Total Polyphenol Content and Other Antioxidant Capacity Indicators in Selected Edible Plants and Herbs

Oxidative stress and antioxidant enzyme activity play a major role in the development of numerous chronic diseases. Edible plants and herbs are rich in polyphenols and other bioactive compounds that may protect cells by neutralizing free radicals and supporting endogenous defense systems. This study compared the antioxidant potential of 10 plant extracts using seven analytical methods. The total polyphenol, flavonoid, and anthocyanin contents were measured, while the antioxidant activity was assessed with DPPH, ABTS, FRAP, and CUPRAC assays. The statistical analyses included an ANOVA and a principal component analysis (PCA). Significant differences were observed among the extracts (p < 0.001). P. rotundifolia showed the highest polyphenol content and the strongest FRAP and ABTS activity. The greatest flavonoid levels were found in C. sativus and A. crassna, whereas E. cardamomum contained the highest anthocyanin levels. A strong correlation was observed between the total polyphenol content and the FRAP results, while the anthocyanin content showed an inverse relationship with the DPPH activity. The findings confirm the high antioxidant potential of the studied plants and suggest their promising application in the development of alternative and complementary therapies in the course of chronic diseases.