Antioxidant activity of tocopherols, tocotrienols, and gamma-oryzanol components from rice bran against cholesterol oxidation accelerated by 2,2'-azobis(2-methylpropionamidine) dihydrochloride

The effect of planting time on nutrients, phenolics, and antioxidant activities of rice grown in different soil salinities

Rice (Oryza sativa) is a staple food crop with a significant role in nutrition and health. Its production yield mainly depends on climatic conditions. Soil salinity, an abiotic factor as a resulting from drought, also impacts rice growth, production, and quality. Researchers have widely investigated newly developed salt-tolerant rice varieties and suitable fertilizers to enhance rice yield and quality. However, the effects of planting times of in- season and off-season rice varieties grown in soils with varying salinity levels on rice qualities, such as nutrients, bioactive compounds, and health-related properties remain unexamined. This study evaluated the qualities (nutrients, phenolics, and antioxidant activities) of thirty-eight in season- and off-season rice samples grown in soils with different physicochemical properties: electrical conductivity extract (ECe), pH (pHH2O), organic matter (OM), available minerals (potassium and phosphorus), and soluble salts (calcium, magnesium, sodium, and potassium). Results indicated that rice nutrients, total phenolic contents (TPCs), and antioxidant activities were influenced by planting seasons rather than rice varieties or the soil salinity marker ECe. The in-season rice samples exhibited higher levels of protein, iron (Fe), TPCs, and antioxidant activities compared to the off-season rice samples, which had higher vitamin B3 content. Principal Component Analysis (PCA) and Pearson's correlation were used to determine the relationships among rice qualities and soil physicochemical properties. The rice samples were divided into four groups: Group 1 consisted of rice samples grown in soil with high ECe and soluble salts, showing unrelated rice nutrients, TPCs, and antioxidant activities; Group 2 included off-season rice samples grown in soil with high OM that contained high vitamin B3 content; Group 3 contained in-season rice samples grown in soil with high pHH2O that had high energy and fat content, and Group 4 comprised in-season rice samples with high protein, Fe, TPCs, and antioxidant activities, demonstrating moderate to very weak correlations with soil properties. This information can be used to determine the appropriate utilization of fertilizer in soil with different salinity levels and assist in the selection of applicable planting seasons for specific rice qualities.

The optimal combination of cooling and equilibration durations, along with the addition of melatonin, gamma-oryzanol, and canthaxanthin, for improving swamp buffalo semen cryopreservation quality

Background and Aim

The success of semen cryopreservation relies on several aspects, including breed, age, season, collection method, extender composition, cooling rate, equilibration period, freezing rate, and thawing rate. This study aimed to investigate the effects of cooling and equilibration duration, as well as the addition of antioxidants to the semen extender, on the cryopreservation of swamp buffalo semen.

Materials and Methods

Semen collected from swamp buffalo bulls was subjected to four different conditions: (T1) 2-h cooling and 2-h equilibration, (T2) 1.5-h cooling and 1.5-h equilibration, (T3) 1-h cooling and 1-h equilibration, and (T4) 0.5-h cooling and 0.5-h equilibration. Spermatozoa motility was evaluated using a computer-assisted semen analyzer. Moreover, this study also investigated the effect of antioxidant supplementation during cryopreservation using tris-citrate egg yolk extenders enriched with various antioxidants: Control (Con), 1 mM melatonin (ML), 0.5 mM gamma-oryzanol (GO), 10 μM canthaxanthin (CX), 1 mM melatonin + 0.5 mM gamma-oryzanol (ML + GO), and 1 mM melatonin + 10 μM canthaxanthin (ML + CX).

Results

Results showed that the (T1) 2-h cooling and 2-h equilibration and (T2) 1.5-h cooling and 1.5-h equilibration groups achieved higher progressive motility than the (T3) 1-h cooling and 1-h equilibration and (T4) 0.5-h cooling and 0.5-h equilibration groups. The ML-treated group exhibited superior progressive motility and total motility.

Conclusion

The optimal approach for cryopreserving swamp buffalo bull semen involves a 1.5-h cooling period followed by a 1.5-h equilibration period, with the incorporation of ML into the semen extender.

Assessment of antioxidant properties in selected pigmented and non-pigmented rice (Oryza sativa L.) germplasm and determination of its association with Rc gene haplotypes

BACKGROUND

Antioxidant properties of rice provide various health benefits due to its ability to inhibit cellular oxidation. Antioxidant content of rice is known to be linked with the pericarp pigmentation. The Rc gene of rice (Os07g0211500) codes for a basic helix-loop-helix (bHLH) protein, acting as a transcriptional factor in regulating proanthocyanidin biosynthesis. The current study was carried out to evaluate the variation of antioxidant properties in a selected panel of rice accessions and assess the possibility of using haplotypes defined based on the Rc gene to predict pericarp pigmentation and antioxidant content in rice.

RESULTS

Thirty-two rice accessions were evaluated for grain pericarp colour and antioxidant properties; total phenolic content (TPC), total flavonoids (TFC), proanthocyanidins (PAC) and radical scavenging activity (RSA). The parameters TPC, TFC and PAC showed significant positive correlation with RSA (r > 0.69; P < 0.01). The study panel showed a wide variation for antioxidant properties and rice accessions such as Sudu Heenati, Deweraddiri, Madathawalu, Masuran, Ld 368, At 311, Kalu Heenati, Bw 272-6B, Pokkali, At 362 and Wanni Dahanala exhibited profound potential with respect to antioxidant properties. Based on three-target sites previously reported as critical for the function of the coded bHLH protein (an A/C SNP at 1,353-bp, a 1-bp insertion/deletion at 1,388-bp, and a 14-bp insertion/deletion at 1,408-1,421-bp positioned in the mRNA corresponding to the exon 6 of rice Rc gene), three haplotypes were defined (H1-H3). Pigmentation of the rice pericarp could be successfully explained based on the defined haplotypes (H1 (C/G/+): red, and H2 (A/G/+) and H3 (C/G/-): white), and the H1 haplotype corresponded to a significantly (P < 0.05) higher TPC, TFC, PAC and RSA compared to the other haplotypes.

CONCLUSIONS

The studied rice accessions showed a significant variation with respect to antioxidant properties. Haplotype H1 defined based on the three-target sites in the exon 6 of Rc gene can detect rice accessions with red pigmented pericarp and high antioxidant properties effectively. Hence, its use can be recommended as an alternative to biochemical assays for screening during rice breeding programs.

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

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

Multitrait engineering of Hassawi red rice for sustainable cultivation

Sustainable agriculture requires locally adapted varieties that produce nutritious food with limited agricultural inputs. Genome engineering represents a viable approach to develop cultivars that fulfill these criteria. For example, the red Hassawi rice, a native landrace of Saudi Arabia, tolerates local drought and high-salinity conditions and produces grain with diverse health-promoting phytochemicals. However, Hassawi has a long growth cycle, high cultivation costs, low productivity, and susceptibility to lodging. Here, to improve these undesirable traits via genome editing, we established efficient regeneration and Agrobacterium-mediated transformation protocols for Hassawi. In addition, we generated the first high-quality reference genome and targeted the key flowering repressor gene, Hd4, thus shortening the plant's lifecycle and height. Using CRISPR/Cas9 multiplexing, we simultaneously disrupted negative regulators of flowering time (Hd2, Hd4, and Hd5), grain size (GS3), grain number (GN1a), and plant height (Sd1). The resulting homozygous mutant lines flowered extremely early (∼56 days) and had shorter stems (approximately 107 cm), longer grains (by 5.1%), and more grains per plant (by 50.2%), thereby enhancing overall productivity. Furthermore, the awns of grains were 86.4% shorter compared to unedited plants. Moreover, the modified rice grain displayed improved nutritional attributes. As a result, the modified Hassawi rice combines several desirable traits that can incentivize large-scale cultivation and reduce malnutrition.

