Rice brans, rice bran oils, and rice hulls: composition, food and industrial uses, and bioactivities in humans, animals, and cells

A Randomized Controlled Trial to Increase Navy Bean or Rice Bran Consumption in Colorectal Cancer Survivors

Consumption of navy beans (NB) and rice bran (RB) have been shown to inhibit colon carcinogenesis. Given the overall poor diet quality in colorectal cancer (CRC) survivors and low reported intake of whole grains and legumes, practical strategies to increase consumption merit attention. This study determined feasibility of increasing NB or RB intake in CRC survivors to increase dietary fiber and examined serum inflammatory biomarkers and telomere lengths. Twenty-nine subjects completed a randomized controlled trial with foods that included cooked NB powder (35 g/day), heat-stabilized RB (30 g/day), or no additional ingredient. Fasting blood, food logs, and gastrointestinal health questionnaires were collected. The amount of NB or RB consumed equated to 4-9% of subjects' daily caloric intake and no major gastrointestinal issues were reported with increased consumption. Dietary fiber amounts increased in NB and RB groups at Weeks 2 and 4 compared to baseline and to control (P ≤ 0.01). Telomere length correlated with age and HDL cholesterol at baseline, and with improved serum amyloid A (SAA) levels at Week 4 (P ≤ 0.05). This study concludes feasibility of increased dietary NB and RB consumption to levels associated with CRC chemoprevention and warrants longer-term investigations with both foods in high-risk populations that include cancer prevention and control outcomes.

Antidiabetic Potential of Purple and Red Rice (Oryza sativa L.) Bran Extracts

Pigmented rice contains anthocyanins and proanthocyanidins that are concentrated in the bran layer. In this study, we determined the phenolic, flavonoid, anthocyanin, and proanthocyanidin content of five rice bran (1 brown, 2 red, and 2 purple) extracts. Each bran extract was evaluated for inhibitory effects on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. All purple and red bran extracts inhibited α-glucosidase activity, however only the red rice bran extracts inhibited α-amylase activity. Additionally, each bran extract was examined for their ability to stimulate glucose uptake in 3T3-L1 adipocytes, a key function in glucose homeostasis. Basal glucose uptake was increased between 2.3- and 2.7-fold by exposure to the red bran extracts, and between 1.9- and 3.1-fold by exposure to the purple bran extracts. In red rice bran, the highest enzyme inhibition and glucose uptake was observed with a proanthocyanidin-enriched fraction. Both IITA red bran and IAC purple bran increased expression of GLUT1 and GLUT4 mRNA, and genes encoding insulin-signaling pathway proteins.

Complex enzyme hydrolysis releases antioxidative phenolics from rice bran

In this study, phenolic profiles and antioxidant activity of rice bran were analyzed following successive treatment by gelatinization, liquefaction and complex enzyme hydrolysis. Compared with gelatinization alone, liquefaction slightly increased the total amount of phenolics and antioxidant activity as measured by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays. Complex enzyme hydrolysis significantly increased the total phenolics, flavonoids, FRAP and ORAC by 46.24%, 79.13%, 159.14% and 41.98%, respectively, compared to gelatinization alone. Furthermore, ten individual phenolics present in free or soluble conjugate forms were also analyzed following enzymatic processing. Ferulic acid experienced the largest release, followed by protocatechuic acid and then quercetin. Interestingly, a major proportion of phenolics existed as soluble conjugates, rather than free form. Overall, complex enzyme hydrolysis releases phenolics, thus increasing the antioxidant activity of rice bran extract. This study provides useful information for processing rice bran into functional beverage rich in phenolics.

Determination of lipophilic and hydrophilic bioactive compounds in raw and parboiled rice bran

Rice bran is one of the most important rice by-products and represents a source of bioactive compounds.

Food supplementation with rice bran enzymatic extract prevents vascular apoptosis and atherogenesis in ApoE-/- mice

PURPOSE

Atherosclerosis is associated with reduced mononuclear cell (MNC) telomere length, and senescent cells have been detected in atherosclerotic plaques. Rice bran is a source of γ-oryzanol, phytosterols and tocols with potential lipid-lowering, antioxidant and anti-inflammatory activities. Here, we tested the hypothesis that rice bran enzymatic extract (RBEE) impacts on apoptosis, telomere length and atherogenesis in mice.

METHODS

Seven-week-old male ApoE-/- mice were fed high-fat diet (HFD) or isocaloric HFD supplemented with 5 % (w/w) RBEE for 23 weeks. Wild-type mice of the same age were kept under standard diet as controls.

