A rice bran oil diet improves lipid abnormalities and suppress hyperinsulinemic responses in rats with streptozotocin/nicotinamide-induced type 2 diabetes

An open label randomized controlled trial of the effects of rice bran oil on cardiometabolic risk factors, lipid peroxidation and antioxidant status in overweight/obese adults with metabolic syndrome

INTRODUCTION

We previously documented the beneficial effects of rice bran oil (RBO) on cardiac function and atherogenic cardiometabolic factors in men with coronary artery disease. Therefore, the existing evidence in this area aims to be expanded by investigating the impact of adding RBO to a daily standard diet on emerging insulin resistance surrogate markers, lipid peroxidation, antioxidant status, and metabolic disturbances in individuals with metabolic syndrome (MetSyn) through an open-label controlled trial.

METHODS

A total of 50 overweight/obese adults (mean body mass index (BMI) = 31.08 kg/m2) with at least 3 MetSyn components were randomly allocated to either the control group, which received a standard diet plan, or the intervention group, which was supplemented with 30 g/d RBO for 8 weeks. BMI, MetSyn components, metabolic score for insulin resistance (METS-IR), triglyceride‒glucose‒BMI (TyG‒BMI), malondialdehyde (MDA), total antioxidant capacity (TAC), and plasma polyphenol levels were measured before and after this open-label trial.

RESULTS

Analysis of covariance (ANCOVA) adjusted for baseline values revealed that, compared with patients who received only a standard diet, those who were supplemented with 30 g/d RBO presented significantly lower total cholesterol (P value = 0.005; effect size (ES):-0.92), LDL-cholesterol (P value = 0.048; ES:-0.62), fasting blood glucose (P value = 0.014; ES:-0.77), MDA (P value = 0.002; ES: -1.01), METS-IR (P value < 0.001; ES: -1.24), and TyG-BMI (P value = 0.007; ES:-0.85) after 8 weeks. Additionally, RBO consumption resulted in significantly higher levels of HDL-C (P value = 0.004; ES:0.94) and TAC (P value < 0.0001; ES:2.05). However, no significant changes were noted in BMI, waist circumference, serum triglycerides, plasma polyphenols, or blood pressure.

CONCLUSION

Although the current findings suggest that the hypocholesterolemic, antihyperglycemic, and antioxidative effects of 30 g/d RBO seem to be promising for MetSyn patients, they should be considered preliminary. Therefore, further well-designed clinical trials with larger sample sizes and longer durations are needed to confirm these findings.

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.

Revealing metabolic and biochemical variations via 1H NMR metabolomics in streptozotocin-nicotinamide-induced diabetic rats treated with metformin

The increasing prevalence of lean diabetes has prompted the generation of animal models that mimic metabolic disease in humans. This study aimed to determine the optimum streptozotocin-nicotinamide (STZ-NA) dosage ratio to elicit lean diabetic features in a rat model. It also used a proton nuclear magnetic resonance (1H NMR) urinary metabolomics approach to identify the metabolic effect of metformin treatment on this novel rat model. Three different STZ-NA dosage regimens (by body weight: Group A: 110 mg/kg NA and 45 mg/kg STZ; Group B: 180 mg/kg NA and 65 mg/kg STZ and Group C: 120 mg/kg NA and 60 mg/kg STZ) were administered to Sprague-Dawley rats along with oral metformin. Group A diabetic rats (A-DC) showed favorable serum biochemical analyses and a more positive response toward oral metformin administration relative to the other STZ-NA dosage ratio groups. Orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed that glucose, citrate, pyruvate, hippurate, and methylnicotinamide differentiating the OPLS-DA of A-MTF rats (Group A diabetic rats treated with metformin) and A-DC model rats. Subsequent metabolic pathway analyses revealed that metformin treatment was associated with improvement in dysfunctions caused by STZ-NA induction, including carbohydrate metabolism, cofactor metabolism, and vitamin and amino acid metabolism. In conclusion, our results identify the best STZ-NA dosage ratio for a rat model to exhibit lean type 2 diabetic features with optimum sensitivity to metformin treatment. The data presented here could be informative to improve our understanding of non-obese diabetes in humans through the identification of possible activated metabolic pathways in the STZ-NA-induced diabetic rats model.

