Purification and identification of components of gamma-oryzanol in rice bran Oil

Antioxidant and antimicrobial evaluation of rice bran (Oryza sativa L.) extracts in a mayonnaise-type emulsion

The objective of this study was to evaluate the in vitro antimicrobial and antioxidant activities of different bran extracts and concentrations, and their influence on the parameters of a mayonnaise-type emulsion. To that end, first ethanol and then water were used to extract two rice bran extracts (RBE) from rice bran. Both these extracts were then added at two different concentrations (0.5 and 2%) to the emulsions that were subsequently analysed after seven days under two different storage temperatures, 4 °C and 20 °C. The antioxidant and antimicrobial ability of the extracts were evaluated, along with a control and a synthetic antioxidant. Results indicate the positive effect of rice bran extracts as additives in the food matrix. Ethanolic rice bran extract (EE) at 2% decreased the oxidation as well as mould and yeast proliferation and preserved the emulsion structure, while the other treatments acted in a similar way although their effect was less pronounced.

γ-Oryzanol mitigates oxidative stress and prevents mutant SOD1-Related neurotoxicity in Drosophila and cell models of amyotrophic lateral sclerosis

Oxidative stress plays a critical role in mutant copper/zinc superoxide dismutase 1 (SOD1)-linked amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease characterized by selective loss of motor neurons. Thus, an anti-oxidative stress remedy might be a promising means for the treatment of ALS. The aim of the present study is to investigate the neuroprotective effects of γ-oryzanol (Orz) and elucidate its relevant molecular mechanisms in mutant hSOD1-linked Drosophila and cell models of ALS. Orz treatment provided neuroprotection in flies with expression of hSOD1-G85R in motor neurons, as demonstrated by the prolonged survival, improvement of motor deficits, reduced oxidative damage and regulated redox homeostasis when compared with those in controls. Moreover, Orz significantly decreased neuronal apoptosis and upregulated the nuclear factor erythroid 2-related factor 2 (Nrf2)/glutamate-cysteine ligase catalytic subunit (GCLC) antioxidant pathway via activating Akt in hSOD1-G93A-expressing NSC-34 cells. In addition, our results showed that both in vivo and in vitro, Akt served as an upstream regulator of signal transducers and activators of transcription (Stat) 3 stimulated by Orz, which further increased the level of another anti-oxidative stress factor heat-shock protein 70 (HSP70). Altogether, these findings provide evidence that Orz has potential neuroprotective effects that may be beneficial in the treatment of ALS disease with SOD1 mutations.

Definitive evidence of the presence of 24-methylenecycloartanyl ferulate and 24-methylenecycloartanyl caffeate in barley

γ-Oryzanol (OZ), which has a lot of beneficial effects, is a mixture of ferulic acid esters of triterpene alcohols (i.e., triterpene alcohol type of OZ (TTA-OZ)) and ferulic acid esters of plant sterols (i.e., plant sterol type of OZ (PS-OZ)). Although it has been reported that OZ is found in several kinds of cereal typified by rice, TTA-OZ (e.g., 24-methylenecycloartanyl ferulate (24MCA-FA)) has been believed to be characteristic to rice and has not been found in other cereals. In this study, we isolated a compound considered as a TTA-OZ (i.e., 24MCA-FA) from barley and determined the chemical structure using by HPLC-UV-MS, high-resolution MS, and NMR. Based on these results, we proved for the first time that barley certainly contains 24MCA-FA (i.e., TTA-OZ). During the isolation and purification of 24MCA-FA from barley, we found the prospect that a compound with similar properties to OZ (compound-X) might exist. To confirm this finding, the compound-X was also isolated, determined the chemical structure, and identified as a caffeic acid ester of 24-methylenecycloartanol (24MCA-CA), which has rarely been reported before. We also quantified these compounds in various species of barley cultivars and found for the first time the existence of 24MCA-FA and 24MCA-CA in various barley. Through these findings, it opens the possibility to use barley as a new source of 24MCA-FA and 24MCA-CA.

Effect of Oil Content on Physiochemical Characteristics of γ-Oryzanol-Loaded Nanostructured Lipid Carriers

Nanostructured lipid carriers (NLCs) are used as alternative carriers for many different drug delivery administration routes. They are composed of both solid lipid and liquid lipid (oil content) with both influencing their structural properties. Amounts of liquid lipid in NLCs play a role in drug release. Effect of liquid lipid (oil content) on physiochemical characteristics of NLCs related to drug-release requires detailed investigation. Here, many techniques were performed to analyze the physiochemical characteristics of NLCs, especially inside the particles. γ-Oryzanol (GO)-loaded NLCs were prepared at varying solid lipid to liquid lipid ratios. Their physicochemical properties, drug release profiles, and stability studies of prepared NLCs were investigated. Oil contents in NLCs were found to play a significant role in physiochemical characteristics related to drug release and stability, and also influence the efficiency of analytical techniques such as transmission electron microscopy (TEM) and dynamic force microscopy (DFM). Moreover, x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) gave information regarding crystallinity inside the NLCs. FTIR showed broad peaks in the range from 1184 cm^-1 to 1475 cm^-1 while XRD presented a broad curve indicated amorphous forms in NLCs. Orthorhombic lattices (β' polymorph) were also elucidated by XRD and differential scanning calorimetry (DSC).

Comparison of Blood Profiles of γ-Oryzanol and Ferulic Acid in Rats after Oral Intake of γ-Oryzanol

γ-Oryzanol (OZ), a bioactive phytochemical abundant in cereals such as rice, has been reported to be mainly hydrolyzed to ferulic acid (FA) in the body. Meanwhile, in our previous study, we revealed that a part of OZ is absorbed into the body and exists in its intact form. However, the comprehensive absorption profile of OZ and its metabolites (e.g., FA) after OZ intake has not been fully elucidated yet. Therefore, in this study, we measured the concentrations of OZ, FA, and FA conjugates (i.e., FA sulfate and glucuronide) in the blood of rats with the use of HPLC-MS/MS after a single oral administration of 300 µmol/kg body weight of rice bran OZ (RBOZ). As a result, intact OZ along with FA and FA conjugates existed in the blood, which implied that these constituents may all contribute to the physiological effects under OZ intake. Additionally, when an equimolar amount of FA (300 µmol/kg body weight) was administered, it was found that the absorption profile of FA was significantly different from that when RBOZ was administered.