RESULTS

RBEE treatment reduced total cholesterol (19.24 ± 1.63 vs 24.49 ± 1.71 mmol/L) and triglycerides (1.13 ± 0.18 vs 1.75 ± 0.22 mmol/L) and augmented HDL-cholesterol (1.86 ± 0.20 vs 1.07 ± 0.20 mmol/L). RBEE attenuated macrophage infiltration by 56.69 ± 4.65 % and plaque development (7737 ± 836 vs 12,040 ± 1001 μm²) in the aortic sinus. In the aorta, RBEE treatment reduced expression of the apoptosis pathway components p16, p53 and bax/bcl-2 ratio. RBEE prevented apoptosis of aortic endothelial cells (2.81 ± 0.71-1.14 ± 0.35 apoptotic nuclei/ring for ApoE-/- HFD and ApoE-/- HFD 5 % RBEE, respectively). In contrast, MNC of RBEE-fed mice exhibited enhanced apoptosis marker expression with increased p53 and bax/bcl-2 protein levels. Compared to WT, ApoE-/- mice on HFD were characterized by significant telomere shortening in aorta (11 ± 2 %) and MNC (73 ± 7 %), which was reduced by supplementation with RBEE (aorta: 40 ± 7 %; MNC: 105 ± 10 %). Expression of telomere repeat-binding factor 2 was increased in RBEE-fed mice.

CONCLUSION

Long-term food supplementation with RBEE lowers cholesterol and prevents atherosclerotic plaque development in ApoE-/- mice. Differential regulation of vascular and MNC apoptosis and senescence were identified as potential mechanisms.

High protective efficacy of rice bran against human rotavirus diarrhea via enhancing probiotic growth, gut barrier function, and innate immunity

Previously, we showed that rice bran (RB) was able to reduce human rotavirus (HRV) diarrhea in gnotobiotic pigs. Here, we investigated its effect on the growth of diarrhea-reducing probiotic Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle (EcN), and the resulting effects on HRV diarrhea, gut epithelial health, permeability and innate immune responses during virulent HRV challenge. On 3, 5, and 7 days of age pigs were inoculated with 2 × 10⁴ colony-forming-units LGG+EcN to initiate colonization. Daily RB supplementation (replacing 10% calorie intake) was started at 5 days of age and continued until euthanasia. A subset of pigs in each group was challenged orally with 10⁵ focus-forming-units of virulent HRV at 33 days of age. RB completely prevented HRV diarrhea in LGG+EcN colonized pigs. RB significantly promoted the growth of both probiotic strains in the gut (~5 logs) and increased the body-weight-gain at 4–5 weeks of age compared to non-RB group. After HRV challenge, RB-fed pigs had significantly lower ileal mitotic index and villus width, and significantly increased intestinal IFN-γ and total IgA levels compared to non-RB group. Therefore, RB plus LGG+EcN colonization may represent a highly effective therapeutic approach against HRV and potentially a variety of other diarrhea-inducing enteric pathogens.

Chemistry, Nutrition, and Health-Promoting Properties of Hericium erinaceus (Lion's Mane) Mushroom Fruiting Bodies and Mycelia and Their Bioactive Compounds

The culinary and medicinal mushroom Hericium erinaceus is widely consumed in Asian countries, but apparently not in the United States, for its nutritional and health benefits. To stimulate broader interest in the reported beneficial properties, this overview surveys and consolidates the widely scattered literature on the chemistry (isolation and structural characterization) of polysaccharides and secondary metabolites such as erinacines, hericerins, hericenones, resorcinols, steroids, mono- and diterpenes, and volatile aroma compounds, nutritional composition, food and industrial uses, and exceptional nutritional and health-promoting aspects of H. erinaceus. The reported health-promoting properties of the mushroom fruit bodies, mycelia, and bioactive pure compounds include antibiotic, anticarcinogenic, antidiabetic, antifatigue, antihypertensive, antihyperlipodemic, antisenescence, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties and improvement of anxiety, cognitive function, and depression. The described anti-inflammatory, antioxidative, and immunostimulating properties in cells, animals, and humans seem to be responsible for the multiple health-promoting properties. A wide range of research advances and techniques are described and evaluated. The collated information and suggestion for further research might facilitate and guide further studies to optimize the use of the whole mushrooms and about 70 characterized actual and potential bioactive secondary metabolites to help prevent or treat human chronic, cognitive, and neurological diseases.

Dissecting a QTL into Candidate Genes Highlighted the Key Role of Pectinesterases in Regulating the Ascorbic Acid Content in Tomato Fruit

Tomato (Solanum lycopersicum) is a crucial component of the human diet because of its high nutritional value and the antioxidant content of its fruit. As a member of the Solanaceae family, it is considered a model species for genomic studies in this family, especially since its genome has been completely sequenced. Among genomic resources available, Solanum pennellii introgression lines represent a valuable tool to mine the genetic diversity present in wild species. One introgression line, IL12-4, was previously selected for high ascorbic acid (AsA) content, and a transcriptomic analysis indicated the involvement of genes controlling pectin degradation in AsA accumulation. In this study the integration of data from different "omics" platforms has been exploited to identify candidate genes that increase AsA belonging to the wild region 12-4. Thirty-two genes potentially involved in pathways controlling AsA levels were analyzed with bioinformatic tools. Two hundred-fifty nonsynonymous polymorphisms were detected in their coding regions, and 11.6% revealed deleterious effects on predicted protein function. To reduce the number of genes that had to be functionally validated, introgression sublines of the region 12-4 were selected using species-specific polymorphic markers between the two Solanum species. Four sublines were obtained and we demonstrated that a subregion of around 1 Mbp includes 12 candidate genes potentially involved in AsA accumulation. Among these, only five exhibited structural deleterious variants, and one of the 12 was differentially expressed between the two Solanum species. We have highlighted the role of three polymorphic pectinesterases and inhibitors of pectinesterases that merit further investigation.

