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

Phytosterols in rice bran and their health benefits

With the continuous technological innovation in the high-value utilization of rice bran byproducts, rice bran oil retains a higher concentration of beneficial components such as a well-balanced composition of fatty acids and abundant phytosterols. This makes it a highly nutritious and healthy vegetable oil. This review provides an overview of the advancements made in separating, purifying, and processing phytosterols in rice bran oil. The review also introduces techniques for assessing the stability of rice bran oil. Moreover, the review emphasizes the nutritional value of phytosterols found in rice bran oil, highlighting their various health benefits, including their anticancer, anti-inflammatory, anti-allergic, antibacterial, cholesterol-lowering, skin-protective, anti-obesity, anti-diabetic, neuroprotective, gastroprotective, and immune-enhancing effects. Attaining a comprehensive understanding of the research progress made in phytosterols derived from rice bran oil can offer valuable guidance for the efficient utilization of rice bran.

Rice Bran Supplementation Ameliorates Gut Dysbiosis and Muscle Atrophy in Ovariectomized Mice Fed with a High-Fat Diet

Rice bran, a byproduct of rice milling, is rich in fiber and phytochemicals and confers several health benefits. However, its effects on gut microbiota and obesity-related muscle atrophy in postmenopausal status remain unclear. In this study, we investigated the effects of rice bran on gut microbiota, muscle synthesis, and breakdown pathways in estrogen-deficient ovariectomized (OVX) mice receiving a high-fat diet (HFD). ICR female mice were divided into five groups: sham, OVX mice receiving control diet (OC); OVX mice receiving HFD (OH); OVX mice receiving control diet and rice bran (OR); and OVX mice receiving HFD and rice bran (OHR). After twelve weeks, relative muscle mass and grip strength were high in rice bran diet groups. IL-6, TNF-α, MuRf-1, and atrogin-1 expression levels were lower, and Myog and GLUT4 were higher in the OHR group. Rice bran upregulated the expression of occludin and ZO-1 (gut tight junction proteins). The abundance of Akkermansiaceae in the cecum was relatively high in the OHR group. Our finding revealed that rice bran supplementation ameliorated gut barrier dysfunction and gut dysbiosis and also maintained muscle mass by downregulating the expression of MuRf-1 and atrogin-1 (muscle atrophy-related factors) in HFD-fed OVX mice.

Cycloartenyl ferulate improves natural killer (NK) cell immunity against cancer by binding to IFNγ receptor 1

Cycloartenyl ferulate (CF) is abundant in brown rice with multiple biologic functions. It has been reported to possess antitumor activity; however, the related mechanism of action of CF has not been clarified. Herein, we unexpectedly uncover the immunological regulation effects of CF and its molecular mechanism. We discovered that CF directly enhanced the killing capacity of natural killer (NK) cells for various cancer cells in vitro. In vivo, CF also improved cancer surveillance in mouse models of lymphoma clearance and metastatic melanoma dependent on NK cells. In addition, CF promoted anticancer efficacy of the anti-PD1 antibody with improvement of tumor immune microenvironment. Mechanistically, we first unveiled that CF acted on the canonical JAK1/2-STAT1 signaling pathway to enhance the immunity of the NK cells by selectively binding to interferon γ receptor 1. Collectively, our results indicate that CF is a promising immunoregulation agent worthy of attention in clinical application in the future. Due to broad biological significance of interferon γ, our findings also provide a capability to understand the diverse functions of CF.

Integrated Microbiota and Metabolite Changes following Rice Bran Intake during Murine Inflammatory Colitis-Associated Colon Cancer and in Colorectal Cancer Survivors

Dietary rice bran-mediated inhibition of colon carcinogenesis was demonstrated previously for carcinogen-induced rodent models via multiple anti-cancer mechanisms. This study investigated the role of dietary rice bran-mediated changes to fecal microbiota and metabolites over the time course of colon carcinogenesis and compared murine fecal metabolites to human stool metabolic profiles following rice bran consumption by colorectal cancer survivors (NCT01929122). Forty adult male BALB/c mice were subjected to azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colitis-associated colon carcinogenesis and randomized to control AIN93M (n = 20) or diets containing 10% w/w heat-stabilized rice bran (n = 20). Feces were serially collected for 16S rRNA amplicon sequencing and non-targeted metabolomics. Fecal microbiota richness and diversity was increased in mice and humans with dietary rice bran treatment. Key drivers of differential bacterial abundances from rice bran intake in mice included Akkermansia, Lactococcus, Lachnospiraceae, and Eubacterium xylanophilum. Murine fecal metabolomics revealed 592 biochemical identities with notable changes to fatty acids, phenolics, and vitamins. Monoacylglycerols, dihydroferulate, 2-hydroxyhippurate (salicylurate), ferulic acid 4-sulfate, and vitamin B6 and E isomers significantly differed between rice bran- and control-fed mice. The kinetics of murine metabolic changes by the host and gut microbiome following rice bran consumption complemented changes observed in humans for apigenin, N-acetylhistamine, and ethylmalonate in feces. Increased enterolactone abundance is a novel diet-driven microbial metabolite fecal biomarker following rice bran consumption in mice and humans from this study. Dietary rice bran bioactivity via gut microbiome metabolism in mice and humans contributes to protection against colorectal cancer. The findings from this study provide compelling support for rice bran in clinical and public health guidelines for colorectal cancer prevention and control.

