Carbenoxolone Could Deteriorate Streptozotocin-induced Diabetes through Induction of Heat Shock Protein 70 and IFN-γ in C57BL/6 Mice

Type 1 diabetes (T1D), a spontaneous autoimmune disease, is associated with destruction of insulin-producing β-cells in the pancreas. Since some heat shock proteins (HSP), such as HSP70 exert a protective effect in both tissues and cells, the present study was conducted to elucidate the effects of carbenoxolone (CBX) as an HSP70 inducer on T1D. The disease was induced in male C57BL/6 mice using streptozotocin (STZ) and subjects were allocated to therapeutic 1 and therapeutic 2 groups, as well as negative and positive control groups. The treated mice (therapeutic 1 and therapeutic 2 groups) received 50 mg/kg CBX intraperitoneally every 24 hours, in the therapeutic 1 group the drug was injected before and after disease induction whereas in the therapeutic 2 group the drug was injected only after disease induction. Serum fasting blood sugar (FBS) level, cytokines production (Interferon-gamma (IFN-γ), Interleukin 10 (IL-10), and IL-17), serum HSP70 level and CD4+CD25+Foxp3+ regulatory T cell (Treg) frequency measurements were outperformed 14 days after the last STZ injection. Our results showed that in the treated groups, serum HSP70, IFN-γ, and IL-17 levels were increased in contrast to the untreated groups. The IL-10 level was markedly decreased in comparison to untreated diabetic mice (p<0.05). Moreover, it was found that the frequency of Tregs in treated mice was lower in comparison to the untreated mice but the difference was not significant (p>0.05). Our results confirm that CBX might through HSP70 induction, followed by increasing IFN-γ level leads to suppression of IL-10 production in diabetic mice resulted in toxic effects on pancreatic islet beta cells and deteriorating of disease.