Dietary rice bran attenuates hepatic stellate cell activation and liver fibrosis in mice through enhancing antioxidant ability

Various endogenous and exogenous stimuli can result in an inflammatory response and collagen deposition in the liver, which affect liver function and increase the risk of developing liver cirrhosis and cancer. Rice bran, the main by-product of rice milling, contains various nutrients which possess hepatoprotective activities. In this study, we investigated the effects of rice bran on carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Mice were fed a rice-bran-containing diet (10% rice bran w/w) or a standard diet with or without an injection of 20% CCl4 to induce liver fibrosis. Our results showed that feeding a rice-bran-containing diet could alleviate CCl4-induced liver damage, collagen deposition, and expressions of fibrosis-related genes, including α-smooth muscle actin (α-SMA), collagen 1a2 (COL1A2), and transforming growth factor-β (TGF-β) in liver tissues. Moreover, consumption of rice bran enhanced phase II detoxification and antioxidant gene expressions, including Gsta3, Gstp1, Catalase, SOD1, SOD2, and SOD3. Treatment with γ-oryzanol, the major bioactive compound in rice bran, decreased the sensitivity of hepatic stellate cells (HSCs) to TGF-β1-induced α-SMA, COL1A2, and phosphorylated smad2 expressions. In conclusion, a rice-bran-containing diet may have beneficial effects on liver fibrogenesis through increased antioxidant and detoxification activities. γ-Oryzanol, the major bioactive compound of rice bran, can inhibit activation of HSCs.

Rice Byproduct Compounds: From Green Extraction to Antioxidant Properties

Currently, rice (Oryza sativa L.) production and consumption is increasing worldwide, and many efforts to decrease the substantial impact of its byproducts are needed. In recent years, the interest in utilizing rice kernels, husk, bran, and germ for the recovery of different molecules, from catalysts (to produce biodiesel) to bioactive compounds, has grown. In fact, rice byproducts are rich in secondary metabolites (phenolic compounds, flavonoids, and tocopherols) with different types of bioactivity, mainly antioxidant, antimicrobial, antidiabetic, and anti-inflammatory, which make them useful as functional ingredients. In this review, we focus our attention on the recovery of antioxidant compounds from rice byproducts by using innovative green techniques that can overcome the limitations of traditional extraction processes, such as their environmental and economic impact. In addition, traditional assays and more innovative methodologies to evaluate the antioxidant activity are discussed. Finally, the possible molecular mechanisms of action of the rice byproduct antioxidant compounds (phenolic acids, flavonoids, γ-oryzanol, and vitamin E) are discussed as well. In the future, it is expected that rice byproduct antioxidants will be important food ingredients that reduce the risk of the development of several human disorders involving oxidative stress, such as metabolic diseases, inflammatory disorders, and cancer.

Health-promoting germinated rice and value-added foods: a comprehensive and systematic review of germination effects on brown rice

Over the last 30 years, thousands of articles have appeared examining the effects of soaking and germinating brown rice (BR). Variable germination conditions and methods have been employed to measure different health-beneficial parameters in a diverse germplasm of BR. Research results may therefore appear inconsistent with occasional anomalies, and it may be difficult to reach consensus concerning expected trends. Herein, we amassed a comprehensive review on germinated brown rice (GBR), attempting to codify 133 peer-reviewed articles regarding the effects on 164 chemical parameters related to health and nutrition in BR and in value-added food products. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-2020) approach was used to direct the flow of the literature search. A pair-wise comparison t-test was performed to deliver an overall approach indicating when a given compound has been found to significantly increase or decrease through germination, which was grouped into GABA and polyamines, γ-Oryzanol and phytosterols, phenolic compounds, vitamins, proteins and amino acids, starchy carbohydrates, free sugars, lipids, minerals and phytic acid. This resource will stimulate interest in germinating rice and optimistically help increase both production and consumption of highly nutritious, health-beneficial rice with pigmented bran.

Effect of processing methods and storage on the bioactive compounds of black rice (Oryza sativa L.): a review

Compared to brown and white rice, black rice contains more nutrients and numerous unique bioactive substances, such as essential amino acids, dietary fiber, γ-oryzanols, γ-aminobutyric acid, phenolic compounds, and anthocyanins, which makes it highly valuable for development and use. Whole-grain black rice typically requires a certain amount of processing prior to consumption, with the primary goal of enhancing the taste and texture of whole grains and their products. However, various new processing technologies have been effectively applied to the processing of black rice and the enhancement of its qualitative characteristics, but they also have both positive and negative effects on its nutritional quality. Therefore, evaluation of changes in concentrations of the bioactive substances as natural antioxidants due to processing and storage conditions is critical for establishing dietary guidelines for rice. This review highlights the primary bioactive components of black rice and provides a discussion of the impact of processing methods and storage on the bioactive components of black rice. Furthermore, we summarized the issues that currently exist in the processing and storage of black rice.

The potential use of Indian rice flour or husk in fortification of pan bread: assessing bread's quality using sensory, physicochemical, and chemometric methods

Hassawi rice is an Indica variety cultivated in Saudi Arabia with a higher nutritional value than the commercial Basmati rice varieties. The present study has investigated the feasibility of combining Hassawi rice flour (HRF) or husk (HRHF), an abundant byproduct, with wheat flour to produce nutritious economical pan bread. To achieve this aim, the physicochemical properties of HRF and HRHF were assessed using techniques such as UPLC-tandem MS, ICP-OES, and colorimeter. The proximate composition (moisture, crude fiber, and ash) and mineral contents of HRHF are significantly (p < 0.05) higher than HRF. On the other hand, the compounds p-coumaric acid, vanillic acid, γ- and δ-tocotrienols, and γ-oryzanol were unique to HRF. We further determined the changes in sensory, technological, and physicochemical properties of wheat flour bread substituted with 5%, 10%, and 15% of HRF or HRHF. The rheological tests showed that the addition of HRF and HRHF increased dough development and stability time. Further, substituting wheat flour for HRF and HRHF at levels higher than 10% affected sensory attributes, such as color, taste, odor, flavor, and appearance. These changes, however, were not always at a significant level. The causes of the differences in properties between control and fortified bread samples were investigated by chemometric methods. Samples of bread + HRF at 5 and 10% had comparable overall profiles to the control. On the other hand, bread + HRHF samples proved to retain higher concentrations of bioactive molecules compared to the control bread. Our findings shed light on the possible use of rice husk fibers in baking goods, notably pan bread. Furthermore, by integrating rice husk fibers into baked goods, we may boost their health benefits while also contributing to the long-term use of agricultural waste.

Effects of Dietary Linoleic Acid on Blood Lipid Profiles: A Systematic Review and Meta-Analysis of 40 Randomized Controlled Trials

Th aim of this meta-analysis was to elucidate whether dietary linoleic acid (LA) supplementation affected blood lipid profiles, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), compared with other fatty acids. Embase, PubMed, Web of Science and the Cochrane Library databases, updated to December 2022, were searched. The present study employed weighted mean difference (WMD) and a 95% confidence interval (CI) to examine the efficacy of the intervention. Out of the 3700 studies identified, a total of 40 randomized controlled trials (RCTs), comprising 2175 participants, met the eligibility criteria. Compared with the control group, the dietary intake of LA significantly decreased the concentrations of LDL-C (WMD: -3.26 mg/dL, 95% CI: -5.78, -0.74, I² = 68.8%, p = 0.01), and HDL-C (WMD: -0.64 mg/dL, 95% CI: -1.23, -0.06, I² = 30.3%, p = 0.03). There was no significant change in the TG and TC concentrations. Subgroup analysis showed that the LA intake was significantly reduced in blood lipid profiles compared with saturated fatty acids. The effect of LA on lipids was not found to be dependent on the timing of supplementation. LA supplementation in an excess of 20 g/d could be an effective dose for lowering lipid profiles. The research results provide further evidence that LA intake may play a role in reducing LDL-C and HDL-C, but not TG and TC.