Enriched Riceberry Bran Oil Exerts Chemopreventive Properties through Anti-Inflammation and Alteration of Gut Microbiota in Carcinogen-Induced Liver and Colon Carcinogenesis in Rats

Riceberry has recently been acknowledged for its beneficial pharmacological effects. Riceberry bran oil (RBBO) exhibited anti-proliferation activity in various cancer cell lines. However, animal studies of RBBO on anti-carcinogenicity and its molecular inhibitory mechanism have been limited. This study purposed to investigate the chemopreventive effects of RBBO on the carcinogen-induced liver and colorectal carcinogenesis in rats. Rats were injected with diethylnitrosamine (DEN) and 1,2-dimethylhydrazine (DMH) and further orally administered with RBBO equivalent to 100 mg/kg body weight of γ-oryzanol 5 days/week for 10 weeks. RBBO administration suppressed preneoplastic lesions including hepatic glutathione S-transferase placental form positive foci and colorectal aberrant crypt foci. Accordingly, RBBO induced hepatocellular and colorectal cell apoptosis and reduced pro-inflammatory cytokine expression. Interestingly, RBBO effectively promoted the alteration of gut microbiota in DEN- and DMH-induced rats, as has been shown in the elevated Firmicutes/Bacteroidetes ratio. This outcome was consistent with an increase in butyrate in the feces of carcinogen-induced rats. The increase in butyrate reflects the chemopreventive properties of RBBO through the mechanisms of its anti-inflammatory properties and cell apoptosis induction in preneoplastic cells. This would indicate that RBBO containing γ-oryzanol, phytosterols, and tocols holds significant potential in the prevention of cancer.

Rice Bran Stabilisation and Oil Extraction Using the Microwave-Assisted Method and Its Effects on GABA and Gamma-Oryzanol Compounds

Rice bran oil (RBO) is a valuable ingredient extracted from rice bran (RB), a side stream of polishing rice grain in the milling process. RBO is rich in bioactive ingredients with potential health benefits, such as gamma-oryzanol (GO) and gamma-aminobutyric acid (GABA). Despite its benefits, the quality of RBO depends on the degree of stabilisation of the RB, which is easily affected by lipase enzymes, and thus needs an effective treatment prior to RBO production. To assess the potential of the microwave-assisted method for RB stabilisation and RBO extraction, three Carolino rice varieties (Ariete, Teti, Luna) were tested. The effect of RB stabilisation was evaluated via acid value, water absorption, and GO and GABA levels. The RBO yield was optimised by solvent, temperature, and solvent-to-sample ratio, and the GO and fatty acid levels were determined. The RB stabilisation for the Luna variety did not affect the GO and GABA; for the Ariete and Teti varieties, the GO decreased by 34.4% and 24.2%, and the GABA increased by 26.5% and 47.0%, respectively. The GO levels in RBO samples were not affected by RB stabilisation. The RBO nutritional value was confirmed by the suitable ratio (>2) between polyunsaturated (PUFA) and saturated fatty acids (SFA), with the Teti variety presenting the highest ratio.

Symbiotic and adverse interplay of hypogeal germination periods on brown rice (Oryza sativa): nutrient and non-nutrient characteristics

This study investigated the symbiotic and adverse consequence of hypogeal germination periods on nutrients and non-nutrient characteristics of brown rice (Oryza sativa). Brown rice paddy was subjected to hypogeal germination for 0–72 h using one-factor design-response surface methodology (OFD-RSM) and evaluated for nutrients and non-nutrient characteristics. The results showed that hypogeal germination caused a significant (p < 0.05) change in the proximate composition: protein (9.42–12.36%), fat (0.88–1.38%), ash (1.87–2.50%); anti-nutrients: saponin (2.03–2.22%), oxalate (2.44–3.45 mg/100 g), phytate (6.99–8.81 mg/100 g); functional properties: water absorption capacity, WAC (121.23–147.78%), oil absorption capacity, OAC (121.39–147.26%); antioxidants properties: 2, 2-diphenyl-1-picrylhydrazyl, DPPH (35.30–43.60%), ferric reducing antioxidant power, FRAP (0.054–0.119 mMolFe2+), metal chelating activity, MCA (44.28–52.99%), total phenolic content, TPC (0.623–0.798 mg gallic acid equipvalent per gram (mgGAE/g)), total flavonoid content, TFC (43.47–50.63 mg rutin equivalent per gram (mgRUTIN/g)); and mineral content: calcium (36.0–41.76 mg/100 g), phosphorus (82.53–94.32 mg/100 g), and magnesium (162.70–168.36 mg/100 g). Germination had significant symbiotic effects (linear and quadratic) on the proximate, DPPH, FRAP, MCA, TPC, WAC, OAC, and anti-nutrients. Whereas, adverse effects (linear and quadratic) of germination were noted in total flavonoids and anti-nutrients. Optimum hypogeal germination period of 72.18 h was established and corresponding protein (12.37 g/100 g), fat (1.37 g/100 g), fibre (2.15 g/100 g), moisture (10.07 g/100 g), DPPH (43.66%), FRAP (0.105mMolFe2+), TPC (0.08mgGAE/g), TFC (50.25MgRUTIN/g), WAC (147.99%), OAC (147.29%), Calcium (41.77 mg/100 g), iron (0.207 mg/100 g), zinc (5.89 mg/100 g), phosphorus (94.77 mg/100 g). Phenolic compounds profile of the optimized germinated brown rice showed the presence of gallic acid (2.84 mg/100 g), 4-hydroxy benzoic acid (3.41 mg/100 g), caffeic acid (4.63 mg/100 g), vanillic acid (6.19 mg/100 g), catechin (3.88 mg/100 g), chlorogenic acid (1.93 mg/100 g), ferulic acid (4.16 mg/100 g), and quercetin (1.27 mg/100 g) whereas, the non-germinated rice showed gallic acid (2.05 mg/100 g), 4-hydroxy benzoic acid (2.53 mg/100 g), caffeic acid (4.11 mg/100 g), vanillic acid (6.08 mg/100 g), catechin (3.35 mg/100 g), chlorogenic acid (1.89 mg/100 g), ferulic acid (4.23 mg/100 g), and quercetin (1.29 mg/100 g). Hypogeal germinated brown rice could find application as a functional ingredient in food formulation.

Low Acrylamide Flatbreads Prepared from Colored Rice Flours and Relationship to Asparagine and Proximate Content of Flours and Flatbreads

Acrylamide is a potentially toxic compound present in many plant-based foods, such as coffee, breads, and potato fries, which is reported to have carcinogenic, neurotoxic, and antifertility properties in vivo, suggesting the need to keep the acrylamide content of widely consumed food as low as possible. As pigmented rice contains bioactive phenolic and flavonoid compounds, the objective of this study was to potentially enhance the beneficial properties of flatbreads by evaluating the acrylamide content and proximate composition of 12 novel flatbreads prepared from the following commercial pigmented rice seeds: Black Japonica, Chinese Black, French Camargue, Himalayan Red, Long Grain Brown, Purple Sticky, Short Grain Brown, Wehani, Wild, Indian Brown Basmati, Organic Brown Jasmine, and Organic Jade Pearl. Although acrylamide levels ranged from 4.9 µg/kg in Long Grain Brown to 50.8 µg/kg in Chinese Black, the absolute values were all low (though statistically significantly differences existed among varieties). Acrylamide content did not correlate with its precursor asparagine. The variations in protein, carbohydrate, fat, ash, dry matter, and water content determined by proximate analysis, and the reported health benefits of colored rice cultivars used to prepare the flatbreads, might also be useful for relating composition to nutritional qualities and health properties, facilitating their use as nutritional and health-promoting functional foods.

Biological and Pharmacological Effects of Gamma-oryzanol: An Updated Review of the Molecular Mechanisms

BACKGROUND

Gamma-oryzanol (γ-oryzanol) is one of the rice bran oil (RBO) compounds, known as a principal food source throughout the world. In recent numerous experimental studies, γ-oryzanol has been revealed to have several useful pharmacological properties, such as anti-oxidant, anti-inflammatory, anti-cancer, anti-diabetic, ameliorating unpleasant menopausal symptoms, cholesterol-lowering, improving plasma lipid pattern, etc. Methods: In this study, we reviewed the scientific literature published up until 2020, which has evaluated the biological and pharmacological activity of gamma-oryzanol. This review summarizes the published data found in PubMed, Science Direct, and Scopus.

RESULTS AND CONCLUSION

The present review attempts to summarize the most related articles about the pharmacological and therapeutic potential from recent studies on γ-oryzanol to gain insights into design further studies to achieve new evidence that confirm the observed effects.

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.

The Study on the Active Ingredients and Potential Targets of Rice Bran Petroleum Ether Extracts for Treating Diabetes Based on Network Pharmacology

AIM AND OBJECTIVE

In ancient China, rice bran was used to treat diabetes and hyperlipidemia. The aim of this paper is to explore the active compounds and underlying mechanism of Rice Bran Petroleum Ether extracts (RBPE) against diabetes using network pharmacology.

MATERIALS AND METHODS

Gas chromatography-mass spectrometer analysis was performed to identify the chemical composition in RBPE. Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, Swiss Target Prediction database, BATMAN-TCM, comprehensive database of human genes and gene phenotypes, therapeutic target database, DurgBank and GeneCards database were used to screen targets. The "component-target-disease" interactive network was constructed by Cytoscape software. Gene ontology and pathways related to the targets were analyzed by ClueGO, and core targets were screened by the MCODE, and Autodock vina was used for molecular docking.

RESULTS

The compounds with a percentage greater than 1.0% were selected for subsequent analysis. The RBPE contains oleic acid, (E)-9-Octadecenoic acid ethyl ester, and other chemical components that can regulate insulin, mitogen-activated protein kinase 3, epidermal growth factor receptor, mitogen-activated protein kinase 1, and other genes, which were mainly related to Pathways in cancer, Human cytomegalovirus infection and AGE-RAGE signaling pathway in diabetic complications, etc. The affinity of the core compounds and the corresponding protein of the gene targets was good.

CONCLUSION

The results of network pharmacology analysis indicate that the RBPE has multiple anti- diabetic ingredients, and RBPE exert anti-diabetic activity through multiple targets and signaling pathways. The present study can provide a scientific basis for further elucidating the mechanism of RBPE against diabetes.

Identification of Phenolic Compounds and Determination of Antioxidant Activity in Extracts and Infusions of Salvia Leaves

The influence of harvest period and drying method of Salvia officinalis L. leaves on the content of essential oils, polyphenols and antioxidant properties was investigated. Sage leaves were collected twice during plant blossoming (in June and July) and dried traditionally in natural conditions and at 35 °C. Antioxidant activity was assayed in methanol-acetone extracts and infusions of dried leaves with the use of free radical scavenging activity (DPPH) and ferric reducing antioxidant power (FRAP) technique. Total phenolic content in extracts as well as in infusions was determined by the means of Folin-Ciocalteu method. Based on the LC/MS analysis, the polyphenol compounds present in both extracts and in infusions were identified. The extracts contained more polyphenols and were characterized by higher antioxidant activity than infusions. In the extracts significant amount of ferulic acid was found, which was influenced both by the harvest period and drying method. The amount of ferulic acid found in extracts obtained from the June leaves dried traditionally was three times lower (6.185 μg/g DW) than in extracts from July leaves dried in the same conditions. Harvest period had a significant effect on the essential oils' content, leaves collected in July contained 15% more oils than those collected in June.

Targeting the tumor immune microenvironment with "nutraceuticals": From bench to clinical trials

The occurrence of immune effector cells in the tissue microenvironment during neoplastic progression is critical in determining tumor growth outcomes. On the other hand, tumors may also avoid immune system-mediated elimination by recruiting immunosuppressive leukocytes and soluble factors, which coordinate a tumor microenvironment that counteracts the efficiency of the antitumor immune response. Checkpoint inhibitor therapy results have indicated a way forward via activation of the immune system against cancer. Widespread evidence has shown that different compounds in foods, when administered as purified substances, can act as immunomodulators in humans and animals. Although there is no universally accepted definition of nutraceuticals, the term identifies a wide category of natural compounds that may impact health and disease statuses and includes purified substances from natural sources, plant extracts, dietary supplements, vitamins, phytonutrients, and various products with combinations of functional ingredients. In this review, we summarize the current knowledge on the immunomodulatory effects of nutraceuticals with a special focus on the cancer microenvironment, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of nutraceuticals for envisioning future therapies employing nutraceuticals as chemoadjuvants.

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.

Isolation and structural elucidation of unique γ-oryzanol species in rice bran oil

Even though γ-oryzanol (OZ) such as 24-methylenecycloartanyl ferulate (24MCAFA) is abundant in purified rice bran oil, we realized that the oil contained the prospect of two additional novels of OZ species. To identify this, we isolated and analyzed their chemical structures by using HPLC-UV-MS, NMR, and IR. We revealed for the first time that the oil had also contained cyclobranyl ferulate (CBFA) and cyclosadyl ferulate (CSFA) which are likely to be exist due to the isomerism of 24MCAFA under acid condition. OZ profile including CBFA and CSFA was roughly similar between commercial rice bran oils and processed foods containing the oils, suggesting that people might have often consumed CBFA and CSFA from rice bran oils and/or processed foods. Since different OZ species are known to have different functionality, this study opens the chance to explore more the contribution of CBFA and CSFA for human health and wellness.

Utilization of quinoa flour (Chenopodium quinoa Willd.) in gluten-free pasta formulation: Effects on nutritional and sensory properties

In this study, raw and germinated quinoa seed flour was utilized in gluten-free pasta formulation. Rice:corn semolina (50:50) blend was used in gluten-free pasta as a control group. Quinoa flours were replaced with rice:corn semolina blend at different (0-30%) ratios in gluten-free pasta formulation. Guar gum (3%) was also used to tolerate structural defects caused by gluten deficiency. Trials were conducted according to (2 × 4) × 2 factorial design. Color values, cooking properties, and chemical and sensory attributes of gluten-free pasta samples were determined. Quinoa flour type and quinoa flour addition ratio factors significantly (p < 0.05) affected the L*, a* color values and all of the cooking properties of the gluten-free pasta samples. Utilization of germinated quinoa flour in gluten-free pasta revealed lower water uptake, volume increase, firmness, and higher cooking loss values than that of raw quinoa flour. Quinoa flour especially improved the mean values of protein, total phenolic content, antioxidant activity from 8.1%, 0.7 mg GAE/g, and 13.4%, up to 12.7%, 1.5 mg GAE/g, and 28.8%, respectively. A significant (p < 0.05) increment was observed in Ca, Fe, K, Mg, P, and Z content of the gluten-free pasta and all addition ratios of quinoa flour. As a result, increasing amount of quinoa flour enriched the nutritional composition of gluten-free pasta but high utilization ratio resulted in slight sensory losses.

The Effect of Rice Bran Extract on Arterial Blood Pressure, Hepatic Steatosis, and Inflammation in Mice Fed with a High-Fat Diet

Background

Inflammation and hypertension are primary mechanisms involving in obesity-associated adverse effects of a high-fat diet. The aim of this study was to evaluate the effects of rice bran extract (RBE) on arterial blood pressure, hepatic steatosis, inflammation, and oxidative stress in high-fat diet (HFD)-induced obese mice.

Methods

Male ICR mice were divided into four groups, including a normal-diet control group, a high-fat diet (HFD) (60% kcal from fat) group, an HFD group treated with RBE (220 mg/kg/day), and an HFD group treated with 1100 mg/kg/day for eight weeks. Besides body weight and arterial blood pressure, we determined liver values of total cholesterol, triglyceride, as well as percent body fat, tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), nuclear factor kappa-B (NF-κB), matrix metalloprotease-9 (MMP-9), cyclooxygenase-2 (COX-2), and mRNA endothelial nitric oxide synthase (eNOS).

Results

The HFD group had increased body weight, increased systolic and diastolic blood pressure, liver total cholesterol, triglyceride, NF-κB, COX-2 and MMP-9 protein levels, and decreased mRNA eNOS in the aorta. Mice of the HFD group receiving RBE had reduced diastolic blood pressure, as well as significantly decreased liver and serum TNF-α and MDA levels in the liver, and reduced NF-κB levels in both the liver and heart.

Conclusions

These results demonstrate that RBE decreases diastolic blood pressure, the liver lipid droplet accumulation, liver and myocardial NF-κB, myocardial COX-2 and MMP-9 protein levels, and oxidative stress. Moreover, RBE may improve endothelial function and may alleviate adverse health effects associated with obesity including obesity-associated hypertension.

Gamma oryzanol impairs alcohol-induced anxiety-like behavior in mice via upregulation of central monoamines associated with Bdnf and Il-1β signaling

Adolescent alcohol exposure may increase anxiety-like behaviors by altering central monoaminergic functions and other important neuronal pathways. The present study was designed to investigate the anxiolytic effect of 0.5% γ-oryzanol (GORZ) and its neurochemical and molecular mechanisms under chronic 10% ethanol consumption. Five-week-old ICR male mice received either control (14% casein, AIN 93 M) or GORZ (14% casein, AIN 93 M + 0.5% GORZ) diets in this study. We showed that GORZ could potentially attenuate alcohol-induced anxiety-like behaviors by significantly improving the main behavioral parameters measured by the elevated plus maze test. Moreover, GORZ treatment significantly restored the alcohol-induced downregulation of 5-hydroxytryptophan and 5-hydroxyindole acetic acid in the hippocampus and improved homovanillic acid levels in the cerebral cortex. Furthermore, a recovery increase in the level of 3-methoxy-4-hydroxyphenylglycol both in the hippocampus and cerebral cortex supported the anxiolytic effect of GORZ. The significant elevation and reduction in the hippocampus of relative mRNA levels of brain-derived neurotrophic factor and interleukin 1β, respectively, also showed the neuroprotective role of GORZ in ethanol-induced anxiety. Altogether, these results suggest that 0.5% GORZ is a promising neuroprotective drug candidate with potential anxiolytic, neurogenic, and anti-neuroinflammatory properties for treating adolescent alcohol exposure.

