Effects of extracts from Gynura bicolor (Roxb. & Willd.) DC. on iron bioavailability in rats

Gynura bicolor (Roxb. & Willd.) DC. is widely distributed in certain areas of Asia and is very popular in vegetarian cuisine in Taiwan. This study investigates the effects of G. bicolor extracts with different polarities of 80 mg/kg body weight (BW) G. bicolor alcohol extract, 80 mg/kg BW G. bicolor water extract, and 80 mg/kg BW G. bicolor ether extract on Fe bioavailability using the hemoglobin repletion efficiency assay. Wistar rats were assigned to five groups: a group receiving an iron-deficient (ID) diet; a group receiving an ID diet supplemented with ferrous sulfate (20 mg Fe/kg BW); and three groups receiving ID diets supplemented with ferrous sulfate and one of G. bicolor alcohol extract, G. bicolor water extract, or G. bicolor water extract. The results indicated that the levels of hemoglobin, serum iron, serum ferritin, liver ferritin, hemoglobin regeneration efficiency, relative biological value, and hepcidin all were significantly higher than those of the ID diet group. Besides, the iron transporter divalent metal transporter-1 was significantly reduced, but iron release protein expression of ferroportin was significantly increased. It was concluded that G. bicolor extracts may promote iron bioavailability and regulate the expressions of divalent metal transporter-1 and ferroportin.