[Study on the mechanism of tripterygium wilfordii ployglycosidium in preventing type 1 nonobese diabetic mice].

OBJECTIVE

To observe the immunity preventive action of Tripterygium wilfordii ployglycosidium (TWP) on type 1 diabetes mellitus (T1DM) in non-obese diabetic (NOD)mice and explore its possible mechanism.

METHODS

Changes of blood glucose, the incidence rate of T1DM and pancreatitis were observed and the expressions of IFN-gamma,TNF-alpha, IL-10mRNA in pancreas of mice detected by RT-PCR after NOD mice were given TWP by adopting cyclophosphamide accelerated induction of T1DM.

RESULTS

The mean blood glucose level in TWP group (10.73 mmol/L) was lower than that in the control group (20. 53 mmol/L) at the end of the experiment(P < 0.01 ). The incidence rate of T1DM in TWP group (43. 33% ) was lower than that in the control group (71.43% , P <0. 01). The mean grade of inflammation of pancreatic islet in TWP group (1.45 +/- 1. 11) was lower than that in the control group (2. 27 +/- 1.22, P <0. 05 ). In TWP group the number of insulin-positive cells was 242. 80 +/-168.93 ,which was more than that of control group with significant difference (95.60 +/- 39.55,P <0.05). The expressions of TNF-alpha mRNA and IFN--gamma mRNA were lower (P <0.01). No obvious change was found in IL-10 mRNA expression.

CONCLUSIONS

TWP could prevent the occurrence of T1DM in NOD mice, whose mechanism might be correlated to the down-regulating of the expression of Thl cytokines in pancreatic tissues.