An Overview of Herbal-Based Antidiabetic Drug Delivery Systems: Focus on Lipid- and Inorganic-Based Nanoformulations

Diabetes is a metabolic pathology with chronic high blood glucose levels that occurs when the pancreas does not produce enough insulin or the body does not properly use the insulin it produces. Diabetes management is a puzzle and focuses on a healthy lifestyle, physical exercise, and medication. Thus far, the condition remains incurable; management just helps to control it. Its medical treatment is expensive and is to be followed for the long term, which is why people, especially from low-income countries, resort to herbal medicines. However, many active compounds isolated from plants (phytocompounds) are poorly bioavailable due to their low solubility, low permeability, or rapid elimination. To overcome these impediments and to alleviate the cost burden on disadvantaged populations, plant nanomedicines are being studied. Nanoparticulate formulations containing antidiabetic plant extracts or phytocompounds have shown promising results. We herein aimed to provide an overview of the use of lipid- and inorganic-based nanoparticulate delivery systems with plant extracts or phytocompounds for the treatment of diabetes while highlighting their advantages and limitations for clinical application. The findings from the reviewed works showed that these nanoparticulate formulations resulted in high antidiabetic activity at low doses compared to the corresponding plant extracts or phytocompounds alone. Moreover, it was shown that nanoparticulate systems address the poor bioavailability of herbal medicines, but the lack of enough preclinical and clinical pharmacokinetic and/or pharmacodynamic trials still delays their use in diabetic patients.

Rice bran oil could favorably ameliorate atherogenicity and insulin resistance indices among men with coronary artery disease: post hoc analysis of a randomized controlled trial

BACKGROUND

Despite recent advances in recognizing more reliable indicators to estimate the coronary artery disease (CAD) patients' response to treatment and prognosis, less attention has been paid to evaluating them in clinical trials. Hence, the present research was conducted to study the impact of rice bran oil (RBO) versus sunflower oil (SFO) on various atherogenicity and insulin resistance markers.

METHODS

In the present 8-week randomized controlled trial, 40 CAD men with an average age of 56 years were allocated randomly into the intervention or control group to use RBO or SFO (30 g/day) plus a standardized dietary plan. As a further analysis, eight atherosclerosis-related indices were calculated before and after the study.

RESULTS

Analysis of covariance test in which potential confounders and baseline levels were considered, indicated that using RBO compared to SFO reduced Castelli's risk index I and II (adjusted means:3.29, 1.52 vs. 4.61, 2.20, respectively), atherogenic coefficient (2.29 vs. 3.61), lipoprotein combine index (6.54 vs. 17.53), and cholesterol index (0.46 vs. 1.20) after the trial (P-value ≤ 0.002). Also, the RBO group yielded significantly lower triglyceride glucose index (8.73 vs. 9.13) (P-value = 0.010). Further, marginally significant amelioration in triglyceride/HDL ratio and atherogenic index of plasma (1.48 and 0.13 vs. 1.86 and 0.24 respectively) were noted (P-value = 0.07). Spearman correlation analysis detected significant positive correlations between alterations in TNF-α serum levels (ng/L) and the majority of evaluated indices (P-value < 0.05).

CONCLUSION

Taken together, incorporating 30 g of RBO into the patient's usual diet appeared effective in ameliorating atherogenicity and insulin resistance indicators among men with CAD, probably in relation to its anti-inflammatory properties.

TRIAL REGISTRATION

The protocol of the current trial was retrospectively recorded in the Iranian clinical trial registration system (IRCT) with the registration number of IRCT20190313043045N1 (URL: https://en.irct.ir/trial/38346 ; Registration date: 2019-04-27).

Enhancing health benefits of milled rice: current status and future perspectives

Milled rice is an essential part of the regular diet for approximately half of the world's population. Its remarkable commercial value and consumer acceptance are mostly due to its promising cooking qualities, appealing sensory properties, and longer shelf life. However, the significant loss of the nutrient-rich bran layer during milling makes it less nutritious than the whole grain. Thus, enhancing the nutritive value of milled rice is vital in improving the health and wellbeing of rice consumers, particularly for those residing in the low-economic zones where rice is the primary source of calories and nutrition. This article provides a critical review on multiple frontiers of recent interventions, such as (1) infusing the genetic diversity to enrich amylose and resistant starch to reduce glycaemic index, (2) enhancing the minerals and vitamins through complementary fortification and biofortification as short and long-term interventions, and (3) developing transgenic solutions to improve the nutrient levels of milled rice. Additionally, the review highlights the benefits of functional ingredients of milled rice to human health and the potential of enhancing them in rice to address the triple burden of malnutrition. The potential merit of milled rice concerning food safety is also reviewed in this article.

The effects of rice bran oil on left ventricular systolic function, cardiometabolic risk factors and inflammatory mediators in men with coronary artery disease: a randomized clinical trial

BACKGROUND/OBJECTIVE

In the current study, we aimed to explore the effects of rice bran oil (RBO) in adjunct to conventional medical therapy on left ventricular ejection fraction (LVEF), cardiometabolic risk factors, and inflammatory mediators in male patients with coronary artery disease (CAD).

