Pre-germinated brown rice extract ameliorates high-fat diet-induced metabolic syndrome

Abstract

This study examined the effect of pre‐germinated brown rice extract (PGBRE), containing no dietary fibers, but γ‐oryzanol, γ‐aminobutyric acid (GABA), flavonoids, and anthocyanidin, on high‐fat‐diet (HFD)‐induced metabolic syndrome. C57BL/6 mice were divided into five groups: regular diet, HFD, HFD with oral PGBRE 30, 300, or 600 mg/kg per day for 18 weeks. In the HFD group, higher body and liver weight gain, hyperglycemia, HbA1c, and insulin; higher TG, TC, LDL‐C, non‐HDL, atherosclerosis index, lower HDL, adiponectin in blood; higher TG in the liver; higher TG, bile acid in feces; and lower protein levels of AMP‐activated protein kinase, insulin receptor, insulin receptor substrate‐1, insulin receptor substrate‐2, peroxisome proliferator‐activated receptor‐γ, phosphatidylinositol‐3‐kinase, Akt/PKB, glucose transporter‐1, glucose transporter‐4, glucokinase in the skeletal muscle; lower glucagon‐like peptide 1 (GLP‐1) in the intestine; higher sterol regulatory element‐binding protein‐1 (SREBP‐1), stearoyl‐CoA desaturase 1 (SCD‐1), fatty acid synthase (FAS), 3‐hydroxy‐3‐methylglutaryl‐CoA reductase, proprotein convertase subtilisin/kexin type 9 (PCSK9), and lower PPAR‐α, low‐density lipoprotein receptor, cholesterol‐7α‐hydroxylase in the liver; higher SREBP‐1, SCD‐1, FAS, and lower PPAR‐α, adiponectin in the adipose tissue were found. In HFD + PGBRE groups, the above biochemical parameters were improved. Practical applications According to the results, we suggested that dietary fibers played a minor role in this study. Extract of PGBR, excluding dietary fiber, showed beneficial activity to ameliorate metabolic syndrome. γ‐oryzanol, GABA, flavonoids, and anthocyanidin in PGBRE can inhibit HFD‐induced metabolic syndrome and we demonstrated clearly its action mechanisms. This is the first report to examine the relation between PGBRE, GLP‐1, and PCSK9. Taken together, PGBRE can potentially be used to develop a good supplement to control metabolic syndrome.

Efficiency comparison of PGBR extract and γ‐oryzanol in antioxidative stress and anti‐inflammatory properties against metabolic syndrome

“…Note that PE increased the insulin levels in HFD‐fed mice. We infer that it may be because of PE enhances GLP‐1 expression, an incretin hormone secreted by intestinal L‐cells that promotes insulin secretion (Hao et al, ; Meloni, Deyoung, Lowe, & Parkes, ).…”

“…In our previous study, we demonstrated that PE as a food supplement might prevent hyperglycemia. The significant contents of PE are γ‐oryzanol, flavonoids, anthocyanin, GABA, and scanty dietary fibers (Chen et al, ; Hao et al, ). At that time, we were not sure if γ‐oryzanol exerts the function.…”

“…The materials and methods for PE extraction were previously described (Chen et al, ; Hao et al, ). About 1 mg of PE contained 16.3 µg of γ‐oryzanol; therefore, our following treatments to HFD fed mice were designed accordingly.…”

“…Among these components, γ‐oryzanol is the principal constituent and claimed to possess immense potential in PGBR extract that can serve as a food supplement. In our previous studies, we showed that PGBR extract prevents high‐fat diet (HFD)‐induced hyperglycemia through elevated insulin secretion (Hao, Lin, Ke, Yen, & Shen, ; Shen et al, , ; Yen et al, ), and attenuates TNF‐α‐induced insulin resistance signaling thorough the enhancement of the phosphatidylinositol‐3‐kinase/protein kinase B (PI3K/Akt) in hepatocytes (Chen et al, ). In this study, we aimed to investigate the detailed mechanisms of PGBR extract (PE) or γ‐oryzanol on controlling the oxidative stress and inflammation in HFD mice featured as the metabolic syndrome.…”

Experimental Study of Drying Characteristics and Mathematical Modeling for Air Drying of Germinated Brown Rice

“…Germinated brown rice (GBR), a kind of brown rice product, is made up of young buds and endosperm with bran layer obtained by germinating brown rice to a certain bud length (Hao et al 2019;Li et al , 2017. That is to say, brown rice is cultured at a certain temperature and humidity, and then dried when it germinates to a certain degree.…”