Increased immune response in mice consuming rice bran oil

Nutrients in rice bran oil and their nutritional functions: a review

Rice is an important food crop throughout the world. Rice bran, the outer layer of rice grain, is a by-product generated during the rice milling process. Rice bran oil (RBO) is extracted from rice bran and has also become increasingly popular. RBO is considered to be one of the healthiest cooking oils due to its balanced proportion of fatty acids, as well as high content of γ-oryzanol together with phytosterols, vitamin E, wax ester, trace and macro elements, carotenoids, and phenolics. The existence of these compounds provides RBO with various functions, including hypotensive and hypolipidemic functions, antioxidant, anticancer, and immunomodulatory functions, antidiabetic function, anti-inflammatory and anti-allergenic functions, hepatoprotective activity function, and in preventing neurological diseases. Recently, research on the nutrients in RBO focused on the detection of nutrients, functions, and processing methods. However, the processing and utilization of rice bran remain sufficiently ineffective, and the processing steps will also affect the nutrients in RBO to different degrees. Therefore, this review focuses on the contents and nutritional functions of different nutrients in RBO and the possible effects of processing methods on nutrients.

Contemporary Views of the Extraction, Health Benefits, and Industrial Integration of Rice Bran Oil: A Prominent Ingredient for Holistic Human Health

Globally, 50% of people consume rice (Oryza sativa), which is among the most abundant and extensively ingested cereal grains. Rice bran is a by-product of the cereal industry and is also considered a beneficial waste product of the rice processing industry. Rice bran oil (RBO) is created from rice bran (20-25 wt% in rice bran), which is the outermost layer of the rice kernel; has a lipid content of up to 25%; and is a considerable source of a plethora of bioactive components. The main components of RBO include high levels of fiber and phytochemicals, including vitamins, oryzanols, fatty acids, and phenolic compounds, which are beneficial to human health and well-being. This article summarizes the stabilization and extraction processes of rice bran oil from rice bran using different techniques (including solvent extraction, microwaving, ohmic heating, supercritical fluid extraction, and ultrasonication). Some studies have elaborated the various biological activities linked with RBO, such as antioxidant, anti-platelet, analgesic, anti-inflammatory, anti-thrombotic, anti-mutagenic, aphrodisiac, anti-depressant, anti-emetic, fibrinolytic, and cytotoxic activities. Due to the broad spectrum of biological activities and economic benefits of RBO, the current review article focuses on the extraction process of RBO, its bioactive components, and the potential health benefits of RBO. Furthermore, the limitations of existing studies are highlighted, and suggestions are provided for future applications of RBO as a functional food ingredient.

Added γ-oryzanol boosted anti-inflammatory effects of canola oil in adult subjects with type 2 diabetes: a randomized controlled clinical trial

PURPOSE

This study was conducted to examine the effects of daily intake of γ-oryzanol (ORZ)-fortified canola oil, as compared with plain canola and sunflower oils, on certain inflammatory and oxidative stress biomarkers in adult subjects with Type 2 Diabetes (T2D).

METHODS

We randomly allocated 92 adult subjects with T2D from both sexes to one of the following groups to receive: (a) ORZ-fortified canola oil (ORZO; n1 = 30); (b) unfortified canola oil (CANO; n2 = 32); or (c) sunflower oil (SUFO; n3 = 30) for 12 weeks. Dietary and laboratory evaluations were performed initially and finally.

RESULTS

Serum hs-CRP concentrations significantly decreased in ORZO group (from 3.1 ± 0.2 to 1.2 ± 0.2 mg/L), as compared with CANO (p = 0.003) and SUFO (p < 0.001) groups. Serum IL-6 significantly decreased just in ORZO (- 22.8%, p = 0.042) and CANO groups (- 19.8%, p = 0.038). However, the between-group differences were not significant. Serum IL-1β slightly decreased in ORZO (- 28.1%, p = 0.11) and increased in SUFO (+ 20.6%, p = 0.079) but between-group difference was statistically significant (p = 0.017). Serum IFN-γ concentrations decreased significantly only in ORZO (from 3.3 ± 0.08 to 2.9 ± 0.21 IU/mL, p = 0.044). Salivary IgA concentrations increased significantly in all three intervention groups. Notwithstanding, only the difference between ORZO and CANO groups was statistically significant (p = 0.042). Similarly, circulating malondialdehyde concentrations significantly decreased in all three groups but with no between-group significant difference.

CONCLUSIONS

Daily consumption of ORZ-fortified canola oil, compared with unfortified canola and sunflower oils, for 12 weeks resulted in boosting of certain anti-inflammatory effects of canola oil. These findings may have preventive implications for both clinicians and policy makers. This clinical trial was registered at clinicaltrials.gov (03.08.2022; NCT05271045).

Efficacy of Phellinus linteus extract on immunity enhancement: A CONSORT-randomized, double-blind, placebo-controlled pilot trial

BACKGROUND

Immunity is a major system that defends the human body from the outside. Recently, interest in foods related to immunity has been increasing.

METHODS

The purpose of this clinical trial was to determine the safety and efficacy of Phellinus linteus (PL) extract in improving immune function. A total of 30 participants were randomly assigned to 3 groups: the PL1000 group (n = 10) took 1000 mg of PL extract and 1000 mg of dextrin per day; the PL2000 group (n = 10) took 2000 mg of PL extract per day; and the placebo group (n = 10) took 2000 mg of dextrin per day. All participants took 2 capsules twice a day for 8 weeks. We measured their natural killer cell activity and cytokine levels in blood before and after consuming the clinical trial food. Variables were also investigated to evaluate safety, such as adverse reactions, vital signs, and abnormal findings. Student t test or the Mann-Whitney U test, a paired t test or the Wilcoxon signed-rank test, a chi-square test, analysis of variance, and Kruskal-Wallis test were conducted according to the characteristics of the data to compare the differences between each group before and after participants ate the clinical trial food.

