Hepatoprotective effect of methylsulfonylmethane against carbon tetrachloride-induced acute liver injury in rats

Structure Modification Converts the Hepatotoxic Tacrine into Novel Hepatoprotective Analogs

The liver is responsible for critical functions such as metabolism, secretion, storage, detoxification, and the excretion of various compounds. However, there is currently no approved drug treatment for liver fibrosis. Hence, this study aimed to explore the potential hepatoprotective effects of chlorinated and nonchlorinated 4-phenyl-tetrahydroquinoline derivatives. Originally developed as tacrine analogs with reduced hepatotoxicity, these compounds not only lacked hepatotoxicity but also displayed a remarkable hepatoprotective effect. Treatment with these derivatives notably prevented the chemically induced elevation of hepatic indicators associated with liver injury. Additionally, the compounds restored the activities of defense antioxidant enzymes as well as levels of inflammatory markers (TNF-α and IL-6), apoptotic proteins (Bax and Bcl2), and fibrogenic mediators (α-SMA and TGF-β) to normal levels. Histopathologic analysis confirmed the hepatoprotective activity of tetrahydroquinolines. Furthermore, computer-assisted simulation docking results were highly consistent with those of the observed in vivo activities. In conclusion, the designed tacrine analogs exhibited a hepatoprotective role in acute liver damage, possibly through their antioxidative, anti-inflammatory, and antifibrotic effects.

The Role of the NLRP3 Inflammasome and Programmed Cell Death in Acute Liver Injury

Acute liver injury (ALI) is a globally important public health issue that, when severe, rapidly progresses to acute liver failure, seriously compromising the life safety of patients. The pathogenesis of ALI is defined by massive cell death in the liver, which triggers a cascade of immune responses. Studies have shown that the aberrant activation of the nod-like receptor protein 3 (NLRP3) inflammasome plays an important role in various types of ALI and that the activation of the NLRP3 inflammasome causes various types of programmed cell death (PCD), and these cell death effectors can in turn regulate NLRP3 inflammasome activation. This indicates that NLRP3 inflammasome activation is inextricably linked to PCD. In this review, we summarize the role of NLRP3 inflammasome activation and PCD in various types of ALI (APAP, liver ischemia reperfusion, CCl₄, alcohol, Con A, and LPS/D-GalN induced ALI) and analyze the underlying mechanisms to provide references for future relevant studies.

Role of Dietary Methyl Sulfonyl Methane in Poultry

Oxidative stress is defined as an imbalance between pro-oxidants and anti-oxidants within biological systems, leading to tissue damage and compromising the health of afflicted animals. The incorporation of dietary anti-oxidants into chicken diets has been a common practice to improve the performance, health, and welfare of the host by protecting against oxidative stress-induced damage. Methyl sulfonyl methane (MSM), a naturally occurring organosulfur compound found in various plant sources, has demonstrated various beneficial biological properties, including anti-inflammatory and anti-oxidant properties in both in vitro and in vivo studies. MSM has been utilized as a dietary supplement for humans for its anti-oxidant, analgesic, and anti-inflammatory properties. It has also been administered to domestic animals, including cattle, pigs, and chickens, owing to its recognized anti-oxidant effect. This review summarizes the biological and physiological functions of dietary MSM in poultry.

Effects of dietary methyl sulfonyl methane and selenium on laying performance, egg quality, gut health indicators, and antioxidant capacity of laying hens

Objective

This study investigated the effects of dietary methyl sulfonyl methane (MSM) and selenium (Se) on the laying performance, egg quality, gut health indicators, egg yolk Se content, and antioxidant markers in laying hens.

Methods

One hundred ninety-two 73-wk-old laying hens were randomly divided into four groups with eight replicates of six hens each. Four diets were prepared in a 2×2 factorial arrangement with or without MSM and Se. The trial lasted for 12 wk.