The effects of rice bran supplementation for management of blood lipids: A GRADE-assessed systematic review, dose-response meta-analysis, and meta-regression of randomized controlled trials

BACKGROUND

We aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to investigate the effects of rice bran supplementation on serum lipid profile levels.

METHODS

We searched PubMed/Medline, Scopus, ISI Web of Science, and Google Scholar using related keywords. Published RCTs exploring the effects of rice bran consumption on lipid profile were searched up to June 2022. Evidence certainty was assessed on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The data were pooled using a random-effects model and reported as weighted mean difference (WMD) and 95% confidence interval (CI) for each outcome.

RESULTS

Meta-analysis of eight RCTs (with 11 effect sizes) showed no significant effect of rice bran supplementation on serum levels of triglyceride (WMD: -11.38 mg/dl; 95% CI: -27.73, 4.96; P = 0.17), total cholesterol (WMD: -0.68 mg/dl; 95% CI: -7.25, 5.88; P = 0.834), low-density lipoprotein cholesterol (WMD: -1.68 mg/dl; 95% CI: -8.46, 5.09; P = 0.627) and high-density lipoprotein cholesterol (WMD: 0.16 mg/dl; 95% CI: -1.52, 1.85; P = 0.848) compared to control group.

CONCLUSION

Our meta-analysis suggests that rice bran supplementation has no significant effects on serum levels of lipid profile components. However, larger studies with longer durations and improved methodological quality are needed before firm conclusions can be reached.

Impacts of Electroextraction Using the Pulsed Electric Field on Properties of Rice Bran Protein

The pulsed electric field (PEF) was applied to improve the extraction yield and properties of rice bran proteins from two rice varieties ("Kum Chao Mor Chor 107" and "Kum Doi Saket"). As compared to the conventional alkaline extraction, PEF treatment at 2.3 kV for 25 min increased the protein extraction efficiency by 20.71-22.8% (p < 0.05). The molecular weight distribution detected by SDS-PAGE and amino acid profiles of extracted rice bran proteins was likely unchanged. The PEF treatment influenced changes in the secondary structures of rice bran proteins, especially from the β-turn to the β-sheet structure. Functional properties of rice bran protein including oil holding capacity and emulsifying properties were significantly improved by PEF treatments by about 20.29-22.64% and 3.3-12.0% (p < 0.05), respectively. Foaming ability and foam stability increased by 1.8- to 2.9-fold. Moreover, the in vitro digestibility of protein was also enhanced, which was consistent with the increment of DPPH and ABTS radical-scavenging activities of peptides generated under in vitro gastrointestinal digestion (37.84-40.45% and 28.46-37.86%, respectively). In conclusion, the PEF process could be a novel technique for assisting the extraction and modification of the protein's digestibility and functional properties.

Antioxidants Supplementation During Exercise: Friends or Enemies for Cardiovascular Homeostasis?

Exercise is a preferred strategy for improving cardiac function, especially for patients with cardiovascular diseases. Increasing evidence indicates that oxidative stress is involved in exercise-induced cardioprotection, while the underlying mechanism remains unclear. Furthermore, the effect of antioxidant supplementation during or post-exercise still exists despite divergences. To explore the effect of oxidative stress and antioxidant supplementation on cardiovascular homeostasis during or post-exercise, we take insights into the progress of exercise-induced oxidative stress, antioxidant supplementation, and cardiovascular homeostasis. In particular, antioxidants such as vitamin C or E, gamma-oryzanol, and other natural antioxidants are discussed concerning regulating exercise-associated oxidative stress. Additionally, our present study reviewed and discussed a meta-analysis of antioxidant supplementation during exercise. Overall, we take an insight into the essential biological adaptations in response to exercise and the effects of antioxidant supplementation on cardiac function, which aid us in giving recommendations on antioxidant supplementation for exercisers and exercised people. A better understanding of these issues will broaden our knowledge of exercise physiology.

Oxidative stability of sunflower and soybean oils enriched with black plum peel extract in comparison with synthetic antioxidants

Black plum peel is the by-product of plum processing and is a valuable source of antioxidants and phenolic compounds. In this research, total phenolic compounds, total flavonoid content and antioxidant activity of black plum peel were measured. After that, black plum peel extract (in concentrations 0, 400, 800, 1200 and 2000 ppm) as a natural antioxidant for improving the stability of soybean and sunflower oil was used. The oxidative stability parameters of oils (peroxide value, free fatty acids, thiobarbituric acid, conjugated dienes, and carbonyl value) were measured at 60 °C for 4-16 days. Antioxidant activity, total phenolic compounds and total flavonoid content of black plum peel were 86.87% and 100.53 mg GA /g and 871.062 mg Quercetin/g respectively. Black plum peel extract could have a significant positive effect (P<0.05) on improvement of the quality and stability parameters of soybean oil and sunflower oil. The oxidative stability parameters for commercial oils and samples containing black plum peel extract were near each other and in an acceptable range. So, black plum peel is recommended as an oxidative stabilizer of oils and alternative synthetic antioxidants.

Lipidomic Profiling of Rice Bran after Green Solid-Liquid Extractions for the Development of Circular Economy Approaches

Rice bran is a rather underutilized by-product of the rice industry that nowadays is far from being valorized. In this study, the lipidomic profile of bran of the Italian rice variety, Roma, has been evaluated through ultra performance liquid chromatography-tandem mass spectrometry. Crude lipid extracts were obtained from rice bran treated with different green solvents (1-butanol, ethanol and methyl tert-butyl ether/methanol mixture) in combination with an ultrasonic pre-treatment, and then compared with extracts obtained with standard solvents (chloroform/methanol mixture). Lipid yield, number and type of lipids and composition of prevalent lipid classes extracted were evaluated in order to provide an exhaustive lipid profile of the rice bran and to identify the most efficient green solvent for solid-liquid extractions. Twelve different lipid classes and a maximum of 276 lipids were identified. Ethanol and methyl tert-butyl ether/methanol solvents provided higher lipid extraction yields, the former being the most effective solvent for the extraction of triglycerides and N-acylethanolamines and the latter the most effective for the extraction of diglycerides, phospholipids and ceramides at 4 °C. Moreover, extraction with ethanol at 20 °C gave similar results as at 4 °C in terms of lipid yield and for most of the classes of lipids extracted. Taken together, our results indicate ethanol and methyl tert-butyl ether/methanol as excellent solvents for lipid extraction from rice bran, with the aim to further valorize this food by-product in the perspective of a circular economy.

Effects of Riceberry Rice Bran Oil Supplementation on Oxidative Stress and Cardiovascular Risk Biomarkers in Older Adults with Prehypertension

We investigated the changes in the oxidative stress and cardiovascular disease risk biomarkers, including the activity of the cardiac autonomic nervous system, in older adults with prehypertension following Riceberry rice bran oil supplementation. A total of 35 women aged 60 to 76 years with prehypertension were randomly allocated to two groups, one of which was supplemented with rice bran oil (n=18) and the other with Riceberry rice bran oil (n=17) at 1,000 mg daily for 8 weeks. Prior to and after the supplementation, oxidative stress and cardiovascular risk biomarkers (primary outcomes), heart rate variability, and blood pressure (secondary outcomes) were investigated. Results showed that plasma malondialdehyde, blood glutathione disulfide, and tumor necrosis factor-alpha levels were significantly decreased, and the ratio of reduced glutathione to glutathione disulfide significantly increased in both groups after supplementation (all P<0.05). No significant differences were observed between groups. Heart rate variability and blood pressure did not statistically significantly change subsequent to supplementation in either group and did not differ between groups. In conclusion, Riceberry rice bran oil supplementation for 8 weeks alleviates oxidative stress and inflammation in older adults with prehypertension to a similar extent as rice bran oil supplementation.

From farm to plate: Spatio-temporal characterization revealed compositional changes and reduced retention of γ-oryzanol upon processing in rice

Background

Antioxidants detain the development and proliferation of various non-communicable diseases (NCDs). γ-oryzanol, a group of steryl ferulates and caffeates, is a major antioxidant present in rice grain with proven health benefits. The present study evaluated the distribution and dynamics of γ-oryzanol and its components in spatial and temporal scales and also delineated the effect of processing and cooking on its retention.

Methods

Six rice varieties (four Basmati and two non-Basmati) belonging to indica group were analyzed at spatial scale in four different tissues (leaf blades, leaf sheaths, peduncle and spikelets) and temporal scale at three developmental stages (booting, milky and dough). Additionally, the matured grains were fractioned into husk, embryo, bran, and endosperm to assess differential accumulation in these tissues. Further, milling and cooking of the samples was done to assess the retention upon processing. After extraction of γ-oryzanol by solvent extraction method, individual components were identified by UPLC-QToF-ESI-MS and quantified by RP-HPLC.

Results

The non-seed tissues were significantly different from the seed tissues for composition and quantitative variation of γ-oryzanol. Cycloartenyl caffeate was predominant in all the non-seed tissues during the three developmental stages while it showed significant reduction during the growth progression toward maturity and was totally absent in the matured grains. In contrary, the 24-methylenecycloartanyl ferulate, campesteryl ferulate and β-sitosteryl ferulate showed significant increment toward the growth progression to maturity. Milling caused significant reduction, retaining only an average of 58.77% γ-oryzanol. Cooking of brown rice in excess water showed relatively lower average retention (43.31%) to samples cooked in minimal water (54.42%). Cooked milled rice showed least mean retention of 21.66%.

Conclusion

The results demonstrate prominent compositional variation of γ-oryzanol during different growth stages. For the first time, the study demonstrated that ferulate esters of γ-oryzanol were predominant in the seed tissues while caffeate esters were dominant in non-seed tissues. Basmati cultivars show differential expression of γ-oryzanol and its components compared to non-Basmati cultivars. Cooking in excess water causes maximum degradation of γ-oryzanol. Post-harvest losses due to milling and cooking indicate the necessity of biofortification for γ-oryzanol content in rice grain.

Gamma-oryzanol supplemented in extender enhances the quality of semen cryopreservation and alters proteomic profile in Thai swamp buffalo

Reactive oxygen species (ROS) exert an adverse effect on sperm quality during the freezing process. Gamma-oryzanol is an effective antioxidant and has the ability to inhibit lipoperoxidation in various cells. Therefore, this study aims to investigate the effect of gamma-oryzanol supplementation in extender on post-thawed motility and proteomic profiles of swamp buffalo spermatozoa. Each ejaculate of an individual bull was divided into four equal aliquots. Gamma-oryzanol was supplemented at 0 (control), 0.1, 0.25, and 0.5 mM in tris-citrate egg yolk extender. The parameters of sperm motility were evaluated using computer assisted semen analyzer (CASA). The results showed that the progressive motility was significantly higher in 0.5 mM of gamma-oryzanol supplementation group when compared with the control group (p < 0.05), but no significant differences were observed among the treatments. In addition, a proteomic approach was applied to analyze the differentially expressed proteins in post-thawed sperm with or without gamma-oryzanol supplementation in extender. We confirmed that 2-phospho-d-glycerate hydro-lyase (ENO1), glutathione s-transferase mu 1 (GSTM1), phospholipid hydroperoxide glutathione peroxidase (GPX4), outer dense fiber protein 2 (ODF2), tektin-4 (TEKT4), tubulin beta-4B chain (TUBB4B), and ATP synthase subunit beta (ATP5B) were up-regulated in 0.5 mM of gamma-oryzanol supplementation group, which might be associated with the improved post-thawed motility observed in this treatment group. These results demonstrate the beneficial effect of gamma-oryzanol on post-thawed survival of swamp buffalo spermatozoa and help advance the understanding about molecular metabolism of sperm in this species.

Gamma-oryzanol protects human liver cell (L02) from hydrogen peroxide-induced oxidative damage through regulation of the MAPK/Nrf2 signaling pathways

Gamma-oryzanol (Orz), a mixture of the ferulic acid ester of triterpene alcohols and phytosterols, was found abundantly in rice bran and rice bran oil which could be available and served as an antioxidant. The present study was to explore the potential protective effects of Orz on oxidative stress and cell apoptosis in human hepatic cells (L02 cells) induced by hydrogen peroxide (H₂ O₂ ). Flow cytometry detection and Hoechst 33258 staining showed that Orz significantly restored cell cycle and ameliorated apoptosis in H₂ O₂ -challenged L02 cells. Orz pretreatment inhibited H₂ O₂ -induced cell apoptosis by increasing the scavenging of hydroxyl radicals (OH·), and efficiently decreasing the production of nitric oxide (NO). Moreover, a loss of total antioxidant capacity (T-AOC) and adenosine triphosphatase (ATPase) were enhanced in H₂ O₂ -mediated L02 cells pretreated with Orz. Furthermore, preincubation with Orz reduced H₂ O₂ -mediated the proapoptotic protein of Bak expression and the phosphorylation of ASK1, p38, JNK, and ERK, and increased the anti-apoptotic protein of Bcl-xl expression and anti-oxidative stress proteins of Nrf2 and HO-1 expression. The findings suggested that Orz exerts the cytoprotective effects in H₂ O₂ -induced L02 cells apoptosis by ameliorating oxidative stress via inhibiting MAPK signaling pathway and activating Nrf2 signaling pathway. PRACTICAL APPLICATIONS: Gamma-oryzanol (Orz), a mixture of the ferulic acid ester of triterpene alcohols and phytosterols, was found abundantly in rice bran and rice bran oil which could be availably served as an antioxidant. In this study, it was found that Orz exerts the cytoprotective effects in H₂ O₂ -induced L02 cell apoptosis by ameliorating oxidative stress via the inhibition of MAPK signaling pathway and the activation of Nrf2 signaling pathway, which provides a theoretical basis for dietary adding natural products to prevent or treat oxidative stress-related diseases.

A novel LOX3-null allele (lox3-b) originated in the aromatic Basmati rice cultivars imparts storage stability to rice bran

Rapid deterioration of rice bran due to the LOX3 enzyme catalysed oxidation of PUFA is the major bottleneck for its utilization in various downstream applications. In the present study, we have identified a set of nine novel LOX3-null rice accessions carrying a deletion of C residue in the exon2 causing a frameshift mutation resulting in a truncated non-functional LOX3 protein. Our study, further manifested the predominance of C deletion based LOX3-null allele, named lox3-b, in the aromatic rice germplasm particularly in the Indian Basmati rice group. The LOX3-null genotypes exhibited significantly reduced rancidity, after six months of storage. They also showed significantly lower percentage reduction of linoleic acid (LA), higher γ-oryzanol content and lower hexanal content. A functional dCAPS marker designed based on the deletion polymorphism clearly differentiated LOX3 and lox3-b alleles, and has the potential application in marker assisted rice breeding programmes to develop cultivars with better bran storability.

Lipid Profiles in Preliminary Germinated Brown Rice Beverages Compared to Non-Germinated Brown and White Rice Beverages

Brown rice is nutritionally superior to white rice, yet oil rancidity can be problematic during processing and storage regarding sensory attributes. Germinating brown rice is known to generally increase some health-promoting compounds. In response to increasing the consumption of plant-based beverages, we sprouted unstabilized brown rice, using green technologies and saccharification enzymes for value-added beverages. ‘Rondo’ paddy rice was dehulled, sorted and germinated, and beverages were produced and compared against non-germinated brown and white brewers rice beverages. The preliminary germinated brown rice beverage contained significantly higher concentrations of total lipids, diacylglycerols, triacylglycerols, free sterols, phytosterol esters and oryzanols than both non-germinated brown and white rice beverages. White rice beverages had significantly higher free fatty acids. Significant lipid losses occurred during sieving, yet novel germinated brown rice beverages contained appreciable levels of valuable health-beneficial lipids, which appeared to form natural emulsions. Further pilot plant investigations should be scaled-up for pasteurization and adjusted through emulsification to ameliorate sieving losses.

