Rice protein improves oxidative stress by regulating glutathione metabolism and attenuating oxidative damage to lipids and proteins in rats

Rice Protein Reduces Triglyceride Levels through Modulating CD36, MTP, FATP, and FABP Expression in Growing and Adult Rats

To elucidate the effect of rice protein on the regulation of triglyceride transport to reduce triglyceride levels, growing and adult male Wistar rats were fed with casein and rice protein for 2 weeks. With the intake of rice protein, the gene and protein expressions of cluster determinant 36 (CD36), microsomal triglyceride transfer protein (MTP), fatty acid transport protein-2 (FATP-2), and fatty acid-binding protein-1 (FABP-1) were, respectively, downregulated in growing and adult rats, suggesting rice protein could effectively regulate triglyceride transport. As a result, rice protein significantly reduced plasma levels of triglyceride and fatty acids, while hepatic accumulations of triglyceride and fatty acids were also decreased via rice protein. The present study demonstrates that RP exerts regulatory effects on CD36, MTP, FATP-2, and FABP-1 expression in growing and adult rats, revealing a link to triglyceride-lowering actions and the modulations of triglyceride transport exerted by rice protein. Results suggest that the aging process cannot attenuate the depression of CD36, MTP, FATP, and FABP 19 expression to reduce triglyceride levels induced by rice protein.

Compensatory Modulation of Seed Storage Protein Synthesis and Alteration of Starch Accumulation by Selective Editing of 13 kDa Prolamin Genes by CRISPR-Cas9 in Rice

Rice prolamins are categorized into three groups by molecular size (10, 13, or 16 kDa), while the 13 kDa prolamins are assigned to four subgroups (Pro13a-I, Pro13a-II, Pro13b-I, and Pro13b-II) based on cysteine residue content. Since lowering prolamin content in rice is essential to minimize indigestion and allergy risks, we generated four knockout lines using CRISPR-Cas9, which selectively reduced the expression of a specific subgroup of the 13 kDa prolamins. These four mutant rice lines also showed the compensatory expression of glutelins and non-targeted prolamins and were accompanied by low grain weight, altered starch content, and atypically-shaped starch granules and protein bodies. Transcriptome analysis identified 746 differentially expressed genes associated with 13 kDa prolamins during development. Correlation analysis revealed negative associations between genes in Pro13a-I and those in Pro13a-II and Pro13b-I/II subgroups. Furthermore, alterations in the transcription levels of 9 ER stress and 17 transcription factor genes were also observed in mutant rice lines with suppressed expression of 13 kDa prolamin. Our results provide profound insight into the functional role of 13 kDa rice prolamins in the regulatory mechanisms underlying rice seed development, suggesting their promising potential application to improve nutritional and immunological value.

Resveratrol improves meat quality traits by activating the lncRNAs-KEAP1-NRF2 axis in pigs

This research aims at uncovering the effects and investigating the molecular mechanisms of dietary resveratrol (RES) supplementation on antioxidant capacity and meat quality of pigs. In this study, 20 μM RES could activate the KEAP1-NRF2 antioxidant defense pathway in response to oxidative stress in porcine skeletal muscle satellite cells was firstly found. Then, twenty-four healthy crossbred castrated boars were allocated to 4 treatments that were fed with a basal diet (control) and a basal diet supplemented with 200 mg, 400 mg or 600 mg RES per Kilogram (kg) of feed for 41 days, respectively. 400 and 600 mg/kg RES-supplemented diet can effectively improve the meat quality traits and activities of antioxidizing enzymes via the KEAP1-NRF2 signaling pathway of pigs. The molecular dynamic simulation further revealed that RES could directly binding to KEAP1 to reduce the tightness of KEAP1-NRF2 protein-protein interaction. More importantly, dietary supplementation of RES also improves antioxidant capacity through a series of KEAP1-NRF2 pathway-related lncRNAs were found by RNA sequencing (RNA-seq). Altogether, this study demonstrated that RES improves meat quality traits by effectively increasing antioxidant levels via the lncRNA-KEAP1-NRF2 axis in vivo and/or in vitro. These results provide new insights into the molecular mechanisms by which RES, as a nutritional agent, regulates antioxidant capacity and improves meat quality in pigs.

Co-exposure to molybdenum and cadmium triggers pyroptosis and autophagy by PI3K/AKT axis in duck spleens

Excessive amounts of molybdenum (Mo) and cadmium (Cd) are toxicant, but their combined immunotoxicity are not clearly understood. To estimate united impacts of Mo and Cd on pyroptosis and autophagy by PI3K/AKT axis in duck spleens, Mo or/and Cd subchronic toxicity models of ducks were established by feeding diets with different dosages of Mo or/and Cd. Data show that Mo or/and Cd cause oxidative stress by increasing MDA concentration, and decreasing T-AOC, CAT, GSH-Px and T-SOD activities, restrain PI3K/AKT axis by decreasing PI3K, AKT, p-AKT expression levels, which evokes pyroptosis and autophagy by elevating IL-1β, IL-18 concentrations and NLRP3, Caspase-1, ASC, GSDME, GSDMA, NEK7, IL-1β, IL-18 expression levels, promoting autophagosomes, LC3 puncta, Atg5, LC3A, LC3B, LC3II/LC3I and Beclin-1 expression levels, and reducing expression levels of P62 and Dynein. Furthermore, the variations of abovementioned indexes are most pronounced in co-treated group. Overall, results reveal that Mo or/and Cd may evoke pyroptosis and autophagy by PI3K/AKT axis in duck spleens. The association of Mo and Cd exacerbates the changes.

