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

Fat-soluble bioactive components in colored rice varieties

Bioactive components in rice vary depending on the variety and growing condition. Fat-soluble components such as γ-oryzanol, tocopherols, tocotrienols, carotenoids, and fatty acids were analyzed in brown, sugary brown, red, and black rice varieties using established high-performance liquid chromatography (HPLC) and GC methodologies. In addition, these colored rice varieties were further analyzed using a high-resolution liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) (LTQ-Orbitrap XL) to identify the [M-H](-) ions of γ-oryzanol, ranging from m/z 573.3949 to 617.4211. The highest content of tocopherols (α-, 1.5; γ-, 0.5 mg/100 g) and carotenoids (lutein 244; trans-β carotene 25 μg/100 g) were observed in black rice; tocotrienols (α-, 0.07; γ-, 0.14 mg/100 g) in red rice, and γ-oryzanol (115 mg/100 g) in sugary brown rice. In all colored rice varieties, the major fatty acids were palmitic (16:0), oleic (18:1n-9), and linoleic (18:2n-6) acids. When the γ-oryzanol components were further analyzed by LC-MS/MS, 3, 10, 8, and 8 triterpene alcohols or sterol ferulates were identified in brown, sugary brown, red, and black rice varieties, respectively. Such structural identification can lead to the elucidation of biological function of each component at the molecular level. Consumption of colored rice rich in beneficial bioactive compounds may be a useful dietary strategy for achieving optimal health.

Changes of Major Antioxidant Compounds and Radical Scavenging Activity of Palm Oil and Rice Bran Oil during Deep-Frying

Changes in antioxidant properties and degradation of bioactives in palm oil (PO) and rice bran oil (RBO) during deep-frying were investigated. The alpha (α)-tocopherol, gamma (γ)-tocotrienol and γ-oryzanol contents of the deep-fried oils were monitored using high performance liquid chromatography, and antioxidant activity was determined using 2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity. Results revealed that the antioxidant activity of PO decreased significantly (p < 0.05), while that of RBO was preserved after deep-frying of fries. As expected, the concentration of α-tocopherol in PO and γ-tocotrienol in both PO and RBO decreased significantly (p < 0.05) with increased frying. Results also showed that γ-tocotrienol was found to be more susceptible to degradation compared to that of α-tocopherol in both PO and RBO. Interestingly, no significant degradation of α-tocopherol was observed in RBO. It is suggested that the presence of γ-oryzanol and γ-tocotrienol in RBO may have a protective effect on α-tocopherol during deep-frying.

Effect of Nigella sativa fixed and essential oils on antioxidant status, hepatic enzymes, and immunity in streptozotocin induced diabetes mellitus

Background

Nigella sativa fixed (NSFO) and essential (NSEO) oils have been used to treat diabetes mellitus and its complications. Present study was undertaken to explore and validate these folkloric uses.

Methods

Sprague dawley rats having streptozotocin (STZ) induced diabetes mellitus were used to assess the role of NSFO and NSEO in the management of diabetes complications. Parameters investigated were antioxidant potential, oxidative stress, and the immunity by in vivo experiments.

Results

The results indicated that STZ decreased the glutathione contents (25.72%), while NSFO and NSEO increased the trait significantly (P < 0.05). Experimental diets increased the tocopherol contents (P < 0.01) and enhanced the expression of hepatic enzymes (P < 0.01). Correlation matrix further indicated that antioxidant potential is positively associated (P < 0.05) responsible for the modulation of hepatic enzymes and the decrease of the nitric oxide production thus controlling the diabetes complications.

Conclusions

Overall, results of present study supported the traditional use of N. sativa and its derived products as a treatment for hyperglycemia and allied abnormalities. Moreover, N. sativa fixed and essential oils significantly ameliorate free radicals and improve antioxidant capacity thus reducing the risk of diabetic complications.

Infrared stabilization of rice bran and its effects on γ-oryzanol content, tocopherols and fatty acid composition

BACKGROUND

Rice bran is a nutritionally valuable by-product of paddy milling. In this study an experimental infrared (IR) stabilization system was developed to prevent rice bran rancidity. The free fatty acid content of raw and IR-stabilized rice bran samples was monitored every 15 days during 6 months of storage. In addition, energy consumption was determined.