Spatial distribution mapping of molecules in the grains of different rice landraces, using desorption electrospray ionization mass spectrometry

RATIONALE

Documentation of the metabolite profiles of rice landraces is essential as most of them have been lost due to the conventional practices of cultivation. Therefore, application of mass spectrometry imaging (MSI) will be an appropriate analytical platform for molecular profiling, as it can provide a detailed understanding of the site-specific localization patterns of biomolecules, and the cues concerning metabolic pathways in organisms.

METHODS

Desorption electrospray ionization mass spectrometry (DESI-MS) is a relatively non-destructive analytical technique for surface sampling in natural conditions. Here, we report the spatial distribution of diverse molecules in the grains of different rice landraces of India using DESI-MSI. Molecules were identified by ESI-MS and tandem MS analysis of rice extracts. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used for the elemental mapping on the rice grains.

RESULTS

DESI-MSI showed a uniform distribution of choline (m/z 104.1), sucrose in the form of its sodium (m/z 365.1) and potassium (m/z 381.0) adducts, linoleic acid (m/z 279.2), 13-HODE-9-HODE (m/z 295.2), unidentified molecules with m/z 535.3, 559.5, and 561.5 and isoschaftoside (m/z 563.1) in the endosperm of rice grains. Gluconic acid (m/z 195.0) and signalling phospholipid intermediate molecules were localized in the embryo whereas oryzanol A (m/z 601.5) and oryzanol C (m/z 615.5) had a restricted localization in the bran region of the grain. SEM-EDS mapping showed the localization of potassium and phosphorus along the bran and embryo.

CONCLUSIONS

DESI-MSI revealed the distribution of lipids and sugar molecules in the specific regions of the rice grains. Thus, molecules unique to some rice varieties were identified with this analytical platform. Mass spectrometry imaging of rice along with the elemental mapping by SEM-EDS will be of use in understanding the localization pattern of certain molecules in the context of metals present in the grain.

γ-Oryzanol Improves Cognitive Function and Modulates Hippocampal Proteome in Mice

Rice (Oryza sativa L.) is the richest source of γ-oryzanol, a compound endowed with antioxidant and anti-inflammatory properties. γ-Oryzanol has been demonstrated to cross the blood-brain barrier in intact form and exert beneficial effects on brain function. This study aimed to clarify the effects of γ-oryzanol in the hippocampus in terms of cognitive function and protein expression. Adult mice were administered with γ-oryzanol 100 mg/kg or vehicle (control) once a day for 21 consecutive days following which cognitive behavior and hippocampal proteome were investigated. Cognitive tests using novel object recognition and Y-maze showed that long-term consumption of γ-oryzanol improves cognitive function in mice. To investigate the hippocampal proteome modulated by γ-oryzanol, 2D-difference gel electrophoresis (2D-DIGE) was performed. Interestingly, we found that γ-oryzanol modulates quantitative changes of proteins involved in synaptic plasticity and neuronal trafficking, neuroprotection and antioxidant activity, and mitochondria and energy metabolism. These findings suggested γ-oryzanol as a natural compound able to maintain and reinforce brain function. Although more intensive studies are needed, we propose γ-oryzanol as a putative dietary phytochemical for preserving brain reserve, the ability to tolerate age-related changes, thereby preventing clinical symptoms or signs of neurodegenerative diseases.

Impact of Crossing Parent and Environment on the Metabolite Profiles of Progenies Generated from a Low Phytic Acid Rice ( Oryza sativa L.) Mutant

The low phytic acid ( lpa) rice mutant Os-lpa-MH86-1, exhibiting a mutation-induced metabolite signature (i.e., increased levels of sugars, sugar alcohols, amino acids, phytosterols, and biogenic amines), was crossed with two commercial wild-type cultivars. The resulting progenies of generation F₈ harvested at three independent field trials were subjected to a GC/MS-based metabolite profiling approach. Statistical assessments via multivariate and univariate analyses demonstrated that the environment had a strong impact on the metabolite profiles of the resulting progenies. In addition, the metabolites of homozygous lpa progenies were significantly influenced by the lipid profiles of the wild-type cultivars employed as the crossing parents. However, for each individual field trial, both the lpa trait and the mutation-specific metabolite signature were consistently expressed in the homozygous lpa mutant progenies of the two crosses. The data underline that cross-breeding can be employed as a tool to generate lpa progeny rice seeds stably exhibiting the mutation-induced metabolic traits.

Anxiolytic effects of γ-oryzanol in chronically- stressed mice are related to monoamine levels in the brain

AIMS

The present study was aimed to investigate the anxiolytic effect of γ-oryzanol (GORZ) during chronic restraint stress treatment (CRST), which is a well-documented model of stress-related disorders, like anxiety, and its potential molecular mechanisms.

MATERIALS AND METHODS

In this experiment, 5-week-old male ICR mice were used and the concentration of GORZ was fixed at 0.5% in the mouse standard diet (14% casein, AIN 93 M). Mice were immobilized daily for 3 h from ZT 2.5 to 5.5 (ZT0 was designated as light-on time) for 20 consecutive days, followed by behavioral testing, including the open field test (OFT) and elevated plus maze (EPM) test. The concentration of serum corticosterone (CORT) was measured. In addition, the expression of central monoamine neurotransmitters with their metabolites in the hippocampus, cerebral cortex, and amygdala of the brain were examined.

KEY FINDINGS

0.5% GORZ partially blocked stress-induced reduction of body weight gain while stressed mice had significantly lower body weights during the entire experimental period. Further, 0.5% GORZ treatment could significantly improve the main behavioral parameters even in CRST situations. The significant increase in serum CORT levels indicated CRST-induced stress, which was almost unaffected by 0.5% GORZ treatment. Moreover, 0.5% GORZ also supported the anxiolytic mechanism with enhancement of 5-HIAA and NE levels in the amygdala of brain after CRST.