Beneficial effects of Gynostemma pentaphyllum honey paste on obesity via counteracting oxidative stress and inflammation: An exploration of functional food developed from two independent foods rich in saponins and phenolics

The development of functional foods that possess a combination of biological functions and good sensory properties is an emerging topic in the field of food and function. Gynostemma pentaphyllum (G. pentaphyllum) is widely considered to exert anti-obesity effect owing to its abundant saponins and other bioactive components, but bitter and unacceptable taste limit its utilization. While honey, a natural sweetener, not only has the pleasure sense but is also usually used as the carrier of functional food due to its phenolic oligosaccharide, etc. In the present study, we proposed the preparation method of a G. pentaphyllum honey paste (GH) and its beneficial effects on obese mice. The results showed that GH contented 0.055 mg/g Gypenoside XLIX, 0.01 mg/g Gypenoside A, and 11 kinds of phenolics. It could down-regulate 23.3% of liver TC level, increase serum ALT activity, improve liver tissue damage and epididymal adipocyte hypertrophy than obese mice. Besides, GH regulated enzyme activities such as SOD and GSH to enhance oxidative stress defense and exerted anti-inflammatory activity via IL-6 (52.4%), TNF-α (38.7%), IFN-γ (32%) and NF-κB (28%) genes down-regulation, which also reshaped the gut microbiota structure, exerting anti-obesity effects. More importantly, GH promoted obese mice appetite with orexin-A compared to G. pentaphyllum alone. This study provided a new perspective on the development of G. pentaphyllum functional foods with both good organoleptic performance and obesity therapy.

l-Arginine prevents 4-hydroxy-2-nonenal accumulation and depresses inflammation via inhibiting NF-κB activation

4-Hydroxy-2-nonenal (HNE) is an inducer of inflammation. The aim of this study was to elicit the link between the inhibition of HNE accumulation and the depression of inflammation whether dependent onl-arginine availability in growing rats. Male Wistar rats were fed with different levels of l-arginine at 250, 500, and 1000 mg/kg body weight for 14 days. The control group was fed with commercial pellets. After 14 days of oral administration, l-arginine significantly reduced hepatic accumulation of HNE and depressed inflammation in rats as compared with the control group. Compared to the control group, the anti-inflammatory action of l-arginine is reflected by upregulation of hepatic interleukin-10 (IL-10) and the suppression of hepatic cyclooxygenase-2, tumor necrotic factor α, IL-1β, and IL-6 expressions in growing rats. With l-arginine administration, the activation of nuclear factor-κB (NF-κB) was efficaciously inhibited through the upregulation of inhibitory κBα, and the depression of phosphoinositide 3-kinase/protein kinase B (PI3K/Akt). In conclusion, this study demonstrated that l-arginine could reduce hepatic HNE levels and depress inflammation in growing rats, revealing a link between the inhibition of HNE accumulation with the depression of inflammation, which was attributed to the availability of l-arginine. A significant finding of this study was that the anti-inflammatory mechanism exerted by l-arginine was to inhibit NF-κB activation via downregulating PI3K/Akt.

Rice protein suppresses 4-hydroxy-2-nonenal-induced inflammation owing to methionine availability

4-Hydroxy-2-nonenal (HNE) is one of the most important products of lipid peroxidation which induces inflammation. In order to investigate the effect of rice protein (RP) on suppressing HNE-induced inflammation and the role of methionine in regulating the anti-inflammatory function of RP, Wistar rats (male, weighing180-200 g) were ad libitum fed either a pellet diet with oral administration of methionine or ad libitum fed RP for two weeks. RP and methionine significantly reduced HNE levels and effectively suppressed the expressions of cyclooxygenase-2, tumor necrosis factor alpha, interleukin (IL)-1β, IL-6, and inducible nitric oxide synthase. The anti-inflammatory action of RP was evident from the upregulation of IL-10 and glutathione S-transferase, which played a role in the detoxification of HNE. The results show that the molecular mechanism responsible for the anti-inflammatory function of RP is the inhibition of nuclear factor-κB activation by the downregulation of protein kinase B/phosphoinositide 3 kinase. Further, this study demonstrates that methionine availability contributes to the suppression of HNE-induced inflammation through up-regulating IL-10 and GST in rats fed RP. Novelty: RP suppresses HNE-induced inflammation. Met plays a role in up-regulating IL-10 and GST. Met availability regulates the inhibition of NF-κB by RP.

Biological Functions and Activities of Rice Bran as a Functional Ingredient: A Review

Rice bran (RB) is a nutrient-rich by-product of the rice milling process. It consists of pericarp, seed coat, nucellus, and aleurone layer. RB is a rich source of a protein, fat, dietary fibers, vitamins, minerals, and phytochemicals (mainly oryzanols and tocopherols), and is currently mostly used as animal feed. Various studies have revealed the beneficial health effects of RB, which result from its functional components including dietary fiber, rice bran protein, and gamma-oryzanol. The health effects of RB including antidiabetic, lipid-lowering, hypotensive, antioxidant, and anti-inflammatory effects, while its consumption also improves bowel function. These health benefits have drawn increasing attention to RB in food applications and as a nutraceutical product to mitigate metabolic risk factors in humans. This review therefore focuses on RB and its health benefits.

In vivo assessment of molybdenum and cadmium co-induce nephrotoxicity via NLRP3/Caspase-1-mediated pyroptosis in ducks

Excessive molybdenum (Mo) and cadmium (Cd) cause toxic effects on animals, but their joint effects on pyroptosis in kidney of ducks remain unclear. 160 healthy 7-day-old ducks were randomly divided into four groups which were fed with basal diet containing different dosages of Mo or/and Cd for 16 weeks. On the 4th, 8th, 12th and 16th weeks, kidney tissue and serum were collected. The results showed that Mo or/and Cd could significantly elevate their contents in kidney, disturb the homeostasis of trace elements, cause renal function impairment and histological abnormality, and oxidative stress as accompanied by increasing hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) concentrations and decreasing glutathione peroxidase (GSH-Px), catalase (CAT) and total-superoxide dismutase (T-SOD) activities. Simultaneously, Mo or/and Cd could markedly increase interleukin-1β (IL-1β), interleukin-18 (IL-18) contents and the expression levels of pyroptosis-related genes (NOD-like receptor protein-3 (NLRP3), Caspase-1, apoptosis-associated speck-like protein (ASC), NIMA-related kinase 7 (NEK7), Gasdermin A (GSDMA), Gasdermin E (GSDME), IL-1β and IL-18) and proteins (NLRP3, Caspase-1 p20, ASC and Gasdermin D (GSDMD)). Moreover, the changes of above these indicators were more obvious in combined group. Taken together, the results illustrate that Mo and Cd might synergistically lead to oxidative stress and induce pyroptosis via NLRP3/Caspase-1 pathway, whose mechanism is somehow related to Mo and Cd accumulation in duck kidneys.