RESULTS

The free fatty acid content of rice bran stabilized at 600 W IR power for 5 min remained below 5% for 165 days. No significant change in γ-oryzanol content or fatty acid composition but a significant decrease in tocopherol content was observed in stabilized rice bran compared with raw bran. IR stabilization was found to be comparable to extrusion with regard to energy consumption.

CONCLUSION

IR stabilization was effective in preventing hydrolytic rancidity of rice bran. By optimizing the operational parameters of IR stabilization, this by-product has the potential for use in the food industry in various ways as a value-added commodity.

Characterization of rice bran wax policosanol and its nanoemulsion formulation

Policosanol, a mixture of long-chain alcohols found in animal and plant waxes, has several biological effects; however, it has a bioavailability of less than 10%. Therefore, there is a need to improve its bioavailability, and one of the ways of doing this is by nanoemulsion formulation. Different droplet size distributions are usually achieved when emulsions are formed, which solely depends on the preparation method used. Mostly, emulsions are intended for better delivery with maintenance of the characteristics and properties of the leading components. In this study, policosanol was extracted from rice bran wax, its composition was determined by gas chromatography mass spectrophotometry, nanoemulsion was made, and the physical stability characteristics were determined. The results showed that policosanol nanoemulsion has a nanosize particle distribution below 100 nm (92.56–94.52 nm), with optimum charge distribution (−55.8 to −45.12 mV), pH (6.79–6.92) and refractive index (1.50); these were monitored and found to be stable for 8 weeks. The stability of policosanol nanoemulsion confers the potential to withstand long storage times.

Cycloartenyl trans-ferulate, a component of the bran byproduct of sake-brewing rice, inhibits mammalian DNA polymerase and suppresses inflammation

During the screening of selective DNA polymerase (pol) inhibitors, we isolated cycloartenyl trans-ferulate (CAF), which is a major component of γ-oryzanol, which is a byproduct formed during the production of Japanese rice wine "sake". CAF selectively inhibited the activity of mammalian A, B, and X pol families, but Y family pols were not affected. CAF did not influence the activities of plant or prokaryotic pols, nor the activity of other DNA metabolic enzymes tested. Individual chemical components of CAF, including cycloartenol (CA) and ferulic acid (FA), did not inhibit pol enzyme activities. CAF suppressed TPA (12-O-tetradecanoylphorbol-13-acetate)-induced inflammation in the mouse ear, but CA and FA did not. The ability to inhibit mammalian pol enzymes in vitro was positively correlated with their propensity to suppress inflammation in vivo. These results suggest that this byproduct formed during the sake-brewing process is useful as an anti-inflammatory agent.

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.

Antioxidant activity and nutritional quality of traditional red-grained rice varieties containing proanthocyanidins

Proanthocyanidin-containing rice varieties have been rarely reported. Antioxidant capacity, major antioxidant components, and nutritional parameters of eight traditional red-grained rice varieties containing proanthocyanidins grown in Sri Lanka were investigated. The tested traditional red varieties, on the average, had over sevenfold higher both total antioxidant capacity and phenolic content than three light brown-grained new-improved rice varieties. Major antioxidant phenolic compounds identified in this study included proanthocyanidins, phenolic acids and γ-oryzanols (ferulic acid derivatives). Proanthocyanidins were detected only in the traditional red varieties, but not found in new-improved ones. Most traditional red varieties also contained significantly higher levels of protein with well balanced amino acids and higher contents of fat, fibre and vitamin E (tocopherols and tocotrienols) than the new-improved ones. Great variations in antioxidant capacity, major phenolics, and nutritional parameters were observed among different rice varieties. These Sri Lankan traditional red-grained rice varieties containing proanthocyanidins may be used as important genetic sources for rice breeding.

Nutritional composition of rice bran submitted to different stabilization procedures

In order to inactivate enzymatic deterioration, whole rice bran samples were subjected to two stabilization methods. Changes in nutritional value in terms of, concerning chemical composition, minerals and fatty acid content, were evaluated to supplement existing data and promote the utilization of rice bran in the human diet. The following homemade heat treatments were applied: roasting on a conventional stove or heating in a microwave oven. Based on the results, the different heating methods affected sample composition, since the levels of some nutrients of treated samples showed significant changes (p<0.05) compared to corresponding raw samples. The rice bran treated on a conventional stove produced products with lower moisture (5.14±0.10 g/100 g) and nutrients such as sodium 11.8%; palmitic acid 9.9% and stearic acid 8.1%. The microwave oven procedure resulted in better nutrient preservation, with slightly higher moisture content (6.28±0.10 g/100 g), and appears to be a practical and rapid tool for home heat stabilization of rice bran.

