Triterpene alcohol and sterol ferulates from rice bran and their anti-inflammatory effects

Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid

Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice.

Anti-inflammatory effect and prostate gene expression profiling of steryl ferulate on experimental rats with non-bacterial prostatitis

Steryl ferulate (SF) is a bioactive mixture extracted from rice bran and shows higher inhibitory activity against inflammation than the corresponding free sterols.

Natural food science based novel approach toward prevention and treatment of obesity and type 2 diabetes: recent studies on brown rice and γ-oryzanol

The prevalences of obesity and type 2 diabetes mellitus are dramatically increasing, and there is a strong need for more effective and safer therapies. However, some of drugs show limited efficacy and considerable adverse effects. Furthermore, artificial energy-dense foods and non-caloric foods may promote overeating and weight gain. In this context, a natural food-based approach may represent a valuable means of tackling the obesity-diabetes syndrome. Although recent studies have shown that brown rice improves glucose intolerance and prevents obesity and type 2 diabetes in humans, the underlying molecular mechanisms remain unclear. We found that one of the major components of brown rice, γ-oryzanol (Orz), plays an important role in the metabolically beneficial effects of brown rice. Orz acts as a chemical chaperone and decreases high fat diet (HFD)-induced endoplasmic reticulum (ER) stress in the hypothalamus, thereby leading to a significant shift in preference from fatty to healthy foods. Orz also decreases HFD-induced ER stress in pancreatic β-cells and improves β-cell function. Notably, Orz directly acts on pancreatic islets and enhances glucose-stimulated insulin secretion (GSIS). This evidence highlights food preference as a promising therapeutic target in obesity-diabetes syndrome and suggests that brown rice and Orz may have potential for the treatment of obesity and type 2 diabetes in humans.

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.

Rice bran extract affects differentiation of mesenchymal stem cells potency into osteogenic cells

As rice bran contains various nutrients and other proteins of which a part has biological effects on animal cells, we tested the effect of rice bran extract on rat mesenchymal stem cells (rMSCs) obtained from bone marrow. These rMSCs are pluripotent and can be readily induced to differentiate into a number of cell types, including bone and cartilage. rMSC was aggregated by culturing in serum-free condition with rice bran extract, but was not aggregated by culturing in serum-free condition or in serum-containing medium. Moreover, the longer aggregates of rMSCs were cultured in serum-free condition with rice bran extract, the more the aggregates grew. After two passages in serum-free conditions, rMSCs lost their potency for differentiation into osteogenic cells; however, the addition of rice bran extract to serum-free medium successfully prevented the loss of this ability for differentiation. In addition, MSC makers CD105 and CD166 gene expression in serum-free condition with rice barn extract corresponded to these expressions in serum-containing medium. This result suggests that certain factors in rice bran could be bioactive and contribute toward retaining the ability of MSCs to differentiate into osteogenic cells after passaging.

γ-Oryzanols of North American Wild Rice (Zizania palustris)

γ-Oryzanol, a natural mixture of ferulic acid esters of triterpene alcohols and sterols, are an important bioactive components present in rice bran oil. In light of the recent increase in the popularity of wild rice among consumers, and the possibility of a direct relationship between γ-oryzanol composition and its bioactivity, the oryzanol profile of major wild rice (Zizania palustris) grown in North America was studied and compared to regular brown rice (Oryza sativa L.). A total of twenty-three γ-oryzanol components were separated, identified and quantified by HPLC coupled to an Orbitrap MS. The distribution of individual γ-oryzanols was similar for all the wild rice but significantly different from those of the regular brown rice. Unlike in the regular brown rice, a significant amount of steryl caffeate and cinnamate were found in the wild rice samples. Generally, the amounts of γ-oryzanol in the wild rice were higher compared to the regular brown rice, 1,352 vs. 688 μg/g. The results from this study showed that wild rice had a more diverse γ-oryzanol composition and the higher amounts compared to the regular brown rice.

