Radical Scavenging Activity and Vitexin Content of Vitex agnus-castus Leaves and Fruits
Alper GÖKBULUT*°, Onural ÖZHAN*, Melek KARACAOĞLU*, Engin ŞARER*
 

* Ankara University, Faculty of Pharmacy, Department of Pharmacognosy, Ankara, Turkey
° Corresponding Author E-mail: gokbulut@pharmacy.ankara.edu.tr

^oCorresponding Author

Summary

The goal of this study was to determine some of the important phenolic constituents of the methanolic extracts of the leaves and fruits of Vitex agnus-castus by RP-HPLC with regard to the results obtained from radical scavenging activity and total phenolic content assays. 1,1-diphenyl-2-picrylhydrazyl (DPPH) test was used to assess the radical scavenging potential of the extracts. Both leaf and fruit extracts exhibited significant radical scavenging activity with IC50 values of 0.449±0.001 mg/mL and 0.612±0.004 mg/mL, respectively. By using Folin-Ciocalteu’s method, the total phenolic content of leaves and fruits of the plant was determined as 123.9±2.281 mg GAE/g extract and 114.5±2.704 mg GAE/g extract, respectively. In continuation of our ongoing studies on the phenolics of Vitex agnus-castus, a simple and accurate HPLC method was used to determine some phenolic compounds such as vitexin, ferulic acid, rutin, and luteolin qualitatively and quantitatively. Contrary to the previous literature, ferulic acid and rutin were determined neither in leaf nor in fruit extracts, while luteolin was determined in trace amount only in fruit extract. Vitexin, one of the important flavonoid constituents of Vitex agnus-castus, was determined in significant amount as 0.252±0.0089% and 0.352±0.0153% in the leaves and fruits, respectively. The results showed that vitexin is partially responsible for the antioxidant potential of the extracts due to its significant amount and the standardization of the extracts should be performed on vitexin by this suitable RP-HPLC method.

Key Words :
Vitex agnus-castus, Antioxidant activity, Vitexin, DPPH, RP-HPLC, Total phenolic content.