Results

There were no interaction effects or main effects (p>0.05) on laying performance and egg quality. However, feed intake increased in Se-fed hens (p = 0.051) and decreased in MSM-fed hens (p = 0.067) compared with that of hens in the control group. Dietary MSM increased (p<0.05) the ileal villus height and villus height:crypt ratio in hens compared with those receiving the non-supplemented control diet. Dietary MSM and Se did not affect the percentage of short-chain fatty acids in the ileal contents. Dietary Se enriched the Se content in egg yolk compared with that of the non-supplemented control diet (p<0.05). Dietary Se increased (p<0.05) glutathione peroxidase levels in the liver and serum samples compared to the control diet. The total antioxidant capacity in the liver increased (p<0.05) in laying hens that were fed MSM-supplemented diets than in hens fed the control diet. Dietary MSM significantly increased the relative superoxide dismutase levels in serum samples (p<0.05).

Conclusion

Supplementation with either MSM or Se independently improved the antioxidant capacity of laying hens. Furthermore, dietary Se produced Se-enriched eggs, but this effect was neither additive nor synergistic with dietary MSM.

Effects of Dietary Organic and Inorganic Sulfur on Laying Performance, Egg Quality, Ileal Morphology, and Antioxidant Capacity in Laying Hens

Simple Summary

Oxidative stress caused by environmental and nutritional factors could be detrimental to poultry production. Dietary natural antioxidants could therefore be beneficial in limiting the deleterious effects of oxidative stress in chickens. Methyl sulfonyl methane is a non-toxic natural organosulfur compound with the chemical formula (CH₃)₂SO₂ and is known as methyl sulfone or dimethyl sulfone. Inorganic sulfate (e.g., sodium sulfate) is involved in the metabolism of many tissues and systems, as well as in important detoxication mechanisms. Dietary sulfur in either organic or inorganic forms exhibits beneficial antioxidant properties in various animals in vivo and in vitro. Therefore, our studies have been conducted to evaluate the role of organic and inorganic sulfur in laying hens.

Abstract

The present study was conducted to investigate the comparative effects of organic and inorganic forms of sulfur, methyl sulfonyl methane (MSM) and sodium sulfate (SS), on laying performance, egg quality, ileal morphology, ileal volatile fatty acids, and antioxidant and stress markers in various biological samples in aged laying hens. A total of 144, 73-week-old Lohman Brown-Lite laying hens were randomly assigned to one of three experimental diets: basal diet (CONT), CONT + 0.2% MSM (MSM), and CONT + 0.3% SS (SS). The trial lasted for 12 weeks. MSM and SS diets contained 0.07% of sulfur, either organic or inorganic. Dietary MSM did not affect egg production or feed conversion ratio at 12 weeks compared with the CONT group. Dietary sulfur did not affect egg quality except for the Haugh unit at 4 weeks, which was lowered (p < 0.05) in the SS group. Compared with the CONT group, a higher (p < 0.05) villus height to crypt depth ratio was observed in the SS group. Dietary sulfur did not affect the percentages of short-chain fatty acids in the ileum. Total antioxidant capacity of the liver increased (p < 0.05) in laying hens fed MSM- and SS-added diets compared with the CONT group. The MSM and SS groups were found to have lowered (p < 0.05) malondialdehyde (MDA) concentration in serum samples compared with CONT. Finally, dietary MSM had the lowest (p < 0.05) MDA concentrations in yolk samples. Taken together, our study showed that dietary organic and inorganic sulfur have positive effects on ileal morphology and antioxidant capacity in laying hens. However, SS-mediated inhibition in laying performance needs to be clarified.

Antioxidant activity and protective effect of propolis against carbon tetrachloride-induced liver and kidney injury by modulation of oxidative parameters

Background and Aim:

Propolis has a protective effect against cellular damage caused by toxic agents such as drugs, metals, xenobiotics, and chemicals. The aim of this study was to investigate the antioxidant activity and the effect of ethanolic extract of propolis on carbon tetrachloride (CCl4)-induced oxidative stress on kidney and liver injury in rat.

