Rice bran enzymatic extract reduces atherosclerotic plaque development and steatosis in high-fat fed ApoE-/- mice

Rice Bran Extract Suppresses High-Fat Diet-Induced Hyperlipidemia and Hepatosteatosis through Targeting AMPK and STAT3 Signaling

Rice bran, a by-product of rice milling, is abundant in bioactive molecules and is highly recognized for its health-promoting properties, particularly in improving metabolic conditions. Building on this knowledge, we aimed to optimize the extraction conditions to maximize the functional efficacy of rice bran extract (RBE) and further validate its impact on lipid metabolism. We found that the optimized RBE (ORBE) significantly suppressed high-fat diet-induced weight gain, hyperlipidemia, and hepatosteatosis in mouse models. ORBE treatment not only suppressed lipid uptake in vivo, but also reduced lipid accumulation in HepG2 cells. Importantly, we discovered that ORBE administration resulted in activation of AMPK and inhibition of STAT3, which are both crucial players in lipid metabolism in the liver. Collectively, ORBE potentially offers promise as a dietary intervention strategy against hyperlipidemia and hepatosteatosis. This study underlines the value of optimized extraction conditions in enhancing the functional efficacy of rice bran.

Enhancement Methods of Antioxidant Capacity in Rice Bran: A Review

Rice (Oryza sativa L.) is a primary food that is widely consumed throughout the world, especially in Asian countries. The two main subspecies of rice are japonica and indica which are different in physical characteristics. In general, both indica and japonica rice consist of three types of grain colors, namely white, red, and black. Furthermore, rice and rice by-products contain secondary metabolites such as phenolic compounds, flavonoids, and tocopherols that have bioactivities such as antioxidants, antimicrobial, cancer chemopreventive, antidiabetic, and hypolipidemic agents. The existence of health benefits in rice bran, especially as antioxidants, gives rice bran the opportunity to be used as a functional food. Most of the bioactive compounds in plants are found in bound form with cell wall components such as cellulose and lignin. The process of releasing bonds between bioactive components and cell wall components in rice bran can increase the antioxidant capacity. Fermentation and treatment with enzymes were able to increase the total phenolic content, total flavonoids, tocotrienols, tocopherols, and γ-oryzanol in rice bran.

Antioxidant and Immunomodulatory Properties of Chia Protein Hydrolysates in Primary Human Monocyte-Macrophage Plasticity

Chia (Salvia hispanica L.) seed has high potential in the development of functional food due to its protein content with a special amino acid profile. Among the hematopoietic-derived cells, monocytes are endowed with high plasticity, responsible for their pro- and anti-inflammatory function in M1 and M2 phenotype polarization, respectively. Indeed, monocytes are involved in several oxidative- and inflammatory-associated disorders such as cancer, obesity, and cardiovascular and neurodegenerative diseases. This study was designed to investigate the role of chia protein hydrolysates (CPHs) in primary human monocyte–macrophage plasticity response using biochemical, RT-qPCR, and ELISA assays. Our results showed that CPHs reduce ROS and nitrite output, as pro-inflammatory cytokine secretion, and enhance the expression and release of anti-inflammatory cytokines. In addition, CPHs reverse LPS-associated M1 polarization into M2. These findings open new opportunities for developing nutritional strategies with chia as a dietary source of biopeptides to prevent the development and progression of oxidative- and inflammatory-related diseases.

Rice Bran By-Product: From Valorization Strategies to Nutritional Perspectives

The aim of this study is to review the innovative techniques based on bioprocessing, thermal or physical treatments which have been proposed during the last few decades to convert rice bran into a valuable food ingredient. Rice bran (Oryza sativa) is the main by-product of rice grain processing. It is produced in large quantities worldwide and it contains a high amount of valuable nutrients and bioactive compounds with significant health-related properties. Despite that, its application in food industry is still scarce because of its sensitivity to oxidation processes, instability and poor technological suitability. Furthermore, the health-related effects of pretreated rice bran are also presented in this review, considering the up-to-date literature focused on both in vivo and in vitro studies. Moreover, in relation to this aspect, a brief description of rice bran arabinoxylans is provided. Finally, the application of rice bran in the food industry and the main technology aspects are concisely summarized.