RESULTS

The natural killer cell activity and interleukin-6 levels of the PL1000 group tended to improve compared to those of the placebo group. Immunoglobulin G1, immunoglobulin G2, and immunoglobulin M levels did not show significant changes, but tended to improve in the PL1000 and PL2000 groups compared to those of the placebo group. Both the Per Protocol and Intention to Treat populations had improved validation parameters. It is safe because no hazards were found in the safety assessment.

CONCLUSION

PL extract can help improve immunity. Evidences to conduct the main clinical trial is secured through this pilot study. A future large-scale main trial will be conducted based on this pilot study results.

Immune-Enhancing Effect of Submerged Culture of Ceriporia lacerata Mycelia on Cyclophosphamide-Induced Immunosuppressed Mice and the Underlying Mechanisms in Macrophages

The white-rot fungi Ceriporia lacerata is used in bioremediation, such as lignocellulose degradation, in nature. Submerged cultures and extracts of C. lacerata mycelia (CLM) have been reported to contain various active ingredients, including β-glucan and extracellular polysaccharides, and to exert anti-diabetogenic properties in mice and cell lines. However, the immunostimulatory effects have not yet been reported. This study aimed to identify the immunomodulatory effects, and underlying mechanisms thereof, of submerged cultures of CLM using RAW264.7 macrophages and cyclophosphamide (CTX)-induced immunosuppression in mice. Compared to CTX-induced immunosuppressed mice, the spleen and thymus indexes in mice orally administered CLM were significantly increased; body weight loss was alleviated; and natural killer (NK) cytotoxicity, lymphocyte proliferation, and cytokine (tumor necrosis factor [TNF]-α, interferon [IFN]-γ, and interleukin [IL]-2) production were elevated in the serum. In RAW264.7 macrophages, treatment with CLM induced phagocytic activity, increased the production of nitric oxide (NO), and promoted mRNA expression of the immunomodulatory cytokines TNF-α, IFN-γ, IL-1β, IL-6, IL-10, and IL-12. In addition, CLM increased the inducible NO synthase (iNOS) concentration in macrophages, similar to lipopolysaccharide (LPS) stimulation. Mechanistic studies showed that CLM induced the activation of the NF-κB, PI3k/Akt, ERK1/2, and JNK1/2 pathways. Moreover, the phosphorylation of NF-κB and IκB induced by CLM in RAW264.7 cells was suppressed by specific MAPKs and PI3K inhibitors. Further experiments with a TLR4 inhibitor demonstrated that the production of TNF-α, IL-1β, and IL-6 induced by CLM was decreased after TLR4 was blocked. Overall, CLM protected against CTX-induced adverse reactions by enhancing humoral and cellular immune functions, and has potential as an immunomodulatory agent.

Growth Performance, Antioxidant Activity, Immune Status, Meat Quality, Liver Fat Content, and Liver Histomorphology of Broiler Chickens Fed Rice Bran Oil

Simple Summary

There are numerous approaches for enrichment of broiler’s meat with valuable nutrients, for instance the enrichment with polyunsaturated fatty acids (PUFA). The addition of vegetable oils in the diets of broilers is an appropriate strategy to enrich the chicken meat with beneficial FA, however, this enrichment is accompanied by a lipid peroxidation with a resultant decrease in the nutritional value, quality, and shelf-life of the meat, and for that reason, the dietary supplementation with antioxidants becomes necessary. What places rice bran oil (RBO) on top of other vegetable oils is its antioxidant components and unique fatty acid profile and it is reported to induce substantial lipid-reducing effects and antioxidant properties. Therefore, this study was performed to determine the influence of RBO inclusion in the diets of broiler chickens on performance, carcass characteristics, blood parameters, meat quality, antioxidant activity, liver lipid content, and liver histological structure. RBO inclusion had a positive effect on the growing performance, dressing percentage, and immune status. Furthermore, RBO supplementation decreased the abdominal fat yield and EE content in the meat, while it increased the content of PUFA in the meat, which may be beneficial for consumers. RBO improved the antioxidant capacity of the meat and the liver, whereas it reduced the concentration of cholesterol and triglycerides in the blood, meat and liver. RBO could be used as an efficient ingredient in broiler chickens’ diets to improve performance, immune status, antioxidant activity, blood lipid profile, and the nutritive value of meat.

Abstract

This trial was performed to determine the effect of rice bran oil (RBO) inclusion in diets of broiler chickens on performance, carcass characteristics, blood parameters, meat quality, antioxidant activity, liver lipid content, and liver histological structure. The 35-day feeding trial was conducted on 240 one-day-old Ross 308 broiler chickens, allocated to four treatment groups with six replicates each. RBO was examined at different inclusion levels, 0% (control), 1% (RBO_1%), 1.5% (RBO_1.5%), and 2% (RBO_2%) in a completely randomized design. The results showed that at the end of the trial (35 days) the RBO supplementation had positive effects (p < 0.001) on the productivity parameters, but the feed intake was linearly decreased due to RBO inclusion. In addition, RBO supplementation linearly improved (p < 0.05) the dressing percentage, breast yield, immune organs relative weights, and meat glutathione concentration, while it decreased (p < 0.01) the abdominal fat yield and meat crude fat, triglycerides, cholesterol, and Malondialdehyde (MDA) contents in broiler’s meat. Moreover, serum total protein, globulin, and high-density lipoprotein contents improved noticeably (p < 0.01) due to offering an RBO-supplemented diet, but serum total lipids, total cholesterol, triglyceride, low-density lipoprotein, and aspartate aminotransferase concentrations linearly reduced (p < 0.01). The RBO supplementation augmented (p < 0.05) the phagocytic index, phagocytic activity, and antibody titer compared to control. On the other hand, RBO inclusion had no effect on the breast, thigh, or abdominal fat color parameters. Moreover, RBO supplementation reduced (p < 0.01) the content of total saturated FA (SFA), but increased (p < 0.01) the content of total monounsaturated FA (MUFA), and polyunsaturated FA in both breast and thigh meat. Chemical analysis of the liver tissue samples revealed that the inclusion of RBO linearly reduced (p < 0.05) hepatic cholesterol, triglyceride, and MDA contents. Histologically, the lipid percentage and number of lipid droplets (p < 0.01) were markedly lessened in the RBO-supplemented groups. The histological structure of the liver asses by light and electron microscope were normal in all groups without any pathological lesions. It is concluded that RBO could be used as a valuable ingredient in broiler chickens’ diets to stimulate the growing performance and immune status, enhance the antioxidant activity and blood lipid profile, augment liver function, and improve the nutritive value of the meat.

