Enhancing metabolic and inflammatory status in insulin-resistant rats: Acute intervention with cocoa flavanols and submaximal aerobic exercise activates intracellular signaling pathways for glucose metabolism

• Published in: Clinical nutrition (Edinburgh, Scotland) Scotland), 2024-12, Vol.44, p.166-177
• Main Authors: Melo, B.P., Zacarias, A.C., Oliveira, J.C.C., de Souza Cordeiro, L.M., Horta, N.A.C., Poletini, M.O., Tonoli, C., Dos Santos, M.L., Wanner, S.P., Meeusen, R., Heyman, E., Avelar, G.F., Soares, D.D.
• Format: Article
• Language: English
• Subjects: Chocolate; Cytokines; Glucose uptake; Physical exercise; Type 2 diabetes
• ISSN: 0261-5614; 1532-1983; 1532-1983
• DOI: 10.1016/j.clnu.2024.11.043

Type 2 diabetes, characterized by hyperglycemia, is closely linked to obesity and low-grade inflammation. Acute cocoa flavanols (CF) intake has demonstrated benefits in vasoreactivity, cognitive functions, and antioxidant enzyme activity. However, the physiological mechanisms of CF concerning glucose uptake, inflammatory mediators, and their interplay with aerobic exercise remain unclear in populations with metabolic diseases. This study aims to investigate the acute effects of CF, alone or combined with acute aerobic exercise on mechanisms involved in glucose uptake and inflammatory mediators in the liver, skeletal muscle, pancreas, and adipose tissue in insulin-resistant (IR) rats. Sixty-four Wistar rats (250 ± 10g; 15 weeks age) were subjected to a regular chow (CON) or an obesity-associated insulin-resistant (IR) state induced by a high-fat diet and fructose-rich beverage for 30 days. Seventy-two hours after an incremental maximal treadmill running test, rats received a placebo solution or CF supplementation (45 mg·kg-1 of body weight). One hour later, they either rested or ran on a treadmill at 60 % of peak oxygen uptake (VO2peak) for 30 min. Euthanasia occurred 30 min post-experimental sessions. Inflammatory and anti-inflammatory cytokines were assayed using ELISA in the liver, pancreas, gastrocnemius muscle, and epididymal adipose tissues. TRB3 and CPT1 mRNA were assessed by q-RTPCR in the liver and gastrocnemius muscle while Akt and AMPK phosphorylation were examined by immunohistochemistry. CF attenuated hyperglycemia observed after submaximal aerobic exercise in IR rats (p