SIGNIFICANCE

Taken together, our studies suggested that 0.5% GORZ is a potential therapeutic drug candidate against anxiety under chronic stress conditions.

Redox Homeostasis and Natural Dietary Compounds: Focusing on Antioxidants of Rice (Oryza sativa L.)

Redox homeostasis may be defined as the dynamic equilibrium between electrophiles and nucleophiles to maintain the optimum redox steady state. This mechanism involves complex reactions, including nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, activated by oxidative stress in order to restore the redox balance. The ability to maintain the optimal redox homeostasis is fundamental for preserving physiological functions and preventing phenotypic shift toward pathological conditions. Here, we reviewed mechanisms involved in redox homeostasis and how certain natural compounds regulate the nucleophilic tone. In addition, we focused on the antioxidant properties of rice and particularly on its bioactive compound, γ-oryzanol. It is well known that γ-oryzanol exerts a variety of beneficial effects mediated by its antioxidant properties. Recently, γ-oryzanol was also found as a Nrf2 inducer, resulting in nucleophilic tone regulation and making rice a para-hormetic food.

γ-oryzanol ameliorates the acute stress induced by behavioral anxiety testing in mice

We evaluated the anxiolytic effect of γ-oryzanol (GORZ) and elucidated the molecular mechanisms involved in its inhibition of behavioral test-induced anxiety. Behavioral tests were conducted on day 13, and mice were subjected to 30 min of acute restraint stress treatment (ARST) before sacrifice on day 16. In other group, behavioral tests were conducted on day 13 and 14 after ARST. 0.5% GORZ significantly weakened the effect of behavioral stress, but not the effect of strong ARST. GORZ downregulated ARST-induced cFos levels in the cerebral cortex. In conclusion, GORZ has potential ant-anxiety effect in the treatment of weak behavioral test-induced stress.

Comparative Rice Bran Metabolomics across Diverse Cultivars and Functional Rice Gene⁻Bran Metabolite Relationships

Rice (Oryza sativa L.) processing yields ~60 million metric tons of bran annually. Rice genes producing bran metabolites of nutritional and human health importance were assessed across 17 diverse cultivars from seven countries using non-targeted metabolomics, and resulted in 378–430 metabolites. Gambiaka cultivar had the highest number and Njavara had the lowest number of metabolites. The 71 rice bran compounds of significant variation by cultivar included 21 amino acids, seven carbohydrates, two metabolites from cofactors and vitamins, 33 lipids, six nucleotides, and two secondary metabolites. Tryptophan, α-ketoglutarate, γ-tocopherol/β-tocopherol, and γ-tocotrienol are examples of bran metabolites with extensive cultivar variation and genetic information. Thirty-four rice bran components that varied between cultivars linked to 535 putative biosynthetic genes using to the OryzaCyc 4.0, Plant Metabolic Network database. Rice genes responsible for bran composition with animal and human health importance is available for rice breeding programs to utilize in crop improvement.

Stability of the Metabolite Signature Resulting from the OsSULTR3;3 Mutation in Low Phytic Acid Rice ( Oryza sativa L.) Seeds upon Cross-breeding

The low phytic acid ( lpa) rice ( Oryza sativa L.) mutant Os-lpa-MH86-1, resulting from the mutation of the putative sulfate transporter gene OsSULTR3;3, was crossed with a commercial rice cultivar. The obtained progenies of generations F₄ to F₇ were subjected to a nontargeted metabolite profiling approach allowing the analyses of a broad spectrum of lipophilic and hydrophilic low-molecular-weight constituents. The metabolite profiles of the homozygous lpa progenies were characterized not only by a decreased concentration of phytic acid but also by increased contents of constituents from various classes, such as sugars, sugar alcohols, amino acids, phytosterols, and biogenic amines. Statistical assessments of the data via multivariate and univariate approaches demonstrated that this mutation-induced metabolite signature was nearly unaffected by the cross-breeding step and consistently expressed over several generations. The data demonstrate that even for complex metabolic changes resulting from a mutation, cross-breeding can be employed as a tool to generate progeny rice seeds stably exhibiting the mutation induced traits.

Phytochemical Profile of Brown Rice and Its Nutrigenomic Implications

Whole grain foods have been promoted to be included as one of the important components of a healthy diet because of the relationship between the regular consumption of whole-grain foods and reduced risk of chronic diseases. Rice is a staple food, which has been widely consumed for centuries by many Asian countries. Studies have suggested that brown rice is associated with a wide spectrum of nutrigenomic implications such as anti-diabetic, anti-cholesterol, cardioprotective and antioxidant. This is because of the presence of various phytochemicals that are mainly located in bran layers of brown rice. Therefore, this paper is a review of publications that focuses on the bioactive compounds and nutrigenomic implications of brown rice. Although current evidence supports the fact that the consumption of brown rice is beneficial for health, these studies are heterogeneous in terms of their brown rice samples used and population groups, which cause the evaluation to be difficult. Future clinical studies should focus on the screening of individual bioactive compounds in brown rice with reference to their nutrigenomic implications.

Lecithin and phytosterols-based mixtures as hybrid structuring agents in different organic phases

In this study the effect of lecithin (L) addition and solvent quality in a well-established oleogel system formed by β-sitosterol and γ-oryzanol (BG) was investigated. Medium chain triglycerides (MCT) and sunflower oil (SFO) were used as triglycerides and hexadecane (HEX) as a model of linear hydrocarbon. Lecithin was proposed due to its natural and versatile properties, showing different functionalities such as emulsifier and co-oleogelator. A study based on hierarchical organization of structured oil was performed applying techniques for bulk, meso and nanoscale. Self-sustained structures could no longer be observed after 40 wt% of BG replacement by lecithin. Small-angle X-ray scattering showed that the formed nanostructures (building blocks) were dependent on type of solvent and BG:L ratio in the mixture of oleogelators. Differential scanning calorimetry showed that stability against temperature was improved decreasing the polarity of the oil, and a time-dependent self-assembly of hybrid systems was observed from thermal and rheological measurements. Microscopy images exhibited changes on typical fibril aggregation of BG as lecithin was added, which promoted to a certain extent the suppression of ribbons. Oscillatory shear and uniaxial compression measurements were influenced by BG:L ratio and solvent mainly at higher lecithin amount. The combination of BG and MCT appeared to be the most affected by lecithin incorporation whereas SFO rendered harder oleogels. These results could contribute to understand the role of both lecithin and solvent type influencing the host oleogelator structure. It was hypothesized that intermolecular BG complex formation is hindered by lecithin, besides this phospholipid also might coexist as a different phase, causing structural changes in the gel network. Addressing the role of co-oleogelator it can provide the opportunity to tune soft materials with adjusted properties.