Molecular spectroscopic studies on the interaction of ferulic acid with calf thymus DNA

The interaction between ferulic acid and calf thymus deoxyribonucleic acid (ctDNA) under physiological conditions (Tris-HCl buffer solutions, pH 7.4) was investigated by UV-Vis spectroscopy, fluorescence spectroscopy, DNA melting techniques, and viscosity measurements. Results indicated that a complex of ferulic acid with ctDNA was formed with a binding constant of K(290K)=7.60×10(4) L mol(-1) and K(310K)=4.90×10(4) L mol(-1). The thermodynamic parameters enthalpy change (ΔH°), entropy change (ΔS°) and Gibbs free energy (ΔG°) were calculated to be -1.69×10(4) J mol(-1), 35.36 J K(-1) mol(-1) and -2.79×10(4) J mol(-1) at 310 K, respectively. The acting forces between ferulic acid and DNA mainly included hydrophobic interaction and hydrogen bonds. Acridine orange displacement studies revealed that ferulic acid can substitute for AO probe in the AO-DNA complex which was indicative of intercalation binding. Thermal denaturation study suggested that the interaction of ferulic acid with DNA could result in the increase of the denaturation temperature, which indicated that the stabilization of the DNA helix was increased in the presence of ferulic acid. Spectroscopic techniques together with melting techniques and viscosity determination provided evidences of intercalation mode of binding for the interaction between ferulic acid and ctDNA.

Limonoids from the fruits of Melia azedarach and their cytotoxic activities

Thirty-one limonoids and one tirucallane-type triterpenoid were isolated from the fruits of Melia azedarach (Meliaceae). The structures of 14 of these isolated compounds were elucidated on the basis of spectroscopic analyses and comparison with literature. All of these compounds were evaluated for their cytotoxic activities against HL60, A549, AZ521, and SK-BR-3 human cancer cell lines. Meliarachin C (IC50 0.65 μM) and 3-O-deacetyl-4'-demethyl-28-oxosalannin (IC50 2.8 μM) exhibited potent cytotoxic activity against HL60 cells, and this was demonstrated mainly due to the induction of apoptosis by flow cytometry. Western blot analysis suggested that both compounds induced apoptosis via both the mitochondrial and death receptor-mediated pathways. In addition, 25 compounds were evaluated for their inhibitory effects against the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells.

Evaluation of γ-oryzanol content and composition from the grains of pigmented rice-germplasms by LC-DAD-ESI/MS

Background

Rice is the staple food and one of the world’s three major grain crops. Rice contains more than 100 bioactive substances including phytic acid, isovitexin, γ-oryzanol, phytosterols, octacosanol, squalene, γ-aminobutyric acid (GABA), tocopherol, tocotrienol derivatives, etc. Out of them, γ-oryzanol is known to have important biological profile such as anti-oxidants, inhibitor of cholesterol oxidation, reduce serum cholesterol levels in animals, effective in the treatment of inflammatory diseases, inhibit tumor growth, reduce blood pressure and promotes food storage stability when used as a food additive, etc. Hence in the present investigation, we aimed to evaluate the content and composition of γ-oryzanol from pigmented rice germplasms using a liquid chromatography with diode array detection and electrospray ionization-mass spectrometry (LC-DAD-ESI/MS).

