Brown Rice: A Promising Therapeutic Strategy for Reducing Inflammatory Markers in the Adipose Tissue of Diet-Induced Obesity Rat Model

Obesity is closely linked to adipose tissue inflammation, where macrophages play a crucial role. One approach to enhance the issue of obesity is by implementing nutritional intervention. This study designed to investigate the impact of administering brown rice and gamma oryzanol (ORZ) on reducing adipose tissue expansion and inflammation in a rat model of diet-induced obesity. The study involved male Sprague-Dawley rats of the Rattus novergicus strain. The negative control group received AIN93M as the standard diet, while the remaining were induced to become obese by high-fat, high fructose (HFHFr) diet. Then, we divided them into 4 treatment groups: mix HFHFr diet with brown rice; white rice; white rice + ORZ; and ORZ only. Treatment was given for 12 weeks. Histological examination was used to measure both the size and number of adipocytes. Immunohistochemical staining was done to evaluate the infiltration of macrophages into adipose tissue, while immunofluorescence labelling was utilized to examine the expression of macrophages M1 and M2. The addition of brown rice and ORZ appears to improve adipocyte expansion. The brown rice group showed the least amount of M1 macrophages, while the negative control group showed the highest amount of M2 macrophages, leading to much lower M1/M2 ratios compared to the other groups. No differences were found in the study of variables in either visceral or subcutaneous adipose tissue. Brown rice and ORZ can potentially improve adipose tissue expansion and suppress the expression of pro-inflammatory macrophages.