Antioxidative attributes of rice bran extracts in ameliorative effects of atherosclerosis-associated risk factors

Oxidative stress, chronic inflammation, dyslipidemia, hyperglycemia, and shear stress (physical effect) are risk factors associated with the pathogenesis of atherosclerosis. Rice bran, a by-product of rice milling process, is known to house polyphenols and vitamins which exhibit potent antioxidant and anti-inflammatory properties. Through recent emerging knowledge of rice bran in health and wellness, the present study was aimed to assess the ameliorative effects of rice bran extracts (RBE) derived from Japanese colored rice varieties in modulating risk factors of atherosclerosis via in vitro and in vivo study models. Pre-treatment of lipopolysaccharide (LPS)-stimulated murine J774A.1 macrophage-like cells with RBE alleviated nitric oxide (NO) overproduction and downregulated gene expressions of pro-inflammatory modulators: tumor necrosis factor-α (TNF-α), interleukin (IL)-α (IL-1α), IL-1β, IL-6, and inducible nitric oxide synthase (iNOS). In addition, RBE also significantly attenuated LPS-stimulated protein expressions of iNOS, TNF-α, IL-1α, and IL-6 in J774A.1 macrophage-like cells as compared to non-treated LPS control group. In in vivo, 12 weeks of RBE dietary supplementations significantly reduced (p < 0.05) total cholesterol, triglycerides, and pro-atherogenic oxidized LDL/β2-glycoprotein I (oxLDL/β2GPI) complexes at plasma levels, in high fat diet (HFD) induced low density lipoprotein receptor knockout (Ldlr^−/-) mice. En face pathological assessments of murine aortas also revealed significant reductions by 38% (p < 0.05) in plaque sizes of RBE-supplemented HFD mice groups as compared to non RBE-supplemented HFD control mice group. Moreover, gene expressions of aortic (iNOS, TNF-α, IL-1β) and hepatic (TNF-α, IL-1α, IL-1β) pro-inflammatory modulators were also downregulated in RBE-supplemented mice groups. Present study has revealed the potent health attributes and application of RBE as a dietary supplement to attenuate risks of inadvertent oxidative damage and chronic inflammation underlying the pathogenesis of atherosclerosis. Intrinsically, present preliminary findings may provide global health prospects for future dietary implementation of RBE in management of atherosclerosis.

The Impact of Dietary Supplementation of Whole Foods and Polyphenols on Atherosclerosis

The purpose of this review is to highlight current research on the benefits of supplementation with foods with a diverse polyphenol composition, including fruits, vegetables, nuts, grains, oils, spices, and teas in blunting atherosclerosis. We searched PubMed for publications utilizing whole food or polyphenols prepared from whole foods in Apolipoprotein E (ApoE) or Low-Density Lipoprotein Receptor (LDLR) knockout mice, and identified 73 studies in which plaque was measured. The majority of the studies reported a reduction in plaque. Nine interventions showed no effect, while three using Agaricus blazei mushroom, HYJA-ri-4 rice variety, and safrole-2', 3'-oxide (SFO) increased plaque. The mechanisms by which atherosclerosis was reduced include improved lipid profile, antioxidant status, and cholesterol clearance, and reduced inflammation. Importantly, not all dietary interventions that reduce plaque showed an improvement in lipid profile. Additionally, we found that, out of 73 studies, only 9 used female mice and only 6 compared both sexes. Only one study compared the two models (LDLR vs. ApoE), showing that the treatment worked in one but not the other. Not all supplementations work in both male and female animals, suggesting that increasing the variety of foods with different polyphenol compositions may be more effective in mitigating atherosclerosis.

Standardized rice bran extract improves hepatic steatosis in HepG2 cells and ovariectomized rats

BACKGROUD/OBJECTIVES

Hepatic steatosis is the most common liver disorder, particularly in postmenopausal women. This study investigated the protective effects of standardized rice bran extract (RBS) on ovariectomized (OVX)-induced hepatic steatosis in rats.

MATERIALS/METHODS

HepG2 cells were incubated with 200 µM oleic acid to induce lipid accumulation with or without RBS and γ-oryzanol. OVX rats were separated into three groups and fed a normal diet (ND) or the ND containing 17β-estradiol (E2; 10 µg/kg) and RBS (500 mg/kg) for 16 weeks.

RESULTS

RBS supplementation improved serum triglyceride and free fatty acid levels in OVX rats. Histological analysis showed that RBS significantly attenuated hepatic fat accumulation and decreased hepatic lipid, total cholesterol, and triglyceride levels. Additionally, RBS suppressed the estrogen deficiency-induced upregulation of lipogenic genes, such as sterol regulatory element-binding protein 1 (SREBP1), acetyl-CoA carboxylase 1, fatty acid synthase, glycerol-3-phosphate acyltransferase, and stearoyl-CoA desaturase 1.