Findings

In the present study, 33 exotic pigmented rice accessions (red, white and purple) have been evaluated. Among them, the contents of γ-oryzanol varied from 3.5 to 21.0Âmg/100Âg with a mean of 11.2Âmg/100Âg. A total of ten components of γ-oryzanol including ∆⁷-stigmastenyl ferulate were identified of which, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components. The mean proportions of steryl ferulates were in the descending order of 24-methylenecycloartanyl ferulate > cycloartenyl ferulate > campesteryl ferulate > sitosteryl ferulate > ∆⁷-campestenyl ferulate > campestanyl ferulate > sitostanyl ferulate > ∆⁷-stigmastenyl ferulate > stigamsteryl ferulate > ∆⁷-sitostenyl ferulate. Almost 11 accessions (33%) showed higher content than the control rice Chucheongbyeo and higher proportions ranged from 10 to 15Âmg/100Âg. Interestingly, the red rice accession Liberian Coll. B11/B-11 (21.0Âmg/100Âg) showed higher content γ-oryzanol than control rice Jeokjinjubyeo (19.1Âmg/100Âg) and the purple rice accession Padi Adong Dumarat, Mardi No.4376 (20.3Âmg/100Âg) showed a similar content with control rice Heugjinjubyeo (21.4Âmg/100Âg).

Conclusions

Most of analyzed rice accessions were found to possess higher contents of γ-oryzanol than the control rice, Chucheongbyeo. In particular, the red accessions showed highest content than the white and purple accessions. The content and composition of γ-oryzanol in 33 exotic pigmented rice accessions have been evaluated and compared significantly by the present investigation.

Preparative separation of triterpene alcohol ferulates from rice bran oil using a high performance counter-current chromatography

A novel method for the separation of two major triterpene alcohol ferulates from rice bran oil (RBO) was developed using a high performance counter-current chromatography (HPCCC). A two-phase solvent system of n-hexane-acetonitrile (1:1, v/v) was applied to purify cycloartenyl ferulate (CAF) and 24-methylene cycloartanyl ferulate (24-mCAF) from RBO. The yields were 20.50±2.60 mg CAF and 12.62±1.15 mg 24-mCAF from 390 mg RBO through a two-step separation procedure. The purities of the two compounds were 97.97±0.90% and 95.50±0.75%, respectively, as determined by high performance liquid chromatography (HPLC). Their chemical structures were confirmed by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), and (1)H, (13)C and 2D nuclear magnetic resonance (NMR). This represents the first report on direct separation of CAF and 24-mCAF from RBO by HPCCC.

γ-Oryzanol protects against acute cadmium-induced oxidative damage in mice testes

Cadmium is a non-essential heavy metal that is present at low levels mainly in food and water and also in cigar smoke. The present study evaluated the testicular damage caused by acute cadmium exposure and verified the protective role of γ-oryzanol (ORY). Mice were administrated with a single dose of 2.5mg/kg of CdCl2, and then treated with ORY (50mM in canola oil, 5mL/kg). Testes were removed after 24h and tested for lipid peroxidation (TBARS), protein carbonylation, DNA breakage, ascorbic acid, cadmium and non-proteic thiols contents, and for the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and δ-aminolevulic acid dehydratase (δ-ALA-D). Cadmium presented a significant alteration in all parameters, except GPx and CAT activities. Therapy reduced in a slight degree cadmium concentration in testes (around 23%). ORY restored SOD and GST activities as well as TBARS production to the control levels. Furthermore, ORY partially recovered δ-ALA-D activity inhibited by cadmium. This study provides the first evidence on the therapeutic properties of ORY in protecting against cadmium-induced testicular toxicity.

Chemical composition and anti-inflammatory properties of the unsaponifiable fraction from awara (Astrocaryum vulgare M.) pulp oil in activated J774 macrophages and in a mice model of endotoxic shock

Awara (Astrocaryum vulgare M.) pulp oil has been shown to possess anti-inflammatory properties in vivo, and contains an unsaponifiable matter rich in bioactive compounds. This study focused on the ethanolic unsaponifiable fraction (EUF) of awara pulp oil. Its chemical composition has been characterized: carotenoid, phytosterol, and tocopherol contents represent 125.7, 152.6, and 6.8 μg/mg of EUF, respectively. We further evaluated this fraction for anti-inflammatory properties in J774 macrophages activated by lipopolysaccharide (LPS) plus interferon (IFN) γ to understand the biological effects of awara pulp oil. EUF strongly decreased nitric oxide (NO), prostaglandin E(2), tumour necrosis factor (TNF) α, and interleukin (IL) -6 and -10 production in activated J774 cells. Moreover, it inhibited expression of inducible NO synthase and cyclooxygenases-2 in vitro. The anti-inflammatory properties of EUF were also confirmed in vivo by modulation of TNFα, IL-6 and IL-10 serum concentration in an endotoxic shock model. Pre-treatment with awara oil fraction offers promise as a protective means to lower the production of excessive amounts of pro-inflammatory molecules.

