Comparative Evaluation of the Content of Antioxidant Polyphenolic Compounds in Selected Bulgarian Medicinal Plants

Abstract

Abstract Polyphenols are strong antioxidants of plant origin that exhibit protective role against the development of several chronic degenerative diseases. Quantitative data on the content of polyphenolic antioxidants in Bulgarian medicinal plants are sporadic and unsystematic. The aim of the study is to determine polyphenols content in series of extracts, infusions and decocts of selected Bulgarian medicinal plants and fruits and to compare their polyphenolic profile. Materials and Methods: In the present study 18 Bulgarian medicinal plants and fruits have been analyzed for Total Phenolic and Total Flavonoids content, along with HPLC analysis for their level of the individual flavonoids (+)-Catechin, (-)-Epicatechin and Rutin. Comparative evaluation of the content of antioxidant polyphenolic compounds was performed by hierarchical cluster analysis. The results show that infusions of Hawthorn (Crategus monogyna) flowers have the highest values of Total Phenolic and Total Flavonoids content, forming a separate Cluster in the analysis of the Agglomeration schedule coefficients. Within fruits, data for Total Phenolics and Total Flavonoids content are more homogenic as the cluster analysis shows distribution of 6 elements in a high mean value group. Elderberry (Sambicus nigra) flowers and fruits are the richest source of Rutin in the selected plants studied. Conclusion: In the present study new data for polyphenolic content in selected Bulgarian medicinal plants and fruits are presented and their degree of similarity in methanolic extracts, infusions and decocts have been assessed in order to provide new data for development of effective antioxidant medicinal plant compositions.