Development of Colorectal-Targeted Dietary Supplement Tablets Containing Natural Purple Rice Bran Oil as a Colorectal Chemopreventive

Colorectal cancer occurs due to various factors. The important risks are dietary lifestyle and inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis. It has been found that the inhibitory enzyme cyclooxygenase-2 (COX-2) in the colorectal region can potentially reduce the risk of colorectal cancer. The present study investigated rice bran oil from natural purple rice bran, which exhibits antioxidant and anti-inflammatory activity. This study aimed to evaluate the bioactive compound content of natural purple rice bran oil (NPRBO) derived from native Thai purple rice and the anti-inflammatory activity of NPRBO in colorectal cancer cells, and to develop a colorectal delivery platform in the form of film-coated tablets. NPRBO from the rice bran of five different Thai purple rice cultivars, namely Khao’ Gam Leum-Phua (KGLP), Khao’ Gam Boung (KGB), Khao’ Gam Thor (KGT), Khao’ Gam Pah E-Kaw (KGPEK), and Khao’ Niaw Dam (KND), were extracted using the supercritical carbon dioxide extraction technique. The amount of γ-oryzanol (ORY), tocotrienols, and tocopherols present in NPRBOs and the in vitro anti-inflammatory activity of NPRBO were investigated. The highest anti-inflammatory NPRBO was transformed into a dry and free-flowing powder by liquisolid techniques. Then, it was compressed into core tablets and coated with Eudragit^®L100 and Eudragit^® NE30D. The in vitro release study of the film-coated NPRBO tablets was performed in three-phase simulated gastrointestinal media. The cultivar KGLP was superior to the other samples in terms of the ORY, tocotrienol and tocopherol contents and anti-inflammatory activity. Aerosil^® was the most suitable absorbent for transforming NPRBO into a free-flowing powder and was used to prepare the NPRBO core tablets. The in vitro KGLP-NPRBO film-coated tablet release profile showed that no ORY was released at gastric pH while 85% of ORY was released at pH 7.4 after 6 h; this would be expected to occur in the colorectal area. Therefore, this study demonstrates the potential of KGLP-NPRBO to prevent colorectal cancer via a specific colorectal dietary supplement delivery system.

Increases in Phenolic, Fatty Acid, and Phytosterol Contents and Anticancer Activities of Sweet Potato after Fermentation by Lactobacillus acidophilus

Phenolic, fatty acid, and phytosterol contents in sweet potato (SP) fermented by Lactobacillus acidophilus were evaluated and compared with those of raw and boiled SPs. The differences in the profiles and levels of phenolics between the raw and boiled SPs were not as significant as the differences between those and the fermented SP. The levels of caffeic acid and 3,5-dicaffeoylquinic acid in fermented SP were more than 4 times higher than those in raw and boiled SPs. Two phenolics, p-coumaric acid and ferulic acid, which were not detected in either raw or boiled SP, were found in fermented SP. The level of each fatty acid or phytosterol increased in fermented SP and decreased in boiled SP. Among the hydrophilic and lipophilic extracts obtained from raw and fermented SPs, the hydrophilic extract of fermented SP exhibited the highest capability of inhibiting cancer-cell PC-12 proliferation. However, each of the extracts had very low cytotoxicities to normal-monkey-kidney-cell growth. The results indicated that SP fermented by L. acidophilus significantly increased free antioxidant-rich phenolics and inhibited cancer-cell-proliferation activity without cytotoxicity to normal cells.

Development of γ-Oryzanol Rich Extract from Leum Pua Glutinous Rice Bran Loaded Nanostructured Lipid Carriers for Topical Delivery

Leum Pua is native Thai glutinous rice that contains antioxidants higher than white rice and other colored rice. One of the major antioxidants in rice brans is γ-oryzanol (GO). In this study, Leum Pua glutinous rice bran was extracted by different solvents. Oleic acid (~40 g/100 g extract), linoleic acid (~30 g/100 g extract), and palmitic acid (~20 g/100 g extract) were found to be major lipid components in the extracts. Methanol extract showed less variety of lipid components compared to the others. However, hexane extract showed the highest percent of γ-oryzanol compared to other solvents. Therefore, the hexane extract was selected to prepare nanostructured lipid carriers (NLC). The prepared NLC had small particles in the size range of 142.9 ± 0.4 nm for extract-loaded NLC and 137.1 ± 0.5 nm for GO-loaded NLC with narrow size distribution (PI < 0.1) in both formulations. The release profile of extract-loaded NLC formulation was slightly higher than GO-loaded NLC formulation. However, they did not follow the Higuchi model because of small amounts of γ-oryzanol loaded in NLC particles.

Bioactive components and functional properties of biologically activated cereal grains: A bibliographic review

Whole grains provide energy, nutrients, fibers, and bioactive compounds that may synergistically contribute to their protective effects. A wide range of these compounds is affected by germination. While some compounds, such as β-glucans are degraded, others, like antioxidants and total phenolics are increased by means of biological activation of grains. The water and oil absorption capacity as well as emulsion and foaming capacity of biologically activated grains are also improved. Application of biological activation of grains is of emerging interest, which may significantly enhance the nutritional, functional, and bioactive content of grains, as well as improve palatability of grain foods in a natural way. Therefore, biological activation of cereals can be a way to produce food grains enriched with health-promoting compounds and enhanced functional attributes.

Vertical liquid crystal orientation of phytochemical-based oryzanol modified polystyrene

The liquid crystal (LC) orientation properties on phytochemical oryzanol modified polystyrene film were investigated. This can contribute to development of eco-friendly LC orientation layers based on bioavailable resources containing polymer films.