Brown rice and its component, γ-oryzanol, attenuate the preference for high-fat diet by decreasing hypothalamic endoplasmic reticulum stress in mice

Brown rice is known to improve glucose intolerance and prevent the onset of diabetes. However, the underlying mechanisms remain obscure. In the current study, we investigated the effect of brown rice and its major component, γ-oryzanol (Orz), on feeding behavior and fuel homeostasis in mice. When mice were allowed free access to a brown rice-containing chow diet (CD) and a high-fat diet (HFD), they significantly preferred CD to HFD. To reduce hypothalamic endoplasmic reticulum (ER) stress on an HFD, mice were administered with 4-phenylbutyric acid, a chemical chaperone, which caused them to prefer the CD. Notably, oral administration of Orz, a mixture of major bioactive components in brown rice, also improved glucose intolerance and attenuated hypothalamic ER stress in mice fed the HFD. In murine primary neuronal cells, Orz attenuated the tunicamycin-induced ER stress. In luciferase reporter assays in human embryonic kidney 293 cells, Orz suppressed the activation of ER stress-responsive cis-acting elements and unfolded protein response element, suggesting that Orz acts as a chemical chaperone in viable cells. Collectively, the current study is the first demonstration that brown rice and Orz improve glucose metabolism, reduce hypothalamic ER stress, and, consequently, attenuate the preference for dietary fat in mice fed an HFD.

The sterols isolated from Evening Primrose oil modulate the release of proinflammatory mediators

Evening Primrose oil is a natural product extracted by cold-pressed from Oenothera biennis L. seeds. The unsaponifiable matter of this oil is an important source of interesting minor compounds, like long-chain fatty alcohols, sterols and tocopherols. In the present study, sterols were isolated from the unsaponifiable matter of Evening Primrose oil, and the composition was identified and quantified by GC and GC-MS. The major components of sterols fraction were β-Sitosterol and campesterol. We investigated the ability of sterols from Evening Primrose oil to inhibit the release of different proinflammatory mediators in vitro by murine peritoneal macrophages stimulated with lipopolysaccharide. Sterols significantly and dose-dependently decreased nitric oxide production. Western blot analysis showed that nitric oxide reduction was a consequence of the inhibition of inducible nitric oxide synthetase expression. Sterols also reduced tumor necrosis factor-α, interleukine 1β and tromboxane B₂. However, sterols did not reduce prostaglandin E₂. The reduction of eicosanoid release was related to the inhibition of cyclooxygenase-2 expression. These results showed that sterols may have a protective effect on some mediators involved in inflammatory damage development, suggesting its potential value as a putative functional component of Evening Primrose oil.

Nutritional quality and health benefits of chickpea (Cicer arietinumL.): a review

Chickpea (Cicer arietinumL.) is an important pulse crop grown and consumed all over the world, especially in the Afro-Asian countries. It is a good source of carbohydrates and protein, and protein quality is considered to be better than other pulses. Chickpea has significant amounts of all the essential amino acids except sulphur-containing amino acids, which can be complemented by adding cereals to the daily diet. Starch is the major storage carbohydrate followed by dietary fibre, oligosaccharides and simple sugars such as glucose and sucrose. Although lipids are present in low amounts, chickpea is rich in nutritionally important unsaturated fatty acids such as linoleic and oleic acids. β-Sitosterol, campesterol and stigmasterol are important sterols present in chickpea oil. Ca, Mg, P and, especially, K are also present in chickpea seeds. Chickpea is a good source of important vitamins such as riboflavin, niacin, thiamin, folate and the vitamin A precursor β-carotene. As with other pulses, chickpea seeds also contain anti-nutritional factors which can be reduced or eliminated by different cooking techniques. Chickpea has several potential health benefits, and, in combination with other pulses and cereals, it could have beneficial effects on some of the important human diseases such as CVD, type 2 diabetes, digestive diseases and some cancers. Overall, chickpea is an important pulse crop with a diverse array of potential nutritional and health benefits.