Gamma Oryzanol Alleviates High-Fat Diet-Induced Anxiety-Like Behaviors Through Downregulation of Dopamine and Inflammation in the Amygdala of Mice

Background

A high-fat diet (HFD) can induce obesity and metabolic disorders that are closely associated with cognitive impairments, and the progression of several psychiatric disorders such as anxiety. We have previously demonstrated the anxiolytic-like effect of Gamma oryzanol (GORZ) in chronic restraint stressed mice.

Objective

We studied the neurochemical and molecular mechanisms that underlie the preventive effect of GORZ in HFD-induced anxiety-like behaviors, monoaminergic dysfunction, and inflammation.

Methods

Eight-week-old Institute of Cancer (ICR) male mice weighing 33–34 g were divided into the following groups and free-fed for 8 weeks: control (14% casein, AIN 93M); HFD; HFD + GORZ (0.5% GORZ). Body weight gain was checked weekly. The anxiolytic-like effects of GORZ were examined via open-field test (OFT) and elevated plus maze (EPM) test. Brain levels of monoamines [5-hydroxy tryptamine (5-HT), dopamine (DA), and norepinephrine (NE)] and their metabolites [5-hydroxyindole acetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG)], proinflammatory cytokines such as tumor necrosis factor-αα (Tnf-α) mRNA levels, and interleukin 1-β (Il-1β) mRNA levels in the cerebral cortex and amygdala were examined using high-performance liquid chromatography-electrochemical detection (HPLC-ECD), and real-time reverse transcription-polymerase chain reaction (RT-PCR), respectively.

Results

Mice fed a HFD for eight weeks showed anxiety-like behaviors in association with HFD-induced body weight gain. GORZ potentially blocked HFD-induced anxiety-like behaviors via significant improvement of the primary behavioral parameters in behavioral tests, with a minor reduction in HFD-induced body weight gain. Furthermore, GORZ treatment significantly downregulated HFD-induced upregulation of dopamine levels in the brain's amygdala. Significant reduction of the relative mRNA expression of Tnf-α and Il-1 β was also observed in the amygdala of HFD + GORZ mice, compared to HFD mice.

Conclusions

Our findings strongly suggest that 0.5% GORZ exerts anxiolytic-like effects, possibly through downregulation of dopamine, and via expression of proinflammatory cytokines Tnf-α and Il-1 β in the case of chronic HFD exposure.

Genetic and genomic approaches to address rapid rancidity of rice bran

Rice bran is an invaluable by-product of paddy processing industry. It is rich in minerals, protein, lipids, and crude fiber. In addition, it also possesses compounds with anti-oxidant, anti-allergic, anti-diabetic, and anti-cancer properties. It forms a basis for the extraction of rice bran oil and preparation of various functional foods with health benefits and potential to prevent chronic health issues. Nevertheless, the rapid deterioration of bran upon storage acts as a major limitation in exploiting the full potential of rice bran. In this review, we have discussed three strategies to address rapid rancidity of rice bran and enhance its shelf life and storability vis-a-vis emphasizing the importance of rice bran in terms of its nutritional composition. One strategy is through exploitation of the null mutations in the genes governing lipases and lipoxygenases leading to nonfunctional enzymes (enzyme deficient approach), another strategy is through reducing the PUFA content that is more prone to oxidation (substrate deficient approach) and a third strategy is through enhancing the antioxidant content that effectively terminate the lipid peroxidation by donating the hydrogen atom.

Exploiting the bioactive properties of γ-oryzanol from bran of different exotic rice varieties

The rice industry is one of the most significant food industries since rice is a widely consumed cereal in the world. As a result of this substantial production, the rice industry has a significant amount of side streams, including bran, representing millions of tons of raw materials mainly designated to animal feed. Rice bran is a rich source of γ-oryzanol, a bioactive compound with substantial health benefits. In this perspective, different bran rice samples from distinct germplasm origins (Philippines, Italy and Portugal) were studied for their γ-oryzanol content by HPLC-PDA, cytotoxicity in four human tumour cell lines, hepatotoxicity in a normal cell line and for their antimicrobial effects on different bacterial and fungal strains. The Ballatinao sample presented the strongest activity against all the tumour cell lines, and was also the sample showing the highest amount of γ-oryzanol, suggesting its contribution to the exhibited cytotoxic properties. Regarding the antimicrobial activity, the tested samples were able to inhibit the majority of bacterial and fungal strains, with the Portuguese Ceres sample being the one presenting the highest bacterial inhibition and the Maluit and Dinorado samples, the highest fungal inhibition. Overall, the results show that rice bran extracts may be considered as potential candidates for antimicrobial agents when incorporated into food matrices.

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

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

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

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

Evaluation of γ-oryzanol Accumulation and Lipid Metabolism in the Body of Mice Following Long-Term Administration of γ-oryzanol

γ-Oryzanol (OZ), abundant in rice bran oil, has gained attention due to its physiological activities (e.g., lipid-lowering effects). However, the absorption and metabolism of orally ingested OZ have not yet been fully elucidated. In this study, diets containing normal or high contents of OZ were fed to obesity model mice for 8 weeks, and OZ concentrations in plasma and organs were analyzed by HPLC-MS/MS. To evaluate the relationship between OZ accumulation and lipid metabolism in vivo, lipid concentrations in the mice plasma and liver were also measured. As a result, the accumulation of intact OZ in plasma and organs was seen in mice fed diets containing OZ, where mice fed diets containing higher OZ contents demonstrated higher levels of OZ accumulation and lower amounts of plasma lipids. These results, in combination with our additional data from a single oral administration test, suggest the possibility that intact OZ, along with its metabolites (e.g., ferulic acid), is biologically-active.

Controlled release and macrophage polarizing activity of cold-pressed rice bran oil in a niosome system

Phytosterols, α-tocopherol and γ-oryzanol are scientifically recognized as major health promoting compounds found in cold-pressed rice bran oil (CRBO).

