Cocoa and Carob Supplementation, Alone or in Combination with Metformin, Protects against Hepatorenal Injury in Zucker Diabetic Fatty Rats

The liver and kidneys are crucial for glucose homeostasis and are seriously damaged in diabetes. Cocoa and carob possess antidiabetic activity, but their hepatorenal protective effects, especially when combined with antidiabetic drugs, are unknown. The aim of this study is to investigate the effects of a cocoa-carob-supplemented diet (CC), either alone or in combination with metformin, on liver and kidney damage in Zucker diabetic fatty (ZDF) rats, a type 2 diabetes model. Male ZDF animals received a control or CC-supplemented diet, with or without metformin, and Zucker lean rats were fed the control diet. The CC-supplemented diet improved glucose tolerance and insulin resistance and alleviated functional and structural alterations in the diabetic liver and renal cortex. The CC-supplemented diet also ameliorated oxidative stress, downregulated apoptosis, and improved insulin signalling and glucose homeostasis. The combination of CC and metformin boosted several benefits as certain parameters related to morphological and structural alterations, apoptosis, oxidative stress, glucose homeostasis, and insulin resistance, were improved in comparison to animals receiving the CC-supplemented diet or metformin alone; these include the following: apoptotic index, Bax, hepatic insulin receptor or glutathione content, among others. These results demonstrate that the CC-supplemented diet alleviates the hepatorenal damage in type 2 diabetic ZDF rats, highlighting its potential alone or as an adjuvant therapy.