Effects of exercise and walnut oil on CES1 and inflammatory factors in the liver of type 2 diabetic rats.

Carboxylesterase 1 (CES1) and inflammatory factors play important roles in regulating lipid metabolism and maintaining glucose homeostasis. Exercise and walnut oil have anti-inflammatory effects, but the effects of exercise and walnut oil on CES1 and inflammatory factors in type 2 diabetes mellitus (T2DM) remain to be revealed. 8-week-old SD male rats were randomly divided into normal control group (NC group, N = 12) and high fat group (HFD group, N = 28) after 1 week of adaptive feeding. HFD rat models were established by high-fat diet and one-time injection of streptozocin. The successfully constructed rats were randomly divided into diabetes control group (T2DM-NC group, N = 6), the diabetes plus moderate intensity exercise group (T2DM-MED group, N = 6), the diabetes plus high intensity intermittent exercise group (T2DM-HIIT group, N = 6), and the diabetes plus walnut oil group (T2DM-WO group, N = 6). After 6 weeks of intervention, ELISAs were used to determine the blood glucose and lipid-related indices of the rats. Histomorphologic changes in the liver were observed by hematoxylin‒eosin staining. The mRNA expression levels of CES1 and inflammatory cytokines were determined by real-time quantitative PCR. The protein expression levels of CES1 and inflammatory factors were determined by immunofluorescence staining. Compared with those in the NC group, in the T2DM-NC group, FBG, TG, LDL-C and HOMA-IR were increased (P < 0.01), FINS activity was decreased (P < 0.01), liver morphology was more disorganized, and CES1 and inflammatory cytokines were highly expressed in the liver tissue (P < 0.05 or P < 0.01). After 6 weeks of intervention, TG levels were significantly decreased (P < 0.05 or P < 0.01), whereas FINS levels were increased (P < 0.05 or P < 0.01), liver morphology was significantly ameliorated, and the CES1, TXNIP and IL-1β expression levels were decreased (P < 0.05 or P < 0.01) in the T2DM-MED, T2DM-HIIT and T2DM-WO groups when compared with those in the T2DM-NC group. The T2DM rats presented abnormal blood glucose and lipid levels, and CES1, TXNIP and IL-1β were highly expressed in the liver. Exercise and walnut oil intervention ameliorated the glycolipid metabolism and liver morphology, and reduce the expression of CES1, TXNIP and IL-1β in the liver.