Effect of Gamma-Oryzanol as Therapeutic Agent to Prevent Cardiorenal Metabolic Syndrome in Animals Submitted to High Sugar-Fat Diet

BACKGROUND

The high consumption of fat and sugar contributes to the development of obesity and co-morbidities, such as diabetes, and cardiovascular and kidney diseases. Different strategies have been used to prevent these diseases associated with obesity, such as changes in eating habits and/or the addition of dietary components with anti-inflammatory and anti-oxidant properties, such as gamma-oryzanol (γOz) present mainly in bran layers and rice germ.

METHODS

Animals were randomly divided into four experimental groups and fed ad libitum for 20 weeks with control diet (C, n = 8), control diet + γOz (C + γOz, n = 8), high-sugar and high-fat diet (HSF, n = 8), and high-sugar and high-fat diet + γOz (HSF + γOz, n = 8). HSF groups also received water + sucrose (25%). The dose of γOz was added to diets to reach 0.5% of final concentration (w/w). Evaluation in animals included food and caloric intake, body weight, plasma glucose, insulin, triglycerides, uric acid, HOMA-IR, glomerular filtration rate, protein/creatinine ratio, systolic blood pressure, and Doppler echocardiographic.

RESULTS

Animals that consumed the HSF diet had weight gain compared to group C, increased insulin, HOMA, glucose and triglycerides, there were also atrial and ventricular structural alterations, deterioration of systolic and diastolic function, decreased glomerular filtration rate, and proteinuria. Gamma-oryzanol is significantly protective against effects on body weight, hypertriglyceridemia, renal damage, and against structural and functional alteration of the heart.

CONCLUSION

Gamma-oryzanol shows potential as a therapeutic to prevent Cardiorenal Metabolic Syndrome.

γ-Oryzanol suppresses COX-2 expression by inhibiting reactive oxygen species-mediated Erk1/2 and Egr-1 signaling in LPS-stimulated RAW264.7 macrophages

Cyclooxygenase (COX)-2 produces prostanoids, which contribute to inflammatory responses. Nuclear factor (NF)-κB is a key transcription factor mediating COX-2 expression. γ-Oryzanol is an active component in rice bran oil, which inhibits lipopolysaccharide (LPS)-mediated COX-2 expression by inhibiting NF-κB. However, the inhibition of COX-2 expression by γ-oryzanol independently of NF-κB is poorly understood. We found that LPS upregulated Egr-1 expression at the transcriptional level. Forced expression of Egr-1 trans-activated the Cox-2 promoter independently of NF-κB. In contrast, silencing of Egr-1 abrogated LPS-mediated COX-2 expression. LPS produced reactive oxygen species (ROS), which, in turn, induced Egr-1 expression via the Erk1/2 MAPK pathway. ROS scavenging activity of γ-oryzanol suppressed Egr-1 expression by inhibiting the Erk1/2 MAPK pathway. Our results suggest that γ-oryzanol inhibits LPS-mediated COX-2 expression by suppressing Erk1/2-mediated Egr-1 expression. This study supports that γ-oryzanol may be useful for ameliorating LPS-mediated inflammatory responses.

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.

The content and distribution of steryl ferulates in wheat produced in Japan

Oryzanol contained in rice bran is a complex mixture of steryl ferulates (SFs) with many identified health benefits. Recently, SF has been shown to exist in other cereals such as wheat, rye, and corn. In this study, SFs in several wheats produced in Japan were analyzed. For instance, SF content of whole wheat grain, Yumekaori (Japan) was 15.2 ± 1.4 mg-oryzanol-equivalent/100 g grain, while that of the imported one, 1CW (Canada) was 11.4 ± 1.3 mg-oryzanol-equivalent/100 g grain. The main SF components in the examined wheats were campesteryl ferulate, campestanyl ferulate, and sitostanyl ferulate. SF distribution in whole wheat grain was investigated using 14 fractions produced by a conventional test milling machine. SF was intensively accumulated in the four bran fractions (24 - 95 mg-oryzanol-equivalent/100 g bran fraction). These results suggest that the wheat bran would be an important source of SF.

Phenolic Compounds of Cereals and Their Antioxidant Capacity

Phenolic compounds play an important role in health benefits because of their highly antioxidant capacity. In this review, total phenolic contents (TPCs), phenolic acid profile and antioxidant capacity of the extracted from wheat, corn, rice, barley, sorghum, rye, oat, and millet, which have been recently reported, are summarized. The review shows clearly that cereals contain a number of phytochemicals including phenolics, flavonoids, anthocyanins, etc. The phytochemicals of cereals significantly exhibit antioxidant activity as measured by trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging, reducing power, oxygen radical absorbance capacity (ORAC), inhibition of oxidation of human low-density lipoprotein (LDL) cholesterol and DNA, Rancimat, inhibition of photochemilumenescence (PCL), and iron(II) chelation activity. Thus, the consumption of whole grains is considered to have significantly health benefits in prevention from chronic diseases such as cardiovascular disease, diabetes, and cancer because of the contribution of phenolic compounds existed. In addition, the extracts from cereal brans are considered to be used as a source of natural antioxidants.

Isolation and Structure Determination of 24-Methylenecycloartanyl Ferulate from Indian Rice Bran and Its Quantitative Analysis

BACKGROUND

γ-oryzanol is a major bioactive constituent in rice. Most of the literature reports isolation of 24-methylenecycloartanyl ferulate (24-mCAF) from rice bran oil (RBO) of other than Indian variety. Current research has successfully applied high-performance thin layer chromatography (HPTLC) method for isolation of 24-mCAF from Indian variety (Indrayani) of RBO.

MATERIALS AND METHODS

HPTLC method was developed for standard γ-oryzanol using tinidazole as an internal standard. The proposed HPTLC method was optimized and validated as per the guidelines stated by the International Conference on Harmonization Q2 R1 recommendations. The mobile phase composed of toluene:ethyl acetate:methanol (15.0:1.7:3.3, (v/v/v) was selected because well-resolved peaks were obtained. The optimum wavelength chosen for detection and quantitation was 317 nm.