Lupenone isolated from Adenophora triphylla var. japonica extract inhibits adipogenic differentiation through the downregulation of PPARγ in 3T3-L1 cells

Adenophora triphylla var. japonica (Campanulaceae) is known to have anti-inflammatory and anti-tussive effects. Dysfunction of adipocytes and adipose tissue in obesity is related to various inflammatory cytokines or adipokines. In this study, we investigated whether lupenone isolated from A. triphylla var. japonica extract inhibits adipocyte differentiation and expression of adipogenic marker genes in 3T3-L1 preadipocytes. We demonstrated that lupenone resulted in a significant reduction in lipid accumulation and expression of adipogenic marker genes in a dose-dependent manner. In addition, lupenone decreased the transcriptional activity of peroxisome proliferator-activated receptor γ (PPARγ) induced by troglitazone, and we also demonstrated that lupenone suppressed the PPARγ and CCAAT-enhancer-binding protein α (C/EBPα) protein levels. These findings demonstrated that lupenone isolated from A. triphylla var. japonica extract effectively inhibited adipocyte differentiation through downregulation of related transcription factor, particularly the PPARγ gene.

The potential of rice to offer solutions for malnutrition and chronic diseases

It is internationally accepted that malnutrition and chronic diseases in developing countries are key limitations to achieving the Millennium Development Goals. In many developing countries, rice is the primary source of nutrition. In those countries, the major forms of malnutrition are Fe-induced anaemia, Zn deficiency and Vitamin A deficiency, whereas the major chronic disease challenges are Type II diabetes, cardiovascular disease and some cancers. There is a growing corpus of evidence regarding both limitations and opportunities as to how rice could be an effective vehicle by which to tackle key nutrition and health related problems in countries with limited resources. Rice breeding programs are able to focus on developing new varieties carrying enhanced amounts of either Fe, Zn or beta-carotene because of large public investment, and the intuitive link between providing a mineral/vitamin to cure a deficiency in that mineral/vitamin. By contrast, there has been little investment in progressing the development of particular varieties for potential impact on chronic diseases. In this review article we focus on the broad battery of evidence linking rice-related nutritional limitations to their impact on a variety of human health issues. We discuss how rice might offer sometimes even simple solutions to rectifying key problems through targeted biofortification strategies and finally, we draw attention to how recent technological (-omics) developments may facilitate untold new opportunities for more rapidly generating improved rice varieties specifically designed to meet the current and future nutritional needs of a rapidly expanding global population.

Phytochemical study and anti-inflammatory, antidiabetic and free radical scavenger evaluations of Krameria pauciflora methanol extract

The plant Krameria pauciflora MOC et. Sessé ex DC. is used as an anti-inflammatory and antidiabetic in traditional medicine. The aim of this study was to evaluate the in vivo anti-inflammatory and antidiabetic effects of a methanol extract from the roots of K. pauciflora. Dichloromethane and ethyl acetate extracts obtained by partitioning the methanol extract were also evaluated. Complete methanol and dichloromethane extracts showed anti-inflammatory effects at 3 mg/kg. An anti-inflammatory effect similar to indomethacin (10 mg/kg) was observed when the methanol and dichloromethane extracts, which contain a cycloartane-type triterpene and an sterol, were administered orally at several doses (3, 10, 30 and 100 mg/kg), whereas no anti-inflammatory effect was observed at any dose for the ethyl acetate extract, which contains catechin-type flavonoids. The antidiabetic effect of each extract was also determined. An antihyperglycaemic effect was observed in diabetic rats, but no effect in normoglycaemic animals was observed when the methanol extract was administrated at 30 mg/kg. All of the extracts exhibited radical scavenger activity. Additionally, constituents from all of the extracts were identified by NMR. This article supports the use of K. pauciflora as an anti-inflammatory because it exhibits a similar effect to indomethacin. However, its antidiabetic effect is not completely clear, although it could be useful for preventing diabetic complications.