Materials and Methods:

The study quantified phenol, flavone, and flavonol in propolis and assessed antioxidant activity using 2, 2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power, and molybdate. The investigators used four groups of rats to study the effect of propolis on CCl₄-induced toxicity. Propolis extract was given orally (500 mg/kg) for 12 days, and CCl_{4 (}1 mL/kg) was administered intraperitoneally on day 5 of the experiment. Blood and tissue samples of the liver and kidney were collected on day 13 to measure biochemical and oxidative parameters. The parameters included malondialdehyde (MDA), protein carbonyl formation (PCO), advanced oxidation protein products (AOPP), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), and ascorbic acid (AA). Biochemical parameters included liver enzymes, blood urea (BU), creatinine, and uric acid (UA).

Results:

CCl₄ decreased antioxidant agents, including CAT, GPx, GSH, and AA in the liver and kidney tissues. The oxidative agents’ levels, including MDA, PCO, and AOPP, increased by CCl₄ compared to the control group. CCl₄ increased liver enzymes, UA, BU, and creatinine in the blood samples. Propolis significantly alleviated liver and kidney function, improved antioxidant parameters, and decreased levels of oxidative agents.

Conclusion:

The data showed for the 1^st time that Moroccan propolis has a protective effect against CCl₄-induced kidney and liver toxicity by maintaining the activity of the antioxidant defense system, which was most likely due to its antioxidant activity.

Astragalus Polysaccharides and Saponins Alleviate Liver Injury and Regulate Gut Microbiota in Alcohol Liver Disease Mice

Astragalus, a medical and edible plant in China, shows several bioactive properties. However, the role of astragalus in attenuating alcoholic liver disease (ALD) is less clear. The objective of this project is to investigate the improving effect of astragalus saponins (AS) and astragalus polysaccharides (AP), which are the two primary constituents in astragalus on hepatic injury induced by alcohol, and the potential mechanisms of action. Different doses of AS (50 and 100 mg/kg bw) and AP (300 and 600 mg/kg bw) were orally given to alcohol-treated mice for four weeks. The results demonstrated that both AP and AS could reverse the increase of the levels of TC, TG, FFA, and LDL-C in serum, and the decrease of serum HDL-C content, as well as the elevation of hepatic TC and TG levels induced by alcohol. The activities of AST, ALT, ALP, and γ-GT in ALD mice were raised after AP and AS supplementation. The antioxidant markers (SOD, CAT, GSH, and GSH-Px) were obviously augmented and the pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) and hepatic histological variations were alleviated by AP and AS, which was in line with the levels of oxidative stress-associated genes (Keap1, Nfe2l2, Nqo1, and Hmox1) and inflammation-associated genes (Tlr4, Myd88 and Nfkb1). In addition, AS exerted a more efficient effect than AP and the results presented dose proportionality. Moreover, AS and AP could modulate the intestinal microbiota disturbance induced by alcohol. Overall, AS and AP administration could ameliorate lipid accumulation in the serum and liver, as well as hepatic function, oxidative stress, inflammatory response, and gut flora disorders in mice as a result of alcohol.

Flavonoid-rich fraction of Lasianthera africana leaves alleviates hepatotoxicity induced by carbon tetrachloride in Wistar rats

Lasianthera africana P. Beauv. (Icacinaceae) is a good source of natural antioxidants, having the potential to protect against oxidative stress-related diseases and complications. This study investigated the antioxidant, hepatoprotective and curative effects of flavonoid-rich fraction of L. africana leaves (LAFRF) against carbon tetrachloride-induced hepatotoxicity in Wistar rats. Phytochemical, nutrient content, and in vitro antioxidant activity of LAFRF were determined by standard methods. Fifty Wistar rats were randomized into 10 groups (n = 5). Groups 1 and 2 served as normal and CCl₄ controls, respectively. Groups 3A-6A constituted the protective study while groups 3B-6B represented the curative study. The effects of LAFRF at 3, 10, and 30 mg/kg body weight (b.w.) on lipid peroxidation, antioxidant status, liver enzymes activities, and histology of CCl₄-intoxicated rats were assessed. LAFRF total flavonoids (281.05 ± 7.44 mg QE/g), indicated LD₅₀ above 5000 mg/kg b.w., and scavenged ABTS*⁺ with an IC₅₀ of 5.05 ± 0.00 µg/mL relative to butylated hydroxytoluene (4.16 ± 0.00 µg/mL), and a concentration-dependent increase in total antioxidant capacity. Carbon tetrachloride (1 mL/kg) triggered significant (p < 0.05) increases in malonedialdehyde concentration (2.67 ± 0.21 mg/mL), with a corresponding decline in antioxidant status, and increases in alkaline phosphatase, alanine and aspartate aminotransferase activities (68.00 ± 9.59 IU/L, 79.60 ± 5.03 IU/L and 81.80 ± 3.96 IU/L), respectively. LAFRF significantly (p < 0.05) lowered lipid peroxidation levels, liver enzyme activities, increased antioxidant status, and improved hepatic histo-architecture of pre- and post LAFRF-treated rats. This demonstrates its high antioxidative, hepatoprotective and curative effects, indicating its potential for future drug development.