Changes in Physicochemical, Structural, and Sensory Properties of Irradiated Brown Japonica Rice during Storage

Brown japonica rice was treated with (60)Co γ irradiation at doses of 0, 0.2, 0.5, 1.0, and 2.0 kGy immediately after harvesting. The effects of irradiation on physicochemical, structural, and sensory properties during long-term storage (18 months) were investigated. The study revealed that the pasting properties, including peak, through, breakdown, final, and setback viscosities, decrease considerably in a dose-dependent manner and vary differently during 18 months of storage. Irradiation reduced the free fatty acid (FFA) content in comparison with unirradiated brown rice with long-term storage (from 12 to 18 months). Scanning electron microscope (SEM) observation showed that the mean range and shape of starch granules did not vary significantly. However, dark spots developed among starch granules and the narrow cracks became wider with increasing irradiation dose and storage time. During sensory evaluation, extremely low scores for odor and overall acceptability were obtained for medium-dose irradiated rice (1.0 and 2.0 kGy); however, no significant difference was found in acceptability between low-dose irradiated rice (0.2 and 0.5 kGy) and the control rice (0 kGy). Overall, low-dose (0.5 kGy or below) irradiation seems to be a promising alternative treatment to increase brown rice shelf life, without affecting the physicochemical and structural characteristics and sensory acceptability.

Rice hull extracts inhibit proliferation of MCF-7 cells with G₁ cell cycle arrest in parallel with their antioxidant activity

Rice (Oryza sativa L.) has been a major dietary staple worldwide for centuries. Growing interest in the beneficial effects of antioxidants has inspired investigation of rice hulls as an attractive source of chemopreventive compounds for breast cancer intervention. We prepared methanol extracts from rice hulls of three Korean bred cultivars (japonica), Ilpum, Heugjinju, and Jeogjinju, and one japonica weedy rice, WD-3. We examined the antiproliferative potential of the hull extracts on MCF-7 human breast cancer cells and the related mechanisms thereof. Hull extracts inhibited proliferation of the cells and mediated G0/G1 phase arrest by suppressing cyclins and cyclin-dependent kinases, where WD-3 extract showed the most potent. Blockage of p21 expression by small interfering RNA transfection attenuated G1 phase arrest induced by WD-3 extract. The WD-3 extract exhibited greater antioxidant potential and total phenolic compounds, compared with other rice hulls. Gas chromatography-mass spectrometry analysis for the F4 fractioned from WD-3 extract revealed that cinnamic acid derivatives were the major active constituents. The F4 fraction most potently inhibited proliferation of MCF-7 cells than WD-3 extract through the suppression of cell cycle regulatory factors. Collectively, our results suggest that the pigmented rice hulls possess greater antioxidant and chemopreventive activity against breast cancer than the other rice cultivars tested, demonstrating that WD-3 rice hulls are an attractive source of chemopreventive bioactive compounds.

Rice Bran Oil Compared to Atorvastatin for Treatment of Dyslipidemia in Patients with Type 2 Diabetes

Objective: To compare the effect of rice bran oil versus statins (atorvastatin drug) on blood glucose, glycosylated hemoglobin (HbA1C) and serum lipid profiles in patients with type 2 diabetes. The safety of the tested rice bran oil and atorvastatin were investigated. Fatty acids contents of RBO, olive and sesame oil were also assessed.Materials and Methods: Forty four eligible patients with type 2 diabetes and moderately hyperlipidemic were randomly and equally allocated into two groups, rice bran oil (RBO) group and atorvastatin group. The RBO group received a low-calorie diet and consumed 30 g / day RBO oil as salad dressing and for use as main cooking oil for 6 months. The Atorvastatin group received a low-calorie diet and 40 mg/day of atorvastatin drug for 6 months. At baseline and after 6 months of study intervention, blood glucose, glycosylated hemoglobin (HbA1c), serum lipid profiles; hepatic, renal and inflammatory biomarkers were estimated.Results: Results showed significant increase in fasting and postprandial blood glucose, HbA1C and liver transaminases (alanine transaminase ALT and aspartate transaminase AST) in the atorvastatin group while a significant reduction was shown in RBO group. Moreover, significant reductions in lipid profile levels, blood urea, serum uric acid and erythrocyte sedimentation rate (ESR) were observed in both RBO and atorvastatin groups after 6 months of the study intervention.Conclusion: The use of rice bran oil together with dietary modifications may have implications in lowering fasting and postprandial blood glucose, suppressing serum lipid levels, reduce the TC/HDL-C ratio and therefore reducing the risk of cardiovascular disease. Moreover, RBO exerts a hypouricemic action and anti-inflammatory effects. The findings obtained from the current study reinforce the use of RBO as an alternative natural potent hypolipidemic agent safer than atorvastatin drug that may induce side effects in some cases in patients intolerant to statins.