Rice Hull Extract (RHE) Suppresses Adiposity in High-Fat Diet-Induced Obese Mice and Inhibits Differentiation of 3T3-L1 Preadipocytes

Abstract

Obesity is one of major health challenges in the industrial world. Although rice hull has been reported to show various bioactivities, no studies have evaluated its anti-obesity effect. We hope to demonstrate the anti-obesity effect of rice hull extract (RHE) and the underlying mechanism in high-fat diet (HFD)-induced obese mice and 3T3-L1 preadipocytes. Serum lipid profiles were determined by enzymatic methods. Histological analysis of liver and epididymis fat tissues was carried out with hematoxylin and eosin stain. The mRNA expression of adipogenic markers was analyzed with qRT-PCR and western blotting. Oral administration of RHE reduced body weight gain and fat accumulation in HFD-fed mice. RHE also reduced lipid accumulation by inhibiting the mRNA expression of adipogenic-related genes in HFD-fed obese mice and differentiated preadipocytes. The downregulation of adipogenesis by RHE was mediated through the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC). In addition, RHE induced the phosphorylation of c-Jun N-terminal kinases (JNK) and extracellular-signal-regulated kinases (ERK) in liver and epididymis adipose tissues of HFD-fed obese mice. Taken together, these findings indicate that RHE could inhibit the differentiation of adipose cell and prevent HFD-induced obesity, suggesting its potential in the prevention of obesity and metabolic syndrome and related-disorders.

IRW (Isoleucine–Arginine–Tryptophan) Improves Glucose Tolerance in High Fat Diet Fed C57BL/6 Mice via Activation of Insulin Signaling and AMPK Pathways in Skeletal Muscle

“…In humans, the reduction of whole-body fat mass after an exercise intervention was associated with increased insulin sensitivity index [ 50 ]. Recently, an extract from rice hulls decreased fat mass by suppressing adipogenic genes in epididymal WAT and liver while enhancing AMPKα protein, consistent with increased fatty acid oxidation [ 51 ]. However, neither AMPKα nor PPARγ abundance changed in visceral WAT after IRW treatment.…”

Liquiritigenin Inhibits Lipid Accumulation in 3T3-L1 Cells via mTOR-Mediated Regulation of the Autophagy Mechanism

“…One study demonstrated that Glycyrrhiza uralensis exhibited antiobesity effects and that several substances, including the LQG in licorice extract, were able to induce UCP1 expression in 3T3-L1 adipocytes, indicating a potential role of LQ in adipocyte browning [ 21 ]. LQG is an important constituent of the flavones in Glycyrrhiza uralensis, which has shown biological properties including anti-inflammation, antihyperglycemia, antineurotoxicity, and cytoprotection [ 18 , 19 , 20 , 28 ]. Additionally, LQG was reported as an aglycone form in vivo [ 28 ] and could be detected in the blood samples of mice administrated licorice-root extract [ 22 ].…”

“…Licorice candy is popular in Europe, and teas and soups made with licorice are popular in various regions of Asia. It was shown that LQG exhibits multiple activities such as anti-inflammation, anti-hyperglycemia, and anti-neurotoxicity [ 18 , 19 , 20 ]. Studies show that Glycyrrhiza uralensis has antiobesity potential through the induction of adipocyte browning [ 21 ].…”

Anti-adipogenic Effects of Sulforaphane-rich Ingredient with Broccoli Sprout and Mustard Seed in 3T3-L1 Preadipocytes

“…We have changed the "mg/g" to "μmol/g", please see the red marked part in Table 4 and We have added the sentence of "In our study, MBP was obtained by the reaction of BSP solution and MSP solution in a ratio of 10:1 (v/v). Referring to the concentration group experiment performed in adipocytes [31][32][33][34], the following experimental groups were formulated to conduct experiments.". Please see lines 171-173.…”