The composition of a bioprocessed shiitake (Lentinus edodes) mushroom mycelia and rice bran formulation and its antimicrobial effects against Salmonella enterica subsp. enterica serovar Typhimurium strain SL1344 in macrophage cells and in mice

Background

Human infection by pathogenic Salmonella bacteria can be acquired by consuming of undercooked meat products and eggs. Antimicrobial resistance against antibiotics used in medicine is also a major concern. To help overcome these harmful effects on microbial food safety and human health, we are developing novel antimicrobial food-compatible formulations, one of which is described in the present study.

Methods

The composition of a bioprocessed (fermented) rice bran extract (BPRBE) from Lentinus edodes liquid mycelia culture was evaluated using gas chromatography and mass spectrometry, and the mechanism of its antibacterial effect against Salmonella Typhimurium, strain SL1344 was investigated in macrophage cells and in mice.

Results

BPRBE stimulated uptake of the bacteria into RAW 264.7 murine macrophage cells. Activation of the cells was confirmed by increases in NO production resulting from the elevation of inducible nitric oxide synthase (iNOS) mRNA, and in protein expression. Salmonella infection down-regulated the expression of the following protein biomarkers of autophagy (a catabolic process for stress adaptation of cellular components): Beclin-1, Atg5, Atg12, Atg16, LC3-I and LC3-II. BPRBE promoted the upregulation of protein expressions that induced bacterial destruction in autolysosomes of RAW 264.7 cells. ELISA analysis of interferon IFN-β showed that inflammatory cytokine secretion and bactericidal activity had similar profiles, suggesting that BPRBE enhances cell-autonomous and systemic bactericidal activities via autophagic capture of Salmonella. The treatment also elicited increased excretion of bacteria in feces and their decreased translocation to internal organs (cecum, mesenteric lymph node, spleen, and liver).

Conclusions

The antibiotic mechanism of BPRBE involves the phagocytosis of extracellular bacteria, autophagic capture of intracellular bacteria, and prevention of translocation of bacteria across the intestinal epithelial cells. The new bioprocessing combination of mushroom mycelia and rice brans forms a potentially novel food formulation with in vivo antimicrobial properties that could serve as a functional antimicrobial food and medical antibiotic.

Recovery of γ-Oryzanol from Rice Bran Acid Oil by an Acid-base Extraction Method with the Assistance of Response Surface Methodology

A rapid and low energy consumption method for the recovery of γ-oryzanol from rice bran acid oil (RBAO), a byproduct of rice bran oil (RBO) refining, is presented. The RBAO was converted to the fatty acid ethyl ester (FAEE) and was used as the starting material. The dissolved γ-oryzanol was separated from the FAEE using an acid-base extraction method with alkaline aqueous ethanol and hexane as extraction media. A systematic investigation of the extraction yield was carried out by applying response surface methodology (RSM) based on central composite design (CCD) and Derringer's desirability function. The concentration of NaOH, the percentage of ethanol in water, the hexane content and their interactions showed significant effects on the yield of γ-oryzanol and FAEE. The optimal extraction conditions were as follows: extraction time of 1 min at room temperature (28-32°C); extraction medium: 1.855 M NaOH; 75.91% ethanol in water and 20.59% hexane in the total volume of the extractant; and FAEE to extractant ratio of 1:10 corresponding to a maximum γ-oryzanol yield of 75.82±3.44% and the desired FAEE yield of 54.42±7.80%. The γ-oryzanol-rich fraction was further purified by washing with a 2% Na₂CO₃ solution, obtaining 69.94% recovery yield with 89.90% purity of γ-oryzanol. The purified γ-oryzanol showed good scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and the ABTS radical and was comparable to the commercial product, clearly suggesting that the presented process was efficient and feasible.

Presence of orally administered rice bran oil γ-oryzanol in its intact form in mouse plasma

Although the beneficial effects (e.g., lipid-lowering activity) of γ-oryzanol (OZ), a mixture of ferulic acid esters of plant sterols and triterpene alcohols, have been extensively investigated, few studies have evaluated the absorption and metabolism of OZ. Moreover, it is unclear whether OZ, once ingested, is directly absorbed by the intestine into the bloodstream at a sufficient level to exhibit activity. Here, we prepared OZ concentrate from purified rice bran oil (Rice Oil OZ), determined the concentration of OZ in the preparation (cycloartenyl ferulate equivalent concentration; 52.2%), and then carried out chromatography-mass spectrometry analysis of plasma samples from mice after oral administration of Rice Oil OZ. The OZ concentrations of plasma from the control (vehicle-treated) mice were low (trace levels); however, at 5 h after a single oral administration of the Rice Oil OZ (600 mg per kg body weight), the levels significantly increased, reaching 17.6 ng mL^-1 for cycloartenyl ferulate, 28.2 ng mL^-1 for 24-methylenecycloartanyl ferulate isomers, 15.6 ng mL^-1 for campesteryl ferulate, and 5.1 ng mL^-1 for β-sitosteryl ferulate, respectively, expressed in equivalence of cycloartenyl ferulate in plasma. These results provided the first mass spectrometric evidence suggesting that a portion of orally administered OZ is directly absorbed by the intestine and is present in the intact form in plasma. The presence of a significant amount of OZ in its intact form in plasma may explain the beneficial effects of OZ in vivo.