RESULTS

The retention factors for tinidazole, 24-mCAF, and CAF were found to be 0.27 ± 0.02, 0.72 ± 0.02, and 0.79 ± 0.02, respectively. The percent content of 24-mCAF in ethanol fraction was found to be 1.02%. The 24-mCAF was isolated from RBO using HPTLC method.

CONCLUSION

The characterization data of 1D, 2D spectral analysis confirm that the isolated compound 1 is 24-mCAF.

SUMMARY

HPTLC method was developed for standard γ-oryzanol using tinidazole as an internal standardThe proposed HPTLC method was optimized and validated as per the guidelines stated by the ICH Q2 R1 recommendationsThe characterization data of 1D, 2D spectral analysis confirms that the isolated compound is 24-methylenecycloartanyl ferulateIn this work, high purity 24-mCAF was successfully isolated from crude RBO using HPTLC with a solvent system composed toluene: ethyl acetate: methanol (15.0:1.7:3.3, v/v/v) Abbreviations used: RBO: Rice Bran Oil, CAF: Cycloartenol ferulic acid, 24-mCAF: 24-Methylcycloartenol ferulic acid, HPLC: High-Performance Liquid Chromatography, HPTLC: High-Performance Thin Layer Chromatography, 1H: Proton nuclear magnetic resonance spectroscopy, 13C: Carbon-13 nuclear magnetic resonance spectroscopy, COSY: Correlation spectroscopy, NOESY: Nuclear overhauser effect spectroscopy, HMBC: Heteronuclear multiple bond correlation nuclear magnetic resonance spectroscopy, HSQC: heteronuclear single quantum coherence nuclear magnetic resonance spectroscopy.

Antioxidant Activity of γ-Oryzanol: A Complex Network of Interactions

γ-oryzanol (Orz), a steryl ferulate extracted from rice bran layer, exerts a wide spectrum of biological activities. In addition to its antioxidant activity, Orz is often associated with cholesterol-lowering, anti-inflammatory, anti-cancer and anti-diabetic effects. In recent years, the usefulness of Orz has been studied for the treatment of metabolic diseases, as it acts to ameliorate insulin activity, cholesterol metabolism, and associated chronic inflammation. Previous studies have shown the direct action of Orz when downregulating the expression of genes that encode proteins related to adiposity (CCAAT/enhancer binding proteins (C/EBPs)), inflammatory responses (nuclear factor kappa-B (NF-κB)), and metabolic syndrome (peroxisome proliferator-activated receptors (PPARs)). It is likely that this wide range of beneficial activities results from a complex network of interactions and signals triggered, and/or inhibited by its antioxidant properties. This review focuses on the significance of Orz in metabolic disorders, which feature remarkable oxidative imbalance, such as impaired glucose metabolism, obesity, and inflammation.

Hypolipidemic mechanism of oryzanol components- ferulic acid and phytosterols

The effect of oryzanol (well known hypolipidemic component in rice bran oil) and its chemical constituents- ferulic acid (FA) and phytosterols on hypolipidemia were investigated.

METHODS AND RESULTS

Docking (in silico) studies showed that FA had a better binding ability with lipase while sterols bound well with HMG-CoA reductase. Further in vivo studies of feeding high fat (30%) to rats increased body weights, serum TC, TG, non-HDL-C and reduced HDL-C were observed, compared to normal diet fed group (ND). ORZ treated groups alleviated the lipid profile. Furthermore, increased organ weights, higher intestinal lipase activity, and liver lipid peroxidation was observed in the high-fat group (HF). These effects were ameliorated in oryzanol concentrate fed groups (ORZ). Higher fecal fat was found in ORZ groups, analysis of fecal matter by mass spectroscopy revealed the presence of FA. In vitro, a bile acid binding study supported the strong affinity of sterol towards bile acids. In conclusion, oryzanol in the intestine is cleaved into FA and sterol by intestinal lipase enzymes both lipase and HMG-CoA reductase activities were inhibited, respectively. These hydrolysates eliminated the bile acids, thus lowering lipid profiles.

Solubility of Bioactive Substances in Ethyl Lactate + Water Mixtures: Ferulic Acid and Caffeine

The solubility of ferulic acid in ethyl lactate + water mixtures was measured at ambient temperature and pressure, and reported for the first time in this work. It was demonstrated that the acid solubility in the respective mixed solvents was considerably higher than in either pure ethyl lactate or water. Similar behavior pattern was recently reported by the authors for the solubility of caffeine in ethyl lactate + water mixtures.

UNIQUAC and modified UNIFAC (Dortmund) were applied to represent the solubility of ferulic acid and caffeine in the mixed solvents and their capabilities to describe adequately the cosolvent effect observed was tested and compared. The results obtained demonstrated that the UNIQUAC model provided excellent correlation of the experimental data for both systems. The UNIFAC model, on the other hand, was applied in a completely predictive manner and produced very good results for ferulic acid solubility and just qualitative predictions for caffeine.

Microwave (MW) promoted high yield expedient synthesis of steryl ferulates--A class of novel biologically active compounds: A comparative study of their antioxidant activity with that of naturally occurring γ-oryzanol

Synthetic steryl ferulates [3-O-(trans-4-feruloyl)-sterols] are currently gaining considerable importance in recent years to be used as nutraceuticals and food additives as well as in pharmaceutical applications substituting γ-oryzanol - a class of naturally occurring steryl ferulates having potent antioxidant and other organoleptic properties. Considering the importance of this class of compounds coupled with green technology associated with microwave energy (MW) in organic synthesis, we report here an expedited and high yield synthesis of steryl ferulates from abundant steroids, viz., cholesterol, cholestanol, stigmasterol, stigmastanol, β-sitosterol, β-campesterol, β-campestanol and ergosterol applying MW energy in the crucial step of esterification process of sterols with trans-4-O-acetylferulic acid to furnish their esterified products, viz., 3-O-(trans-4-O-acetylferuloyl)-sterols for their eventual deprotection to their respective steryl ferulates. We further report an efficient and scalable process of producing acetylferulic acid. Testing of synthesized steryl ferulates against antioxidant assays has also been highlighted.