The involvement of TGF-β1 /FAK/α-SMA pathway in the antifibrotic impact of rice bran oil on thioacetamide-induced liver fibrosis in rats

The objective of the current study is to investigate the effect of rice bran oil (RBO) on hepatic fibrosis as a characteristic response to persistent liver injuries. Rats were randomly allocated into five groups: the negative control group, thioacetamide (TAA) group (thioacetamide 100 mg/kg thrice weekly for two successive weeks, ip), RBO 0.2 and 0.4 groups (RBO 0.2mL and 0.4 mL/rat/day, po) and standard group (silymarin 100 mg/kg/day, po) for two weeks after TAA injection. Blood and liver tissue samples were collected for biochemical, molecular, and histological analyses. Liver functions, oxidative stress, inflammation, liver fibrosis markers were assessed. The obtained results showed that RBO reduced TAA-induced liver fibrosis and suppressed the extracellular matrix formation. Compared to the positive control group, RBO dramatically reduced total bilirubin, AST, and ALT blood levels. Furthermore, RBO reduced MDA and increased GSH contents in the liver. Simultaneously RBO downregulated the NF-κβ signaling pathway, which in turn inhibited the expression of some inflammatory mediators, including Cox-2, IL-1β, and TNF-α. RBO attenuated liver fibrosis by suppressing the biological effects of TGF-β1, α-SMA, collagen I, hydroxyproline, CTGF, and focal adhesion kinase (FAK). RBO reduced liver fibrosis by inhibiting hepatic stellate cell activation and modulating the interplay among the TGF-β1 and FAK signal transduction. The greater dosage of 0.4 mL/kg has a more substantial impact. Hence, this investigation presents RBO as a promising antifibrotic agent in the TAA model through inhibition of TGF-β1 /FAK/α-SMA.

Biostimulant Capacity of an Enzymatic Extract From Rice Bran Against Ozone-Induced Damage in Capsicum annum

Ozone is a destructive pollutant, damaging crops, and decreasing crop yield. Therefore, there is great interest in finding strategies to alleviate ozone-induced crop losses. In plants, ozone enters leaves through the stomata and is immediately degraded into reactive oxygen species (ROS), producing ROS stress in plants. ROS stress can be controlled by ROS-scavenging systems that include enzymatic or non-enzymatic mechanisms. Our research group has developed a product from rice bran, a by-product of rice milling which has bioactive molecules that act as an antioxidant compound. This product is a water-soluble rice bran enzymatic extract (RBEE) which preserves all the properties and improves the solubility of proteins and the antioxidant components of rice bran. In previous works, the beneficial properties of RBEE have been demonstrated in animals. However, to date, RBEE has not been used as a protective agent against oxidative damage in agricultural fields. The main goal of this study was to investigate the ability of RBEE to be used as a biostimulant by preventing oxidative damage in plants, after ozone exposure. To perform this investigation, pepper plants (Capsicum annuum) exposed to ozone were treated with RBEE. RBEE protected the ozone-induced damage, as revealed by net photosynthetic rate and the content of photosynthetic pigments. RBEE also decreased the induction of antioxidant enzyme activities in leaves (catalase, superoxide dismutase, and ascorbate peroxidase) due to ozone exposure. ROS generation is a common consequence of diverse cellular traumas that also activate the mitogen-activated protein kinase (MAPK) cascade. Thus, it is known that the ozone damages are triggered by the MAPK cascade. To examine the involvement of the MAPK cascade in the ozone damage CaMPK6-1, CaMPK6-2, and CaMKK5 genes were analyzed by qRT-PCR. The results showed the involvement of the MAPK pathway in both, not only in ozone damage but especially in its protection by RBEE. Taken together, these results support that RBEE protects plants against ozone exposure and its use as a new biostimulant could be proposed.

Evaluating the Efficacy of Lotion Containing Black Rice Bran (Oryza sativa L. indica) Extract as Skin Brightening Agent: A Clinical Trial

Background: Ultraviolet exposure is an extrinsic factor to initiate melanogenesis, the process of melanin formation in the skin. Nowadays, natural ingredients tend to be more prevalent in cosmetic formulations due to consumers’ concern about synthetic ingredients and the risks they may represent for human health. Rice bran, the outer layer of a rice grain, can be utilized as a skin-lightening agent. Objectives: This study aimed to determine the efficacy of a lotion containing black rice bran (Oryza sativa L. indica) ethanolic extract as a skin lightening agent. Methods: The black rice bran ethanolic extract was formulated into oil in water (o/w) lotion. In this study, 34 women applied the lotion at one side of the forearm and base placebo lotion as control at the other side of forearm. The results were tested with a paired t-test by GraphPad Prism 8.3.0 software. Results: There was a significant decrease in the melanin index and erythema index in the forearm with a lotion containing black rice bran extract (P-value < 0.0001). Conclusions: The lotion containing 10% black rice bran extract was effective as a skin lightener because it effectively reduced skin melanin production when applied topically.

Apoptosis Induction through MAPK Signaling Pathway in LoVo Cells by Fatty Acid Fraction from Rice Bran Oil

Colorectal cancer is one of the five leading cancer incidents and mortality in Thailand and worldwide. Fatty acids (FA) are bioactive molecules which have potential as adjunctive chemotherapeutic agents. To study the effect of fatty acid fraction (FAs) extracted from organic rice bran oil on apoptosis induction and growth inhibition in human colorectal cancer cell line, LoVo cells. The results demonstrated that FAs inhibited cell viability and induced cell death via apoptosis associated with MAPKs pathway. The EC₅₀ of FAs in LoVo was 172.80 ± 1.05 µg/ml. FAs treatment significantly increased nuclear condensation and decreased mitochondrial membrane potential. Moreover, FAs activated Bax, Caspase-9, -7 and PARP cleavage, while inhibited Bcl-2 expression. Furthermore, FAs increased p53 expression and phosphorylation of ERK and p38. FAs extracted from organic rice bran oil inhibited LoVo cell viability and induced apoptosis via MAPKs pathway. These data suggest the potential use of FAs extracted from organic rice bran oil to prevent or treat colon cancer in the future.

Rice Compounds with Impact on Diabetes Control

Rice is one of the most cultivated and consumed cereals worldwide. It is composed of starch, which is an important source of diet energy, hypoallergenic proteins, and other bioactive compounds with known nutritional functionalities. Noteworthy is that the rice bran (outer layer of rice grains), a side-stream product of the rice milling process, has a higher content of bioactive compounds than white rice (polished rice grains). Bran functional ingredients such as γ-oryzanol, phytic acid, ferulic acid, γ-aminobutyric acid, tocopherols, and tocotrienols (vitamin E) have been linked to several health benefits. In this study, we reviewed the effects of rice glycemic index, macronutrients, and bioactive compounds on the pathological mechanisms associated with diabetes, identifying the rice compounds potentially exerting protective activities towards disease control. The effects of starch, proteins, and bran bioactive compounds for diabetic control were reviewed and provide important insights about the nutritional quality of rice-based foods.

Metabolite Profiling Reveals Distinct Modulation of Complex Metabolic Networks in Non-Pigmented, Black, and Red Rice (Oryza sativa L.) Cultivars

Comprehensive profiling of primary and secondary metabolites was performed to understand metabolic differences associated with color formation in pigmented rice (Oryza sativa L.). Overall, 110 metabolites from non-pigmented, black, and red rice cultivars were identified. Black and red rice contained high levels of flavonoids associated with plant color. Black rice also contained high levels of terpenoids (carotenoids, tocopherols, phytosterols, and monoterpenes). The non-pigmented rice contained relatively low levels of secondary metabolites. Multivariate and pathway analyses were performed to data-mine the metabolite profiles. Hierarchical clustering analysis of correlation coefficients revealed metabolite clusters based on nitrogen and carbon sources. These clusters suggested a negative correlation between nitrogen and carbon. Pathway analysis revealed that black rice was rich in carbon-based secondary metabolites, with relatively low levels of primary metabolites compared with other rice cultivars. These data highlight the complex interactions between nitrogen and carbon metabolism of primary and secondary metabolites in rice. For the first time, the relationships and metabolic differences in terpenoid content (monoterpenes, triterpenes, and tetraterpenes) of non-pigmented and pigmented rice cultivars were analyzed. These findings should greatly contribute to the understanding of pigmented rice metabolome and inform breeding programs for new rice cultivars.

