Characterization and antioxidant activities of procyanidins from lotus seedpod, mangosteen pericarp, and camellia flower

A highly sensitive high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry method was established for the identification of procyanidin components in the lotus seedpod, mangosteen pericarp, and camellia flower. It was shown that the main procyanidins of lotus seedpod were monomer, dimmer, and trimer-procyanidins, in which dimers and trimers were in the majority (80.8%). However, mangosteen pericarp and camellia flower procyanidins were mostly composed of monomers (47.7 and 62.4%, respectively). In addition, their antioxidant activities were also compared and the strongest antioxidant activities were found in lotus seedpod (1,1-diphenyl-2-picrylhydrazyl: 1.57 mol Trolox equivalent/g dry weight; 2'-azino-bis-(3-ethyl-benzthiazoline-6-sulphonate acid): 1.23 mol Trolox equivalent/g dry weight; Fe2+/H2O2: 2.17 mol Trolox equivalent/g dry weight), followed by mangosteen pericarp and camellia flower. Moreover, the lotus seedpod, mangosteen pericarp, and camellia flower extracts exhibited considerable dose-dependent protective effects on the H2O2-induced damage of human umbilical vein endothelial cells. Among them, lotus seedpod extracts showed relatively stronger cell-based antioxidant enzyme activities and lower contents of malondialdehyde and nitric oxide than those of camellia flower and mangosteen pericarp. From these results, lotus seedpod, mangosteen pericarp, and camellia flower would be available agricultural wastes and their utilization may produce easier access of functional ingredients for medicinal exploration.