Study of Insulin-Loaded Chitosan Nanoparticle Effects on TGF-[beta]1 and Fibronectin Expression in Kidney Tissue of Type 1 Diabetic Rats

In diabetes, the increasing blood glucose levels through oxidative stress, with increase in inflammatory cytokines and growth factors, such as TGF-[beta]1, can cause long-term complications, including nephropathy. Subcutaneous injection of insulin is a common method used to treat Type 1 diabetes, which can lead to problems such as hypoglycemia and edema. In the present study, we examined the effect of insulin in its two injectable and oral forms on the expression of TGF-[beta]1 and fibronectin in kidney tissue of STZ diabetic rats. A total of 25 male Wistar rats were randomly divided into 5 groups: C: normal control, D: diabetic control, D+NP, oral insulin-loaded trimethyl chitosan nanoparticles (8 IU/kg), and subcutaneously injected insulin (8 IU/kg). The groups were treated from 8th to 10th weeks. After 10 weeks, FBS was measured. Also, the TGF-[beta]1 and fibronectin mRNA expression and serum TGF-[beta]1 protein were examined in the kidney tissue. Structural changes in the kidney tissue were studied using H&E staining. After 10 weeks of diabetes induction, the rats showed significant change in blood glucose, weight, serum TGF-[beta]1, Fibronectin and TGF-[beta]1 expression of kidney in diabetic groups (p < 0.05). Oral insulin-loaded trimethyl chitosan nanoparticles treatment, similar to injected insulin, significantly ameliorate blood glucose and rats' weight (p < 0.05). However, the reduction in fibronectin and TGF-[beta]1 expression and serum TGF-[beta]1 protein by both treatments was not statistically significant (p > 0.05). These data showed that oral insulin-loaded trimethyl chitosan nanoparticles were better therapeutic intervention than injected insulin for Type 1 diabetes.