CF3-substituted diselenide modulatory effects on oxidative stress, induced by single and repeated morphine administrations, in susceptible tissues of mice

Studies reveal that oxidative stress is associated with adverse effects of long-term morphine treatment. The m-trifluoromethyl-diphenyl diselenide (CF3) is a multi-target organoselenium compound that has antioxidant properties in different experimental models. This study aimed to investigate the CF3 effects against redox imbalance in peripheral and central tissues of mice, after single or multiple morphine doses. Swiss male mice received a single dose of morphine (5 mg/kg, s.c.) and CF3 (10 mg/kg, i.g.), or morphine was repeatedly injected (5 mg/kg, s.c.) and CF3 (10 mg/kg, i.g.) administered twice daily for 7 days. Oxidative stress was determined in the hippocampus, liver, and kidney. CF3 reversed the increase in reactive species caused by single and multiple morphine doses in the peripheral tissues. CF3 increased hepatic non-protein thiol levels and the superoxide dismutase (SOD) activity decreased by a single morphine dose. CF3 reversed the reduction in SOD activity in the kidney of mice repeatedly exposed to morphine. The study demonstrates that peripheral tissues were more susceptible than the hippocampus to oxidative stress induced by morphine in mice. The results show that CF3 modulated parameters of oxidative stress modified by single and multiple morphine administrations in peripheral and central tissues of mice.

The effect of ammonia exposure on energy metabolism and mitochondrial dynamic proteins in chicken thymus: Through oxidative stress, apoptosis, and autophagy

Ammonia (NH₃) gas is an atmospheric pollutant, produced from different sources. In poultry houses NH₃ is produced from the biological process of liter, manure, and protein composition. It has been well documented that NH₃ adversely effects the health of chickens. However, the underlying mechanism of NH₃ toxicity on chicken thymus is still unknown. Thymus is an important immune organ, which play a critical role in eliciting protective immune responses to ensure healing process and elimination of harmful stimuli. The results showed that NH₃ exposure reduced antioxidant activities and induced oxidative stress in thymus tissues. Histological observation showed normal morphology of chicken thymus in control group. In contrast, increased number of nuclear debris, vacuoles, and cristae break were seen in NH₃ affected chickens. Ultrastructural analysis indicated mitochondrial breakdown, disappearance, vacuoles, and chromatin condensation in NH₃ treated groups. The mRNA and protein expression of apoptosis related genes were significantly enhanced in the chicken thymus of NH₃ affected chickens compared to control group. Moreover, Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay results suggested that NH₃ exposure increased positive stained nuclei in the chicken thymus. Meanwhile, NH₃ exposure reduced the number of CD8⁺ T-lymphocytes, decreased the adenosine triphosphate (ATPase) activities. The mRNA and protein expression of autophagy, energy metabolism, and mitochondrial dynamics proteins were altered by NH₃ exposure. In summary, these results showed that NH₃ induced oxidative stress, apoptosis and autophagic cell death (ACD), which could be the possible causes of immune damage and structural impairment in chicken thymus.

Rice protein stimulates endogenous antioxidant response attributed to methionine availability in growing rats

Methionine sulfoxide reductase (Msr) and glutathione (GSH) are two endogenous antioxidant systems for depressing oxidative stress. The aim of this study is to investigate the role of methionine in involving the stimulation of endogenous antioxidant capacity of rice protein (RP). Seven-week-old male Wistar rats (body weight 180-200 g) were fed with commercial pellets (as control), methionine, and RP for 2 weeks. Compared with control, GSH synthesis and expressions of MsrA, MsrB2, and MsrB3 were stimulated by methionine and RP. After 2 weeks of feeding, Nrf2 was activated by RP and methionine, whereas the expressions of Keap1 and Cul3 were depressed. The ARE-driven antioxidant expressions (GCLC, GCLM, GS, HO-1, NQO1, CAT, SOD, GR, GST, GPx) were upregulated by methionine and RP. Results suggest that the endogenous antioxidant response induced by RP is primarily attributed to the methionine availability, in which the stimulation of Msr and GSH antioxidant system via Nrf2-ARE pathway. PRACTICAL APPLICATIONS: Rice protein is a major plant protein, which is rich in sulfur-containing amino acids and widely consumed in the world. This paper emphasizes that the amino acid plays a key role in inducing the antioxidant activity of rice protein. The present study provides an insight that the methionine availability of rice protein will be a useful target for health promoting by activating endogenous antioxidant response against ROS-induced oxidative damage.

Physiological Multifunctions of Rice Proteins of Endosperm and Bran

Although it is considered a staple food, rice intake is under serious debate for its physiological usefulness, especially for diabetic patients, because of starch content. However, rice protein, the second major component of rice, has gained attention recently for its newly-discovered functions, which were previously unknown. Rice protein, a plant protein, shows multiple beneficial functions on lipid metabolism and diabetes and its complications, nephropathy, fatty liver and osteoporosis. Rice proteins of endosperm and bran, an ingredient of white rice and an unused product of brown rice, respectively, are valuable components for human health.

Rice Protein Exerts Endogenous Antioxidant Capacity via Methionine Sulfoxide Reductase and the Nrf2 Antioxidant System Independent of Age

The major aim of this study was to investigate the effect of rice protein (RP) on the activation of endogenous antioxidant defense in growing and adult rats. After 2 weeks, RP activated nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) by suppressing Kelch-like ECH-associated protein 1 (Keap1) and Cullin 3 (Cul3) in growing and adult rats. Compared with casein, the upregulation of antioxidant responsive element (ARE)-driven antioxidant expression levels (glutamate cysteine ligase catalytic subunit, glutamate cysteine ligase modulatory subunit, glutathione synthase, glutathione reductase, glutathione S-transferase, glutathione peroxidase, catalase, superoxide dismutase, heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1) were found in RP groups. Also, RP upregulated methionine sulfoxide reductase (MsrA, MsrB2, and MsrB3) expression levels in growing and adult rats. As a result, RP enhanced endogenous antioxidative capacities to reduce hepatic accumulations of malondialdehyde, protein carbonyl, and reactive oxygen species. This study demonstrates that RP exerts the endogenous antioxidant capacity in growing and adult rats, which is due to stimulating Msr antioxidant expression and activating Nrf2-ARE pathway. Results suggest that the antioxidant activity induced by RP is independent of age.

