The Impact of pH Value in the Phenolic Content and Antioxidant Potential of Medicinal Plant Extract

In this research, the aim was to investigate the influence of pH value in the extraction medium on the phytochemical composition and antioxidant activity of Artemisia herba-alba species used in traditional medicine. For this reason, two analytical methods were used (UV-visible spectroscopy, HPLC). Antioxidant properties of the extracts at different pH were estimated by two tests: total antioxidant capacity (TAC) and DPPH free radical scavenging capacity. The results of the evaluation of phenolic compounds showed that the aqueous extracts in a weak acid medium had a high percentage of phenol content, and the highest value for total phenol content was 90.759±1.267mg GAE/g. Whereas, the HPLC analysis indicated the presence of most of the standard phenolic compounds in the majority of the extracts. For antioxidant activity, the best antioxidants reported in extract at pH=6, with a semi-maximal inhibitory concentration (0.151±0,032mg/ml) and a total antioxidant capacity (TAC) of 66.840±0.241mg EAA/g, which indicates that it is effective antioxidant for therapeutic applications.