Rice bran, an off-shoot to newer therapeutics in neurological disorders

Normal brain functioning involves the interaction of interconnected molecular and cellular activities, which appear to alter normal to abnormal brain functioning when worsened, contributing to the emergence of neurological disorders. There are currently millions of people who are living with brain disorders globally and this will rise if suitable prevention strategies are not explored. Nutraceutical intended to treat numerous health goals with little adverse effect possible together can be more beneficial than pharmaceutical monotherapy for fostering balanced brain functioning. Nutraceutical provides a specific composition of effective macronutrients and micronutrients that are difficult to synthesize in the laboratory. Numerous elements of rice fibers in rice bran are characterized as natural anti-oxidant and having potential anti-inflammatory activity. The rice bran captures interest among the researchers as it is widespread, affordable, and rich in nutrients including protein, fat, carbohydrates, bioactive components, and dietary fiber. This review covers the neuroprotective multiplicity of rice bran and its constituents to deter pathological conditions of the brain and to facilitate balanced brain functioning at the same time.

Comparative Studies on the Hepatoprotective Effect of White and Coloured Rice Bran Oil against Acetaminophen-Induced Oxidative Stress in Mice through Antioxidant- and Xenobiotic-Metabolizing Systems

Rice bran oil (RBO) comprises various nutrients and phytochemicals which exhibit several health benefits. There are no studies regarding the functional effects of different colours of RBO. This study was aimed to compare the constituents and antioxidant activities of white rice bran oil (WRBO) and coloured rice bran oil (CRBO). Each RBO showed similar free fatty acid profiles. However, greater amounts of vitamin E, phytosterols, carotenoids, and chlorophylls were found in CRBO, which had lower γ-oryzanol content than WRBO. Oxidative stress was induced in male mice by an overdose of acetaminophen (APAP) at 300 mg/kg body weight. The mice were then fed with RBO at the equivalent dose to 100 mg/kg body weight of γ-oryzanol three hours later and sacrificed six hours after APAP treatment. The administration of 100 mg γ-oryzanol equivalent in CRBO ameliorated APAP-induced hepatotoxicity in mice more strongly than 100 mg γ-oryzanol equivalent in WRBO, as evidenced by the significant reduction of serum ALT, hepatocellular necrosis, and hepatic lipid peroxidation. CRBO could improve xenobiotic-metabolizing and antioxidant enzyme activities, including glutathione S-transferase, superoxide dismutase, glutathione peroxidase, and glutathione reductase, and also increase mRNA expression of various antioxidant-responsive genes. Vitamin E, phytosterols, carotenoids, and chlorophyll might be the protective compounds in CRBO that alleviate APAP-induced hepatotoxicity through the interruption of APAP metabolism and the activation of antioxidant systems at both transcriptional and enzymatic levels. These findings might provide a protective role of CRBO on oxidative stress associated with several degenerative diseases.

Differences in the Compositions of Vitamin E Tocochromanol (Tocopherol and Tocotrienol) in Rice Bran Oils Produced in Japan and Other Countries

In this study, we investigated the compositions of vitamin E tocochromanol [tocopherol (Toc) and tocotrienol (T3)] in crude and refined rice bran oil (RBO) produced in Japan and other countries, including Brazil, Thailand, and Vietnam, based on high-performance liquid chromatography analysis. All RBO analyzed contained α-, β- and γ-Toc and α-, γ- and δ-T3. Japanese crude RBO, although not refined RBO, also contained β-T3. Furthermore, total Toc contents in both Japanese crude and refined oils were found to be higher than those in the crude and refined RBO from other countries. Total T3 contents in Japanese crude RBO were similar to those in the crude RBO from Brazil and Vietnam. The α-Toc and α-T3 contents in Japanese crude and refined RBO were considerably higher than those in the crude and refined RBO produced in other countries, whereas in contrast, γ-Toc and γ-T3 contents in Japanese crude and refined RBO were lower. Consequently, the ratios of total α-Toc and α-T3 contents to total γ-Toc and γ-T3 contents in Japanese crude and refined RBO (1.75 and 1.91, respectively) were notably higher than those in the crude and refined RBO produced in other countries. Similarly, the ratios of total Toc to total T3 in Japanese crude and refined RBO were higher than those in the crude and refined RBO produced in other countries. These results accordingly indicate that the ratio of total α-Toc and α-T3 contents to γ-Toc and γ-T3 contents could be used as an effective index to discriminate between the RBO produced in Japan and that produced in other countries.

Influence of enzyme concentrations in enzymatic bioprocessing of red rice bran: A detailed study on nutraceutical compositions, antioxidant and human LDL oxidation inhibition properties

Enzymes and their concentrations are crucial factors in improving the release of nutraceuticals bounded to rice bran's cell wall matrix. This study aims to investigate the optimal concentrations of Viscozyme and Fiberzyme at 3-30 beta-glucanase units/2 g in improving the release of phenolics, tocopherols, tocotrienols, and γ-oryzanol fractions and enhancing the bioactivities of red rice bran. At specific concentrations, Fiberzyme increased ferulic (301%) and caffeic acid (691%) in soluble phenolics, p-coumaric acid (98%), and catechin (161%) in bound phenolics as well as γ-oryzanol fractions(32%-134%) and increased ferric reducing power (90%), DPPH (41%), and hydroxyl (25%) radical scavenging activities. Viscozyme enhanced δ,γ,α-tocopherols (11%-164%) and tocotrienols (39%-271%) and scavenging activities against nitric oxide (144%), superoxide anion (120%), and inhibition of human LDL oxidation (40%). Cycloartenyl ferulate, ferulic acid, soluble phenolics, campesteryl ferulate, 24-methylenecycloartanyl ferulate, and α-tocotrienol showed a significant positive correlation with bioactivities. Thus, optimization of enzymatic processing will help process the red rice bran into a nutraceutical rich ingredient having higher biological activity.

Rice bran modulates renal disease risk factors in animals submitted to high sugar-fat diet

Introduction:

Obesity, diabetes, and hypertension are common risk factors for chronic kidney disease (CKD). CKD arises due to many pathological insults, including inflammation and oxidative stress, which affect renal function and destroy nephrons. Rice bran (RB) is rich in vitamins and minerals, and contains significant amount of antioxidants. The aim of this study was to evaluate the preventive effect of RB on renal disease risk factors.

Methods:

Male Wistar rats (±325 g) were divided into two experimental groups to received a high sugar-fat diet (HSF, n = 8) or high sugar-fat diet with rice bran (HSF + RB, n = 8) for 20 weeks. At the end, renal function, body composition, metabolic parameters, renal inflammatory and oxidative stress markers were analyzed.

Results:

RB prevented obesity [AI (HSF= 9.92 ± 1.19 vs HSF + RB= 6.62 ± 0.78)], insulin resistance [HOMA (HSF= 83 ± 8 vs. HSF + RB= 42 ± 11)], dyslipidemia [TG (HSF= 167 ± 41 vs. HSF + RB=92 ± 40)], inflammation [TNF-α (HSF= 80 ± 12 vs. HSF + RB=57 ± 14), IL-6 (903 ± 274 vs. HSF + RB=535 ± 277)], oxidative stress [protein carbonylation (HSF= 3.38 ± 0.18 vs. HSF + RB=2.68 ± 0.29), RAGE (HSF=702 ± 36 vs. RSF + RB=570 ± 190)], and renal disease [protein/creatinine ratio (HSF=1.10 ± 0.38 vs. HSF + RB=0.49 ± 0.16)].

Conclusion:

In conclusion, rice bran prevented renal disease by modulating risk factors.