Rice Protein Exerts Anti-Inflammatory Effect in Growing and Adult Rats via Suppressing NF-κB Pathway

To elucidate the effect of rice protein (RP) on the depression of inflammation, growing and adult rats were fed with caseins and RP for 2 weeks. Compared with casein, RP reduced hepatic accumulations of reactive oxygen species (ROS) and nitro oxide (NO), and plasma activities of alanine transaminase (ALT) and aspartate transaminase (AST) in growing and adult rats. Intake of RP led to increased mRNA levels, and protein expressions of phosphoinositide 3 kinase (PI3K), protein kinase B (Akt), nuclear factor-κB 1 (NF-αB1), reticuloendotheliosis viral oncogene homolog A (RelA), tumor necrotic factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and monocyte chemoattractant protein-1 (MCP-1) were decreased, whereas hepatic expressions of interleukin-10 (IL-10) and heme oxygenase 1 (HO-1) were increased by RP. The activation of NF-κB was suppressed by RP through upregulation of inhibitory κB α (IκBα), resulting in decreased translocation of nuclear factor-κB 1 (p50) and RelA (p65) to the nucleus in RP groups. The present study demonstrates that RP exerts an anti-inflammatory effect to inhibit ROS-derived inflammation through suppression of the NF-κB pathway in growing and adult rats. Results suggest that the anti-inflammatory capacity of RP is independent of age.

Rice protein reduces DNA damage by activating the p53 pathway and stimulating endogenous antioxidant response in growing and adult rats

BACKGROUND

Reactive oxygen species (ROS) can cause DNA damage. Rice protein (RP) inhibits ROS accumulation. However, a link between the reduction of ROS-derived DNA damage and the intake of RP is far from clear. The main objective of this study is to elucidate the effects of RPs on the reduction of DNA damage in growing and adult rats.

RESULTS

An intake of RP for 2 weeks significantly reduced the hepatic accumulation of ROS and 8-hydroxydeoxyguanosine (8-OHdG) in growing and adult rats, whereas the hepatic p53 content was markedly increased by RPs. After 2 weeks' feeding, the mRNA levels and protein expressions of p53, ataxia-telangiectasia mutated (ATM), and Checkpoint kinase 2 (Chk2) were up-regulated by RPs, whereas Murine Double Minute 2 (MDM2) expressions were markedly inhibited by RPs, resulting in more p53 being translocated into the nucleus. Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) was activated by RP by reducing Kelch-like ECH-associated protein 1 (Keap1), resulting in the up-regulation of antioxidant expressions of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in RP groups.

CONCLUSION

Rice protein can exert an endogenous antioxidant activity to reduce ROS-derived DNA damage by activating the Nrf2-Keap1 pathway. This study suggests that the activation of the ATM-Chk2-p53 pathway might be one of the mechanisms exerted by RP for reducing DNA damage in growing and adult rats. © 2019 Society of Chemical Industry.

l-Methionine activates Nrf2-ARE pathway to induce endogenous antioxidant activity for depressing ROS-derived oxidative stress in growing rats

BACKGROUND

Methionine is an essential sulfur-containing amino acid. To elucidate the influence of l-methionine on activation of the nuclear factor erythroid 2-related factor 2-antioxidant responsive element (Nrf2-ARE) antioxidant pathway to stimulate the endogenous antioxidant activity for depressing reactive oxygen species (ROS)-derived oxidative stress, male Wistar rats were orally administered l-methionine daily for 14 days.

RESULTS

With the intake of l-methionine, Nrf2 was activated by l-methionine through depressing Keap1 and Cul3, resulting in upregulation of ARE-driven antioxidant expression (glutamate cysteine ligase catalytic subunit, glutamate cysteine ligase modulatory subunit, glutathione synthase (GS), catalase (CAT), superoxide dismutase (SOD), heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1, glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPx)) with increasing l-methionine availability. Upon activation of Nrf2, glutathione synthesis was increased through upregulated expression of methionine adenosyltransferase, S-adenosylhomocysteine hydrolase, cystathionine β-synthase, cystathionine γ-lyse, glutamate cysteine ligase (GCL) and GS, while hepatic expressions of methionine sulfoxide reductases (MsrA, MsrB2, MsrB3) and hepatic enzyme activities (CAT, SOD, GCL, GR, GST, GPx) were uniformly stimulated with increasing consumption of l-methionine. As a result, hepatic content of ROS and MDA were effectively reduced by l-methionine intake.

CONCLUSION

The present study demonstrates that methionine availability plays a critical role in activation of the Nrf2-ARE pathway to induce an endogenous antioxidant response for depressing ROS-derived oxidative stress, which is primarily attributed to the stimulation of methionine sulfoxide reductase expression and glutathione synthesis. © 2019 Society of Chemical Industry.

Impaired immune function and structural integrity in the gills of common carp (Cyprinus carpio L.) caused by chlorpyrifos exposure: Through oxidative stress and apoptosis

As one of the mucosal lymphatic tissues, the gill is an important immune organ in fish. Water environmental pollutants enter fish body through the gill. Therefore, the gill is the initial site where pollutants produce toxic effects in water. Chlorpyrifos (CPF), a broad-spectrum organophosphate insecticide, is widely used for agricultural pests and causes river pollution. In the present study, we investigated histopathological effect, oxidative stress indexes (SOD, GSH, T-AOC, and MDA), and apoptosis-related genes (P53, PUMA, Bax, Bcl-2, Apaf-1, Caspase-9, and Caspase-3) in the gills of common carp exposed to CPF. The results indicated that CPF exposure decreased SOD, T-AOC, and GSH; increased MDA; decreased Bcl-2 mRNA expression; and increased P53, PUMA, Bax, Apaf-1, Caspase-9, and Caspase-3 mRNA expressions in common carp gills. Our results proved that CPF exposure caused oxidative stress and apoptosis in common carp gills; CPF exposure destroyed the structural integrity and affected the immune function through oxidative stress and apoptosis in common carp gills. These will provide evidence for the toxic effects of water environmental pollutants on immune function and structural integrity in fish gills.

Methionine Augments Antioxidant Activity of Rice Protein during Gastrointestinal Digestion

To elucidate the influence of methionine, which is an essential sulfur-containing amino acid, on the antioxidant activity of rice protein (RP), methionine was added to RP (RM). The addition of methionine to RM0.5, RM1.0, RM1.5, RM2.0, and RM2.5 was 0.5-, 1.0-, 1.5-, 2.0-, and 2.5-fold of methionine of RP, respectively. Using the in vitro digestive system, the antioxidant capacities of scavenging free radicals (superoxide; nitric oxide; 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, ABTS), chelating metal (iron), and reducing power were investigated in the hydrolysates of RP and RMs. Upon pepsin-pancreatin digestion, the weakest antioxidant capacity was produced by RP. With the addition of methionine, RMs exhibited more excellent responses to free radical scavenging activities and reducing power than RP, whereas RMs did not produce the marked enhancements in iron chelating activity as compared to RP. The present study demonstrated that RMs differently exerted the free radical scavenging activities that emerged in the protein hydrolysates, in which the strongest scavenging capacities for ABTS, superoxide, and nitric oxide were RM1.5, RM2.0, and RM2.5, respectively. Results suggested that the availability of methionine is a critical factor to augment antioxidant ability of RP in the in vitro gastrointestinal tract.

Oxidative Stress and Heavy Metals in Plants

Oxidative stress is a pathological process related to not only animal kingdom but also plants. Regarding oxidative stress in plants, heavy metals are frequently discussed as causative stimuli with relevance to ecology. Because heavy metals have broad technological importance, they can easily contaminate the environment. Much of previous effort regarding the harmful impact of the heavy metals was given to their toxicology in the animals and humans. Their implication in plant pathogeneses is less known and remains underestimated.The current paper summarizes basic facts about heavy metals, their distribution in soil, mobility, accumulation by plants, and initiation of oxidative stress including the decline in basal metabolism. The both actual and frontier studies in the field are summarized and discussed. The major pathophysiological pathways are introduced as well and link between heavy metals toxicity and their ability to initiate an oxidative damage is provided. Mobility and bioaccessibility of the metals is also considered as key factors in their impact on oxidative stress development in the plant. The metals like lead, mercury, copper, cadmium, iron, zinc, nickel, vanadium are depicted in the text.Heavy metals appear to be significant contributors to pathological processes in the plants and oxidative stress is probably an important contributor to the effect. The most sensitive plant species are enlisted and discussed in this review. The facts presented here outline next effort to investigate pathological processes in the plants.

Hepatoprotective effects of rice-derived peptides against acetaminophen-induced damage in mice

Glutathione, the most abundant intracellular antioxidant, protects cells against reactive oxygen species induced oxidative stress and regulates intracellular redox status. We found that rice peptides increased intracellular glutathione levels in human hepatoblastoma HepG2 cells. Acetaminophen is a commonly used analgesic. However, an overdose of acetaminophen causes severe hepatotoxicity via depletion of hepatic glutathione. Here, we investigated the protective effects of rice peptides on acetaminophen-induced hepatotoxicity in mice. ICR mice were orally administered rice peptides (0, 100 or 500 mg/kg) for seven days, followed by the induction of hepatotoxicity via intraperitoneal injection of acetaminophen (700 mg/kg). Pretreatment with rice peptides significantly prevented increases in serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels and protected against hepatic glutathione depletion. The expression of γ-glutamylcysteine synthetase, a key regulatory enzyme in the synthesis of glutathione, was decreased by treatment with acetaminophen, albeit rice peptides treatment recovered its expression compared to that achieved treatment with acetaminophen. In addition, histopathological evaluation of the livers also revealed that rice peptides prevented acetaminophen-induced centrilobular necrosis. These results suggest that rice peptides increased intracellular glutathione levels and could protect against acetaminophen-induced hepatotoxicity in mice.

In vitro antioxidant activity of rice protein affected by alkaline degree and gastrointestinal protease digestion

BACKGROUND

To elucidate whether and how alkali treatment, which is a common process for rice protein (RP) extraction, affects antioxidant activity of RP, the different degree of alkali (from 0.1% to 0.4% of NaOH) was used to extract RP (RP-1, RP-2, RP-3, RP-4).

RESULTS

The antioxidant capacities of scavenging free radicals [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid] diammonium salt, ABTS; 1,1-diphenyl-2-picrylhydrazyl, DPPH), chelating metals (iron, copper) and reducing power investigated in the hydrolysates of RPs (RP-1, RP-2, RP-3, RP-4) during in vitro pepsin-pancreatin digestion were effectively affected by alkali treatment. The present study demonstrated that the weakest antioxidant responses to ABTS radical-scavenging activity, DPPH radical-scavenging activity, iron chelating activity, copper chelating activity and reducing power were produced by RP-4 extracted by the highest alkali proportion (0.4% NaOH).

CONCULSION

The present study indicates that antioxidant capacity of RP could be more readily depressed by strict alkali degree and affected by gastrointestinal proteases. Results suggest that alkali extraction is a vital process to regulate the antioxidant activity of RP through modifying the compositions of amino acids, which are dependent on alkali magnitude. © 2016 Society of Chemical Industry.

Rice endosperm protein slows progression of fatty liver and diabetic nephropathy in Zucker diabetic fatty rats

We previously reported that rice endosperm protein (REP) has renoprotective effects in Goto-Kakizaki rats, a non-obese diabetic model. However, whether these effects occur in obese diabetes remains unclear. This study aimed to clarify the effects of REP on obese diabetes, especially on fatty liver and diabetic nephropathy, using the obese diabetic model Zucker diabetic fatty (ZDF) rats. In total, 7-week-old male ZDF rats were fed diets containing 20 % REP or casein (C) for 8 weeks. Changes in fasting blood glucose levels and urinary markers were monitored during the experimental period. Hepatic lipids and metabolites were measured and renal glomeruli were observed morphologically. HbA1c levels were significantly lower in rats fed REP, compared with C (P<0·05). Compared with C in the liver, REP prevented lipid accumulation (total lipid, TAG and total cholesterol, P<0·01). Liver metabolome analysis indicated that levels of metabolites associated with glycolysis, the pentose phosphate pathway and carnitine metabolism were significantly greater in the REP group than in the C group (P<0·05), suggesting activation of both glucose catabolism and fatty acid oxidation. The metabolite increases promoted by REP may contribute to suppression of liver lipid accumulation. Urinary excretion of albumin and N-acetyl-β-d-glucosaminidase was significantly reduced in rats fed REP for 8 weeks (P<0·01). In addition, there was a distinct suppression of mesangial matrix expansion and glomerular hypertrophy in response to REP (P<0·01). Thus, REP had preventive effects on obese diabetes, fatty liver and diabetic nephropathy.

