ABSTRACT
The physiological functions of 70% ethanol extracts of 6 edible flowers of different colors—Chrysanthemum morifolium (Chry., yellow), Rosa miniature (Rosa, red), Dendrobium phalaenopsis (Dend., purple), Viola x wittrockiana cv. fluna (Fluna, white), Viola x wittrockiana cv. pansy (Pansy, orange), and Primula x juliana (Prim., blue)—were evaluated in vitro. Anti-oxidant activity was evaluated based on the DPPH radical scavenging activity. Anti-diabetic activity, anti-hypertensive activity, and anti-adiposity activity were evaluated based on α-amylase/α-glucosidase, ACE, and lipase inhibitory activity, respectively. The extracts showed 2 - 3-fold higher anti-oxidative activity than α-tocopherol, which was not in accordance with their polyphenol content and colors. The anti-diabetic activity of the extracts showed a unique pattern: the extracts from Rosa and Dend. showed only α-amylase inhibitory activity, where as those of Chry. and Prim. selectively showed α-glucosidase activity. The extracts from Fluna and Pansy showed both α-amylase and α-glucosidase inhibitory activity. Except for the extract from Dend., the ACE inhibitory activity of the extracts was relatively high, and that of Chry. showed the highest inhibition with an IC50 value of 69.1 ng/mL. None of the extracts showed inhibitory activity of lipase. These results suggested that daily consumption of the edible flowers used in this study would help prevent diabetes and hypertensive diseases.