Functional Profiling and Future Research Direction of Rice Bran Oil in Bangladesh

Rice bran oil (RBO) has been demonstrated to affect complex malfunctioned conditions such as oxidative stress, hyperlipidemia, hyperglycemia, hypertension, inflammation, abnormal cell growth (cancer), ulceration, immune and cognitive modulation. This unique effect of RBO is due to the presence of well-balanced fatty acid composition and several bioactive compounds, γ- oryzanol (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesterol ferulate, and β-sitosteryl ferulate), vitamin E (tocopherol and tocotrienol), phytosterols (β-sitosterol, campesterol and stigmasterol) and other nutrients. The RBO composition of bioactive compounds varied geographically, thus the clear-cut mechanisms of action on complex disease cascades are still required. This review article summarized the RBO compositional profiling and compared it with other edible oils. This article also summarized Bangladesh RBO profiling and their proposed mechanism of action as well as the first line of defense in the prevention, management, and control of complex disease conditions. This review indicates how Bangladesh RBO increase their opportunity to be functional food for 21st century's ailment.

Pediococcus Pentosaceus from the Sweet Potato Fermented Ger-Minated Brown Rice Can Inhibit Type I Hypersensitivity in RBL-2H3 Cell and BALB/c Mice Models

In this study, the effect of GBR fermented with the Pediococcus pentosaceus SP024 strain on IgE/Ag mediated passive cutaneous anaphylaxis (PCA) was investigated. Protocatechuic acid and trans-ferulic acid levels in GBR-SP024 increased more than those in unfermented GBR, respec-tively. The inhibitory activity of GBR-SP024 on β-hexosaminidase release and the level of proin-flammatory cytokine mRNA expression (tumor necrosis factor-α (TNF-α) and interleukin 4 (IL-4)) was observed in IgE/Ag-stimulated RBL-2H3 cells. Western blot analysis showed that GBR-SP024 significantly inhibited the phosphorylation of the linker for activation of T cell (LAT) and nuclear factor-κB (NF-κB) in IgE/Ag-stimulated RBL-2H3 cells. Further, we investigated the anti-allergic effect of GBR-SP024 using PCA murine model. The number of infiltrated immune cells and degranulated mast cells in GBR-SP024 treated dermis was lower than that in the GBR-treated mice. In addition, mRNA expression of 5-lipoxygenase (5-LOX) in the dermis of ear tissue declined in the GBR-SP024–treated group, compared to that in the GBR group. GBR-SP024 was also more effective than GBR at reducing the levels of IL-33 protein expression in IgE/Ag-stimulated BALB/c mice. Our study suggests the potential usage of GBR-SP024 as a dietary supplement or an adjuvant for treating IgE-dependent-allergic diseases.

Advances on the Valorisation and Functionalization of By-Products and Wastes from Cereal-Based Processing Industry

Cereals have been one of the major food resources for human diets and animal feed for thousands of years, and a large quantity of by-products is generated throughout the entire processing food chain, from farm to fork. These by-products mostly consist of the germ and outer layers (bran) derived from dry and wet milling of the grains, of the brewers' spent grain generated in the brewing industry, or comprise other types obtained from the breadmaking and starch production industries. Cereal processing by-products are an excellent low-cost source of various compounds such as dietary fibres, proteins, carbohydrates and sugars, minerals and antioxidants (such as polyphenols and vitamins), among others. Often, they are downgraded and end up as waste or, in the best case, are used as animal feed or fertilizers. With the increase in world population coupled with the growing awareness about environmental sustainability and healthy life-styles and well-being, the interest of the industry and the global market to provide novel, sustainable and innovative solutions for the management of cereal-based by-products is also growing rapidly. In that respect, these promising materials can be valorised by applying various biotechnological techniques, thus leading to numerous economic and environmental advantages as well as important opportunities towards new product development (NPD) in the food and feed industry and other types such as chemical, packaging, nutraceutical (dietary supplements and food additives), cosmetic and pharmaceutical industries. This review aims at giving a scientific overview of the potential and the latest advances on the valorisation of cereal-based by-products and wastes. We intended it to be a reference document for scientists, technicians and all those chasing new research topics and opportunities to explore cereal-based by-products through a circular economy approach.

Rice bran oil ameliorates inflammatory responses by enhancing mitochondrial respiration in murine macrophages

