Kinetics of Initiated Oxidation of Phosphatidylcholine Liposomes with Introduced Aloe Extracts and Determination of Their Antioxidant Activity
Numerous species of the genus Aloe have attracted the attention of researchers because of different biological benefits and their capacity to act as antioxidants. This paper presents a comparative study of the kinetics of the inhibitory effect of ethanol extracts of five species of Aloe which was made using a model system of the oxidation of phosphatidylcholine liposomes. It was found that plant extracts of A. marlothii and A. congolensis , have higher antioxidant activity (by a factor of 13 and 10, respectively) than the best known Aloe species:arborescens and A. vera. The total phenolic content values of A. marlothii and A. congolensis are higher than those of A. arborescens and A. vera but in a lesser degree (by a factor of 5-6) than antioxidant activity was. This may indicate the presence of very active phenolic antioxidants in A. Marlothii and A. congolensis. Analysis of the influence of extracts introduced into liposomes on the liposome size showed that the most active extracts of A. marlothii, A. congolensis and A. pillansii reduce the average liposome size compared to pure liposomes, and extracts with weaker antioxidant activity increase it, what is probably due to changes in the lipid structure of liposomes by the components of extracts. Based on the results obtained, A. marlothii, A. congolensis, and A. pillansii are suitable for studying other types of their biological activity that might contribute to new drug development.