Conjugation with Methylsulfonylmethane Improves Hyaluronic Acid Anti-Inflammatory Activity in a Hydrogen Peroxide-Exposed Tenocyte Culture In Vitro Model

Rotator cuff tears (RCTs) and rotator cuff disease (RCD) are important causes of disability in middle-aged individuals affected by nontraumatic shoulder dysfunctions. Our previous studies have demonstrated that four different hyaluronic acid preparations (HAPs), including Artrosulfur^® hyaluronic acid (HA) (Alfakjn S.r.l., Garlasco, Italy), may exert a protective effect in human RCT-derived tendon cells undergoing oxidative stress damage. Recently, methylsulfonylmethane (MSM) (Barentz, Paderno Dugnano, Italy) has proven to have anti-inflammatory properties and to cause pain relief in patients affected by tendinopathies. This study aims at evaluating three preparations (Artrosulfur^® HA, MSM, and Artrosulfur^® MSM + HA) in the recovery from hydrogen peroxide-induced oxidative stress damage in human tenocyte. Cell proliferation, Lactate Dehydrogenase (LDH) release, and inducible nitric oxide synthases (iNOS) and prostaglandin E2 (PGE2) modulation were investigated. In parallel, expression of metalloproteinases 2 (MMP2) and 14 (MMP14) and collagen types I and III were also examined. Results demonstrate that Artrosulfur^® MSM + HA improves cell escape from oxidative stress by decreasing cytotoxicity and by reducing iNOS and PGE2 secretion. Furthermore, it differentially modulates MMP2 and MMP14 levels and enhances collagen III expression after 24 h, proteins globally related to rapid acceleration of the extracellular matrix (ECM) remodelling and thus tendon healing. By improving the anti-cytotoxic effect of HA, the supplementation of MSM may represent a feasible strategy to ameliorate cuff tendinopathies.

Safety and Molecular-Toxicological Implications of Cannabidiol-Rich Cannabis Extract and Methylsulfonylmethane Co-Administration

Cannabidiol (CBD) is a biologically active, non-psychotropic component of Cannabis sativa whose popularity has grown exponentially in recent years. Besides a wealth of potential health benefits, ingestion of CBD poses risks for a number of side effects, of which hepatotoxicity and CBD/herb-drug interactions are of particular concern. Here, we investigated the interaction potential between the cannabidiol-rich cannabis extract (CRCE) and methylsulfonylmethane (MSM), a popular dietary supplement, in the mouse model. For this purpose, 8-week-old male C57BL6/J mice received MSM-containing water (80 mg/100 mL) ad libitum for 17 days. During the last three days of treatment, mice received three doses of CRCE administered in sesame oil via oral gavage (123 mg/kg/day). Administration of MSM alone did not result in any evidence of liver toxicity and did not induce expression of mouse cytochrome P450 (CYP) enzymes. Administration of CRCE did produce significant (p < 0.05) increases in Cyp1a2, Cyp2b10, Cyp2c29, Cyp3a4, Cyp3a11, Cyp2c65, and Cyp2c66 messenger RNA, however, this effect was not amplified by MSM/CRCE co-treatment. Similarly, no evidence of liver toxicity was observed in MSM/CRCE dosed mice. In conclusion, short-term MSM/CRCE co-administration did not demonstrate any evidence of hepatotoxicity in the mouse model.

