A comparative study of the total phenol and flavonoid contents and biological activities of different medicinal parts of Penthorum chinense Pursh

Abstract

Penthorum chinense Pursh, a famous functional food in China, has long been used in the treatment of liver diseases. The three different above ground parts (flowers, leaves, and stems) are sold separately with different prices in the market. However, rarely studies have focused on the comparative study of the three parts and it is necessary to carry out in-depth investigations to further reveal the differences in the phytochemical profiles and multiple associated biological activities of the three parts. In the present study, a comprehensive comparative study was performed. The 95% ethanol extracts of the flowers and leaves had higher total phenol contents than those of the stems and displayed stronger in vitro antioxidant and tumor cytotoxic capacities. Additionally, three main constituents, namely, quercetin-3-O-α-l-rhamnopyranoside (1), thonningianin B (2) and thonningianin A (3) were isolated and identified from the flower extract. Further pharmacological study showed that thonningianin A has the potential for the development of drugs for the inhibition of tumor metastasis. Based on the above results, an increased amount of flowers and leaves relative to that of stems are suggested to be clinically used in the treatment of diseases related to oxidative stress and hepatocellular carcinoma.