Hyperglycemia Lowering Effect Of Oyster Extract On Diabetic Mice

Objective: To investigate the hyperglycemia lowing roles of oyster extract on alloxan-induced diabetic mice and their mechanisms. Methods: Male KW mice of 200 were divided for 3 different experiments: prevention experiment group , therapy experiment group and normal experiment group. Every experiment comprised a normal control group (NC) and OE groups with three different dosages of oyster extract. In prevention experiment, the hyperglycemic model control group(MC) also included , and the mice in OE groups were administrated with oyster extract of 2mg/kg, 4mg/kg, 12mg/kg, while the NC and MC group were administrated with the same volume of saline. 4 weeks later, the mice in MC and OE groups were injected with alloxan (200mg/Kg bw) for diabetic model, at the same time the NC group were administrated with the same volume of saline. In therapy experiment .firstly mice were injected with alloxan (200mg/Kg bw) for diabetic model , then the hyperglycemic mice were randomly allocated into the hyperglycemic model control group(MC), the positive group and three OE groups, and were administrated with the same volume of saline , Glibenclamide Tablets and OE of different dosages respectively. Synchronously the NC included and were administrated with saline. In normal experiment, the NC and OE groups only were given the saline and OE of three dosages respectively feed for 4 weeks. When the three experiments end, all mice were weighed, drawed eyeball to let blood and killed, then thymus, spleen, liver, kidney were collected to be weighed and calculated the organ coefficient, pancreas and islets were observed under optical microscope, the FBG , TG, CHO, SOD, MDA, INS, TNF in serum weredetected, with enzymology method and Radioimmunoassay , and the IAI was calculated.results: In prevention experiment, the data showed that the thymus and spleen coefficient of the MC group mice declined significant (P<0. 05), but there were no differences among the OE groups and the NC group. Compared with MC group, the level of FBG in the middle and high dosage of OE group were markedly reduced (P<0. 05, P<0. 01) , the levels of INS and SOD were notably elevated (P<0. 05) , MDA and TNF notably reduced in the two groups (P<0. 05) . Moreover,the MDA level in the low dosage group also reduced significantly (P<0.05) . And compared with MC group, the damages of pancreatic islets in all OE groups were mitigated.In therapy experiment, the level of FBG in alloxan-induced diabetic mellitus mice increased markedly, But after giving OE for 4 weeks, the FBG level of OE groups were notably lower than the MC group, approaching the positive group. Compared with MC group, the levels of INS and SOD were evidently elevated, MDA, TG, CHO and TNF notably reduced in the middle and high dosage of OE group, the MDA level in the low dosage group also reduced significantly. Furthermore, Glibenclamide Tablets and the high dosage group could increase the ISI. Compared with MC group, the pancreatic islets in all OE groups were improved.In normal experiment, compared with MC group, the blood glucose, weight and the liver, kidney coefficient of the mice in OE groups had no significant difference and the thymus and spleen coefficient of them increased markedly. Conclusion:1. Oyster Extract could prevent alloxan-induced hyperglycemia and the rise of MDA , inhibit the fall of INS and SOD, and control the abnormal expression of TNF. It indicated that OE protected alloxan-induced hyperglycemia from occurring and pancreatic islet from injuring toa certain degree.2. Oyster Extract could decrease the blood-glucose of diabetic mice effectively and reduce the expression of TNF. It implied that OE could promote the injured pancreatic islet to restore and recover it' s function to secrete.3. Oyster Extract enhanced the activity of SOD and the thymus and spleen coefficient, oyster extract also decreased the level of MDA , TG and CHO. It indicated that OE had an effect on regulating the metabolism of blood lipid, Free-radical scavenging, enhancing the antioxidant ability, potentiating immune function.4. Oyster Extract have no effect on the blood-glucose and organic weight of normal mice.