Evaluation of nonpolar metabolites in plant extracts by 13C NMR spectroscopy

(13)C nuclear magnetic resonance (NMR) spectroscopy was explored as a simple and efficient technique for the quantitative analysis of nonpolar metabolites in plants. The method was first optimized with a mixture of known metabolites and then applied to the nonpolar leaf extracts of plants harvested in the Valencian community (eastern Spain) belonging to three different genera: Euphorbia (Euphorbiaceae), Araujia (Apocynaceae), and Morus (Moraceae). Furthermore, an exhaustive analysis of Euphorbia characias leaf and stem extracts from different geographic locations allowed that quantitative (13)C NMR spectroscopy is a suitable tool for metabolic profiling purpose.

One-step isolation of γ-oryzanol from rice bran oil by non-aqueous hydrostatic countercurrent chromatography

The value-added γ-oryzanol was purified in one step from crude rice bran oil (RBO) using a preparative hydrostatic countercurrent chromatography (hydrostatic CCC) method, operating in the dual mode. The fractionation was performed using a non-aqueous biphasic solvent system consisting of heptane-acetonitrile-butanol (1.8:1.4:0.7, v/v/v), leading rapidly to the target compounds. Transfer of the analytical CCC method to large-scale isolation was also carried out yielding a high quantity-high purity fraction of γ-oryzanol. In addition, a fraction of hydroxylated triterpene alcohol ferulates (polar γ-oryzanol) was clearly separated and obtained. Furthermore, a fast HPLC-APCI(±)-HRMS method was developed and applied for the identification of γ-oryzanol as well as the polar γ-oryzanol in RBO and the resulting fractions. The purity of γ-oryzanol fraction was estimated as 97% based on HPLC-APCI-HRMS analysis.

Potential interaction of natural dietary bioactive compounds with COX-2

Bioactive natural products present in the diet play an important role in several biological processes, and many have been involved in the alleviation and control of inflammation-related diseases. These actions have been linked to both gene expression modulation of pro-inflammatory enzymes, such as cyclooxygenase 2 (COX-2), and to an action involving a direct inhibitory binding on this protein. In this study, several food-related compounds with known gene regulatory action on inflammation have been examined in silico as COX-2 ligands, utilizing AutoDock Vina, GOLD and Surflex-Dock (SYBYL) as docking protocols. Curcumin and all-trans retinoic acid presented the maximum absolute AutoDock Vina-derived binding affinities (9.3 kcal/mol), but genistein, apigenin, cyanidin, kaempferol, and docosahexaenoic acid, were close to this value. AutoDock Vina affinities and GOLD scores for several known COX-2 inhibitors significatively correlated with reported median inhibitory concentrations (R² = 0.462, P < 0.001 and R² = 0.238, P = 0.029, respectively), supporting the computational reliability of the predictions made by our docking simulations. Moreover, docking analysis insinuate the synergistic action of curcumin on celecoxib-induced inhibition of COX-2 may occur allosterically, as this natural compound docks to a place different from the inhibitor binding site. These results suggest that the anti-inflammatory properties of some food-derived molecules could be the result of their direct binding capabilities to COX-2, and this process can be modeled using protein-ligand docking methodologies.