Oryzanol Modifies High Fat Diet-Induced Obesity, Liver Gene Expression Profile, and Inflammation Response in Mice

In Western countries and China, the dietary habit of high calories usually results in hyperlipidemia, which is closely associated with cardiovascular diseases. In the study, we investigated the antihyperlipidemic effect of oryzanol and its molecular mechanism in the high fat diet (HFD) mouse model. In total, 60 ICR mice were randomly divided into control group, HFD group, and HFD+Ory group. The mice from the HFD+Ory group were additionally fed with 100 mg/kg of oryzanol by intragastric administration. Our data indicated that oryzanol treatment for 10 weeks significantly reduced bodyweight, liver weight, and adipose tissues weight of the mice; lowered the contents of total cholesterol (TC), triglycerides (TG), and low density lipoprotein-cholesterol (LDL-C); and elevated high density lipoprotein-cholesterol (HDL-C) in the plasma of HFD mice. Compared with the HFD group, H&E staining showed that oryzanol treatment decreased the size of fat droplets of liver tissues and the size of adipocytes. Gene chip data found that oryzanol administration caused 32 genes to increase expressions while 60 genes had reduced expressions in the liver tissues of HFD mice. IPA software was used to analyze the protein interaction network and found that transcript factor NF-κB located in the central role of network, meaning NF-κB may have important function in the lipid-lowering effect of oryzanol. Western blotting and RT-qPCR confirmed that lipid metabolism-related gene expressions were obviously regulated by oryzanol administration. Oryzanol also inhibited expressions of inflammatory factor in the liver tissues of HDF mice. Taken together, our data indicate that oryzanol treatment can regulate lipid metabolism-related gene expressions and inhibit HDF-caused obesity in mice.

Plant Sterol Esters in Extruded Food Model Inhibits Colon Carcinogenesis by Suppressing Inflammation and Stimulating Apoptosis

Plant sterols in their free forms are known to inhibit colon cancer. Whether these activities persist when compounds are incorporated into processed food is not reported yet. This study aimed to test the ability of plant sterol esters (PSE) incorporated into a nonpuffed extruded food (NPE) model to inhibit colon carcinogenesis. PSE was added into NPE at four concentrations (0.0%, 0.7%, 1.4%, and 2.1%). PSE-NPE activity was tested in azoxymethane/dextran sodium sulfate-induced Balb/c mice. The groups given PSE-NPE did not show any colon tumor formation. Immunohistochemistry results revealed that the group fed with 1.4% PSE had the lowest histoscore for cyclooxygenase-2 expression and the highest histoscore for cleaved caspase-3, cleaved caspase-8, and cleaved caspase-9expressions. The results of this study indicated that even after incorporation into a food system, which is processed using high pressure and temperature, PSE retained its chemopreventive activity. The proposed mechanisms are by suppressing inflammation and inducing apoptosis.

Factors influencing antioxidant compounds in rice

Epidemiological and clinical studies suggest that the additive/synergistic effects of several bioactive compounds are responsible for the health benefits of rice. Among the leading contenders are phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocotrienols, tocopherols, λ-oryzanol, and phytic acid, which all possess strong antioxidant activities in vitro. In this review, data related to health effects of rice antioxidants using cultured cells, rodents and humans models are first summarized. The evidence is strong that consumption of rice tocotrienols translates into improved health outcomes. Current research, however, does not strongly support the health-promoting effects of rice tocopherols and phenolic acids. The crucial limitations in studies using rice flavonoids, anthocyanins, proanthocyanidins, λ-oryzanol and phytic acid appear to be the appropriateness of the substance tested (i.e., purity), and the scarcity of animal and human interventions. In a second part, rice antioxidants are reviewed with an emphasis on their composition and contents. Taking into account the bioavailability of these compounds, it is evident that a number of factors affect the antioxidant composition of rice, making it difficult to estimate dietary intake. Before harvest, factors including soil type, atmospheric CO₂, chemical inputs, temperature, and degree of ripening are important. After harvest, rice is subjected to processing methods that include drying, parboiling, storage, irradiation, milling, stabilization, soaking, germination, fermentation, boiling, steaming, roasting, baking, and extrusion. Quantitative knowledge about the effects of these processes is summarized in this review. Surprisingly, a high level of agreement was found among study results, which could be useful in manipulating the growing and processing techniques of rice grains to facilitate efficient and safe consumption of antioxidant compounds.

Scientific Evidence of Rice By-Products for Cancer Prevention: Chemopreventive Properties of Waste Products from Rice Milling on Carcinogenesis In Vitro and In Vivo

Cancer is a significant global health concern affecting men and women worldwide. Although current chemopreventive drugs could inhibit the growth of cancer cells, they exert many adverse side effects. Dietary factor plays a crucial role in the management of cancers and has drawn the attention of researchers to be used as an option to combat this disease. Both in vitro and in vivo studies showed that rice and its by-products display encouraging results in the prevention of this disease. The mechanism of anticancer effect is suggested partly through potentiation of bioactive compounds like vitamin E, phytic acid, γ-aminobutyric acid (GABA), γ-oryzanol, and phenolics. Nevertheless, the bioactivity of rice and its by-products is still incompletely understood. In this review, we present the findings from a preclinical study both in in vitro and in animal experiments on the promising role of rice by-products with focus on cancer prevention.

Effect of pulsed electric fields - assisted extraction on anti-inflammatory and cytotoxic activity of brown rice bioactive compounds

The bioactive compounds of brown rice exhibit many beneficial health effects, ranging from antioxidant to cytotoxic activities. Pulsed Electric Field (PEF) pretreatment can significantly enhance their extraction, through the induction of the electro-permeabilization of the cell membranes. This paper aims to demonstrate that PEF-assisted extraction of brown rice enables not only enhanced yields of antioxidant compounds, such as γ-oryzanol, polyphenols and phenolic acids, and of saturated and unsaturated fatty acids, but also increased cytotoxic effects on cancer cells. Initially, the PEF-assisted extraction conditions have been defined by the assessment of the cell permeabilization index via impedance measurements and the DPPH antioxidant activity. Subsequently, the biological effects of PEF have been evaluated on the cytotoxicity and anti-inflammatory properties against human colon cancer cell line HT29. The results show that PEF-assisted extraction, enhancing the yield of bioactive compounds, with respect to untreated extracts, significantly promotes their antioxidant activity, which is correlated with an increased HT29 cells cytotoxicity. In addition, PEF extracts of brown rice substantially inhibit also gene expression and interleukin production in colon cancer cells, suggesting their exploitation as natural anti-inflammatory agents. The integration of PEF pretreatment in the solvent extraction process of bioactives from brown rice appears, therefore, as a promising practice to significantly enhance their biological activity.

