Phytochemical analysis, cellular antioxidant and α-glucosidase inhibitory activities of various herb plant organs

Herb plant organs are aboundant in phytochemicals and possess multiple bioactivities. Investigation in the phytochemicals of herb plants organs and associated functionalities essential to explore the potential and deepened the understanding of herb plants. In this study, phytochemicals, antioxidant activity, and a-glucosidase inhibitory activity of leaf, flower, peel, root and seed herb plant organ extracts were investigated. A combination of colorimetric assays and high performance liquid chromatography were applied, and the cellular antioxidant activity was evaluated in the HepG2 model. Results show that leaf and flower organs had the highest total phenolics, flavonoids, flavonols and proanthocyanidins contents. Flower organ possessed the highest 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity, cellular antioxidant activity and a-glucosidase inhibitory activity. Leaf organ had the strongest oxygen radical absorbance capacity and glucose consumption. Ferulic acid, salicylic acid, chlorogenic acid and epigallocatechin gallate were the common phytochemical compounds in plant organs. Phytochemical contents showed significant positive correlations (p < 0.05) with antioxidant and hypoglycemic effects. Results revealed that compared with other plant organs in this study, flower organ possessed excellent antioxidant and glucose regulating activities and could provide basis for the development of related health food and products for the diabetes patients.