Dietary methylsulfonylmethane supplementation and oxidative stress in broiler chickens

Methylsulfonylmethane (MSM) is an organic, sulfur-containing compound widely used as a dietary supplement to improve joint health and treat arthritic pain. An experiment was conducted to study the effects of feeding 0.05% MSM to broilers exposed to diet-induced oxidative stress on tissue MSM distribution, growth performance, oxidative stress biomarkers, and immune responsivity. A total of 528 birds were allocated to 4 dietary treatments (fresh oil-no MSM, fresh oil-MSM, oxidized oil-no MSM, oxidized oil-MSM) as provided ad libitum to 11 replicate cages of 12 birds per treatment. Blood and tissue samples were collected to analyze MSM concentrations, and oxidative stress biomarkers including concentrations of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), total glutathione, and glutathione peroxidase (GPx) and reductase (GR) activities. Additionally, blood samples collected at day 25 were used to quantify T-cell (TC) populations using flow cytometry. Overall, MSM was quantified in all tissues and plasma samples of MSM-treated groups at all time points. Oxidized oil reduced (P = 0.006) feed intake over the 21-d feeding period, but MSM did not affect growth equally across time points. No effects (P > 0.2) of MSM or oil type were observed on TC populations. In the presence of oxidized oil, MSM reduced (P = 0.013) plasma TBARS and increased (P = 0.02) liver GPx at day 21, and increased (P = 0.06) liver GR at day 7. Irrespective of dietary oil type, groups supplemented with MSM showed higher plasma TAC at day 7 (P = 0.023), liver GPx activity at day 21 (P = 0.003), and liver GR activity at day 7 (P = 0.004) compared with groups not receiving MSM. In conclusion, 0.05% dietary MSM supplementation partially protected birds from oxidative stress but did not affect immune cell profiles.

Toxicity and tissue distribution of methylsulfonylmethane following oral gavage in broilers

An experiment was conducted to investigate the toxicity and tissue distribution of methylsulfonylmethane (MSM) following oral gavage in broilers. A total of four hundred and thirty-two 15-day-old Ross 308 male broilers were allotted to 6 treatments with 6 replicates of 12 birds per replicate and administered a single oral dose of MSM at 0, 50, 100, 300, 1,000, or 2,000 mg/kg BW (Study 1). Another one hundred and sixty-eight 3-day-old chicks were allotted to either control or test group (Study 2) and administered a daily oral gavage of either 0 or 1, 500 mg/kg BW of MSM for 21 D consecutively. Blood and tissue samples were collected over a 48 h (Study 1) or 21 D (Study 2) period and analyzed for MSM concentrations. Toxicity was assessed through changes in hematology and clinical blood chemistry. In Study 1, plasma MSM concentrations were below 167 μg/mL at all time-points in birds receiving up to 300 mg/kg BW, and were significantly higher (P < 0.05) in birds receiving 1,000 or 2,000 mg/kg BW. Similarly, only the highest 2 MSM dosages elicited increased lymphocyte and decreased heterophil counts at 8 h (P < 0.003) and decreased hematocrit at 48 h (P = 0.015). Growth performance variables were unaffected by MSM in Study 2, and plasma and tissue MSM concentrations were highest on study day 21, with MSM-dosed birds always exhibiting higher (P < 0.03) concentrations compared with the control. Birds in Study 2 that were dosed with MSM had decreased liver enzyme concentrations at day 7 and 21 and decreased glucose and phosphorus at day 7. Importantly, MSM was detected in plasma and all tissues of control groups, confirming that MSM is synthesized de novo in chickens. In conclusion, oral MSM at either acute (single dose at 1,000 to 2,000 mg/kg BW) or sub-chronic (1,500 mg/kg BW daily for 21 D) concentrations did not cause any adverse effects on growth or clinical outcomes and appeared to be absorbed and distributed throughout the body.