Investigation of nutriactive phytochemical - gamma-oryzanol in experimental animal models

Gamma-oryzanol (GO) is an abundant dietary antioxidant that is considered to have beneficial effects in cardiovascular disease, cancer and diabetes. Other potential properties of GO include inhibition of gastric acid secretion and decreased post-exercise muscle fatigue. GO is a unique mixture of triterpene alcohol and sterol ferulates present in rice bran oil, a byproduct of rice processing. GO has been studied by many researchers over the last three decades. In particular, the utility of GO supplementation has been documented in numerous animal models. A large variety of species was examined, and various experimental methodologies and targets were applied. The aim of this study was to summarize the body of research on GO supplementation in animals and to examine possible mechanisms of GO action. Furthermore, while the safety of GO supplementation in animals has been well documented, studies demonstrating pharmacokinetics, pharmacodynamics and efficiency are less clear. The observed differences in these findings are also discussed.

Kinetic study of the quenching reaction of singlet oxygen by seven rice bran extracts in ethanol solution. Development of a singlet oxygen absorption capacity (SOAC) assay method

Measurements of singlet oxygen (1O2) quenching rates (kQ (S)) and the relative singlet oxygen absorption capacity (SOAC) values were performed for seven rice bran extracts 1–7, which contained different concentrations of antioxidants (AOs) (such as α-, β-, γ-, and δ-tocopherols and -tocotrienols, three carotenoids (lutein, β-carotene, and zeaxanthin), and γ-oryzanol), in ethanol at 35 °C using UV–vis spectrophotometry. The concentrations of four tocopherols and four tocotrienols, three carotenoids, and γ-oryzanol contained in the extracts were determined using HPLC-MS/MS, UV-HPLC, and UV–vis absorption spectroscopy, respectively. Furthermore, comparisons of kQ (S) (Obsd.) values observed for the above extracts 1–7 with the sum of the product { [AO-i]} of the values obtained for each AO-i and the concentration ([AO-i]) of AO-i contained in extracts 1–7 were performed. From the results, it has been ascertained that the SOAC method is applicable to general food extracts to evaluate their 1O2-quenching activity.

Nigella sativa fixed and essential oil modulates glutathione redox enzymes in potassium bromate induced oxidative stress

BACKGROUND

Nigella sativa is an important component of several traditional herbal preparations in various countries. It finds its applications in improving overall health and boosting immunity. The current study evaluated the role of fixed and essential oil of Nigella sativa against potassium bromate induced oxidative stress with special reference to modulation of glutathione redox enzymes and myeloperoxidase.

METHODS

Animals; 30 rats (Sprague Dawley) were divided in three groups and oxidative stress was induced using mild dose of potassium bromate. The groups were on their respective diets (iso-caloric diets for a period of 56 days) i.e. control and two experimental diets containing N. sativa fixed (4%) and essential (0.3%) oils. The activities of enzymes involved in glutathione redox system and myeloperoxidase (MPO) were analyzed.

RESULTS

The experimental diets modulated the activities of enzymes i.e. glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx) positively. Indices of antioxidant status like tocopherols and glutathione were in linear relationship with that of GPx, GR and GST (P<0.01). MPO activities were in negative correlation with GST (P<0.01) but positive correlation with some other parameters.

CONCLUSIONS

Our results indicated that both Nigella sativa fixed and essential oil are effective in improving the antioxidant indices against potassium bromate induced oxidative stress.

Oryzanol as natural antioxidant for improving sunflower oil stability

Sunflower oil is being made shelf stable by the incorporation of synthetic antioxidants such as tertiary butyl hydroquinone (TBHQ), while natural antioxidants like oryzanol and tocopherols can also be used. The aim of the current investigation was to evaluate the antioxidant effect of natural oryzanol (Oz) concentrate (15.5 % oryzanol) and purified Oz (80 % oryzanol) on oxidative and thermal stability of sunflower oil. Sunflower oil was incorporated with Oz concentrate to provide 0, 0.12, 0.25, 0.50, 0.84, 1.0, 1.60, 2.0, 2.5 and 3.20 % oryzanol in the oil, stored for 5 weeks at 37 °C and oxidative stability was evaluated. It was found that the oryzanol concentrate showed good antioxidant effect with increase in concentration of oryzanol. In another set of experiments, sunflower oil containing purified Oz at 1 % level individually and in combination with 0.1 % α- tocopherol (α-T) was heated at 120 °C for 24 h to evaluate thermal stability. Sunflower oil containing 1 % Oz (80 % purity) showed 98.40 % and sunflower oil containing 1 % Oz and 0.1 % α-T showed 108.75 % antioxidant effect compared to TBHQ taken as 100 %. The study indicated that sunflower oil containing 1 % Oz (80 % purity) and 0.1 % α-T combination provides a synergistic effect in inhibiting primary and secondary products and showed highest thermal stability. SFO containing 1 % Oz added as concentrate also showed good antioxidant effect during storage. Hence, instead of using synthetic antioxidants like TBHQ, we can add natural oryzanol (purified or as concentrate) to sunflower oil to increase its oxidative and thermal stability.

Metabolite profiling of barley grain subjected to induced drought stress: responses of free amino acids in differently adapted cultivars

To investigate cultivar-specific metabolite changes upon drought stress in barley grain, differently adapted cultivars were field-grown under drought conditions using a rain-out shelter and under normal weather conditions (2010-2012). The grain was subjected to a gas chromatography-mass spectrometry-based metabolite profiling approach allowing the analyses of a broad spectrum of lipophilic and hydrophilic low molecular weight constituents. Multi- and univariate analyses demonstrated that there are grain metabolites which were significantly changed upon drought stress, either decreased or increased in all cultivars. On the other hand, for proteinogenic free amino acids increased concentrations were consistently observed in all seasons only in cultivars for which no drought resistance/tolerance had been described. Consistent decreases were seen only in the group of stress tolerant/resistant cultivars. These cultivar-specific correlations were particularly pronounced for branched-chain amino acids. The results indicate that free amino acids may serve as potential markers for cultivars differently adapted to drought stress.