Oral administration of γ-aminobutyric acid and γ-oryzanol prevents stress-induced hypoadiponectinemia

Metabolic syndrome is a cluster of risk factors including insulin resistance and type 2 diabetes and is found to associate partly with chronic stress at work in human. Adiponectin circulates in mammal blood mainly as a low molecular weight (LMW) trimer, hexamer, and a high molecular weight (HMW) multimers. Low circulating levels of adiponectin are related to metabolic syndrome. We have then investigated the influence of immobilization stress on plasma adiponectin concentrations in mice. Relative LMW and HMW adiponectin levels were markedly reduced by immobilization stress (0.66±0.07 and 0.59±0.06 after 102 h, respectively), significantly different from the control values (p<0.01 and 0.05, respectively). γ-Aminobutyric acid (GABA) and γ-oryzanol abundantly contained in germinated brown rice have some physiological functions. We further investigated the effect of GABA, γ-oryzanol, GABA plus γ-oryzanol on adiponectin levels in mice subjected to immobilization stress. GABA and γ-oryzanol significantly increased the relative LMW and HMW adiponectin levels under immobilization stress (1.10±0.11 and 0.99±0.19 after 102 h, respectively, for GABA; 1.08±0.17 and 1.15±0.17 after 102 h, respectively, for γ-oryzanol). Additionally, the co-administration of GABA and γ-oryzanol also increased both relative LMW and HMW adiponectin levels (1.02±0.07 and 0.99±0.10 after 102 h, respectively) and was effective in an earlier phase from 30 to 54 h. The results indicate that the co-administration of GABA and γ-oryzanol might be effective in preventing stress-induced hypoadiponectinemia in mice and be also a promising tool for improving metabolic syndrome aggravated by chronic stress.

γ-Oryzanol recovers mouse hypoadiponectinemia induced by animal fat ingestion

Adiponectin is an insulin-sensitizing adipocyte-derived adipokine. The decrease in plasma adiponectin level (hypoadiponectinemia) is involved in the development of insulin resistance and the resulting type 2 diabetes. Our previous studies have demonstrated that γ-oryzanol (ORZ) from rice bran suppressed NF-κB activation and increased adiponectin secretion from adipocyte. In this study, we have evaluated effects of oral administration of animal fat (beef tallow) and palmitate on mouse serum adiponectin level. Oral administrations of beef tallow and palmitate significantly suppressed serum adiponectin levels into around half of the initial level from 48 to 96 h after administration compared with the case of corn oil (P<0.05). Coadministration of ORZ successfully remedied mouse hypoadiponectinemia induced by ingestion of beef tallow and the relative adiponectin levels attained to 1.66±0.23 at 96 h after administration (mean value±s.e., P<0.05). Diverse physiological functions of ORZ in crop bran might be promising us to prevent chronic inflammations in the pathogeneses of the metabolic or insulin resistance syndromes.

Secondary metabolites from Glycine soja and their growth inhibitory effect against Spodoptera litura

The wild soybean (Glycine soja Sieb. et Zucc) has been reported to be relatively resistant to insect and pathogenic pests. However, the responsible secondary metabolites in the aerial part of this important plant are largely unknown. From the aerial part of G. soja, 13 compounds were isolated and identified, including seven isoflavonoids (1-7), a cyclitol (8), two sterol derivatives (9 and 10), and three triterpenoids (11-13). Compound 7 is a new isoflavonoid, and compounds 9 and 10 are reported as natural products for the first time. The growth inhibitory activity of 1, 3, 4, and 8 against the larvae of Spodoptera litura was investigated. The most abundant isoflavonoid in the aerial part of G. soja, daidzein (1), which could not be metabolized by S. litura, was found to inhibit the insect larvae growth significantly in 3 days after feeding diets containing the compound. Compounds 3, 4, and 8, which could be partially or completely metabolized, were inactive. Our results suggested that the isoflavonoid daidzein (1) might function as a constitutive defense component in G. soja against insect pests.