Phytosterols esterified with conjugated linoleic acid. In vitro intestinal digestion and interaction on cholesterol bioaccessibility

Intestinal in vitro digestion of phytosterols esterified with conjugated linoleic acid (PS-CLA) was performed to study (1) the potential bioaccessibility of the released bioactive-lipid products and (2) the interference with cholesterol bioaccessibility. Commercial food-grade PS ester (PS-C) was assayed as reference. Hydrolysis of PS-CLA by digestive enzymes was similar to that of PS-C (51 and 47%, respectively), most lipids products being mainly included in the bioaccessible fraction, namely, the micellar phase (MP). Control assays in the absence of PS esters showed most cholesterol solubilized within the MP, whereas a displacement of total cholesterol was caused from MP after digestion of PS esters (14 and 36% displacement for PS-CLA and PS-C, respectively), cholesterol being partially precipitated. Precipitated cholesterol was linearly related to a parallel precipitation of saturated-chain PS, mainly determined by sitosterol (R² = 0.936). The higher composition in sitosteryl esters of PS-C with respect to PS-CLA might explain their different effects on cholesterol. Therefore, besides being a lipid delivery form of PS similar to other commercial esterified PS, the PS-CLA might have the additional advantage of being a lipid delivery form of CLA. Moreover, PS-CLA might hinder the bioaccessibility of cholesterol. Furthermore, the qualitative/quantitative profile in esterified PS forms might determine the magnitude of cholesterol interaction.

Dietary rice bran component γ-oryzanol inhibits tumor growth in tumor-bearing mice

SCOPE

We investigated the effects of rice bran and components on tumor growth in mice.

METHODS AND RESULTS

Mice fed standard diets supplemented with rice bran, γ-oryzanol, Ricetrienol®, ferulic acid, or phytic acid for 2 weeks were inoculated with CT-26 colon cancer cells and fed the same diet for two additional weeks. Tumor mass was significantly lower in the γ-oryzanol and less so in the phytic acid group. Tumor inhibition was associated with the following biomarkers: increases in cytolytic activity of splenic natural killer (NK) cells; partial restoration of nitric oxide production and phagocytosis in peritoneal macrophages increases in released the pro-inflammatory cytokines tumor necrosis factor-α, IL-1β, and IL-6 from macrophages; and reductions in the number of blood vessels inside the tumor. Pro-angiogenic biomarkers vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and 5-lipoxygenase-5 (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. ELISA of tumor cells confirmed reduced expression of COX-2 and 5-LOX up to 30%. Reduced COX-2 and 5-LOX expression downregulated VEGF and inhibited neoangiogenesis inside the tumors.

CONCLUSION

Induction of NK activity, activation of macrophages, and inhibition of angiogenesis seem to contribute to the inhibitory mechanism of tumor regression by γ-oryzanol.

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.

Characterization of high-value bioactives in some selected varieties of Pakistani Rice (Oryza sativa L.)

The present study reports the composition and variation of fatty acids, sterols, tocopherols and γ-oryzanol among selected varieties namely Basmati Super, Basmati 515, Basmati 198, Basmati 385, Basmati 2000, Basmati 370, Basmati Pak, KSK-139, KS-282 and Irri-6 of Pakistani rice (Oryza sativa L). Oil content extracted with n-hexane from different varieties of brown rice seed (unpolished rice) ranged from 1.92% to 2.72%. Total fatty acid contents among rice varieties tested varied between 18240 and 25840 mg/kg brown rice seed. The rice tested mainly contained oleic (6841-10952 mg/kg) linoleic (5453-7874 mg/kg) and palmitic acid (3613-5489 mg/kg). The amounts of total phytosterols (GC and GC-MS analysis), with main contribution from β-sitosterol (445-656 mg/kg), campesterol (116-242 mg/kg), Δ(5)-avenasterol (89-178 mg/kg) and stigmasterol (75-180 mg/kg) were established to be 739.4 to 1330.4 mg/kg rice seed. The content of α-, γ- and δ-tocopherols as analyzed by HPLC varied from 39.0-76.1, 21.6-28.1 and 6.5-16.5 mg/kg rice seed, respectively. The amounts of different γ-oryzanol components (HPLC data), identified as cycloartenyl ferulate, 24-methylene cycloartanyl ferulate, campesteryl ferulate and β-sitosteryl ferulate, were in the range of 65.5-103.6, 140.2-183.1, 29.8-45.5 and 8.6-10.4 mg/kg rice seed, respectively. Overall, the concentration of these bioactives was higher in the Basmati rice cultivars showing their functional food superiority. In conclusion, the tested varieties of Pakistani rice, especially the Basmati cultivars, can provide best ingredients for functional foods.