Chronic Intake of Japanese Sake Mediates Radiation-Induced Metabolic Alterations in Mouse Liver

Sake is a traditional Japanese alcoholic beverage that is gaining popularity worldwide. Although sake is reported to have beneficial health effects, it is not known whether chronic sake consumption modulates health risks due to radiation exposure or other factors. Here, the effects of chronic administration of sake on radiation-induced metabolic alterations in the livers of mice were evaluated. Sake (junmai-shu) was administered daily to female mice (C3H/He) for one month, and the mice were exposed to fractionated doses of X-rays (0.75 Gy/day) for the last four days of the sake administration period. For comparative analysis, a group of mice were administered 15% (v/v) ethanol in water instead of sake. Metabolites in the liver were analyzed by capillary electrophoresis-time-of-flight mass spectrometry one day following the last exposure to radiation. The metabolite profiles of mice chronically administered sake in combination with radiation showed marked changes in purine, pyrimidine, and glutathione (GSH) metabolism, which were only partially altered by radiation or sake administration alone. Notably, the changes in GSH metabolism were not observed in mice treated with radiation following chronic administration of 15% ethanol in water. Changes in several metabolites, including methionine and valine, were induced by radiation alone, but were not detected in the livers of mice who received chronic administration of sake. In addition, the chronic administration of sake increased the level of serum triglycerides, although radiation exposure suppressed this increase. Taken together, the present findings suggest that chronic sake consumption promotes GSH metabolism and anti-oxidative activities in the liver, and thereby may contribute to minimizing the adverse effects associated with radiation.

Carbon dots-based ratiometric nanosensor for highly sensitive and selective detection of mercury(ii) ions and glutathione

Ratiometric fluorescent nanohybrid system for detection of Hg²⁺ and GSH.

Thai red rice extract provides liver protection in paracetamol-treated mice by restoring the glutathione system

CONTEXT

The incidence of drug-induced liver disease associated with oxidant-antioxidant imbalance is increasing. Colored rice can potentially improve these hepatic disorders through antioxidative and glutathione-restoring effects.

OBJECTIVES

The objective of this study is to determine the in vitro antioxidant properties of extracts from red (Hom-Dang and Hom-Kularb-Dang) and black (Hom-Dum-Sukhothai and Kum-Doi-Saket) Thai rice cultivars [Oryza sativa L. (Poaceae)] and to examine the in vivo hepatoprotective potential of Hom-Dang extract in paracetamol-treated mice.

MATERIALS AND METHODS

The in vitro antioxidant properties of the extracts were determined by ABTS, [Formula: see text], [Formula: see text], metal chelating capacity, and lipid peroxidation assays. To investigate hepatoprotective effects in vivo, mice administered 60 mg/kg/d paracetamol were given Hom-Dang extract (128, 256, and 512 mg/kg/d) and/or control antioxidant N-acetyl-cysteine (NAC, 150 mg/kg/d) for 7 and 30 d. Liver health was ascertained by measuring levels of hepatic transaminases (GPT/GOT), determining the glutathione profile (GSH/GSSG ratio), and histomorphological examination of liver tissue.

RESULTS

Hom-Dang extract showed the highest in vitro antioxidant potency (an IC50 value of 36.50 ± 0.46, 12.98 ± 0.23, 21.83 ± 2.58, 15.87 ± 0.30, and 86.21 ± 2.45 mg/mL for ABTS, OH(•), [Formula: see text], metal chelating, and lipid peroxidation, respectively). Mice administered paracetamol exhibited increases in GPT/GOT with decreases in GSH and GSH/GSSG ratio followed by histomorphological signs of liver injury. In the presence of the Hom-Dang extract, the GPT/GOT values were normalized, GSH production was induced, and the GSH/GSSG ratio was increased.

CONCLUSION

Thai colored rice cultivars, especially the Hom-Dang variety, are promising candidates for health supplements due to their antioxidative and hepatoprotective properties.

Cyclocarya paliurus prevents high fat diet induced hyperlipidemia and obesity in Sprague-Dawley rats

Cyclocarya paliurus (CP; qing qian liu), which is used as an herbal tea in China, has been confirmed to have therapeutic effects on hyperlipidemia and obesity, and therefore it is widely consumed to prevent metabolic diseases such as hyperlipidemia and diabetes. In this study, we investigated the preventive effects of CP on obesity and hyperlipidemia, as well as the underlying mechanisms involved in intestinal secretion of apolipoprotein (apo) B48. Sprague-Dawley rats were fed a high-fat diet (HFD) and with or without various concentrations of an ethanol extract of CP (CPE; 2, 4, or 8 g·(kg body mass)(-1)) administered by gavage for 8 weeks. From the results we see that CPE dose-dependently blocked increases in body mass, and decreased food utilization as well as visceral fat mass. Decreased serum levels of total cholesterol, triglycerides, and low density lipoprotein cholesterol, and elevated levels of high density lipoprotein cholesterol, as well as lowered levels of total cholesterol and triglycerides in the liver were also noticed in CPE-treated rats. Magnetic resonance images indicated that the abnormal fat storage induced by the HFD was obviously suppressed by CPE. In addition, ELISA analysis showed reduced fasting serum apoB48 in the CPE treatment groups. Based on the above results, CPE shows a promising preventive effect on obesity and hyperlipidemia, partially through suppressing intestinal apoB48 overproduction.