Anticlastogenicity and Anticarcinogenicity of Purple Rice Extract in Rats

Oryza sativa L. var. indica cv. Kum Doi Saket is a pigmented rice variety grown in northern Thailand. Our previous study found that the methanol extract of purple rice seed had the highest level of antimutagenicity in a Salmonella mutation assay. The present study was designed to evaluate its in vivo anticlastogenic and anticarcinogenic potentials. The purple rice extract had no acute toxicity on rats. The oral administration of 1,000 mg/kg body weight (bw) of the extract for 28 days did not increase the number of micronucleated hepatocytes. Interestingly, it significantly reduced the amount of micronucleus formation in the liver of diethylnitrosamine (DEN)-treated rats. The inhibitory mechanism involved the induction of hepatic glutathione S-transferase (GST) activity. In addition, oral administration of 500 mg/kg bw extract for 10 weeks significantly decreased the number of hepatic GST placental form positive foci, but did not modulate the number of colonic aberrant crypt foci in DEN- and dimethylhydrazine-initiated rats. In conclusion, the methanol extract of purple rice seed showed no toxicity, clastogenicity, or carcinogenicity in laboratory rats. It did display chemopreventive activity against the early stages of rat hepatocarcinogenesis.

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

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

Mutagenicity and antimutagenicity of hydrophilic and lipophilic extracts of Thai northern purple rice

Purple rice (Oryza sativa L. var. indica) cv. Kum Doisaket is cultivated in northern Thailand. This study evaluated the mutagenic and antimutagenic properties of hydrophilic and lipophilic components of purple rice using the Ames test. The seed and hull of purple rice were extracted with hexane, methanol, ethanol, and water. The methanol extracts had the highest amounts of phenolic acids and flavonoids, while the hexane extracts contained large amount of tocols and γ-oryzanol. None of the extracts were mutagenic in Salmonella typhimurium strains TA98 and TA100. The hexane extract of rice hull and the methanol extract of rice seed were strongly effective against aflatoxin B1- and 2-amino-3, 4 dimethylimidazo (4, 5-f) quinoline-induced mutagenesis, while aqueous extracts showed weakly antimutagenic properties. All extracts with the exception of aqueous extracts enhanced the number of revertant colonies from benzo (a) pyrene induced-mutagenesis. None of the extracts inhibited mutagenesis induced by the direct mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and sodium azide. The hull extracts showed more potent antimutagenicity than the seed extracts. Based on a chemical analysis, γ-oryzanol and γ-tocotrienol in the hull and cyanidin-3-glucoside and peonidin-3-glucoside in the seed are candidate antimutagens in purple rice. The antimutagenic mechanisms of purple rice might be related to either modulation of mutagen metabolizing enzymes or direct attack on electrophiles. These findings supported the use of Thai purple rice as a cancer chemopreventive agent.

Chemistry and anticarcinogenic mechanisms of glycoalkaloids produced by eggplants, potatoes, and tomatoes

Inhibition of cancer can occur via apoptosis, a genetically directed process of cell self-destruction that involves numerous biomarkers and signaling pathways. Glycoalkaloids are nitrogen-containing secondary plant metabolites found in numerous Solanaceous plants including eggplants, potatoes, and tomatoes. Exposure of cancer cells to glycoalkaloids produced by eggplants (α-solamargine and α-solasonine), potatoes (α-chaconine and α-solanine), and tomatoes (α-tomatine) or their hydrolysis products (mono-, di-, and trisaccharide derivatives and the aglycones solasodine, solanidine, and tomatidine) inhibits the growth of the cells in culture (in vitro) as well as tumor growth in vivo. This overview comprehensively surveys and consolidates worldwide efforts to define the following aspects of these natural compounds: (a) their prevalence in the three foods; (b) their chemistry and structure-activity relationships; (c) the reported factors (biomarkers, signaling pathways) associated with apoptosis of bone, breast, cervical, colon, gastric, glioblastoma, leukemia, liver, lung, lymphoma, melanoma, pancreas, prostate, and squamous cell carcinoma cell lines in vitro and the in vivo inhibition of tumor formation and growth in fish and mice and in human skin cancers; and (d) future research needs. The described results may make it possible to better relate the structures of the active compounds to their health-promoting function, individually, in combination, and in food, and allow the consumer to select glycoalkaloid-containing food with the optimal content of nontoxic beneficial compounds. The described findings are expected to be a valuable record and resource for further investigation of the health benefits of food-related natural compounds.

The Tomato Glycoalkaloid α-Tomatine Induces Caspase-Independent Cell Death in Mouse Colon Cancer CT-26 Cells and Transplanted Tumors in Mice

Tomatoes (Solanum lycopersicum) produce the bioactive glycoalkaloid α-tomatine. This study determined the effect of commercial α-tomatine on CT-26 colon cancer cells in vitro and in vivo in an intracutaneously transplanted mouse tumor. Cytotoxicity experiments showed that α-tomatine induces about 50% lysis of the colon cancer cells at 3.5 μM after 24 h of treatment. Large proportions of cells were found to be in the annexin V (+)/propidium iodide (+) phase of cell death, implying late phase apoptotic/necrotic status. However, α-tomatine induced cell death in CT-26 cancer cells through caspase-independent signaling pathways. This conclusion was supported by Western blot analysis showing a localization of apoptosis-inducing mitochondrial protein (AIF) to the nucleus and down-regulation of survivin (an inhibitor of apoptosis) expression as well as failure to detect the active form of caspase-3, -8, and -9 produced by proteolytic cleavage in CT-26 cancer cells. Intraperitoneally administered α-tomatine (5 mg/kg body weight) also markedly inhibited growth of the tumor using CT-26 cancer cells without causing body and organ weight changes. The reduced tumor growth in the mice by 38% after 2 weeks was the result of increased caspase-independent apoptosis associated with increased nuclear translocation of AIF and decreased survivin expression in tumor tissues. α-Tomatine in pure form and in tomatine-rich green tomatoes might prevent colon cancer.