The effects of brown rice as functional food on Lee Index, adipose tissues and PRDM16 levels in obesity model <i>Rattus norvegicus</i>

Abstract

Brown rice is a functional food known to improve the Lee Index, influencing PRDM16 levels in obesity conditions. Therefore, this study aims to determine the differences in Lee Index, Brown Adipose Tissue (BAT) weight, White Adipose Tissue (WAT) weight, BeAT weight, total body fat, and PRDM16 levels of obese model rats with the intervention of brown and white rice, as well as ℽ-oryzanol. A true experimental method was used with a post-test-only control group in vivo design. The obesity model was constructed with male Sprague Dawley rats (Rattus norvegicus), divided into five diet groups namely standard and HFHF diet control, as well as HFHF + brown rice, HFHF + white rice, and HFHF + ℽ-oryzanol combination diet. The experiment was carried out for 26 weeks, with details of 14 weeks to form an obese model and 12 weeks for the intervention. Before statistical correlation was tested, Lee index values, adipose tissues, and PRDM16 were analyzed. The anthropometric data collection method was carried out by weighing before and after the intervention, while adipose tissue was collected by weighing after sacrifice. The immunofluorescence method was used to collect the expression of PRDM16 and the mean of PRDM16 levels was analyzed in the ImageJ application. After the data collection process, analysis was performed using SPSS to determine possible differences in each group. Normally distributed data were analyzed using One-Way ANOVA, while those without normal distribution were assessed using the Kruskall-Walis method and the Mann Whitney-U advanced test, with a p-value of <0.05 considered significantly different.The result showed that there were differences among several groups regarding total body fat (p=0.012), WAT (p=0.026), and BAT (p=0.025). However, no differences were found between all groups regarding the Lee index (p=0.275), BeAT (p=0.079), and PRDM16 level (p=0.292). In conclusion, brown rice intervention did not significantly affect Lee index values, the expression of PRDM16, and adipose tissue weights at the end of the intervention.