γ-Oryzanol reduces adhesion molecule expression in vascular endothelial cells via suppression of nuclear factor-κB activation

γ-Oryzanol (γ-ORZ) is a mixture of phytosteryl ferulates purified from rice bran oil. In this study, we examined whether γ-ORZ represents a suppressive effect on the lipopolysaccharide (LPS)-induced adhesion molecule expression on vascular endothelium. Treatment with LPS elevated the mRNA expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin in bovine aortic endothelial cells (BAECs). Pretreatment with γ-ORZ dose-dependently decreased the LPS-mediated expression of these genes. Western blotting also revealed that pretreatment with γ-ORZ dose-dependently inhibited LPS-induced VCAM-1 expression in human umbilical vein endothelial cells. Consistently, pretreatment with γ-ORZ dose-dependently reduced LPS-induced U937 monocyte adhesion to BAECs. In immunofluorescence, LPS caused nuclear factor-κB (NF-κB) nuclear translocation in 40% of BAECs, which indicates NF-κB activation. Pretreatment with γ-ORZ, as well as its components (cycloartenyl ferulate, ferulic acid, or cycloartenol), dose-dependently inhibited LPS-mediated NF-κB activation. Collectively, our results suggested that γ-ORZ reduced LPS-mediated adhesion molecule expression through NF-κB inhibition in vascular endothelium.

γ-Oryzanol and tocopherol contents in residues of rice bran oil refining

Rice bran oil (RBO) contains significant amounts of the natural antioxidants γ-oryzanol and tocopherols, which are lost to a large degree during oil refining. This results in a number of industrial residues with high contents of these phytochemicals. With the aim of supporting the development of profitable industrial procedures for γ-oryzanol and tocopherol recovery, the contents of these phytochemicals in all the residues produced during RBO refining were evaluated. The samples included residues from the degumming, soap precipitation, bleaching earth filtering, dewaxing and deodorisation distillation steps. The highest phytochemical concentrations were found in the precipitated soap for γ-oryzanol (14.2 mg g(-1), representing 95.3% of total γ-oryzanol in crude RBO), and in the deodorisation distillate for tocopherols (576 mg 100 g(-1), representing 6.7% of total tocopherols in crude RBO). Therefore, among the residues of RBO processing, the deodorisation distillate was the best source of tocopherols. As the soap is further processed for the recovery of fatty acids, samples taken from every step of this secondary process, including hydrosoluble fraction, hydrolysed soap, distillation residue and purified fatty acid fraction, were also analyzed. The distillation residue left after fatty acid recovery from soap was found to be the best source of γ-oryzanol (43.1 mg g(-1), representing 11.5% of total γ-oryzanol in crude RBO).

Nutritional and sensory profile of two Indian rice varieties with different degrees of polishing

Traditional hand-pounded rice has been replaced today with highly polished white rice in the Asian Indian diets. The study aimed to evaluate the nutritional as well as the sensory differences between the brown (0% polish) and the rice milled to different degrees of polish (2.3, 4.4 and 8.0%). Bapatla and Uma (red pigmented) varieties in both raw and parboiled forms were used. The protein, fat, dietary fibre, γ-oryzanol, polyphenols, vitamin E, total antioxidant activity and free radical scavenging abilities of the brown rice decreased while the available carbohydrates increased with polishing. Sensory attributes of the cooked rice samples (whiteness, grain intactness, fluffiness, firmness, stickiness, chewiness and the cooked rice aroma) were evaluated by trained panelists. Scores for branny taste and chewiness decreased with polishing. On the whole, brown rice of both the varieties was readily accepted by the well-informed sensory trained panelists.

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.

