Ameliorating effects of fermented rice bran extract on oxidative stress induced by high glucose and hydrogen peroxide in 3T3-L1 adipocytes

Development of Green Banana Fruit Wines: Chemical Compositions and In Vitro Antioxidative Activities

This study aimed to develop functional fruit wines using whole fruit, pulp, and peels from green bananas. The boiled banana homogenates were mixed with cane sugar before wine fermentation. Quality parameters, phenolic compounds, flavor components, and antioxidative properties of the green banana peel wine (GBPW), green banana pulp wine (GBMW), and whole banana wine (GBW) were determined. High-performance liquid chromatography was used to determine the phytochemical compounds in three wines, and the flavor components were further analyzed using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. The flavor components and in vitro antioxidant activities were, respectively, determined using the relative odor activity value and the orthogonal projections on latent structure discrimination analysis (OPLS-DA). In vitro antioxidative capacities for these wines were evaluated using antioxidant chemical assays and cell culture methods. The total phenolic and total tannin content of the GBPW, GBMW, and GBW showed reducing trends with increasing fermentation days, whereas the total flavonoid content of the wine samples exhibited downward trends. The antioxidant capacities of the three wine samples were higher than those of the raw fruit samples, except for the metal chelation rate (%). Additionally, the main flavor component in the wine samples was 3-methyl-1-butanol. Its percentages in the GBPW, GBMW, and GBW were 72.02%, 54.04%, and 76.49%, respectively. The OPLS-DA results indicated that the three wines presented significantly different antioxidant activities. The cell-culture-based antioxidant analysis showed that these wine samples had protective effects against the oxidative stress of the 3T3-L1 preadipocytes induced by hydrogen peroxide. This study provided a theoretical basis for defining the antioxidant characteristics of banana wines and expanding novel channels for using banana peels to develop nutraceuticals.

Development of Green Banana Fruit Wines: Chemical Compositions and In Vitro Antioxidative Activities

This study aimed to develop functional fruit wines using whole fruit, pulp, and peels from green bananas. The boiled banana homogenates were mixed with cane sugar before wine fermentation. Quality parameters, phenolic compounds, flavor components, and antioxidative properties of the green banana peel wine (GBPW), green banana pulp wine (GBMW), and whole banana wine (GBW) were determined. High-performance liquid chromatography was used to determine the phytochemical compounds in three wines, and the flavor components were further analyzed using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. The flavor components and in vitro antioxidant activities were, respectively, determined using the relative odor activity value and the orthogonal projections on latent structure discrimination analysis (OPLS-DA). In vitro antioxidative capacities for these wines were evaluated using antioxidant chemical assays and cell culture methods. The total phenolic and total tannin content of the GBPW, GBMW, and GBW showed reducing trends with increasing fermentation days, whereas the total flavonoid content of the wine samples exhibited downward trends. The antioxidant capacities of the three wine samples were higher than those of the raw fruit samples, except for the metal chelation rate (%). Additionally, the main flavor component in the wine samples was 3-methyl-1-butanol. Its percentages in the GBPW, GBMW, and GBW were 72.02%, 54.04%, and 76.49%, respectively. The OPLS-DA results indicated that the three wines presented significantly different antioxidant activities. The cell-culture-based antioxidant analysis showed that these wine samples had protective effects against the oxidative stress of the 3T3-L1 preadipocytes induced by hydrogen peroxide. This study provided a theoretical basis for defining the antioxidant characteristics of banana wines and expanding novel channels for using banana peels to develop nutraceuticals.

Role of polyphenols in combating Type 2 Diabetes and insulin resistance

Compromised carbohydrate metabolism leading to hyperglycemia is the primary metabolic disorder of non-insulin-dependent diabetes mellitus. Reformed digestion and altered absorption of carbohydrates, exhaustion of glycogen stock, enhanced gluconeogenesis and overproduced hepatic glucose, dysfunction of β-cell, resistance to insulin in peripheral tissue, and impaired insulin signaling pathways are essential reasons for hyperglycemia. Although oral anti-diabetic drugs like α-glucosidase inhibitors, sulfonylureas and insulin therapies are commonly used to manage Type 2 Diabetes (T2D) and hyperglycemia, natural compounds in diet also play a significant role in combating the effect of diabetes. Due to their vast bioavailability and anti-hyperglycemic effect with least or no side effects, polyphenolic compounds have gained wide popularity. Polyphenols such as flavonoids and tannins play a significant role in carbohydrate metabolism by inhibiting key enzymes responsible for the digestion of carbohydrates to glucose like α-glucosidase and α-amylase. Several polyphenols such as resveratrol, epigallocatechin-3-gallate (EGCG) and quercetin enhanced glucose uptake in the muscle and adipocytes by translocating GLUT4 to plasma membrane mainly by the activation of the AMP-activated protein kinase (AMPK) pathway. This review provides an insight into the protective role of polyphenols in T2D, highlighting the aspects of insulin resistance.

