanol, aqueous were subjected to evaluate their antibacterial activity by Aromatogram method against S.aureus, B. cereus, E. coli, P. aeruginosa, A. baumanii. The minimum inhibitory concentrations (MIC) were determinated by the medium agar incorporation method. Then, the antioxidant properties of all extracts and fractions were evaluated by using Hydroxyl radical scavenging, Galvinoxyl radical scavenging and Phenanthroline assays. The photoprotective activity was measured by determination in vitro of sun protection factor. The cytotoxicity of extracts and fractions was tested by Brine shrimp lethality method. The yields of methanol, chloroform, ethyl acetate, n-butanol, aqueous, acetone extracts are respectively 20.56% ± 0.38, 3.4% ± 0.11, 1.58% ± 0.12, 14.16% ± 0.11, 13.56% ± 0.78, 0.68% ± 0.50. By LC-MS analysis, 8 bioactive phytochemical compounds were identified. The antibacterial activity showed that the n-butanol fraction, acetone and methanol extracts had an effect against all the bacteria. The MIC value ranged from 1.25 to 10 mg/mL. The chloroform fraction exhibited highest antioxidant activity in (OH•2) scavenging assay (IC50 value: 79.53 ± 0.66 μg/mL) and in GOR scavenging assay (IC50 value: 80.18 ± 1.21 μg/mL), the acetone extract exhibited highest antioxidant activity in phenanthroline assay (A0.50 value: 46.75 ± 0.35 μg/mL). Furthermore, the all extracts and fractions showed high photoprotective activity. The acetone, chloroform and ethyl acetate fractions have displayed significant effect against the brine shrimp larvae.