Iridoid glycoside from the leaves of Clerodendrum volubile beauv. shows potent antioxidant activity against oxidative stress in rat brain and hepatic tissues.

AIM: This study aims at reporting the isolation, structure elucidation, and antioxidant potentials of ajugoside from C. volubile leaves in sodium nitroprusside (SNP)-induced oxidative stressed rat brain and hepatic tissues. MATERIALS AND METHOD: An iridoid monoterpene, ajugoside was isolated from the n-butanol fraction of C. volubile and evaluated for its antioxidant protective potential on brain and liver tissues of male Wister rats in an ex vivo model. Two molar concentrations (6.4 × 10(-4) M and 1.28 × 10(-3) M) of the metabolite and SNP were incubated with the tissues homogenate at 37°C for 2 hr prior to the test and assayed for catalase, superoxide dismutase (SOD) activities, and lipid peroxidation. α tocopherol (6.4 × 10(-4) M) was used as standard. RESULTS: Both molar concentrations exhibited high catalase activity in the tissues. However, 6.4 × 10(-4) M ajugoside exhibited a very high SOD activity (liver: 96.45 and brain: 96.30%) and inhibition of lipid peroxidation (liver: 88.11 and brain: 93.27%) compared to the standard. 1.28 × 10(-3) M ajugoside also exhibited good activities but lower than that of the standard and 6.4 × 10(-4) M ajugoside. DISCUSSION AND CONCLUSION: Ajugoside showed potent antioxidant activities as evidenced by the synergistic high activities of SOD and catalase as well as inhibition of lipid peroxidation in the studied tissues.

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 D-glucose 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.