Effect of Grewia asiatica fruit on Glycemic index and phagocytosis tested in healthy human subjects

The Grewia asiatica (commonly known as Phalsa or Fasla) is a shrub or small tree found in southern Asia. It produces purple to black color fruit when ripe. In folk medicine the edible Grewia asiatica fruit is used in a number of pathological conditions. The current study described the effects of Grewia asiatica fruit on glycemic index (GI) and phagocytosis in healthy non-diabetic human subjects. The results showed that Grewia asiatica fruit has low GI value of 5.34 with modest hypoglycemic activity. Luminol-enhanced chemiluminescence assay was carried out to determine the production of reactive oxygen species (ROS) in the oxidative burst activity of whole blood. ROS production was found to be significantly affected, having the 78.3, 58.6 and 30.8% when the subjects were fed with D-glucose, mixture of Dglucose and Grewia asiatica fruit and Grewia asiatica fruit alone respectively as compared to the control. The aqueous, methanolic and butanolic extracts of Grewia asiatica fruits were found to produce a stimulatory effect on ROS production however; the chloroform, hexane and ethanol-acetate extracted exerted significant inhibitory effect. These results demonstrated that Grewia asiatica fruit has desirable effects on blood glucose metabolism manifested as low glycemic response and modulation of ROS production.