Postponed effect of neostigmine on oxidative homeostasis

Cholinesterases are enzymes able to hydrolyze the neurotransmitter acetylcholine and thus to terminate transmission. Once the enzymes are inhibited, excitotoxicity can appear in the adjacent cells. It is well known that oxidative stress is involved in the toxicity of cholinesterase inhibitors. Commonly, stress follows inhibition of cholinesterases and disappears shortly afterwards. In the present experiment, it was decided to test the impact of an inhibitor, neostigmine, on oxidative stress in BALB/c mice after a longer interval. The animals were sacrificed three days after onset of the experiment and spleens and livers were collected. Reduced glutathione (GSH), glutathione reductase (GR), glutathione S-transferase (GST), thiobarbituric acid reactive substances (TBARS), ferric reducing antioxidant power (FRAP), caspase-3 and activity of acetylcholinesterase (AChE) were assayed. The tested markers were not altered with exceptions of FRAP. The FRAP values indicate accumulation of low molecular weight antioxidants in the examined organs. The role of low molecular weight antioxidants in the toxicity of AChE inhibitors is discussed.

Whey Peptide-Based Formulas With ω-3 Fatty Acids Are Protective in Lipopolysaccharide-Mediated Sepsis

BACKGROUND

Sepsis and septic shock syndrome are among the leading causes of death in critically ill patients. Lipopolysaccharide (LPS) released by bacteria within the colon may translocate across a compromised epithelium, leading to oxidative stress, inflammation, sepsis, and eventually death.

METHODS

We examined the effects of a whey-based enteral formula high in cysteine (antioxidant precursor) and the addition of ω-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), against a mouse model of LPS-induced sepsis. Mice were fed either a whey-based diet with EPA-DHA (PAF), a whey-based diet without EPA-DHA (PSTD), or a casein-based control diet (CONT).

RESULTS

Mice fed PAF or PSTD were protected against LPS-induced weight loss. Whey-based diets suppressed inflammatory cytokine release and oxidative stress damage. Furthermore, PAF and PSTD were able to inhibit autophagy, a mechanism in which the cell recycles damaged organelles. These anti-inflammatory and antioxidative effects of PSTD and PAF resulted in decreased liver inflammation and intestinal damage and promoted protective microbiota within the intestines.

CONCLUSIONS

These data suggest a clinical role for whey peptide-based diets in promoting healing and recovery in critically ill patients.

Morphine as a Potential Oxidative Stress-Causing Agent

Morphine exhibits important pharmacological effects for which it has been used in medical practice for quite a long time. However, it has a high addictive potential and can be abused. Long-term use of this drug can be connected with some pathological consequences including neurotoxicity and neuronal dysfunction, hepatotoxicity, kidney dysfunction, oxidative stress and apoptosis. Therefore, most studies examining the impact of morphine have been aimed at determining the effects induced by chronic morphine exposure in the brain, liver, cardiovascular system and macrophages. It appears that different tissues may respond to morphine diversely and are distinctly susceptible to oxidative stress and subsequent oxidative damage of biomolecules. Importantly, production of reactive oxygen/nitrogen species induced by morphine, which have been observed under different experimental conditions, can contribute to some pathological processes, degenerative diseases and organ dysfunctions occurring in morphine abusers or morphine-treated patients. This review attempts to provide insights into the possible relationship between morphine actions and oxidative stress.

Antioxidant capacity responsible for a hypocholesterolemia is independent of dietary cholesterol in adult rats fed rice protein

Dietary cholesterol and aging are major risk factors to accelerate oxidation process for developing hypercholesterolemia. The major aim of this study is to elucidate the effects of rice protein on cholesterol level and oxidative stress in adult rats fed with and without cholesterol. After 2 weeks of feeding, hepatic and plasma contents of cholesterol, reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA) and protein carbonyl (PCO) were measured. In liver, total antioxidative capacity (T-AOC), activities of antioxidant enzymes (total superoxide dismutase, T-SOD; catalase, CAT), glutathione metabolizing enzyme activities and gene expression levels (γ-glutamylcysteine synthetase, γ-GCS; glutathione reductase, GR; glutathione peroxidase, GPx) were determined. Under cholesterol-free/enriched dietary condition, T-AOC, activities of T-SOD and CAT, glutathione metabolism related enzymes' activities and mRNA levels (γ-GCS, GR and GPx) were effectively stimulated by rice proteins as compared to caseins. Compared with caseins, rice proteins significantly increased hepatic and plasma GSH contents, whereas hepatic and plasma accumulations of MDA, PCO and GSSG were significantly reduced by rice protein-feedings. As a result, the marked reductions of cholesterol in the plasma and in the liver were observed in adult rats fed rice proteins with and without cholesterol. The present study demonstrates that the hypocholesterolemic effect of rice protein is attributable to inducing antioxidative response and depressing oxidative damage in adult rats fed cholesterol-free/enriched diets. Results suggest that the antioxidant capability involved in the hypocholesterolemic action exerted by rice protein is independent of dietary cholesterol during adult period.

The glutathione-related detoxication responses to juvenile and ecdysone hormones in Galleria mellonella

The effect of 20-hydroxyecdysone (20E) and juvenile hormone (JH) on the glutathione pathway of the greater wax moth Galleria mellonella (Lepidoptera: Pyralidae) was determined by investigating glutathione peroxidase (GSH-Px), glutathione S-transferases (GST), and glutathione reductase (GR) activities as well as reduced and oxidized glutathione (GSH and GSSG) content with respect to developmental stage. The continuous decreases of GSH-Px and GST activities dependent on the growth period of G. mellonella occurred in JH and 20E groups over and under their controls, respectively. While the GR activities of G. mellonella showed increases in young pupa (YP) for both control and in old larvae (OL) for the 20E groups after the minimum at these periods, they also increased after old pupa (OP) for the JH group with a maximum in OL period. Although GR activity levels in the JH group were significantly higher compared with controls and 20E groups up to OP period, the activity levels for the control and 20E groups were higher than those of the JH group at adult (AD) and old pupa (OP) periods, respectively. In spite of increases in the GR activity of 20E and control groups of G. mellonella, decreased GSH and increased GSSG levels were observed at aging period. GSH levels in the JH group reached a maximum at prepupa (PP) and then decreased with non-significant changes from OL to AD period. According to the results, GSH and GSSG levels, as well as GSH/GSSG ratios, were below and over control levels in 20E and JH groups, respectively, during all of the investigated developmental stages. On the contrary, the LPO levels were higher than the control for 20E and lower for the JH groups during the developmental period. These results show that while ecdysone hormone has a negative effect on the glutathione-related detoxication capacity of G. mellonella, the juvenile hormone has a positive effect on this process.

