Exercise Training but not Curcumin Supplementation Decreases Immune Cell Infiltration in the Pancreatic Islets of a Genetically Susceptible Model of Type 1 Diabetes

Abstract

Background: The main mechanism involved in the pathogenesis of autoimmunity is an uncontrolled inflammatory response against self-antigens. Therefore, anti-inflammatory factors, such as the intake of bioactive compounds and a physically active lifestyle, may decrease or cease the development of autoimmune diseases. Type 1 diabetes (T1D) is an autoimmune disease characterized by pancreatic β cell destruction. The non-obese diabetic (NOD) mouse is a model of spontaneous T1D and is the model most similar to human disease.

Methods: To determine the effects of exercise training and curcumin supplementation on T1D progression, 48 NOD mice, 5 weeks old, were randomly divided into four groups: control, curcumin supplementation, trained, and trained plus curcumin. Every 2 weeks, blood glucose was measured using a glucometer. At the end of 20 weeks, a histopathological procedure was used to assess immune cells infiltration into pancreatic β cells (insulitis).

Results: Moderate intensity exercise training has the potential to protect pancreatic β cells against an immune response in vivo. However, curcumin supplementation failed to attenuate insulitis in NOD mice.

Conclusions: These data provide evidence that exercise training can mitigate T1D development in genetically susceptible mice.

Keywords: Autoimmunity; Bioactive compound; Curcumin; Exercise training; Insulitis; Type 1 diabetes.

Fig. 1

Blood glucose during the 20-week experimental protocol from control (C), curcumin (CUR), trained (T), and trained + curcumin (TC). NOD mice were 5 weeks old at the beginning. Data are mean ± standard deviation

Fig. 2

Quantitative/representative analysis of insulitis. Insulitis distribution (a), insulitis extension (b), and representative image used to label insulitis level (c). Control (C), curcumin (CUR), trained (T), and trained + curcumin (TC).*Different from control; #different from curcumin

Fig. 3

Cytokine levels after the 20-week experimental protocol from control (C), curcumin (CUR), trained (T), trained plus curcumin (TC) NOD mice