CONCLUSIONS

RBS and γ-oryzanol effectively reduced lipid accumulation in a HepG2 cell hepatic steatosis model. RBS improves OVX-induced hepatic steatosis by regulating the SREBP1-mediated activation of lipogenic genes, suggesting the benefits of RBS in preventing fatty liver in postmenopausal women.

Rice bran attenuated obesity via alleviating dyslipidemia, browning of white adipocytes and modulating gut microbiota in high-fat diet-induced obese mice

Obesity has become an international public health problem. In this study, an obese mice diet was supplemented with raw rice bran (RRB) or infrared radiation-stabilized rice bran (IRRB) to investigate the attenuation of obesity induced by a high-fat diet. Mice were fed a normal diet or a high-fat diet with and without rice bran supplementation (300 mg per kg body weight per day) by oral gavage for 39 days to investigate the obesity preventive effect. The results indicate that different rice bran supplements reduced body weight, relative adipose tissue weight, inflammation, and serum parameters, and relieve liver steatosis to varying degrees. The data of real-time qPCR and western blots (WB) showed that rice bran activated brown adipose tissue (BAT) and increased white adipose tissue (WAT) browning. Rice bran also reduced the ratio of Firmicutes/Bacteroidetes and enhanced the relative abundance of Akkermansia. In summary, our findings suggest that rice bran intervention played a significant role in reducing dyslipidemia, alleviating inflammation, enhancing thermogenesis and modulating gut microbiota for the prevention and control of obesity.

Phytosterols and Inflammation

Besides the well-characterized effect of foods and supplements enriched with plant sterols/stanols on serum LDL-C concentrations, evidence is now emerging that phytosterols exert beneficial effects on non-lipid variables such as inflammatory and oxidative stress markers, coagulation parameters and endothelial function. This makes sterols and stanols an attractive alternative for dietary interventions in cardiovascular disease prevention, particularly in populations at low or medium risk. This review aims to summarize the current knowledge derived from experimental studies and human data on the anti-inflammatory effects of phytosterols/stanols and their relevance in promoting atheroprotection and preventing cardiovascular disease. The anti-inflammatory effects induced by plant sterols/stanols have been demonstrated in in vitro studies and in experimental animal models. However, not all the beneficial effects seen at an experimental level have translated into clinical benefit. Indeed, clinical studies that evaluate the association between phytosterols consumption and inflammatory variables (CRP and cytokines) are inconsistent and have not yet provided a solid answer. Plant sterols have been proposed as useful adjuncts to statin therapy to further reduce the risk of cardiovascular disease. However, there is limited available data and more research needs to be done.

Rice Bran Derived Bioactive Compounds Modulate Risk Factors of Cardiovascular Disease and Type 2 Diabetes Mellitus: An Updated Review

Cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) are two chronic diseases that have claimed more lives globally than any other disease. Dietary supplementation of functional foods containing bioactive compounds is recognised to result in improvements in free-radical-mediated oxidative stress. Emerging evidence indicates that bioactive compounds derived from rice bran (RB) have therapeutic potential against cellular oxidative stress. This review aims to describe the mechanistic pathways behind CVD and T2DM development and the therapeutic potential of polyphenols derived from RB against these chronic diseases.

Dietary Fiber, Atherosclerosis, and Cardiovascular Disease

Observational studies have shown that dietary fiber intake is associated with decreased risk of cardiovascular disease. Dietary fiber is a non-digestible form of carbohydrates, due to the lack of the digestive enzyme in humans required to digest fiber. Dietary fibers and lignin are intrinsic to plants and are classified according to their water solubility properties as either soluble or insoluble fibers. Water-soluble fibers include pectin, gums, mucilage, fructans, and some resistant starches. They are present in some fruits, vegetables, oats, and barley. Soluble fibers have been shown to lower blood cholesterol by several mechanisms. On the other hand, water-insoluble fibers mainly include lignin, cellulose, and hemicellulose; whole-grain foods, bran, nuts, and seeds are rich in these fibers. Water-insoluble fibers have rapid gastric emptying, and as such may decrease the intestinal transit time and increase fecal bulk, thus promoting digestive regularity. In addition to dietary fiber, isolated and extracted fibers are known as functional fiber and have been shown to induce beneficial health effects when added to food during processing. The recommended daily allowances (RDAs) for total fiber intake for men and women aged 19–50 are 38 gram/day and 25 gram/day, respectively. It is worth noting that the RDA recommendations are for healthy people and do not apply to individuals with some chronic diseases. Studies have shown that most Americans do not consume the recommended intake of fiber. This review will summarize the current knowledge regarding dietary fiber, sources of food containing fiber, atherosclerosis, and heart disease risk reduction.