Aloe vera phytosterols act as ligands for PPAR and improve the expression levels of PPAR target genes in the livers of mice with diet-induced obesity

Summary Lophenol (Lo) and cycloartanol (Cy), minor phytosterols of Aloe vera gel, were previously identified as anti-diabetic compounds, and these compounds also reduced body fat in a type 2 diabetic model animal. In this study, we investigated the effects of Lo and Cy on peroxisome proliferator activated receptors (PPAR) using a luciferase reporter assay. DNA microarray and real-time quantitative RT-PCR (qPCR) analyses were also performed in a diet-induced obesity (DIO) mouse model. The Aloe phytosterols activated PPAR in a dose-dependent manner. The expression levels of many PPAR target genes were changed in the Aloe phytosterol group compared with those in the control high-fat diet (HFD) group. In particular, the expression levels of Fatp1 , Acox1 , Cpt1 , and Hmgcs2 were significantly increased in the Aloe phytosterol group compared with those in the control HFD group; however, the expression level of ApoCIII was significantly decreased in the Aloe phytosterol group. We confirmed that Aloe phytosterols activate PPAR transcription in vitro . In addition, quantitative gene expression analysis in DIO mice suggested that Aloe phytosterols improve fatty acid metabolism in the liver.