A novel aqueous extract from rice fermented with Aspergillus oryzae and Saccharomyces cerevisiae possesses an anti-influenza A virus activity

Human influenza virus infections occur annually worldwide and are associated with high morbidity and mortality. Hence, development of novel anti-influenza drugs is urgently required. Rice Power^® extract developed by the Yushin Brewer Co. Ltd. is a novel aqueous extract of rice obtained via saccharization and fermentation with various microorganisms, such as Aspergillus oryzae, yeast [such as Saccharomyces cerevisiae], and lactic acid bacteria, possessing various biological and pharmacological properties. In our previous experimental screening with thirty types of Rice Power^® extracts, we observed that the 30^th Rice Power^® (Y30) extract promoted the survival of influenza A virus-infected Madin-Darby canine kidney (MDCK) cells. Therefore, to identify compounds for the development of novel anti-influenza drugs, we aimed to investigate whether the Y30 extract exhibits anti-influenza A virus activity. In the present study, we demonstrated that the Y30 extract strongly promoted the survival of influenza A H1N1 Puerto Rico 8/34 (A/PR/8/34), California 7/09, or H3N2 Aichi 2/68 (A/Aichi/2/68) viruses-infected MDCK cells and inhibited A/PR/8/34 or A/Aichi/2/68 viruses infection and growth in the co-treatment and pre-infection experiments. The pre-treatment of Y30 extract on MDCK cells did not induce anti-influenza activity in the cell. The Y30 extract did not significantly affect influenza A virus hemagglutination, and neuraminidase and RNA-dependent RNA polymerase activities. Interestingly, the electron microscopy experiment revealed that the Y30 extract disrupts the integrity of influenza A virus particles by permeabilizing the viral membrane envelope, suggesting that Y30 extract has a direct virucidal effect against influenza A virus. Furthermore, we observed that compared to the ethyl acetate (EtOAc) extract, the water extract of Y30 extract considerably promoted the survival of cells infected with A/PR/8/34 virus. These results indicated that more anti-influenza components were present in the water extract of Y30 extract than in the EtOAc extract. Our results highlight the potential of a rice extract fermented with A. oryzae and S. cerevisiae as an anti-influenza medicine and a drug source for the development of anti-influenza compounds.

Dietary Polyphenols and Gene Expression in Molecular Pathways Associated with Type 2 Diabetes Mellitus: A Review

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder with various contributing factors including genetics, epigenetics, environment and lifestyle such as diet. The hallmarks of T2DM are insulin deficiency (also referred to as β-cell dysfunction) and insulin resistance. Robust evidence suggests that the major mechanism driving impaired β-cell function and insulin signalling is through the action of intracellular reactive oxygen species (ROS)-induced stress. Chronic high blood glucose (hyperglycaemia) and hyperlipidaemia appear to be the primary activators of these pathways. Reactive oxygen species can disrupt intracellular signalling pathways, thereby dysregulating the expression of genes associated with insulin secretion and signalling. Plant-based diets, containing phenolic compounds, have been shown to exhibit remedial benefits by ameliorating insulin secretion and insulin resistance. The literature also provides evidence that polyphenol-rich diets can modulate the expression of genes involved in insulin secretion, insulin signalling, and liver gluconeogenesis pathways. However, whether various polyphenols and phenolic compounds can target specific cellular signalling pathways involved in the pathogenesis of T2DM has not been elucidated. This review aims to evaluate the modulating effects of various polyphenols and phenolic compounds on genes involved in cellular signalling pathways (both in vitro and in vivo from human, animal and cell models) leading to the pathogenesis of T2DM.

