The effect of Chitosan on antioxidant activity and some secondary metabolites of Mentha piperita L

Plants are almost reach sources of phenolic compounds such as flavonoids which are the most important natural antioxidants. Antioxidant compounds are essential for protecting human body against oxidative stress. However use elicitors could increase the antioxidant activity of plant. The purpose of this study was to evaluate the effects of Chitosan on the content of phenolic and flavonoid compounds and also antioxidant activity Mentha piperita L.In this study, firstly the Mentha piperita L. were grown up for 6-week period at greenhouse conditions and then were treated with 50-100 µm of chitosan, then total phenolic and flavonoid contents were determined using spectrophotometry and finally antioxidant activities of extracts were evaluated with 2,2-diphenyl-1-picryl hydrazyl (DPPH) method and the results were analyzed with Excel software and Variance analysis testing method with SPSS software. The results showed the content of phenolic compounds in the methanol extract based on sample mg of Gallic acid /g for control with water, 50µm and 100µm treatments respectively were 146.8,233.1,339.1. Meanwhile the total volume of flavonoid content of the methanol extract per mg of Rutin/g respectively were 9.88,12.11,14.06 and concentration of the said extracts respectively were 196.3,147.7,128.62. In regard to the above results it can be concluded that due to having phenolic and flavonoid contents, Mentha piperita L showed that antioxidant activity could be stimulated upon Chitosan treatment moreover, antioxidant activity increased by increasing Chitosan treatment content. Therefore, this method can be used to increase antioxidant effect of plant as a natural antioxidant and all the phenolic and flavonoid contents.