Previous studies have revealed the anti-inflammatory properties of rice bran oil (RBO), but the detailed mechanisms are poorly understood. Recent studies on the molecular/cellular anti-inflammatory mechanisms of dietary components have demonstrated that mitochondrial respiration plays a key role in macrophage functioning. Since dietary lipids are major substrates for mitochondrial respiration through β-oxidation, the current study examined whether RBO regulates inflammatory responses by modulating mitochondrial energy metabolism. Palm oil (PO), enriched with palmitic acid which are known to be effectively taken up by cells and used for oxidative phosphorylation, served as a positive control. In the in vitro model of LPS-stimulated RAW 264.7 murine cells, the levels of pro-inflammatory cytokines (IL-6 and TNF-α) in the culture supernatant were significantly reduced by RBO treatment. In contrast, secretion of the anti-inflammatory cytokine IL-10 was upregulated by RBO. Transcription of genes encoding inflammatory mediator molecules (COX-2 and iNOS) and expression of activation markers (CD80, CD86, and MHC-II) in LPS-stimulated RAW 264.7 cells were suppressed by RBO. Mitochondrial respiration (as assessed by an extracellular flux analyzer) increased upon RBO treatment, as the basal respiration, maximal respiration, ATP production, and spare respiratory capacity were upregulated. In an in vivo study, C57BL/6 mice were fed a negative control diet containing corn oil (CO), PO, or RBO for 4 weeks, and bone marrow-derived macrophages (BMDM) were isolated from their tibias and femurs. In pro-inflammatory M1-polarized BMDM (M1-BMDM), the RBO-induced suppression of IL-6 and TNF-α was recapitulated in vivo. Mitochondrial respiration in M1-BMDM also increased following the RBO intervention and the PO control treatment as compared to CO fed negative control. Overall, the current study for the first time demonstrates that RBO regulates inflammatory responses in murine macrophages by upregulating mitochondrial respiration. Further clinical studies are required to validate the animal study.

Efficacy of energy supplementation on growth performance and immune response of suckling pigs

Three studies were performed to determine the effects of oral energy sources on the performance, immune status, and intestinal morphology of piglets. In Exp. 1, 50 litters were selected based on genotype and parity order to determine the optimum amount of supplemental energy for neonatal pigs. They were distributed according to a 5 × 5 Latin square design, in which columns were represented by 5 sows and rows were represented by 5 newborn weight categories. Treatments consisted of 2 oral doses of 0, 2, 4, 8, or 16 mL of rice bran oil (RBO). There was a positive response of RBO on BW with a numerical difference (P = 0.12) and a significant linear effect (P = 0.04) at weaning. In Exp. 2, litters (n = 340) were randomly allotted to a 2 × 2 factorial arrangement of treatments: RBO supplemented either through oral doses (without supplementation or with 2 mL of RBO) or through prestarter feed (without supplementation or with 2% of RBO replacing 2% of soybean oil). Piglets orally receiving RBO showed a numerical increase in BW at weaning (P = 0.101) compared with the control group. Moreover, piglets supplemented by prestarter feed tended to increase feed intake (P = 0.084). In Exp. 3, litters (n = 245) were selected based on genotype and parity order and they were distributed according to a 7 × 7 Latin square design planed in the same way as in Exp. 1. Each neonatal pig within a litter was randomly assigned to 1 of 7 treatments: 1) control (no supplementation), 2) 2 mL of RBO enriched with omega-3 fatty acids, 3) 2.33 mL of pure glycerin, 4) 1.3 mL of soybean oil, 5) 1.4 mL of linseed oil, 6) 1.68 mL of coconut oil, and 7) 2 mL of RBO. Animal performance was analyzed using 2 data sets: all data (average initial BW of 1.479 kg) and low birth weight (LBW) piglet data (≤1.220 kg initial BW with average of 0.985 kg). Body weight or BW gain (BWG) were not different among treatments (P > 0.10) when all data were analyzed. However, LBW piglets fed coconut oil tended to increase BW (P = 0.099) during the first week. In conclusion, the oral use of RBO may increase BW at weaning and the supplementation by prestarter feed may enhance the feed intake of piglets. In addition, coconut oil may increase BW of LBW piglets in the first week of life without affecting mortality, immune response, or gut morphology. The routine practice of oral supplementation of energy for newborn pigs could be an important tool in swine production.

Immunomodulatory Effects of Kuseonwangdogo-Based Mixed Herbal Formula Extracts on a Cyclophosphamide-Induced Immunosuppression Mouse Model

Aim

Kuseonwangdogo is a traditional Korean immunomodulatory polyherbal prescription. However, there are no systemic findings on its complex immunomodulatory effects on in vivo models. In this study, we observed the immunomodulatory effects of Kuseonwangdogo-based mixed herbal formula aqueous extracts (MHFe) on cyclophosphamide- (CPA-) induced immunosuppression mouse model.

Methods

In total, 60 male 6-week-old ICR mice (10 mice/group) were selected based on body weight 24 h after the second CPA treatment and used in this experiment. Twelve hours after the end of the last (fourth) oral administration of MHFe, the animals were sacrificed.

Results

Following CPA treatment, a noticeable decrease in the body, thymus, spleen, and submandibular lymph node (LN) weights; white blood cell, red blood cell, platelet number, hemoglobin, and hematocrit concentrations; serum interferon-γ levels; splenic tumor necrosis factor-α, interleukin- (IL-) 1β, and IL-10 content; and peritoneal and splenic natural killer cell activities was observed. Depletion of lymphoid cells in the thymic cortex, splenic white pulp, and submandibular LN-related atrophic changes were also observed. However, these CPA-induced myelosuppressive signs were markedly and dose-dependently inhibited by the oral administration of 125, 250, and 500 mg/kg MHFe.

Conclusion

MHFe can be a promising, potent immunomodulatory therapeutic agent for various immune disorders.

Telfairia occidentalis Hook.f. - associated haematopoietic effect is mediated by cytokines but independent of testosterone: A preliminary report

ETHNOPHARMACOLOGICAL RELEVANCE

Telfairia occidentalis Hook.f. (TO) is popular in Nigeria for the ethnopharmacological use of its leaves to improve haematological parameters in normal and anaemic subjects. Cytokines are well-known to regulate haematopoiesis. However, their involvement in TO-associated haematopoietic effect is not known and necessitated this study.

MATERIALS AND METHODS

Twenty-five (25) male rats were randomly divided into 3 oral treatment groups as follows: Group 1 (control, n=5) received 0.2 ml/kg normal saline for 14 days. Groups 2 and 3 (n= 10 each) were subdivided into 2 (n=5) and received 100 mg/kg and 200 mg/kg of aqueous extract of TO respectively for 7 or 14 days.

RESULTS

TO had dose- and duration-dependent effects on the estimated parameters. Both doses of TO increased the RBC, WBC and erythropoietin concentrations at 14 but not 7 days. Moreover, its 100 mg/kg increased haemoglobin, neutrophil, and interleukin-3 concentrations at 7 days, while 200 mg/kg increased PCV and neutrophils at 14 days, lymphocytes at 7 days, and haemoglobin at both durations.

CONCLUSION

The haematopoietic effect of TO might be partly mediated by cytokines (interleukin-3 and erythropoietin) but independent of testosterone.

Reduction of liver tumerogenic effect of N-nitrosodiethylamine by treatment with ɣ-oryzanol in Balb/C mice

In recent years, naturally occurring phytochemicals with antioxidant capacity have generated surmount interest in their therapeutic usage against a wide range of pathological and toxicological conditions. The present study was designed to evaluate potential of ɣ-oryzanol (OZ), a bio-active natural antioxidant against hepatocellular carcinoma effect of the carcinogen N-nitrosodiethylamine in Balb/c mice. OZ inhibited the proliferation of Hep-3B cell line in concentration dependent manner. Administration of OZ to N-nitrosodiethylamine induced Balb/c mice for 16 and 32 weeks showed reduction in levels of liver injury markers, restored the levels of liver tumor markers, suppressed the hepatic nodular incidence and multiplicity, and favorably modulated the liver antioxidant status in a time dependent manner. Histologically, no obvious signs of neoplasia in the liver tissues were observed in OZ supplemented rats with N-nitrosodiethylamine induced liver tumerogenesis. OZ was found to be effective for reduction of N-nitrosodiethylamine induced hepatocellular carcinoma.

A novel neurological function of rice bran: a standardized rice bran supplement promotes non-rapid eye movement sleep in mice through histamine H1 receptors

SCOPE

Although rice bran has been shown to be associated with a wide spectrum of health benefits, to date, there are no reports on its effects on sleep. We investigated the effect of rice bran on sleep and the mechanism underlying this effect.

METHODS AND RESULTS

Electroencephalography was used to evaluate the effects of standardized rice bran supplement (RBS) and doxepin hydrochloride (DH), a histamine H₁ receptor (H₁ R) antagonist used as a positive control, on sleep in mice. The mechanism of RBS action was investigated using knockout (KO) mice and ex vivo electrophysiological recordings. Oral administration of RBS and DH significantly decreased sleep latency and increased the amount of non-rapid eye movement sleep (NREMS) in mice. Similar to DH, RBS fully inhibited H₁ R agonist-induced increase in action potential frequency in tuberomammillary nucleus neurons. In H₁ R KO mice, neither RBS nor DH administration led to the increase in NREMS and decrease in sleep latency observed in WT mice. These results indicate that the sleep-promoting effect of RBS is completely dependent on H₁ R antagonism.

CONCLUSIONS

RBS decreases sleep latency and promotes NREMS through the inhibition of H₁ R, suggesting that it could be a promising therapeutic agent for insomnia.

Scientific Evidence of Rice By-Products for Cancer Prevention: Chemopreventive Properties of Waste Products from Rice Milling on Carcinogenesis In Vitro and In Vivo

Cancer is a significant global health concern affecting men and women worldwide. Although current chemopreventive drugs could inhibit the growth of cancer cells, they exert many adverse side effects. Dietary factor plays a crucial role in the management of cancers and has drawn the attention of researchers to be used as an option to combat this disease. Both in vitro and in vivo studies showed that rice and its by-products display encouraging results in the prevention of this disease. The mechanism of anticancer effect is suggested partly through potentiation of bioactive compounds like vitamin E, phytic acid, γ-aminobutyric acid (GABA), γ-oryzanol, and phenolics. Nevertheless, the bioactivity of rice and its by-products is still incompletely understood. In this review, we present the findings from a preclinical study both in in vitro and in animal experiments on the promising role of rice by-products with focus on cancer prevention.

Effects of extracted rice bran supplementation on growth performance, nutrient digestibility, diarrhea score, blood profiles, and fecal microbial shedding in comparison with apramycin (antibiotic growth promoter) in weanling pigs

This study evaluated the efficacy of extracted rice bran (ERB) in weanling piglets. One hundred forty weanling pigs [(Yorkshire × Landrace) × Duroc] with an average BW of 5.70 ± 1.41 kg (21 d of age) were fed in two phases in a 6-wk experiment. Weanling pigs were allotted to diets containing 0 or 0.1 g kg−1 of ERB, and 0 or 165 mg kg−1 of apramycin according to a 2 × 2 factorial arrangement of treatments. Both apramycin and ERB supplementation increased growth efficiency (G:F) during phase 1 and overall, respectively (P < 0.05). The apparent total tract digestibility (ATTD) of dry matter (DM) was increased in response to either ERB or apramycin at wk 2 and 6 (P < 0.05). Supplementation of ERB decreased total cholesterol (TC) and increased high-density lipoprotein cholesterol (HDL-C) in diets lacking ERB at wk 6 (P < 0.05). Pigs receiving diets supplemented with apramycin reduced Escherichia coli at wk 2 and 6, and Salmonella counts at wk 6 (P < 0.05). Supplementation of ERB increased fecal Lactobacillus and reduced Salmonella counts at wk 6 (P < 0.05). In conclusion, results indicated that dietary supplementation of ERB improved performance in weanling pigs.

Nootropic and anti-stress effects of rice bran oil in male rats

Rice bran oil (RBO) is an important product of rice bran. It is considered to be one of the most important nutritious oil due to its favorable fatty acid composition and unique composition of naturally occurring biologically active antioxidant compounds. This study was designed to monitor the effects of oral intake of RBO on stress response in rats. RBO was extracted using hexane. Rats were divided into Control and test (RBO-treated). RBO-treated rats were given 0.2 ml/day RBO for 6 weeks. Food intake and body weight changes were monitored weekly. After 6 weeks open field activity and Morris Water Maze (MWM) test were performed. Results showed that weekly cumulative food intake but not body weight were lower in RBO-treated rats during 1st to 5th week of treatment, which were normalized at the end of treatment. Exploratory activity of RBO-treated rats in an open field was increased. Spatial memory in Morris water maze was enhanced in RBO-treated than control rats. An episode of 2 h restraint stress decreased the 24 h food intake of both control and RBO-treated animals. Behavioral deficits were lower in RBO-treated rats. Exposure of 2 h restraint stress increased brain serotonin (5-hydroxytryptamine: 5-HT) metabolism. These increases were lower in RBO-treated restrained than their respective control animals. Serotonergic neurotransmitter mechanism is implicated in stress. The findings of the study show beneficial effects of RBO in learning and memory functions. Moreover, the study also highlights the attenuating effect of RBO on stress induced behavioral and neurochemical effects in rats.

In vitro antioxidant assay of medium chain fatty acid rich rice bran oil in comparison to native rice bran oil

The study aimed to evaluate the in vitro antioxidant activity of medium chain fatty acid (MCFA) rich-rice bran oils in comparison with native rice bran oil. Different in vitro methods were used to evaluate the free radical scavenging activity, metal chelation activity, reducing acitivity, ABTS radical scavenging activity, thiobarbituric acid (TBA) value and so on at different concentrations of the oils such as 10-100 μg/mL. Inhibition of lipid peroxidation was evaluated measuring thiobarbituric acid responsive substance (TBARS) and conjugated diene formation. All the oils showed potent antioxidant activity at 100 μg/mL concentration. TBARS formation and conjugated diene formation was lower with MCFA rich oils i.e. the inhibition of lipid peroxidation was more in MCFA rich oils than original rice bran oil. Caprylic acid rich rice bran oil showed maximum antioxidant activity in comparison to capric- and lauric acid rich rice bran oils. Overall the MCFA rich rice bran oils showed to be more potent antioxidant than rice bran oil due to their lower unsaturated fatty acid content.

Dietary rice bran protects against rotavirus diarrhea and promotes Th1-type immune responses to human rotavirus vaccine in gnotobiotic pigs

Rice bran (RB) contains a distinct stoichiometry of phytochemicals that can promote gut mucosal immune responses against enteric pathogens. The effects of RB on rotavirus diarrhea and immunogenicity of an attenuated human rotavirus (HRV) vaccine were evaluated in gnotobiotic pigs. The four treatment groups studied were RB plus vaccine, vaccine only, RB only, and mock control. Pigs in the RB groups were fed the amount of RB that replaced 10% of the pigs' total daily calorie intake from milk starting from 5 days of age until they were euthanized. Pigs in the vaccine groups were orally inoculated with two doses of the attenuated HRV vaccine. A subset of pigs from each group was orally challenged with the homologous virulent HRV on postinoculation day 28. Diarrhea and virus shedding were monitored daily from postchallenge day 0 to day 7. RB feeding significantly protected against diarrhea upon virulent HRV challenge and enhanced the protective rate of the vaccine against rotavirus diarrhea. Consistent with protection, RB significantly increased gamma interferon (IFN-γ)-producing CD4(+) and CD8(+) T cell responses in intestinal and systemic lymphoid tissues. Furthermore, RB also increased the number of total IgM- and IgA-secreting cells, total serum IgM, IgG, and IgA titers, and HRV-specific IgA titers in intestinal contents. RB reduced the numbers of intestinal and systemic HRV-specific IgA and IgG antibody-secreting cells and reduced serum HRV-specific IgA and IgG antibody titers before the challenge. These results demonstrate clear beneficial effects of RB in protection against rotavirus diarrhea and stimulation of nonspecific and HRV-specific immune responses, as well as its biased Th1-type adjuvant effect for the vaccine.

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

Rice plants produce bioactive rice brans and hulls that have been reported to have numerous health-promoting effects in cells, animals, and humans. The main objective of this review is to consolidate and integrate the widely scattered information on the composition and the antioxidative, anti-inflammatory, and immunostimulating effects of rice brans from different rice cultivars, rice bran oils derived from rice brans, rice hulls, liquid rice hull smoke derived from rice hulls, and some of their bioactive compounds. As part of this effort, this paper also presents brief summaries on the preparation of health-promoting foods including bread, corn flakes, frankfurters, ice cream, noodles, pasta, tortillas, and zero-trans-fat shortening as well as industrial products such bioethanol and biodiesel fuels. Also covered are antibiotic, antiallergic, anticarcinogenic, antidiabetic, cardiovascular, allelochemical, and other beneficial effects and the mechanisms of the bioactivities. The results show that food-compatible and safe formulations with desirable nutritional and biological properties can be used to develop new multifunctional foods as well as bioethanol and biodiesel fuel. The overlapping aspects are expected to contribute to a better understanding of the potential impact of the described health-promoting potential of the rice-derived brans, oils, and hulls in food and medicine. Such an understanding will enhance nutrition and health and benefit the agricultural and industrial economies.

Chemopreventive properties of dietary rice bran: current status and future prospects

Emerging evidence suggests that dietary rice bran may exert beneficial effects against several types of cancer, such as breast, lung, liver, and colorectal cancer. The chemopreventive potential has been related to the bioactive phytochemicals present in the bran portion of the rice such as ferulic acid, tricin, β-sitosterol, γ-oryzanol, tocotrienols/tocopherols, and phytic acid. Studies have shown that the anticancer effects of the rice bran-derived bioactive components are mediated through their ability to induce apoptosis, inhibit cell proliferation, and alter cell cycle progression in malignant cells. Rice bran bioactive components protect against tissue damage through the scavenging of free radicals and the blocking of chronic inflammatory responses. Rice bran phytochemicals have also been shown to activate anticancer immune responses as well as affecting the colonic tumor microenvironment in favor of enhanced colorectal cancer chemoprevention. This is accomplished through the modulation of gut microflora communities and the regulation of carcinogen-metabolizing enzymes. In addition, the low cost of rice production and the accessibility of rice bran make it an appealing candidate for global dietary chemoprevention. Therefore, the establishment of dietary rice bran as a practical food-derived chemopreventive agent has the potential to have a significant impact on cancer prevention for the global population.

Consumption of rice bran increases mucosal immunoglobulin A concentrations and numbers of intestinal Lactobacillus spp

Gut-associated lymphoid tissue maintains mucosal homeostasis by combating pathogens and inducing a state of hyporesponsiveness to food antigens and commensal bacteria. Dietary modulation of the intestinal immune environment represents a novel approach for enhancing protective responses against pathogens and inflammatory diseases. Dietary rice bran consists of bioactive components with disease-fighting properties. Therefore, we conducted a study to determine the effects of whole dietary rice bran intake on mucosal immune responses and beneficial gut microbes. Mice were fed a 10% rice bran diet for 28 days. Serum and fecal samples were collected throughout the study to assess total immunoglobulin A (IgA) concentrations. Tissue samples were collected for cellular immune phenotype analysis, and concentrations of native gut Lactobacillus spp. were enumerated in the fecal samples. We found that dietary rice bran induced an increase in total IgA locally and systemically. In addition, B lymphocytes in the Peyer's patches of mice fed rice bran displayed increased surface IgA expression compared with lymphocytes from control mice. Antigen-presenting cells were also influenced by rice bran, with a significant increase in myeloid dendritic cells residing in the lamina propria and mesenteric lymph nodes. Increased colonization of native Lactobacillus was observed in rice bran-fed mice compared with control mice. These findings suggest that rice bran-induced microbial changes may contribute to enhanced mucosal IgA responses, and we conclude that increased rice bran consumption represents a promising dietary intervention to modulate mucosal immunity for protection against enteric infections and induction of beneficial gut bacteria.

New prebiotics from rice bran ameliorate inflammation in murine colitis models through the modulation of intestinal homeostasis and the mucosal immune system

BACKGROUND

Enzyme-treated rice fiber (ERF) is a recently developed prebiotic product made from rice bran by heat-resistant amylase, protease and hemicellulase treatment. Although the detailed mechanism of inflammatory bowel disease (IBD) is still unclear, the role of the resident luminal bacteria and its interaction on the mucosal barrier seem to be an important factor in the development of IBD and its chronicity. With the objective of manipulating the intestinal microbiota in IBD, this study was carried out to evaluate the effects of ERF on IBD with using experimental colitis models.

METHODS

Three colitis models were used and they were induced by the oral administration of dextran sodium sulfate in male Sprague-Dawley rats or BALB/c mice and transferring CD4+ CD45RB(high) T cells to female SCID mice, sequentially their CD4+ T cells were retransferred to new SCID mice. The evaluation included the measurement of body weight, spleen weight, colon length, histological examination, serum and mucosal cytokine (tumor necrosis factor-alpha (TNF-α), an interferon-gamma (IFN-γ), interleukin-12 p70 (IL-12p70), IL-1β, IL-6, IL-4) analysis, mucosal serotonin (5HT), and organic acid production and a microbiota analysis of the cecal contents. The characteristics of T cell surface markers including CD4, CD69, CD45RB of spleen and mesenteric lymph nodes (MLN) were also analyzed. In addition, the effects of ERF on the change in the induction of dendritic cells (DCs) were evaluated.

RESULTS

The preventive effect of ERF on colitis was significantly superior to that of raw material rice bran or control group. An overexpression of inflammatory cytokine production was attenuated by ERF treatment, which was accompanied with a decrease in both the colonic mucosal damage and 5HT production. Furthermore, ERF significantly attenuated the T cell activation (CD4+CD69+) of spleen and MLN, and this characteristic was inherited by the retransferred mice. ERF significantly suppressed the growth of Clostiridium, and increased short-chain fatty acids (acetate, propionate and butyrate) content in colitis. The relatively hydrophilic fraction of ERF (ethanol-methanol soluble fraction) is therefore considered to have a potent ability to attenuate the induction of DCs.

CONCLUSION

A new prebiotic, ERF, reduced inflammation by modulating the colonic environment and regulating immune cell differentiation. Although a more detailed study is required, this study showed the promising anti-inflammatory effects of an adjunctive prebiotic treatment for IBD.

Metabolomic and functional genomic analyses reveal varietal differences in bioactive compounds of cooked rice

Emerging evidence supports that cooked rice (Oryza sativa L.) contains metabolites with biomedical activities, yet little is known about the genetic diversity that is responsible for metabolite variation and differences in health traits. Metabolites from ten diverse varieties of cooked rice were detected using ultra performance liquid chromatography coupled to mass spectrometry. A total of 3,097 compounds were detected, of which 25% differed among the ten varieties. Multivariate analyses of the metabolite profiles showed that the chemical diversity among the varieties cluster according to their defined subspecies classifications: indica, japonica, and aus. Metabolite-specific genetic diversity in rice was investigated by analyzing a collection of single nucleotide polymorphisms (SNPs) in genes from biochemical pathways of nutritional importance. Two classes of bioactive compounds, phenolics and vitamin E, contained nonsynonymous SNPs and SNPs in the 5′ and 3′ untranslated regions for genes in their biosynthesis pathways. Total phenolics and tocopherol concentrations were determined to examine the effect of the genetic diversity among the ten varieties. Per gram of cooked rice, total phenolics ranged from 113.7 to 392.6 µg (gallic acid equivalents), and total tocopherols ranged between 7.2 and 20.9 µg. The variation in the cooked rice metabolome and quantities of bioactive components supports that the SNP-based genetic diversity influenced nutritional components in rice, and that this approach may guide rice improvement strategies for plant and human health.

Dietary fish oil n-3 fatty acids increase regulatory cytokine production and exert anti-inflammatory effects in two murine models of inflammation

The higher incidence of inflammatory diseases in Western countries might be related, in part, to a high consumption of saturated fatty acids and n-6 polyunsaturated fatty acids (PUFA) and an insufficient intake of n-3 fatty acids. The purpose of this study was to examine the effects of dietary n-3 fatty acids on innate and specific immune response and their anti-inflammatory action in models of contact and atopic dermatitis. Balb/C mice were fed for 3 wk either n-6 or n-3 PUFA-fortified diets. After inducing a contact or an atopic dermatitis, immunological parameters were analyzed to evaluate the anti-inflammatory potential of these n-3 PUFA. n-3 PUFA reduced innate and specific immune responses through inhibition of TH1 and TH2 responses, increase of immunomodulatory cytokines such as IL-10, and regulation of gene expression. The inhibition of both kinds of responses was confirmed by the anti-inflammatory effect observed in contact and atopic dermatitis. Reduction in weight, edema, thickness, leukocyte infiltration, and enhancement of antioxidant defenses in the inflamed ears of mice from both models along with the prevention of delayed-type hypersensitivity induced in atopic dermatitis proved n-3 PUFA efficacy. Our data suggest that dietary fish oil-derived n-3 fatty acids have immunomodulatory effects and could be useful in inflammatory disorders.

Membrane fatty acids, oxidative burst and phagocytosis after enrichment of P388D1 monocyte/macrophages with essential 18-carbon fatty acids

The fatty acid composition of cell membranes can be modified in cell culture. The role of different fatty acid families in modulating phagocytosis and oxidative burst is not clear and therefore the influence of 18-carbon polyunsaturated fatty acids (PUFA) on these processes was examined. The mouse monocyte/macrophage line P388D1 was cultured in medium supplemented with 2 or 20 micromol/l 18:2n-6 (linoleic acid; LA) or 18:3n-3 (alpha-linolenic acid; LNA) and fatty acid enrichment of the cells was tested after 8 days. The macrophages were activated with phorbol ester in order to promote oxidative burst and intracellular dihydrorhodamine oxidation was determined. To test phagocytosis capacity uptake of fluorescence-labeled Escherichia coli was determined. Activation of the transcription factor nuclear factor (NF)-kappaB was also determined. Cells grown in medium with 20 micromol/l LA contained 2- to 3-fold more n-6 PUFA including 4-fold more arachidonic acid. Cells grown in medium with 20 micromol/l LNA contained 4-fold more n-3 PUFA. Both LA and LNA enhanced phagocytosis and decreased oxidative burst, with little difference between the fatty acids. NF-kappaB activation at 1 h post-stimulation was not affected by adding LA or LNA to the culture medium. We conclude that the fatty acid composition of macrophages influences their ability to phagocytose and mount oxidative burst.

Diet supplementation for 5 weeks with polyphenol-rich cereals improves several functions and the redox state of mouse leucocytes

BACKGROUND

Cereals naturally contain a great variety of polyphenols, which exert a wide range of physiological effects both in vitro and in vivo. Many of their protective effects, including an improvement of the function and redox state of immune cells in unhealthy or aged subjects come from their properties as powerful antioxidant compounds. However, whether cereal-based dietary supplementation positively affects the immune function and cellular redox state of healthy subjects remains unclear.

AIM OF THE STUDY

To investigate the effects of supplementation (20% wt/wt) for 5 weeks with four different cereal fractions on healthy mice.

METHODS

Several parameters of function and redox state of peritoneal leukocytes were measured. The cereals, named B (wheat germ), C (buckwheat flour), D (fine rice bran) and E (wheat middlings) contained different amounts of gallic acid, p-hydroxybenzoic acid, vanillic acid, sinapic acid, p-coumaric acid, ferulic acid, quercetin, catechin, rutin and oryzanol as major polyphenols.

RESULTS

In general, all cereal fractions caused an improvement of the leukocyte parameters studied such as chemotaxis capacity, microbicidal activity, lymphoproliferative response to mitogens, interleukin-2 (IL-2) and tumor necrosis factor (TNFalpha) release, as well as oxidized glutathione (GSSG), GSSG/GSH ratio, catalase (CAT) activity and lipid oxidative damage. We observed similar effects among the cereal fractions.

CONCLUSIONS

The results suggest that some of these effects may due, at least partially, to the antioxidant activity of the polyphenols naturally present in cereals. Since an appropriate function of the leukocytes has been proposed as marker of the health state, a short-term intake of cereals seems to be sufficient to exert a benefit in the health of the general population. However, further studies are needed to assess the optimal doses and to find out which active polyphenols are able to mediate the observed physiological effects before recommending their regular consumption.

Effect of dietary argan oil on fatty acid composition, proliferation, and phospholipase D activity of rat thymocytes

OBJECTIVE

Argan oil is receiving increasing attention due to its potential health benefits in the prevention of cardiovascular risk, but no information to date is available about its possible effect on immune cells and functions.

METHODS

To address this issue male rats were fed one of five diets that contained fish oil, argan oil, olive oil, coconut oil, or sunflower oil for 4 wk. The fatty acid composition of plasma and thymocyte lipids was then analyzed in relation to the mitogen-induced proliferation and phospholipase D (PLD) activity of thymocytes.

RESULTS

The 18:2omega-6 proportion in thymocyte phospholipids from rats fed argan oil was significantly lower than that observed in phospholipids from rats fed sunflower oil and fish oil but higher than that found in the olive oil and coconut oil groups. Further, a significant positive linear relation was found between thymocyte proliferation and the 18:2omega-6 proportion in thymocyte phospholipids, whatever the diet. The proliferation response of thymocytes to mitogenic activation was also inversely correlated to PLD activity measured in intact thymocytes. Subsequent western blotting experiments indicated that the diet-induced variations in PLD activity mainly reflected variations in the expression of PLD2 protein.

CONCLUSIONS

On the whole, the present study shows that the effects of argan oil on immune cells are very similar to those of olive oil, and that, as a consequence, argan oil can be used as a balanced dietary supply without marked adverse effects on immune cell function.