The anti-cancer activity and potential clinical application of rice bran extracts and fermentation products

Rice bran is the main by-product of rice processing and contains approximately 64% of the nutrients in rice. Its various nutrient elements include rice bran proteins, oil, oryzanol, vitamins, polysaccharides, etc. The use of fermented technology can increase the content of bioactive peptides, promote the absorption efficiency, and further improve the functionality and added value of rice bran. In recent years, the nutritional value and function of the extracts and fermented products of rice bran have been emphatically studied. Rice bran extracts and fermentation products serve a critical role in the anti-inflammatory reaction, reducing the plasma lipid effect and increasing anti-cancer activity. Moreover, few review studies have been reported on the anti-cancer activity and potential mechanism of action of rice bran extract and its fermentation products. In this review, we focused on the anti-cancer function, mechanisms, and potential clinical usage of rice bran extracts and fermentation products in the adjuvant therapy of cancer patients.

Fermentation Biotechnology Applied to Cereal Industry By-Products: Nutritional and Functional Insights

Cereals are one of the major food sources in human diet and a large quantity of by-products is generated throughout their processing chain. These by-products mostly consist of the germ and outer layers (bran), deriving from dry and wet milling of grains, brewers' spent grain originating from brewing industry, or others originating during bread-making and starch production. Cereal industry by-products are rich in nutrients, but still they end up as feed, fuel, substrates for biorefinery, or waste. The above uses, however, only provide a partial recycle. Although cereal processing industry side streams can potentially provide essential compounds for the diet, their use in food production is limited by their challenging technological properties. For this reason, the development of innovative biotechnologies is essential to upgrade these by-products, potentially leading to the design of novel and commercially competitive functional foods. Fermentation has been proven as a very feasible option to enhance the technological, sensory, and especially nutritional and functional features of the cereal industry by-products. Through the increase of minerals, phenolics and vitamins bioavailability, proteins digestibility, and the degradation of antinutritional compounds as phytic acid, fermentation can lead to improved nutritional quality of the matrix. In some cases, more compelling benefits have been discovered, such as the synthesis of bioactive compounds acting as antimicrobial, antitumoral, antioxidant agents. When used for baked-goods manufacturing, fermented cereal by-products have enhanced their nutritional profile. The key factor of a successful use of cereal by-products in food applications is the use of a proper bioprocessing technology, including fermentation with selected starters. In the journey toward a more efficient food chain, biotechnological approaches for the valorization of agricultural side streams can be considered a very valuable help.

Dietary Anthocyanins and Insulin Resistance: When Food Becomes a Medicine

Insulin resistance is an abnormal physiological state that occurs when insulin from pancreatic β-cells is unable to trigger a signal transduction pathway in target organs such as the liver, muscles and adipose tissues. The loss of insulin sensitivity is generally associated with persistent hyperglycemia (diabetes), hyperinsulinemia, fatty acids and/or lipid dysregulation which are often prevalent under obesity conditions. Hence, insulin sensitizers are one class of drugs currently employed to treat diabetes and associated metabolic disorders. A number of natural products that act through multiple mechanisms have also been identified to enhance insulin sensitivity in target organs. One group of such compounds that gained interest in recent years are the dietary anthocyanins. Data from their in vitro, in vivo and clinical studies are scrutinized in this communication to show their potential health benefit through ameliorating insulin resistance. Specific mechanism of action ranging from targeting specific signal transduction receptors/enzymes to the general antioxidant and anti-inflammatory mechanisms of insulin resistance are presented.

Hypotheses on the Potential of Rice Bran Intake to Prevent Gastrointestinal Cancer through the Modulation of Oxidative Stress

Previous studies have suggested the potential involvement of oxidative stress in gastrointestinal cancers. In light of this, research efforts have been focused on the potential of dietary antioxidant intake to prevent gastrointestinal cancer through the modulation of oxidative stress. Rice bran, a by-product of rice milling, has been shown to contain an abundance of phytochemicals, which are dietary antioxidants. To date, a number of studies have shown the antioxidative effect of rice bran intake, and some demonstrated that such an effect may contribute to gastrointestinal cancer prevention, largely through the antioxidative properties of rice bran phytochemicals. In addition, these phytochemicals were shown to provide protection against cancer through mechanisms linked to oxidative stress, including β-catenin-mediated cell proliferation and inflammation. The present article provides an overview of current evidence for the antioxidative properties of rice bran and its phytochemicals, and for the potential of such properties in cancer prevention through the oxidative-stress-linked mechanisms mentioned above. The article also highlights the need for an evaluation of the effectiveness of rice bran dietary interventions among cancer survivors in ameliorating oxidative stress and reducing the level of gastrointestinal cancer biomarkers, thereby establishing the potential of such interventions among these individuals in the prevention of cancer recurrence.