Using metabolomic approaches to explore chemical diversity in rice

Rice (Oryza sativa) is an excellent resource; it comprises 25% of the total caloric intake of the world's population, and rice plants yield many types of bioactive compounds. To determine the number of metabolites in rice and their chemical diversity, the metabolite composition of cultivated rice has been investigated with analytical techniques such as mass spectrometry (MS) and/or nuclear magnetic resonance spectroscopy and rice metabolite databases have been constructed. This review summarizes current knowledge on metabolites in rice including sugars, amino and organic acids, aromatic compounds, and phytohormones detected by gas chromatography-MS, liquid chromatography-MS, and capillary electrophoresis-MS. The biological properties and the activities of polar and nonpolar metabolites produced by rice plants are also presented. Challenges in the estimation of the structure(s) of unknown metabolites by metabolomic approaches are introduced and discussed. Lastly, examples are presented of the successful application of metabolite profiling of rice to characterize the gene(s) that are potentially critical for improving its quality by combining metabolite quantitative trait loci analysis and to identify potential metabolite biomarkers that play a critical role when rice is grown under abiotic stress conditions.

Kinetic study of the scavenging reaction of the aroxyl radical by seven kinds of rice bran extracts in ethanol solution. Development of an aroxyl radical absorption capacity (ARAC) assay method

Recently, a new assay method that can quantify the aroxyl radical (ArO•) absorption capacity (ARAC) of antioxidants (AOHs) was proposed. In the present work, the second-order rate constants (ks(Extract)) and ARAC values for the reaction of ArO• with seven kinds of rice bran extracts 1-7, which contain different concentrations of α-, β-, γ-, and δ-tocopherols and -tocotrienols (α-, β-, γ-, and δ-Tocs and -Toc-3s) and γ-oryzanol, were measured in ethanol at 25 °C using stopped-flow spectrophotometry. The ks(Extract) value (1.26 × 10(-2) M(-1) s(-1)) of Nipponbare (extract 1) with the highest activity was 1.5 times larger than that (8.29 × 10(-3)) of Milyang-23 (extract 7) with the lowest activity. The concentrations (in mg/100 g) of α-, β-, γ-, and δ-Tocs and -Toc-3s and γ-oryzanol found in the seven extracts 1-7 were determined using HPLC-MS/MS and UV-vis absorption spectroscopy, respectively. From the results, it has been clarified that the ArO•-scavenging rates (ks(Extract)) (that is, the relative ARAC value) obtained for the seven extracts 1-7 may be approximately explained as the sum of the product {Σ ks(AOH-i) [AOH-i]/10(5)} of the rate constant (ks(AOH-i)) and the concentration ([AOH-i]/10(5)) of AOH-i (Tocs, Toc-3s, and γ-oryzanol) included in rice bran extracts. The contribution of γ-oryzanol to the ks(Extract) value was estimated to be between 3.0-4.7% for each extract. Taken together, these results suggest that the ARAC assay method is applicable to general food extracts.

Effect of germinated brown rice extracts on pancreatic lipase, adipogenesis and lipolysis in 3T3-L1 adipocytes

BACKGROUND

This study investigated anti-obesity effects of seven different solvent (n-hexane, toluene, dicholoromethane, ethyl acetate, absolute methanol, 80% methanol and deionized water) extracts of germinated brown rice (GBR) on pancreatic lipase activity, adipogenesis and lipolysis in 3T3-L1 adipocytes.

METHODS

GBR were extracted separately by employing different solvents with ultrasound-assisted. Pancreatic lipase activity was determined spectrophotometrically by measuring the hydrolysis of p-nitrophenyl butyrate (p-NPB) to p-nitrophenol at 405 nm. Adipogenesis and lipolysis were assayed in fully differentiated 3T3-L1 adipocytes by using Oil Red O staining and glycerol release measurement.

RESULTS

GBR extract using hexane showed the highest inhibitory effect (13.58 ± 0.860%) at concentration of 200 μg/ml followed by hexane extract at 100 μg/ml (9.98 ± 1.048%) while ethyl acetate extract showed the lowest (2.62 ± 0.677%) at concentration of 200 μg/ml on pancreatic lipase activity. Water extract at 300 μg/ml showed 61.55 ± 3.824% of Oil Red O staining material (OROSM), a marker of adipogenesis. It significantly decrease (p < 0.05) lipid accumulation than control (OROSM = 100%), follow by ethyl acetate extract at 300 μg/ml (OROSM = 65.17 ± 3.131%). All the GBR extracts induced lipolysis with 1.22-1.83 fold of greater glycerol release than control.

CONCLUSIONS

GBR extracts especially the least polar and intermediate polar solvent extracts exhibited inhibitory effect on pancreatic lipase, decrease fat accumulation by adipocyte differentiation inhibition, and stimulate lipolysis on adipocytes. Therefore, GBR could be furthered study and developed as a functional food in helping the treatment and/or prevention of obesity.

Stability of oryzanol fortified biscuits on storage

Biscuit can be used as a functional food to deliver nutraceuticals to consumers. One such natural nutraceutical oryzanol is present in rice bran oil. Oryzanol possesses a variety of health benefits which include reduction of cholesterol in blood, improvement of capillary action of blood vessels, anti-aging effect and others. Biscuit is a well known cereal based processed food and the fortification of oryzanol into the biscuits will go a long way to provide antioxidant rich, highly stable and acceptable functional food to the consumers. Biscuits were prepared with commercially available fat (CF) and oryzanol fortified fat (OFF). The control biscuits (CB) and oryzanol fortified biscuits (OFB) were packed in 200 gauge polypropylene pouches, stored at 27 °C with different relative humidity (RH 11 %, 22 %, 32 %, 44 % and 56 %) and analysed for its stability during storage of 120 days. Critical moisture content of OFB (4.8 %) was slightly less than that of CB (5.3 %). The fat content of the CB (12.2 %) and OFB (12.5 %) did not change during storage while free fatty acid content (0.36 % and 0.60 %) and peroxide value (0.08 and 0.17 meq. O2/100 g biscuit) respectively for CB and OFFB was showed small but significant changes during storage. Oryzanol content (292 mg) and radical scavenging activity (81.1 %) of OFB did not change during storage. The biscuits had a shelf life of minimum 3 months at 27 °C. Oryzanol in OFB showed good stability during baking and storage of biscuits.