Inhibitory Effect of Thai Purple Rice Husk Extract on Chemically Induced Carcinogenesis in Rats

This study investigated the cancer chemopreventive effects of an acidic methanol extract of purple rice husk on chemically induced carcinogenesis in rats. This purple rice husk extract (PRHE) had high polyphenol contents. Vanillic acid was a major phenolic compound in PRHE. Three major anthocyanins found in PRHE were malvidin-3-glucoside, peonidin-3-glucoside and cyanidin-3-glucoside. PRHE was not toxic and clastogenic in rats. The LD50 of PRHE was greater than 2000 mg kg-1 body weight (BW). The oral administration of 300 or 1000 mg kg-1 BW of PRHE for 28 days significantly decreased the number of micronucleated hepatocytes in diethylnitrosamine-initiated rats. The inhibitory mechanisms were associated with the reduction of cytochrome P450 2E1 expression and induction of some detoxifying enzymes in the liver. In addition, treatment with 500 mg kg-1 BW of PRHE for eight weeks did not induce preneoplastic lesions in the liver and colon. It significantly inhibited hepatic glutathione-S-transferase positive foci formation induced by diethylnitrosamine and 1,2-dimethylhydrazine by suppression of hepatocyte proliferation and induction of apoptosis. In conclusion, PRHE did not present toxicity, clastogenicity or carcinogenicity in rats. It exhibited cancer chemopreventive properties against chemically induced early stages rat hepatocarcinogenesis. Anthocyanins and vanillic acid might be candidate anticarcinogenic compounds in purple rice husk.

Comparative Evaluation of the Nutritional, Antinutritional, Functional, and Bioactivity Attributes of Rice Bran Stabilized by Different Heat Treatments

The objective of this study was to evaluate the effects of different stabilization treatments—namely, dry-heating, infrared-radiation, and microwave-heating—on the nutritional, antinutritional, functional, and bioactivity attributes of rice bran (RB). Among the heating treatments, infrared-radiation exerted the strongest inactivation, resulting in 34.7% residual lipase activity. All the stabilization methods were found to be effective in the reduction of antinutrients, including phytates, oxalate, saponins, and trypsin inhibitors. No adverse effect of stabilization was noted on chemical composition and fatty acid profile of RB. Instead, stabilization by all heat treatments caused a significant decrease of vitamin E and total phenolics content in RB; the same trend was observed for the antioxidant activity as evaluated by the DPPH test. The antioxidant activity, as evaluated by ABTS and FRAP tests, and water absorption capacity were improved by the stabilization of RB, whereas the oil absorption capacity and emulsifying properties decreased. Microwave-heating enhanced the foaming properties, whereas infrared-radiation improved the water solubility index and swelling power of RB. Consequently, treatment of RB with infrared-radiation has a potential for industrialization to inactivate the lipase and improve some functional properties of this material for uses as a nutraceutical ingredient in food and cosmetic products.

Rice Bran Extract Protected against LPS-Induced Neuroinflammation in Mice through Targeting PPAR-γ Nuclear Receptor

PPAR-γ anti-inflammatory functions have received significant attention since its agonists have been shown to exert a wide range of protective effects in many experimental models of neurologic diseases. Rice bran is very rich in polyunsaturated fatty acids, which are reported to act as PPAR-γ partial agonists. Herein, the anti-inflammatory effect of rice bran extract (RBE) through PPAR-γ activation was evaluated in LPS-induced neuroinflammatory mouse model in comparison to pioglitazone (PG) using 80 Swiss albino mice. RBE (100 mg/kg) and PG (30 mg/kg) were given orally for 21 days and LPS (0.25 mg/kg) was injected intraperitoneally for the last 7 days. TNF-α and COX-2 brain contents were evaluated by real-time PCR and immunohistochemical analysis. In addition, NFκB binding to its response element was evaluated alongside with the effect of treatments on IκB gene expression. Furthermore, PPAR-γ sumoylation was also studied. Finally, histopathological examination was performed for different brain areas. RBE administration was found to protect against the LPS-induced inflammatory effects by decreasing the inflammatory mediator expression in mice brains. It also decreased PPAR-γ sumoylation without significant effect on IκB expression or NFκB binding to its response element. The majority of the effects were attenuated in presence of PPAR-γ antagonist (GW9662). Level of significance was set to P < 0.05. Such findings highlight the agonistic effect of RBE component(s) on PPAR-γ and support the hypothesis of involvement of PPAR-γ activation in its neuroprotective effect.

Characterization and determination of free phytosterols and phytosterol conjugates: The potential phytochemicals to classify different rice bran oil and rice bran

Phytosterols are important beneficial compounds found in rice bran (RB) and rice bran oil (RBO). Although relationships have been confirmed between the forms of phytosterols and their bioactivities, the analysis of different forms of phytosterols in RB and RBO has been lacking. In this study, high temperature gas chromatography-mass spectrometry (HTGC-MS) was combined with the single standard to determine multi-components (SSDMC) method to determine free sterols (FSs) and steryl glycosides (SGs) in RB and RBO. High-performance liquid chromatography (HPLC) was used to determine steryl ferulates (SFs). There was clear variation in the composition of FS, SF and SG, indicating that different forms of phytosterols can discriminate between different RB and RBO. The developed method may be also useful for the detection of other compounds of interest in oils, oil seeds or cereals.

A clinical empirical study on the role of refined rice bran in the prevention and improvement of metabolic syndrome

Rice bran contains lipolytic enzymes with extremely high activity that facilitate the hydrolysis of triglycerides into glycerol and fatty acids. This also causes rice bran to easily deteriorate, limiting its use, and they are not popular in the market. Researchers look forward to seeing the refined rice brans work well for metabolic syndrome. This study used gas cooling by liquid nitrogen and an instant sterilization system operated at high temperature to stabilize and refine the rice bran. The refined rice bran was compared using in vitro tests with three other types of rice bran that had not been specially treated. The refined rice bran was discovered to have superior solubility, fast absorption, and excellent oxidation resistance compared with the other three rice bran samples. In a human subject test, significant improvements in waistline, systolic pressure, diastolic pressure, fasting plasma glucose, glycated hemoglobin, and triglyceride level were discovered after participants ingested refined rice bran for 8 weeks. This indicated that consuming refined rice bran can reduce the waistline, control blood pressure and blood glucose, and inhibit fate formation. The items for which significance was obtained are also the indicators of metabolic syndrome, as stipulated by the World Health Organization. Therefore, according to the results of the human subject test, ingesting refined rice bran can improve the metabolic syndrome. PRACTICAL APPLICATIONS: This refinement improved the in vivo absorption and stabilized the properties of the rice bran for better preservation. In this study, excellent results were obtained using the refined rice bran in both in vitro tests and a human subject test. Refined rice bran thus has potential for mass production and used as a health supplement. It can alleviate the symptoms of metabolic syndrome and reduce the incidence of cardiovascular diseases.

In vivo anti-ageing activity of cream containing niosomes loaded with purple glutinous rice (Oryza sativa Linn.) extract

OBJECTIVE

To evaluate the anti-ageing activity of cream containing the methanolic purple glutinous rice extract loaded in niosomes.

METHODS

The in vitro biological activities of the purple glutinous rice extracted by methanol maceration were determined. The extract loaded in niosomes and the cream containing the niosomes were developed. The in vivo anti-ageing activity in 20 human volunteers including skin hydration, pigmentation, roughness and elasticity after daily application for 28 days compared to at initial was evaluated by Corneometer, Mexameter, Visiometer and Cutometer, respectively.

RESULTS

The purple glutinous rice extract showed free radical scavenging (SC₅₀ ), lipid peroxidation inhibition (IPC₅₀ ), metal ion chelating (CC₅₀ ) and tyrosinase inhibition (IC₅₀ ) values at 32.31 ± 1.28, 57.40 ± 2.12, 85.05 ± 5.43 and 43.89 ± 2.14 mg/mL which were 0.00031, 0.011, 0.0078 and 0.0016 times of the standards (0.01 ± 0.00, 0.62 ± 0.14, 0.66 ± 0.05 and 0.07 ± 0.01), respectively. The purple glutinous rice extract contained 0.35 µg of anthocyanin/1 mg of the extract determined by HPLC. After loaded in niosomes, the solubility of the extract was not only increased in various solvents, but also the chemical stability in different environments (weak base, reducing agent and acid salt) was improved. The cream formulation containing niosomes loaded with 1%w/v of the purple glutinous rice extract indicated the anthocyanin remaining percentages after 6 cycles of heating and cooling test at 52.28% of the initial. For in vivo anti-ageing activities, cream containing niosomes loaded with the extract gave significant decreased melanin index and skin roughness reduction of -14.05 and -9.95% of the initial, respectively. The % changes of the increased skin hydration, skin elastic extension and skin elastic recovery when applied on human volunteers' skin with this formulation were +48.73, -24.51 and +35.98%, respectively.

CONCLUSION

The cream containing niosomes loaded with the 1%w/v methanolic purple glutinous rice extract gave not only the suitable in vitro antioxidant activity and physical stability of the active anthocyanin, but also the superior in vivo anti-ageing activity on human skin compared to the cream base and before application which can be further developed as a novel anti-ageing cosmeceutical product.

The Effect of Degree of Milling on the Nutraceutical Content in Ecofriendly and Conventional Rice (Oryza sativa L.)

We investigated the effects of the type of rice and degree of milling (DOM) on the nutraceutical content and antioxidant activity of rice (Oryza sativa L.). The fatty acid (FA), vitamin E homolog, and phenolic contents in organic (OR), pesticide-free (PFR), and conventional rice (CR) decreased significantly with an increase in the DOM of rice grains, particularly for a DOM of 7 and 9 (p < 0.05). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity also decreased with the DOM; particularly, this activity decreased significantly, by approximately 60%, in rice grains with a DOM between 7 and 11, as compared to that of brown rice (p < 0.05). α-Tocopherol (r = 0.854) and p-coumaric acid (r = 0.501) showed the strongest correlation with DPPH activity in each chemical group. Stepwise discriminant analysis enabled the correct original and cross-validated classification of 87.0% and 81.5% of rice types, respectively. Additionally, the original and cross-validated classification of rice DOM levels showed that, overall, 93.8% and 92.6% of rice samples were correctly classified. Our findings reveal variations in the nutraceutical levels and antioxidant activities in rice grains based on the rice type and DOM, which can help improve the nutritional evaluation of human-health-promoting rice grains.

Revealing the thermal oxidation stability and its mechanism of rice bran oil

Although the stability of rice bran oil (RBO) has been showed on several studies, the factors which make it capable on maintaining its stability under thermal oxidation has not been sure yet. We hypothesized that its fatty acid composition [high composition of oleic acid (OA), lower composition of linoleic acid (LA) and α-linolenic acid (LnA)] and/or its antioxidant agents [γ-oryzanol (OZ)] and vitamin E [tocopherol (Toc), tocotrienol (T3)] might be the biggest factor. To prove the hypothesis, we thermally oxidized RBO under 40 °C for 17 days to mimic the harsh daily storage condition, and compared it with soybean oil (SO) and rapeseed oil (RPO) then monitoring their primary oxidation products [triacylglycerol hydroperoxide (TGOOH)] from easily oxidized fatty acid contained in triacylglycerol (TG) and the amount loss of antioxidant agents. As a result, RBO showed the lowest TGOOH/TG ratio, followed by RPO and SO. The superior stability RPO compared SO might occur due to because of the influence of the fatty acid profile (higher OA and lower LA). For RBO’s case, besides its fatty acid profile, the existence of OZ and the synergistic effect of OZ and vitamin E might have a greater contribution in maintaining its stability under thermal oxidation.

Green Processing, Germinating and Wet Milling Brown Rice (Oryza sativa) for Beverages: Physicochemical Effects

Plant-based beverage consumption is increasing markedly. Value-added dehulled rice (Oryza sativa) germination was investigated to improve beverage qualities. Germinating brown rice has been shown to increase health-promoting compounds. Utilizing green processing, wholesome constituents, including bran, vitamins, minerals, oils, fiber and proteins should should convey forward into germinated brown rice beverages. Rapid visco-analyzer (RVA) data and trends established that brown rice, preheated brown rice and germinated brown rice had higher pasting temperatures than white rice. As pasting temperature in similar samples may be related to gelatinization, RVA helped guide the free-flowing processing protocol using temperatures slightly above those previously reported for Rondo gelatinization. Particle size analysis and viscometric evaluations indicate that the developed sprouted brown rice beverage is on track to have properties close to commercial samples, even though the sprouted brown rice beverage developed has no additives, fortifications, added oils or salts. Phenolics and γ-aminobutyric acid increased slightly in germinated brown rice, however, increases were not maintained throughout most stages of processing. Significantly lower inorganic arsenic levels (113 ng/g) were found in germinated (sprouted) brown rice, compared to Rondo white and brown rice, which is far below the USA threshold level of 200 ng/g.

Novel bio-analytical technique for estimation of gamma oryzanol in rat plasma and brain homogenate using HPLC

Gamma oryzanol, a component of rice bran oil is used for its anticancer and antihyperlipidemic properties. Bioanalytical method for rat plasma and brain homogenate was developed by HPLC system with a PDA detector in which drug elution was performed using C-18 column (4.6mm×150cm, 5μ) with 1% acetic acid in methanol: acetonitrile (65/35, v/v) as mobile phase at 1.2ml/min flow rate and detected at 326nm wavelength. Liquid liquid extraction method was chosen for extraction of oryzanol from plasma as well as brain homogenate as it provided highest recovery (95% in plasma, 85% in brain homogenate). Various extraction solvents for each body fluid were analysed, out of which highest recovery for plasma (95%), in acetone: IPA (1/1, v/v) and for brain homogenate (85%) in isopropyl alcohol (IPA) was observed. Observed linearity was between 500ng/mL-5000ng/mL. The interday and intraday precision (i.e. %RSD) was less than 10% and accuracy was±5%. Selectivity and matrix effect was checked and found as per USFDA criteria. Plasma samples were found to be stable over the analysis period, HQC samples were stable up to third cycle in freeze and thaw stability while LQC samples were stable over fourth cycle. The method proved to be simple, useful and is appropriate, for preclinical and experimental research.

Nutritional and Organoleptic Evaluation of Baked Products Incorporating Stabilized Rice Bran

Background:

Rice bran, a byproduct of rice milling is a rich source of fiber, proteins, fats and micronutrients. There is an increasing demand for functional foods that can provide a variety of nutrients besides providing bioactives rendering therapeutic value thereby reducing the risk of chronic diseases.

Methods:

The study was carried out to evaluate the physicochemical and in vitro antioxidative potential of stabilized rice bran powder [full-fat rice bran (FFRB) and defatted rice bran (DFRB)] in baked products. Three variants of each product viz. rusks and twisted sticks were prepared by incorporating FFRB and DFRB at 5%, 10% and 15% level along with the standard (control) without the addition of rice bran powder.

Results:

The results indicated that DFRB showed higher antioxidative potential and improved water absorption capacity (WAC), oil absorption capacity (OAC) than FFRB. Proximate analysis revealed that the protein and ash content of the baked products improved significantly (p ≤ 0.05) with an increased level of incorporation of FFRB and DFRB as compared to control. The DPPH activity of DFRB (78.7 ± 0.46) was significantly higher than FFRB (35.5 ± 2.89). Sensory appraisal of the rusk revealed that variant I and II with 5% and 10% level of incorporation were more acceptable as compared to control. The sensory appraisal of twisted sticks revealed that all the three variants were equally acceptable as the control sample.

Conclusion:

The incorporation of full fat and defatted rice bran powders to baked products enhanced their nutritional profile and physicochemical characteristics without affecting the organoleptic properties.