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.

Ligularia fischeri extract attenuates liver damage induced by chronic alcohol intake

Context Ligularia fischeri (Ledebour) Turcz. (Compositae) has been used as a leafy vegetable and in traditional medicine to treat hepatic disorder in East Asia. Objective The present study explores the antioxidant activity of LF aqueous extract on EtOH-induced oxidative stress accompanied by hepatotoxicity both in vitro and in vivo. Materials and methods In vitro study using the mouse liver NCTC-1469 cell line was conducted to estimate the cytotoxicity as well as the inhibitory effect of LF extract against alcohol-treated cell damage. In vivo study used an alcohol-fed Wister rat model orally administered EtOH (3.95 g/kg of body weight/d) with or without LF extract (100 or 200 mg/kg body weight) for 6 weeks. Serum and liver tissue were collected to evaluate hepatic injury and antioxidant-related enzyme activity. Results The EC50 value for the DPPH radical scavenging capacity of LF extract was 451.5 μg/mL, whereas the IC50 value of LF extract in terms of EtOH-induced reactive oxygen species (ROS) generation was 98.3 μg/mL without cell cytotoxicity. LF extract (200 mg/kg body weight) significantly reduced the triglyceride content of serum (33%) as well as hepatic lipid peroxidation (36%), whereas SOD activity was elevated three-fold. LF extract suppressed expression of CYP2E1 and TNF-α, and attenuated alcohol-induced abnormal morphological changes. Discussion and conclusion LF extract attenuated liver damage induced by alcoholic oxidative stress through inhibition of ROS generation, down-regulation of CYP2E1, and activation of hepatic antioxidative enzymes. Homeostasis of the antioxidative defence system in the liver by LF extract mitigated hepatic disorder following chronic alcohol intake.

Cytoprotective mechanism of ferulic acid against high glucose-induced oxidative stress in cardiomyocytes and hepatocytes

Background

Ferulic acid (FA), a phenolic acid, is a potential therapy for diabetes mellitus. FA has been shown to protect against hepatic and myocardial injury and oxidative stress in obese rats with late-stage diabetes, but the mechanism of the antioxidative activity of FA is still unclear.

Objective

The aim of this study was to elucidate whether FA can prevent damage to cardiomyocytes and hepatocytes caused by high glucose (HG)-induced oxidative stress and whether the protection effects of FA on these cells are related to the Keap1-Nrf2-ARE signaling pathways.

Design

Cells were divided into four groups: a control group (cultured with normal medium), an HG group (medium containing 80 mmol/L glucose), an FA+HG group (medium containing 80 mmol/L glucose and 1, 5, or 10 µg/mL FA), and a dimethylbiguanide (DMBG)+HG group (medium containing 80 mmol/L glucose and 50 µg/mL DMBG).

Results

FA treatment significantly increased cell viability and significantly decreased cell apoptosis compared with the HG-treated group. Moreover, FA down-regulated the expression of Keap1 protein and up-regulated the expression of Nrf2 protein and gene transcription of HO-1 and glutathione S-transferase (GST) in a dose-dependent manner.

Conclusion

FA alleviated the HG-induced oxidative stress and decreased cell apoptosis in hepatocytes and cardiomyocytes. These effects were associated with the Keap1-Nrf2-ARE signaling pathway.

Anti-Oxidant and Anti-Adipogenic Effects of Ethanol Extracts from Wheat Germ and Wheat Germ Fermented with Aspergillus oryzae

Most of the wheat germ in cereal grains is removed during the milling process. Various physiological effects have been reported for bioactive substances in wheat germ such as phenolic acids and flavonoids. In this study, the anti-oxidant and anti-adipogenic effects of ethanol extracts from wheat germ (WGE) and wheat germ fermented with Aspergillus oryzae (F-WGE) were investigated in HepG2 and 3T3-L1 cells. The anti-oxidant activity of F-WGE was demonstrated by a dose-dependent increase in the enhanced scavenging capacity of hydroxyl radicals and Cu²⁺-chelating activity compared to WGE. WGE and F-WGE treatment at doses between 10 and 400 μg/mL did not affect the viability of HepG2 and 3T3-L1 cells. Intracellular ROS levels from Cu²⁺-induced oxidative stress were significantly decreased by F-WGE treatment in HepG2 cells compared to WGE. Lipid accumulation was increased in 3T3-L1 adipocytes by 100 μM Fe²⁺ treatment, but the accumulation was strongly inhibited by 100 μg/mL of WGE and F-WGE treatment. These results suggest that changes in bioactive substances during the fermentation of wheat germ can potentiate scavenging activities against transition metal-induced oxidative stress and lipid accumulation in 3T3-L1 adipocytes. Therefore, we propose that F-WGE is a novel food materials and provided scientific evidences for its efficacy in the development of functional foods.

