Effects of Germinated Brown Rice and Its Bioactive Compounds on the Expression of the Peroxisome Proliferator-Activated Receptor Gamma Gene

Abstract

Dysregulated metabolism is implicated in obesity and other disease conditions like type 2 diabetes mellitus and cardiovascular diseases, which are linked to abnormalities of peroxisome proliferator-activated receptor gamma (PPARγ). PPARγ has been the focus of much research aimed at managing these diseases. Also, germinated brown rice (GBR) is known to possess antidiabetic, antiobesity and hypocholesterolemic effects. We hypothesized that GBR bioactive compounds may mediate some of the improvements in metabolic indices through PPARγ modulation. Cultured HEP-G2 cells were treated with 50 ppm and 100 ppm of extracts from GBR (GABA, ASG and oryzanol) after determination of cell viabilities using MTT assays. Results showed that all extracts upregulated the expression of the PPARγ. However, combination of all three extracts showed downregulation of the gene, suggesting that, in combination, the effects of these bioactives differ from their individual effects likely mediated through competitive inhibition of the gene. Upregulation of the gene may have therapeutic potential in diabetes mellitus and cardiovascular diseases, while its downregulation likely contributes to GBR’s antiobesity effects. These potentials are worth studying further.

Rice bran prevents high-fat diet-induced inflammation and macrophage content in adipose tissue

“…Also, analysis of adipose tissue biomarkers associated with macrophage polarization in insulin resistance (i.e., Emr1, Itgax/MRC1 ratio, adiponectin and PPARγ) [40,41] revealed a significant restoration in the expression levels of these markers after 1 % RBEE administration. In agreement with this, oryzanol, one of the major components in rice bran, upregulated PPARγ expression in adipocytes [42][43][44][45]. Altogether, our data suggest that RBEE administration could change macrophage polarization in obesity.…”

Mitochondrial Dysfunction and Biogenesis in Neurodegenerative diseases: Pathogenesis and Treatment

“…Abnormalities result in mitochondrial dysfunction Reference AD Deposition of Ab within mitochondria in the brain of patients with AD [51-54] Impairment of mitochondrial OXPHOS in the brain of patients with AD Downregulation of PGC-1 in the brain of patients with AD Modulation of Ab aggregation cascade through PPAR-c dysregulation PD Significant reduction in ATP in the putamen and midbrain [21,[55][56][57][58] Significant reduction in PCr in the putamen Enhanced formation of free radicals Induction of permeability transition Impairment of intracellular calcium homeostasis Induction of Oxidative Stress Downregulation of PGC-1 in the brain of patients with PD Development of neurodegeneration through PPAR-c dysregulation HD Impairment of mitochondrial function by mHtt [59][60][61][62][63]…”

Commonalities in the Association between PPARG and Vitamin D Related with Obesity and Carcinogenesis

“…In disease, PPARG activation seems to improve metabolic parameters, but in the healthy population its downregulation shows antiobesity effects [39]. …”