Health benefits of whole grain phytochemicals

A whole grain consists of the intact, ground, cracked, or flaked caryopsis, whose principal anatomical components--the starchy endosperm, germ, and bran--are present in the same relative proportions as they exist in the intact caryopsis. Whole grain food products can be intact, consisting of the original composition of bran, germ, and endosperm, throughout the entire lifetime of the product, or reconstituted, in which one or more of the original components of a whole grain is recombined to the relative proportion naturally occurring in the grain kernel. Increased consumption of whole grains has been associated with reduced risk of major chronic diseases including cardiovascular disease, type II diabetes, and some cancers. Whole grain foods offer a wide range of phytochemicals with health benefits that are only recently becoming recognized. The unique phytochemicals in whole grains are proposed to be responsible for the health benefits of whole grain consumption. In this paper, whole grain phytochemicals and the health benefits associated with their consumption are reviewed.

Gamma-oryzanol rich fraction regulates the expression of antioxidant and oxidative stress related genes in stressed rat's liver

Background

Gamma-oryzanol (OR), a phytosteryl ferulate mixture extracted from rice bran oil, has a wide spectrum of biological activities in particular, it has antioxidant properties.

Methods

The regulatory effect of gamma-oryzanol rich fraction (ORF) extracted and fractionated from rice bran using supercritical fluid extraction (SFE) in comparison with commercially available OR on 14 antioxidant and oxidative stress related genes was determined in rat liver. Rats were subjected to a swimming exercise program for 10 weeks to induce stress and were further treated with either ORF at 125, 250 and 500 mg/kg or OR at 100 mg/kg in emulsion forms for the last 5 weeks of the swimming program being carried out. The GenomeLab Genetic Analysis System (GeXPS) was used to study the multiplex gene expression of the selected genes.

Results

Upon comparison of RNA expression levels between the stressed and untreated group (PC) and the unstressed and untreated group (NC), seven genes were found to be down-regulated, while seven genes were up-regulated in PC group compared to NC group. Further treatment of stressed rats with ORF at different doses and OR resulted in up-regulation of 10 genes and down regulation of four genes compared to the PC group.

Conclusions

Gamma-oryzanol rich fraction showed potential antioxidant activity greater than OR in the regulation of antioxidants and oxidative stress gene markers.

Influence of the input system (conventional versus organic farming) on metabolite profiles of maize ( Zea mays ) kernels

Maize ( Zea mays ) kernels grown conventionally and organically, respectively, were investigated using a gas chromatography/mass spectrometry (GC/MS)-based metabolite profiling methodology. By analysis of three cultivars grown at two locations with different input systems and at a third location where both organic and conventional farming were applied, the impact of the growing regime on the metabolite spectrum should be put into the context of natural variability. The applied analytical approach involved consecutive extraction of freeze-dried maize flour and subsequent subfractionation. Approximately 300 compounds from a broad spectrum of chemical classes were detected, of which 167 were identified. The metabolite profiling data were statistically assessed via principal component analysis (PCA) and analysis of variance (ANOVA). The PCA demonstrated that the observed separations were mainly due to genetic differences (cultivars) and environmental influences. The different input systems (conventional/organic) only led to minor differentiations. ANOVA and quantification of selected constituents confirmed these observations. Only three metabolites (malic acid, myo-inositol, and phosphate) were consistently different because of the employed input system if samples from all field trials were considered.

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.

Cycloartenyl ferulate, a component of rice bran oil-derived gamma-oryzanol, attenuates mast cell degranulation

IgE-targeting therapy could provide significant progress in the treatment of allergic inflammation. In this study, we examined the effect of cycloartenyl ferulate (cycloartenol ferulic acid ester; CAF), a natural product from rice bran oil-derived gamma-oryzanol, on allergic reaction. When CAF and gamma-oryzanol were injected intradermally with anti-DNP IgE into the dorsal skin of rats, the passive cutaneous anaphylaxis reaction induced by DNP-HSA was attenuated. CAF and gamma-oryzanol also inhibited the degranulation of DNP-IgE sensitized RBL-2H3 mast cells stimulated with anti-DNP-HSA. IgE conjugated with CAF could not be detected by anti-IgE antibody in the ELISA analysis. Although incubation of IgE with CAF did not decrease the amount of IgE, it was possible to precipitate IgE by centrifugation. These results demonstrate that CAF captures IgE, prevents it from binding to FcepsilonRI, and attenuates mast cell degranulation.