A multistrategic approach in the development of sourdough bread targeted towards blood pressure reduction

Rising prevalence of hypertension is pushing food industry towards the development of innovative food products with antihypertensive effects. The aim was to study the effect of reduced sodium content and 21% addition of wholemeal wheat sourdough (produced by Lactobacillus brevis CECT 8183 and protease) on proximate composition, γ-aminobutyric acid (GABA) and peptide content of wheat bread. Angiotensin converting enzyme I (ACE) inhibitory and antioxidant activities were also evaluated. Sodium replacement by potassium salt did not affect chemical composition and biological activities of bread. In contrast, GABA and peptides <3 kDa contents in sourdough bread (SDB) were 7 and 3 times higher, respectively, than the observed in control. ACE inhibitory and antioxidant activities of the peptide fraction < 3 kDa from SDB was 1.7 and 2.6-3.0 times higher than control. Therefore, the combination of reduced sodium content with enriched concentrations of bioactive compounds in bread making may provide interesting perspectives for development of innovative breads towards blood pressure reduction.

Mechanism of the antiadipogenic-antiobesity effects of a rice hull smoke extract in 3T3-L1 preadipocyte cells and in mice on a high-fat diet

Photomicrographs and dose-dependent lipid reduction in adipocyte cells induced by the rice hull extract.

Rice brans, rice bran oils, and rice hulls: composition, food and industrial uses, and bioactivities in humans, animals, and cells

Rice plants produce bioactive rice brans and hulls that have been reported to have numerous health-promoting effects in cells, animals, and humans. The main objective of this review is to consolidate and integrate the widely scattered information on the composition and the antioxidative, anti-inflammatory, and immunostimulating effects of rice brans from different rice cultivars, rice bran oils derived from rice brans, rice hulls, liquid rice hull smoke derived from rice hulls, and some of their bioactive compounds. As part of this effort, this paper also presents brief summaries on the preparation of health-promoting foods including bread, corn flakes, frankfurters, ice cream, noodles, pasta, tortillas, and zero-trans-fat shortening as well as industrial products such bioethanol and biodiesel fuels. Also covered are antibiotic, antiallergic, anticarcinogenic, antidiabetic, cardiovascular, allelochemical, and other beneficial effects and the mechanisms of the bioactivities. The results show that food-compatible and safe formulations with desirable nutritional and biological properties can be used to develop new multifunctional foods as well as bioethanol and biodiesel fuel. The overlapping aspects are expected to contribute to a better understanding of the potential impact of the described health-promoting potential of the rice-derived brans, oils, and hulls in food and medicine. Such an understanding will enhance nutrition and health and benefit the agricultural and industrial economies.

Oxidative stress and protein carbonylation in adipose tissue - implications for insulin resistance and diabetes mellitus

While historically considered simply as a depot for excess energy, white adipose tissue is a dynamically active endocrine organ capable of responding to a variety of efferent stimuli resulting in the synthesis and secretion of peptides, proteins and metabolites that serve as signal transducers to the peripheral and central circulation. Such regulation controls a variety of physiological processes including energy expenditure, food intake, reproductive capacity and responsiveness to insulin. Indeed, the accumulation of inflammatory cells in white adipose tissue is considered to be causative in the development of insulin resistance and eventually type 2 diabetes mellitus. A large body of evidence suggests that oxidative stress in adipose tissue not only correlates with insulin resistance but is also causative in its development. Moreover, using the available plasma oxidative stress biomarkers, many clinical studies have shown the presence of systemic oxidative stress in obese insulin resistant subjects, and its decrease after the successful treatment of obesity. In this review we emphasize the role of protein carbonylation in dysfunctional obese white adipose tissue and its metabolic implications. We focus on glutathione S-transferase A4 as the key enzyme for trans-4-hydroxy-2-nonenal and trans-4-oxo-2-nonenal removal from the cell, thus preventing protein carbonylation. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine.