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

•Herb plant organs abound in functional phytochemicals such as flavonoids and phenolics.•Herb plant organ phytochemicals exhibited potent cellular antioxidative and α-glucosidase inhibitory activities.•There were significantly positive correlations (p < 0.01) between phytochemicals and antioxidant/hypoglycemic effects.•Plant flower organ possessed excellent antioxidant and glucose regulating activities.