Synthesis of isopropyl ferulate using silica-immobilized lipase in an organic medium

Immobilization of lipases has proved to be a useful technique for improving an enzyme's activity in organic solvents. In the present study, the performance of a silica-immobilized lipase was evaluated for the synthesis of isopropyl ferulate in DMSO. The biocatalyst was cross-linked onto the matrix with 1% glutaraldehyde. The effects of various parameters, molar ratio of ferulic acid to isopropyl alcohol (25 mM : 100 mM), concentration of biocatalyst (2.5–20 mg/mL), molecular sieves (25–250 mg/mL), and various salt ions, were studied consecutively as a function of percent esterification. Immobilized lipase at 25 mg/mL showed maximum esterification (~84%) of ferulic acid and isopropanol at a molar ratio of 25 mM : 100 mM, respectively, in DMSO at 45°C in 3 h under shaking (150 rpm). To overcome the inhibitory effect of water (a byproduct) if any, in the reaction mixture, molecular sieves (3 Å × 1.5 mm; 100 mg/mL) were added to the reaction mixture to promote the forward reaction. Salt ions like Ca²⁺, Cd²⁺, and Fe²⁺ enhanced the activity of immobilized biocatalyst while a few ions like Co²⁺, Zn²⁺, Mg²⁺, Mn²⁺, Al³⁺, and Na⁺ had mild inhibitory effect. Approximately, one third of total decrease in the esterification efficacy was observed after the 5th repetitive cycle of esterification.

Effects of genotype and environment on steryl ferulates in wheat and rye in the HEALTHGRAIN diversity screen

The effects of genetic and environmental factors on the content and composition of steryl ferulates in wheat and rye were studied. The wheat and rye genotypes were grown at the same location in Hungary over three consecutive years (28 genotypes) or at four different locations across Europe during a single year (12 genotypes). The steryl ferulates were analyzed using HPLC. The genotype and growing location significantly affected the content and composition of wheat steryl ferulates, whereas the year of growth did not result in considerable variation. Less variation was observed in rye, due to fewer genotypes. Campestanyl and sitostanyl ferulates were the main species in both cereals. Knowledge of the natural variation in steryl ferulates and other bioactive compounds allows cultivators and plant breeders to select genotypes with high, stable levels of beneficial compounds. Thus, it is possible to enhance the intake of health-promoting compounds from natural sources.

Physicochemical properties and antioxidant activity of gamma-oryzanol-loaded liposome formulations for topical use

The objective of this study is to prepare the gamma-oryzanol-loaded liposomes and investigate their physicochemical properties and antioxidant activity intended for cosmetic applications. Liposomes, Composing phosphatidylCholine (PC) and Cholesterol (Chol), CHAPS or sodium taurocholate (NaTC) were prepared by sonication method. Gamma-oryzanol-loaded liposomes were prepared by using 3, 5 and 10% gamma-oryzanol as an initial concentration. The formulation factors in a particular type and composition of lipid and initial drug loading on the physicochemical properties (i.e., particle size, zeta potential, entrapment efficiency, drug release) and antioxidant activity were studied. The particle sizes of bare liposomes were in nanometer range. The gamma-oryzanol-loaded liposomes in formulations of PC/CHAPS and PC/NaTC liposomes were smaller than PC/Chol liposomes. The incorporation efficiency of 10% gamma-oryzanol-loaded PC/Chol liposomes was less than gamma-oryzanol-loaded PC/CHAPS liposomes and PC/NaTC liposomes allowing higher in vitro release rate due to higher free gamma-oryzanol in buffer solution. The antioxidant activity of gamma-oryzanol-loaded liposomes was not different from pure gamma-oryzanol. Both gamma-oryzanol-loaded PC/CHAPS liposomes and PC/NaTC liposomes were showed to enhance the antioxidant activity in NHF cells. gamma-oryzanol-loaded PC/Chol liposomes demonstrated the lowest cytotoxicity in NHF cells. It was conceivably concluded that liposomes prepared in this study are suitable for gamma-oryzanol incorporation without loss of antioxidant activity.