Some Phytochemical properities and antimicrobial activity of Aloe vera (L.) Burm. f.

Aloe vera (L.) Burm. f. known as a perennial and succulent that is called the plant of immortality, has been used for beneficial effects over the centuries. In this study, some phytochemical characteristics and antimicrobial activities of the gel and green leaf part of Aloe vera were tested. Water and fat-soluble vitamins, β-carotene, lycopene, and 4-HNE were determined by HPLC, and total phenolics and flavonoids, ABTS, and DPPH radical scavenging activity were determined using a UV-Vis spectrophotometer. The antimicrobial activities of Aloe vera was determined by the disc-diffusion method. According to the results, the highest amounts of thiamine, riboflavin, pyridoxal, and vitamin B12 were determined in the green leaf part of Aloe vera with values of 1.86±0.07 μg/g, 4.71±0.11 μg/g, 3.67±0.16 μg/g, 4.96±0.13 μg/g, and 22.56±1.03 μg/g, respectively. On the other hand, the highest concentration of ascorbic acid, nicotinic acid, nicotinamide, pantothenic acid, pyridoxine, and folic acid was observed in the gel with values of: 3.17±0.14 μg/g, 90.55±2.63 μg/g, 39.8±0.99, 5.42±0.36 μg/g, 14.93±0.30 μg/g, 12.72±0.49 μg/g, and 0.23±0.01 μg/g, respectively. In the green leaf part of Aloe vera, the amounts of vitamin A, E, lycopene, β-carotene, and 4-HNE were found to be 0.17±0.03, 3.6±0.57, 7.6±1.50, 0.63±0.14, and 5.6±1.07 μg/g, respectively. On the other hand, were 0.26±0.05, 1.1±0.09, 0.07±0.01, and 3.68±0.74 μg/g, respectively, in the gel. The obtained results detected that the amounts of total phenolic content (μg GAE/g), total flavonoid content (μg QE/g), DPPH (IC50 (μg/mL)), and ABTS (μmol trolox/g) were 0.17±0.01, 0.96±0.15, 133.9±7.08, and 25.1±2.28, respectively, in the green leaf part of Aloe vera. While in the gel found to be 407.95±9.42, 0.95±0.67, 0.04±0.00, and 0.26±0.05, respectively. It was determined that the green leaf part of Aloe vera had the highest antimicrobial efficacy against Bacillus megaterium, with a diameter of 11.6±0.32 mm of inhibition zone, while demonstrating the lowest efficacy against Escherichia coli (8.3±0.30 mm). The gel exhibited the greatest antimicrobial activity against Staphylococcus aureus (20.0±0.29 mm), while showing the weakest efficacy against Pseudomonas aeruginosa and Proteus vulgaris (15.5±0.29 mm). As a result, it can be said that Aloe vera is a good source of antioxidant and antimicrobial activity that can be used for medicinal and cosmetic purposes.