Rice protein exerts a hypocholesterolemic effect through regulating cholesterol metabolism-related gene expression and enzyme activity in adult rats fed a cholesterol-enriched diet

The major aim of this study is to elucidate the hypocholesterolemic mechanism exerted by rice protein (RP) in adult rats under cholesterol-enriched dietary condition. Compared with casein, the cholesterol levels in plasma and the liver were significantly reduced by RP, accompanying significant inhibition of cholesterol absorption. RP increased the activity and mRNA level of cholesterol 7α-hydroxylase, whereas acyl-CoA:cholesterol acyltransferase activity and gene expression were significantly depressed with consumption of RP. Neither the activity nor gene expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase of RP differed from that of casein. The gene expression of the peroxisome proliferator-activated receptor α and liver X receptor α were significantly activated by consumption of RP. RP did not modify the mRNA level of sterol regulatory element-binding protein-2 with respect to casein. These results suggest RP can induce a cholesterol-lowering effect through modifying cholesterol metabolism-related gene expression and enzyme activity in adult rats.

Nutrition of the critically ill &#8212; a 21st-century perspective

Health care-induced diseases constitute a fast-increasing problem. Just one type of these health care-associated infections (HCAI) constitutes the fourth leading cause of death in Western countries. About 25 million individuals worldwide are estimated each year to undergo major surgery, of which approximately 3 million will never return home from the hospital. Furthermore, the quality of life is reported to be significantly impaired for the rest of the lives of those who, during their hospital stay, suffered life-threatening infections/sepsis. Severe infections are strongly associated with a high degree of systemic inflammation in the body, and intimately associated with significantly reduced and malfunctioning GI microbiota, a condition called dysbiosis. Deranged composition and function of the gastrointestinal microbiota, occurring from the mouth to the anus, has been found to cause impaired ability to maintain intact mucosal membrane functions and prevent leakage of toxins - bacterial endotoxins, as well as whole bacteria or debris of bacteria, the DNA of which are commonly found in most cells of the body, often in adipocytes of obese individuals or in arteriosclerotic plaques. Foods rich in proteotoxins such as gluten, casein and zein, and proteins, have been observed to have endotoxin-like effects that can contribute to dysbiosis. About 75% of the food in the Western diet is of limited or no benefit to the microbiota in the lower gut. Most of it, comprised specifically of refined carbohydrates, is already absorbed in the upper part of the GI tract, and what eventually reaches the large intestine is of limited value, as it contains only small amounts of the minerals, vitamins and other nutrients necessary for maintenance of the microbiota. The consequence is that the microbiota of modern humans is greatly reduced, both in terms of numbers and diversity when compared to the diets of our paleolithic forebears and the individuals living a rural lifestyle today. It is the artificial treatment provided in modern medical care - unfortunately often the only alternative provided - which constitute the main contributors to a poor outcome. These treatments include artificial ventilation, artificial nutrition, hygienic measures, use of skin-penetrating devices, tubes and catheters, frequent use of pharmaceuticals; they are all known to severely impair the microbiomes in various locations of the body, which, to a large extent, are ultimately responsible for a poor outcome. Attempts to reconstitute a normal microbiome by supply of probiotics have often failed as they are almost always undertaken as a complement to - and not as an alternative to - existing treatment schemes, especially those based on antibiotics, but also other pharmaceuticals.

Nutrition of the critically ill - emphasis on liver and pancreas

About 25 million individuals undergo high risk surgery each year. Of these about 3 million will never return home from hospital, and the quality of life for many of those who return is often significantly impaired. Furthermore, many of those who manage to leave hospital have undergone severe life-threatening complications, mostly infections/sepsis. The development is strongly associated with the level of systemic inflammation in the body, which again is entirely a result of malfunctioning GI microbiota, a condition called dysbiosis, with deranged composition and function of the gastrointestinal microbiota from the mouth to the anus and impaired ability to maintain intact mucosal membrane functions and prevent leakage of toxins-bacterial endotoxins and whole or debris of bacteria, but also foods containing proteotoxins gluten, casein and zein and heat-induced molecules such as advanced glycation end products (AGEs) and advanced lipoxidation end products (ALEs). Markedly lower total anaerobic bacterial counts, particularly of the beneficial Bifidobacterium and Lactobacillus and higher counts of total facultative anaerobes such as Staphylococcus and Pseudomonas are often observed when analyzing the colonic microbiota. In addition Gram-negative facultative anaerobes are commonly identified microbial organisms in mesenteric lymph nodes and at serosal "scrapings" at laparotomy in patients suffering what is called "Systemic inflammation response system" (SIRS). Clearly the outcome is influenced by preexisting conditions in those undergoing surgery, but not to the extent as one could expect. Several studies have for example been unable to find significant influence of pre-existing obesity. The outcome seems much more to be related to the life-style of the individual and her/his "maintenance" of the microbiota e.g., size and diversity of microbiota, normal microbiota, eubiosis, being highly preventive. About 75% of the food Westerners consume does not benefit microbiota in the lower gut. Most of it, refined carbohydrates, is already absorbed in the upper part of the GI tract, and of what reaches the large intestine is of limited value containing less minerals, less vitamins and other nutrients important for maintenance of the microbiota. The consequence is that the microbiota of modern man has a much reduced size and diversity in comparison to what our Palelithic forefathers had, and individuals living a rural life have today. It is the artificial treatment provided by modern care, unfortunately often the only alternative, which belongs to the main contributor to poor outcome, among them; artificial ventilation, artificial nutrition, hygienic measures, use of skin penetrating devices, tubes and catheters, frequent use of pharmaceuticals, all known to significantly impair the total microbiome of the body and dramatically contribute to poor outcome. Attempts to reconstitute a normal microbiome have often failed as they have always been undertaken as a complement to and not an alternative to existing treatment schemes, especially treatments with antibiotics. Modern nutrition formulas are clearly too artificial as they are based on mixture of a variety of chemicals, which alone or together induce inflammation. Alternative formulas, based on regular food ingredients, especially rich in raw fresh greens, vegetables and fruits and with them healthy bacteria are suggested to be developed and tried.