SUBJECTS/METHODS

The present randomized controlled trial included 40 men diagnosed with CAD (mean age = 55.76 years) who were randomly allocated into two groups to receive either 30 grams per day of RBO (intervention group) or sunflower oil (control group) plus a standard diet for eight weeks. At the initial visit, demographic and anthropometric data and blood samples were collected. LVEF levels and serum concentrations of lipid profile, glucose, uric acid, hs-CRP, and TNF-α were investigated.

RESULTS

A total of 37 participants completed the study (n = 18 in the intervention group, n = 19 in the control group). Analysis of covariance (ANCOVA) adjusted for baseline values, age and body mass index revealed that RBO significantly improved LVEF (51.34%) and reduced triglyceride (125.01 mg dl^-1), blood sugar (110.4 mg dl^-1), total cholesterol (123.01 mg dl^-1) and low density lipoprotein (56.88 mg dl^-1) levels compared to sunflower oil ((45.56%), (155.93 mg dl^-1), (128.94 mg dl^-1), (163.93 mg dl^-1) and (83.79 mg dl^-1), respectively) following a 8-week trial (P-values < 0.05). Additionally, the test demonstrated that RBO consuming patients had significantly lower levels of serum uric acid (4.60 mg dl^-1), TNF-α (6.99 ng L^-1) and hs-CRP (2.11 mg L^-1) compared to the control group ((5.92 mg dl^-1), (15.23 ng L^-1), (4.47 mg L^-1), respectively) (P-value < 0.05). However, no significant changes were found regarding weight, blood pressure or serum HDL levels throughout the trial.

CONCLUSION

Consumption of 30 grams per day RBO within a standard diet could be considered an effective non-pharmacological approach in improving LVEF, cardiometabolic risk factors, and inflammatory state in CAD. However, future trials are recommended for more clarification.

Influence of germinated brown rice-based flour modified by MAse on type 2 diabetic mice and HepG2 cell cytotoxic capacity

This study aimed to discover whether using maltogenic amylase (MAse) to modify starch in germinated brown rice flour may enhance slow digestion starch and release more bioactive compounds (BCs) content. To achieve this aim, the starch was modified with four levels of MAse (0 U, 133 U, 266 U and 399 U MAse/g flour) for 1 hr at pH 5 and then spray-dried to make modified flour. The biochemical impacts of the products were then accessed in normal and type 2 diabetic mice for 4 weeks. The result showed that when the starch was modified by MAse 266 U/g, a significant reduction of rapidly digested starch to 22.35% from 61.56%, an increase in slowly digested starch to 33.09% while resistant starch as 2.92% corresponding to the increase of γ-amino butyric acid to 528.1 ± 44.1 mg/L and 120.6 ± 10.9 mg/L of ferulic acid. The extract from modified flour showed very strong cytotoxic activity against HepG2 cell (>80% inhibition). The result in vivo showed that the type-2 diabetic mice fed with this modified product could better improve the stability of the glycemic index. Also, atherosclerotic plaque assessment further supports these findings. The results indicated that BCs released considerably couple with the changes in starch properties caused by MAse enhanced the effectiveness of this product to diabetes as well as positive effect on cytotoxic activity against HepG2 cell.

Modulation of Lipid Transport and Adipose Tissue Deposition by Small Lipophilic Compounds

Small lipophilic molecules present in foods of plant origin have relevant biological activities at rather low concentrations. Evidence suggests that phytosterols, carotenoids, terpenoids, and tocopherols can interact with different metabolic pathways, exerting beneficial effects against a number of metabolic diseases. These small molecules can modulate triacylglycerol absorption in the intestine and the biosynthesis of chylomicrons, the lipid carriers in the blood. Once in the bloodstream, they can impact lipoprotein clearance from blood, thereby affecting fatty acid release, incorporation into adipocytes and triglyceride reassembling and deposit. Consequently, some of these molecules can regulate pathophysiological processes associated to obesity and its related conditions, such as insulin resistance, metabolic syndrome and type-2 diabetes. The protective capacity of some lipophilic small molecules on oxidative and chemotoxic stress, can modify the expression of key genes in the adaptive cellular response, such as transcription factors, contributing to prevent the inflammatory status of adipose tissue. These small lipophilic compounds can be incorporated into diet as natural parts of food but they can also be employed to supplement other dietary and pharmacologic products as nutraceuticals, exerting protective effects against the development of metabolic diseases in which inflammation is involved. The aim of this review is to summarize the current knowledge of the influence of dietary lipophilic small biomolecules (phytosterols, carotenoids, tocopherols, and triterpenes) on lipid transport, as well as on the effects they may have on pathophysiological metabolic states, related to obesity, insulin resistance and inflammation, providing an evidence-based summary of their main beneficial effects on human health.

Actions of annatto-extracted tocotrienol supplementation on obese postmenopausal women: study protocol for a double-blinded, placebo-controlled, randomised trial

INTRODUCTION

Obesity is a major health concern in postmenopausal women, and chronic low-grade inflammation contributes to the development of obesity. Cellular studies and high-fat-diet-induced obese mouse model mimicking obesity show the antiobesity effect of annatto-extracted tocotrienols (TT) with antioxidant capability. We aim to assess the safety and efficacy of TT consumption for lipid-related parameters in obese postmenopausal women.

METHODS AND ANALYSIS

Eligible obese postmenopausal women will be randomly assigned to placebo group (430 mg olive oil) and TT group (DeltaGold Tocotrienol 70%) for 24 weeks. In the present study, the primary outcome is total/regional fat mass and visceral adipose tissue. The secondary outcomes include lipid profile in serum, mRNA expression of fatty acid synthase and carnitine palmitoyltransferase 1A in fat tissue, oxylipins and endocannabinoids in plasma and adipose tissue, abundance and composition of intestinal microbiome in faeces, high-sensitivity C-reactive protein (hs-CRP) in serum and leptin in serum. Every participant will be evaluated at 0 (prior to starting intervention) and 24 weeks of intervention, except for serum lipid profile and hs-CRP at 0, 12 and 24 weeks. 'Intent-to-treat' principle is employed for data analysis. Hierarchical linear modelling is used to estimate the effects of dietary TT supplementation while properly accounting for dependency of data and identified covariates. To our knowledge, this is the first randomised, placebo-controlled, double-blinded study to determine dietary TT supplementation on an obese population. If successful, this study will guide the future efficacy TT interventions and TT can be implemented as an alternative for obese population in antiobesity management.

ETHICS AND DISSEMINATION

This study has been approved by the Bioethics Committee of the Texas Tech University Health Sciences Center, Lubbock. An informed consent form will be signed by a participant before enrolling in the study. The results from this trial will be actively disseminated through academic conference presentation and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03705845.

Potential Role of Tocotrienols on Non-Communicable Diseases: A Review of Current Evidence

Tocotrienol (T3) is a subfamily of vitamin E known for its wide array of medicinal properties. This review aimed to summarize the health benefits of T3, particularly in prevention or treatment of non-communicable diseases (NCDs), including cardiovascular, musculoskeletal, metabolic, gastric, and skin disorders, as well as cancers. Studies showed that T3 could prevent various NCDs, by suppressing 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in the mevalonate pathway, inflammatory response, oxidative stress, and alternating hormones. The efficacy of T3 in preventing/treating these NCDs is similar or greater compared to tocopherol (TF). TF may lower the efficacy of T3 because the efficacy of the combination of TF and T3 was lower than T3 alone in some studies. Data investigating the effects of T3 on osteoporosis, arthritis, and peptic ulcers in human are limited. The positive outcomes of T3 treatment obtained from the preclinical studies warrant further validation from clinical trials.

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.

The Role of Tocotrienol in Protecting Against Metabolic Diseases

Obesity is a major risk factor for diabetes, and these two metabolic conditions cause significant healthcare burden worldwide. Chronic inflammation and increased oxidative stress due to exposure of cells to excess nutrients in obesity may trigger insulin resistance and pancreatic β-cell dysfunction. Tocotrienol, as a functional food component with anti-inflammatory, antioxidant, and cell signaling-mediating effects, may be a potential agent to complement the current management of obesity and diabetes. The review aimed to summarize the current evidence on the anti-obesity and antidiabetic effects of tocotrienol. Previous studies showed that tocotrienol could suppress adipogenesis and, subsequently, reduce body weight and fat mass in animals. This was achieved by regulating pathways of lipid metabolism and fatty acid biosynthesis. It could also reduce the expression of transcription factors regulating adipogenesis and increase apoptosis of adipocytes. In diabetic models, tocotrienol was shown to improve glucose homeostasis. Activation of peroxisome proliferator-activated receptors was suggested to be responsible for these effects. Tocotrienol also prevented multiple systemic complications due to obesity and diabetes in animal models through suppression of inflammation and oxidative stress. Several clinical trials have been conducted to validate the antidiabetic of tocotrienol, but the results were heterogeneous. There is no evidence showing the anti-obesity effects of tocotrienol in humans. Considering the limitations of the current studies, tocotrienol has the potential to be a functional food component to aid in the management of patients with obesity and diabetes.

The relationship between lipid phytochemicals, obesity and its related chronic diseases

This review focuses on phytochemicals in oils, and summarizes the mechanisms of the anti-obesity effects of these compounds in in vitro studies, animal models, and human trials.

Heat-stabilised rice bran consumption by colorectal cancer survivors modulates stool metabolite profiles and metabolic networks: a randomised controlled trial

Rice bran (RB) consumption has been shown to reduce colorectal cancer (CRC) growth in mice and modify the human stool microbiome. Changes in host and microbial metabolism induced by RB consumption was hypothesised to modulate the stool metabolite profile in favour of promoting gut health and inhibiting CRC growth. The objective was to integrate gut microbial metabolite profiles and identify metabolic pathway networks for CRC chemoprevention using non-targeted metabolomics. In all, nineteen CRC survivors participated in a parallel randomised controlled dietary intervention trial that included daily consumption of study-provided foods with heat-stabilised RB (30 g/d) or no additional ingredient (control). Stool samples were collected at baseline and 4 weeks and analysed using GC-MS and ultra-performance liquid chromatography-MS. Stool metabolomics revealed 93 significantly different metabolites in individuals consuming RB. A 264-fold increase in β-hydroxyisovaleroylcarnitine and 18-fold increase in β-hydroxyisovalerate exemplified changes in leucine, isoleucine and valine metabolism in the RB group. A total of thirty-nine stool metabolites were significantly different between RB and control groups, including increased hesperidin (28-fold) and narirutin (14-fold). Metabolic pathways impacted in the RB group over time included advanced glycation end products, steroids and bile acids. Fatty acid, leucine/valine and vitamin B₆ metabolic pathways were increased in RB compared with control. There were 453 metabolites identified in the RB food metabolome, thirty-nine of which were identified in stool from RB consumers. RB consumption favourably modulated the stool metabolome of CRC survivors and these findings suggest the need for continued dietary CRC chemoprevention efforts.

Vitamin E As a Potential Interventional Treatment for Metabolic Syndrome: Evidence from Animal and Human Studies

A constellation of medical conditions inclusive of central obesity, hyperglycemia, hypertension, and dyslipidemia is known as metabolic syndrome (MetS). The safest option in curtailing the progression of MetS is through maintaining a healthy lifestyle, which by itself, is a long-term commitment entailing much determination. A combination of pharmacological and non-pharmacological approach, as well as lifestyle modification is a more holistic alternative in the management of MetS. Vitamin E has been revealed to possess anti-oxidative, anti-inflammatory, anti-obesity, anti-hyperglycemic, anti-hypertensive and anti-hypercholesterolemic properties. The pathways regulated by vitamin E are critical in the development of MetS and its components. Therefore, we postulate that vitamin E may exert some health benefits on MetS patients. This review intends to summarize the evidence in animal and human studies on the effects of vitamin E and articulate the contrasting potential of tocopherol (TF) and tocotrienol (T3) in preventing the medical conditions associated with MetS. As a conclusion, this review suggests that vitamin E may be a promising agent for attenuating MetS.

Muscadine grape seed oil as a novel source of tocotrienols to reduce adipogenesis and adipocyte inflammation

Tocotrienols are unsaturated forms of vitamin E previously shown to reduce adipogenesis and adipose inflammation. In this study, muscadine grape seed oil (MGSO) was identified as a novel source of tocotrienols containing significant amounts of α- and γ-tocotrienol (T3) with minor seasonal changes. The aim of this study was to assess the anti-adipogenic and anti-inflammatory potential of MGSO by using primary human adipose-derived stem cells (hASCs). Differentiating hASCs were treated with MGSO and compared with rice bran and olive oil. Accumulation of triglyceride was significantly lower in MGSO-treated hASCs than rice bran and olive oils. A tocotrienol rich fraction (TRF) from MGSO was prepared by solid phase extraction and eluted with 15% 1,4-dioxane in hexane. The MGSO-derived TRF treatment significantly reduced mRNA and protein expression that are crucial to adipogenesis (e.g., PPARγ and aP2) in hASCs. Furthermore, TRF from MGSO markedly reduced LPS-induced proinflammatory gene expression in human adipocytes and cytokine secretion to the medium (IL-6 and IL-8). Collectively, our work suggests that MGSO is a stable and reliable natural source of T3 and MGSO may constitute a new dietary strategy to attenuate obesity and its associated adipose inflammation.

Regulation of Obesity and Metabolic Complications by Gamma and Delta Tocotrienols

Tocotrienols (T3s) are a subclass of unsaturated vitamin E that have been extensively studied for their anti-proliferative, anti-oxidative and anti-inflammatory properties in numerous cancer studies. Recently, T3s have received increasing attention due to their previously unrecognized property to attenuate obesity and its associated metabolic complications. In this review, we comprehensively evaluated the recent published scientific literature about the influence of T3s on obesity, with a particular emphasis on the signaling pathways involved. T3s have been demonstrated in animal models or human subjects to reduce fat mass, body weight, plasma concentrations of free fatty acid, triglycerides and cholesterol, as well as to improve glucose and insulin tolerance. Their mechanisms of action in adipose tissue mainly include (1) modulation of fat cell adipogenesis and differentiation; (2) modulation of energy sensing; (3) induction of apoptosis in preadipocytes and (4) modulation of inflammation. Studies have also been conducted to investigate the effects of T3s on other targets, e.g., the immune system, liver, muscle, pancreas and bone. Since δT3 and γT3 are regarded as the most active isomers among T3s, their clinical relevance to reduce obesity should be investigated in human trials.

Effect of Cichorium intybus L. on the expression of hepatic NF-κB and IKKβ and serum TNF-α in STZ- and STZ+ niacinamide-induced diabetes in rats

BACKGROUND

Inflammation is an early event in the development of diabetes type 2 (T2D). Cichorium intybus L. (chicory) possesses anti-inflammatory action. We compared the anti-inflammatory aspect of aqueous chicory seed extract (CSE) in early and late stage T2D in rats.

METHODS

Wistar albino rats were divided into nine final groups (n = 6). Three main groups consisted of non-diabetic (Control), early stage diabetes (ET2D; niacinamide/streptozotocin, i.e., NIA/STZ), and late stage diabetes (LT2D; STZ). Within each main group, a subgroup was treated with CSE (125 mg/kg; i.p.); within each diabetic group (STZ and NIA/STZ) a subgroup received metformin (100 mg/kg; i.p.); another subgroup in STZ group received aspirin (120 mg/kg; oral). After 21 days, fasting blood glucose (FBS), insulin, and TNF-α level were measured in serum; IKKβ and NF-κB (p65) mRNA and protein expression were evaluated by real time PCR and Western blotting; p65 DNA binding activity was determined by ELISA, in liver tissue.

RESULTS

The mRNA and protein expression levels of IKKβ, and P65 genes increased in both stages of T2D (p < 0.01); CSE decreased their expression (p < 0.001, mRNAs; p < 0.05, proteins). The increased DNA-binding capacity of NF-κB (p < 0.0001) in diabetes was lowered by CSE (p < 0.001). The effect of CSE was limited to ET2D requiring insulin.

CONCLUSIONS

The anti-inflammatory action of CSE is due to a direct modulation of cytokine expression. The dependency of chicory action on the presence of insulin indicates its usefulness in the early stages of diabetes and for the purpose of preventing and delaying diabetes onset.

Rice bran oil and canola oil improve blood lipids compared to sunflower oil in women with type 2 diabetes: A randomized, single-blind, controlled trial

BACKGROUND

Hypolipidemic effects of vegetable oils have been demonstrated in a number of studies, but there is no study, which compares the effects of canola oil (CO) and rice bran oil (RBO) on diabetic patient. We aimed to compare the effects of CO and RBO consumption on blood lipids in women with type 2 diabetes.

METHODS

Seventy-five postmenopausal women with type 2 diabetes participated in this single-center, randomized, controlled, parallel-group trial in Shiraz, Iran. Participants were randomly allocated to three groups including a control group (balance diet + 30 g/d sunflower oil) and two intervention groups (balance diet + 30 g/day CO or RBO). At baseline and after 8 weeks, serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured.

RESULTS

At 8 weeks, mean of serum levels of TG (mg/dL), TC (mg/dL), and LDL-C (mg/dL) significantly decreased in the CO group (-23.66, P < .001; -11.92, P < .001; and -6.33, P = .013, respectively) and RBO group (-38.62, P < .001; -17.25, P < .001; and -8.90, P = .002, respectively) compared with the controls (7.01, 4.06, and 2.90, respectively). Also, in comparison with CO group, the changes of TG, LDL-C, and non-HDL-C levels were significantly more in the RBO group (P = .007, P = .012, and P = .011, respectively). Levels of serum HDL-C remained unchanged in all groups at the end of study.

CONCLUSIONS

Substitution of RBO or CO for sunflower oil could attenuate lipid disorders in type 2 diabetes women. Moreover, RBO could improve lipid profile more efficiently than CO.

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.

Pharmacological potential of tocotrienols: a review

Tocotrienols, members of the vitamin E family, are natural compounds found in a number of vegetable oils, wheat germ, barley, and certain types of nuts and grains. Like tocopherols, tocotrienols are also of four types viz. alpha, beta, gamma and delta. Unlike tocopherols, tocotrienols are unsaturated and possess an isoprenoid side chain. Tocopherols are lipophilic in nature and are found in association with lipoproteins, fat deposits and cellular membranes and protect the polyunsaturated fatty acids from peroxidation reactions. The unsaturated chain of tocotrienol allows an efficient penetration into tissues that have saturated fatty layers such as the brain and liver. Recent mechanistic studies indicate that other forms of vitamin E, such as γ-tocopherol, δ-tocopherol, and γ-tocotrienol, have unique antioxidant and anti-inflammatory properties that are superior to those of α-tocopherol against chronic diseases. These forms scavenge reactive nitrogen species, inhibit cyclooxygenase- and 5-lipoxygenase-catalyzed eicosanoids and suppress proinflammatory signalling, such as NF-κB and STAT. The animal and human studies show tocotrienols may be useful against inflammation-associated diseases. Many of the functions of tocotrienols are related to its antioxidant properties and its varied effects are due to it behaving as a signalling molecule. Tocotrienols exhibit biological activities that are also exhibited by tocopherols, such as neuroprotective, anti-cancer, anti-inflammatory and cholesterol lowering properties. Hence, effort has been made to compile the different functions and properties of tocotrienols in experimental model systems and humans. This article constitutes an in-depth review of the pharmacology, metabolism, toxicology and biosafety aspects of tocotrienols. Tocotrienols are detectable at appreciable levels in the plasma after supplementations. However, there is inadequate data on the plasma concentrations of tocotrienols that are sufficient to demonstrate significant physiological effect and biodistribution studies show their accumulation in vital organs of the body. Considering the wide range of benefits that tocotrienols possesses against some common human ailments and having a promising potential, the experimental analysis accounts for about a small fraction of all vitamin E research. The current state of knowledge deserves further investigation into this lesser known form of vitamin E.

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.

Pharmacological potential of tocotrienols: a review

Tocotrienols, members of the vitamin E family, are natural compounds found in a number of vegetable oils, wheat germ, barley, and certain types of nuts and grains. Like tocopherols, tocotrienols are also of four types viz. alpha, beta, gamma and delta. Unlike tocopherols, tocotrienols are unsaturated and possess an isoprenoid side chain. Tocopherols are lipophilic in nature and are found in association with lipoproteins, fat deposits and cellular membranes and protect the polyunsaturated fatty acids from peroxidation reactions. The unsaturated chain of tocotrienol allows an efficient penetration into tissues that have saturated fatty layers such as the brain and liver. Recent mechanistic studies indicate that other forms of vitamin E, such as γ-tocopherol, δ-tocopherol, and γ-tocotrienol, have unique antioxidant and anti-inflammatory properties that are superior to those of α-tocopherol against chronic diseases. These forms scavenge reactive nitrogen species, inhibit cyclooxygenase- and 5-lipoxygenase-catalyzed eicosanoids and suppress proinflammatory signalling, such as NF-κB and STAT. The animal and human studies show tocotrienols may be useful against inflammation-associated diseases. Many of the functions of tocotrienols are related to its antioxidant properties and its varied effects are due to it behaving as a signalling molecule. Tocotrienols exhibit biological activities that are also exhibited by tocopherols, such as neuroprotective, anti-cancer, anti-inflammatory and cholesterol lowering properties. Hence, effort has been made to compile the different functions and properties of tocotrienols in experimental model systems and humans. This article constitutes an in-depth review of the pharmacology, metabolism, toxicology and biosafety aspects of tocotrienols. Tocotrienols are detectable at appreciable levels in the plasma after supplementations. However, there is inadequate data on the plasma concentrations of tocotrienols that are sufficient to demonstrate significant physiological effect and biodistribution studies show their accumulation in vital organs of the body. Considering the wide range of benefits that tocotrienols possesses against some common human ailments and having a promising potential, the experimental analysis accounts for about a small fraction of all vitamin E research. The current state of knowledge deserves further investigation into this lesser known form of vitamin E.

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.

Simultaneous HPLC quantification of five major triterpene alcohol and sterol ferulates in rice bran oil using a single reference standard

A high performance liquid chromatography (HPLC) method was developed for simultaneous quantification of five major triterpene alcohol and sterol ferulates in rice bran oils (RBO) with a single internal standard, cycloartenyl ferulate. The five compounds are cycloartenyl ferulate (1), 24-methylene cycloartanyl ferulate (2), campesteryl ferulate (3), sitosteryl ferulate (4) and stigmastanyl ferulate (5). All five compounds had good linear concentration-measurement relationships (r(2) ≥ 0.9995) and possessed similar relative response factors. The relative deviation of this method was less than 2.5% for intra- and inter-day assays, and the average recovery varied from 95.1% to 99.4%. The new method was validated by comparing the amount of 24-methylene cycloartanyl ferulate (2) in 17 RBO samples obtained with this method and that with an external standard method. This method was also successfully applied to determine five major triterpene alcohol and sterol ferulates in 17 batches of RBO samples. The results demonstrated that the present method could be utilised for quality control of RBO since some of the reference standards are not commercially available.

Effects of rice bran oil on the intestinal microbiota and metabolism of isoflavones in adult mice

This study examined the effects of rice bran oil (RBO) on mouse intestinal microbiota and urinary isoflavonoids. Dietary RBO affects intestinal cholesterol absorption. Intestinal microbiota seem to play an important role in isoflavone metabolism. We hypothesized that dietary RBO changes the metabolism of isoflavonoids and intestinal microbiota in mice. Male mice were randomly divided into two groups: those fed a 0.05% daidzein with 10% RBO diet (RO group) and those fed a 0.05% daidzein with 10% lard control diet (LO group) for 30 days. Urinary amounts of daidzein and dihydrodaidzein were significantly lower in the RO group than in the LO group. The ratio of equol/daidzein was significantly higher in the RO group (p < 0.01) than in the LO group. The amount of fecal bile acids was significantly greater in the RO group than in the LO group. The composition of cecal microbiota differed between the RO and LO groups. The occupation ratios of Lactobacillales were significantly higher in the RO group (p < 0.05). Significant positive correlation (r = 0.591) was observed between the occupation ratios of Lactobacillales and fecal bile acid content of two dietary groups. This study suggests that dietary rice bran oil has the potential to affect the metabolism of daidzein by altering the metabolic activity of intestinal microbiota.

Dietary rice bran promotes resistance to Salmonella enterica serovar Typhimurium colonization in mice

Background

Dietary rice bran consists of many bioactive components with disease fighting properties; including the capacity to modulate the gut microbiota. Studies point to the important roles of the gut microbiota and the mucosal epithelium in the establishment of protection against enteric pathogens, such as Salmonella. The ability of rice bran to reduce the susceptibility of mice to a Salmonella infection has not been previously investigated. Therefore, we hypothesized that the incorporation of rice bran into the diet would inhibit the colonization of Salmonella in mice through the induction of protective mucosal responses.

Results

Mice were fed diets containing 0%, 10% and 20% rice bran for one week prior to being orally infected with Salmonella enterica serovar Typhimurium. We found that mice consuming the 10 and 20% rice bran diets exhibited a reduction in Salmonella fecal shedding for up to nine days post-infection as compared to control diet fed animals (p < 0.05). In addition, we observed decreased concentrations of the pro-inflammatory cytokines, TNF-alpha, IFN-gamma, and IL-12 (p < 0.05) as well as increased colonization of native Lactobacillus spp. in rice bran fed mice (p < 0.05). Furthermore, in vitro experiments revealed the ability of rice bran extracts to reduce Salmonella entry into mouse small intestinal epithelial cells.

Conclusions

Increasing rice bran consumption represents a novel dietary means for reducing susceptibility to enteric infection with Salmonella and potentially via induction of native Lactobacillus spp.

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.

Effects of rice bran oil on the blood lipids profiles and insulin resistance in type 2 diabetes patients

The aim of this study was to investigate the influence of rice bran oil consumption on plasma lipids and insulin resistance in patients with type 2 diabetes. Thirty-five patients with type 2 diabetes were randomly assigned to a placebo group or a rice bran oil group. The placebo group consumed 250 mL soybean oil-modified milk (18 g soybean oil) daily for 5 weeks, and the rice bran oil group consumed 250 mL rice bran oil modified milk (18 g rice bran oil) daily for 5 weeks. At week 0 and week 5, anthropometric measurements, hematology tests, and an oral-glucose-tolerance test were conducted. The results showed that the homeostasis model assessment index of insulin resistance, the area under the curve for postprandial serum insulin, and serum low-density-lipoprotein cholesterol concentrations increased significantly in the placebo group. In the rice bran oil group, fasting and 2-h postprandial blood glucose concentrations and the area under the curve for postprandial plasma glucose increased significantly; however, total serum cholesterol and low-density-lipoprotein cholesterol concentrations decreased significantly. However, the homeostasis model assessment index of insulin resistance was not significantly different. Consumption of 18 g rice bran oil modified milk daily for 5 weeks significantly decreased total serum cholesterol concentrations and tended to decrease low-density-lipoprotein cholesterol concentrations in patients with type 2 diabetes. However, no significant influence on insulin resistance was observed.

Tocotrienols, the vitamin E of the 21st century: its potential against cancer and other chronic diseases

Initially discovered in 1938 as a "fertility factor," vitamin E now refers to eight different isoforms that belong to two categories, four saturated analogues (α, β, γ, and δ) called tocopherols and four unsaturated analogues referred to as tocotrienols. While the tocopherols have been investigated extensively, little is known about the tocotrienols. Very limited studies suggest that both the molecular and therapeutic targets of the tocotrienols are distinct from those of the tocopherols. For instance, suppression of inflammatory transcription factor NF-κB, which is closely linked to tumorigenesis and inhibition of HMG-CoA reductase, mammalian DNA polymerases and certain protein tyrosine kinases, is unique to the tocotrienols. This review examines in detail the molecular targets of the tocotrienols and their roles in cancer, bone resorption, diabetes, and cardiovascular and neurological diseases at both preclinical and clinical levels. As disappointment with the therapeutic value of the tocopherols grows, the potential of these novel vitamin E analogues awaits further investigation.