Methylsulfonylmethane: Applications and Safety of a Novel Dietary Supplement

Methylsulfonylmethane (MSM) has become a popular dietary supplement used for a variety of purposes, including its most common use as an anti-inflammatory agent. It has been well-investigated in animal models, as well as in human clinical trials and experiments. A variety of health-specific outcome measures are improved with MSM supplementation, including inflammation, joint/muscle pain, oxidative stress, and antioxidant capacity. Initial evidence is available regarding the dose of MSM needed to provide benefit, although additional work is underway to determine the precise dose and time course of treatment needed to provide optimal benefits. As a Generally Recognized As Safe (GRAS) approved substance, MSM is well-tolerated by most individuals at dosages of up to four grams daily, with few known and mild side effects. This review provides an overview of MSM, with details regarding its common uses and applications as a dietary supplement, as well as its safety for consumption.

Hepatoprotective activity of chrysin is mediated through TNF-α in chemically-induced acute liver damage: An in vivo study and molecular modeling

Chrysin (5,7-dihydroxyflavone) is a naturally occurring flavonoid present at high levels in honey, propolis and numerous plant extracts. Chrysin is known to have hepatoprotective activity, however, the mechanisms by which it exerts this effect remain unclear. In the present study, the effects of chrysin in carbon tetrachloride (CCl₄)-induced acute liver damage were investigated and the results used to infer a possible mechanism behind chrysin's hepatoprotective activity. Prior to an intraperitoneal injection of CCl4 (1 ml/kg) to induce acute liver damage, chrysin (50 mg/kg) was administered orally to mice for 7 days. The positive control group was given 50 mg/kg standardized silymarin, a well-studied hepatoprotective flavonoid. Twenty-four h following CCl4 administration, an increase in the activity levels of serum aspartate-amino-transferase and alanine-amino-transferase was found. This was accompanied by extended centrilobular necrosis, steatosis and an altered hepatocyte ultrastructure. In addition, CCl4-induced acute hepatotoxicity was associated with an increase in hepatic tumor necrosis factor-α (TNF-α) and α-smooth muscle actin (α-SMA) protein expression, which was significantly decreased in the livers of mice pre-treated with chrysin (P<0.001), similar to the results of the silymarin pre-treated group (P<0.001). Treatment with chrysin prior to CCl4 exposure significantly reduced the activity of enzymes used as biochemical markers of poor liver function compared with the group which did not receive pre-treatment (P<0.001). In addition, the results of histopathological and electron microscopy liver examination showed chrysin pre-treatment reduced the effects of CCl4 treatment. Molecular modeling results demonstrated that the hepatoprotective activity of chrysin is mediated through TNF-α, as it reduces soluble TNF-α generation via blocking TNF-α-converting enzyme activity. In conclusion, the results of the present study suggest that inflammatory pathways are activated in CCl4-induced acute liver damage, which are ameliorated by chrysin pre-treatment. This indicates that chrysin is a potent hepatoprotective agent, similarly to silymarin at the same dose, which has the potential to be a viable alternative to conventional hepatoprotective treatments.

Methylsulfonylmethane (MSM), an organosulfur compound, is effective against obesity-induced metabolic disorders in mice

Methylsulfonylmethane (MSM), an organosulfur compound, has been used as a dietary supplement that can improve various metabolic diseases. However, the effect of MSM on obesity-linked metabolic disorders remains unclear. The goal of the current study is to determine whether MSM has beneficial effects on glucose and lipid homeostasis in obesity-associated pathophysiologic states. High-fat diet-induced obese (DIO) and genetically obese diabetic db/db mice treated with MSM (1%-5% v/v, by drinking water) were studied. Metabolic parameters involved in glucose and lipid metabolism were determined. Treatment of DIO mice with MSM leads to a significant decrease in blood glucose levels. DIO mice treated with MSM are hypersensitive to insulin, as evidenced by decreased serum insulin and an increase in the area above the curve during an ITT. Concurrently, MSM reduces hepatic triglyceride and cholesterol contents in DIO mice. These effects are accompanied by reductions in gene expression of key molecules involved in lipogenesis and inflammation. FACS analysis reveals that MSM markedly increases the frequency of B cells and decreases the frequency of myeloid cells in peripheral blood and in bone marrow. Moreover, overnutrition-induced changes of femur microarchitecture are restored by MSM. In db/db mice, a marked impairment in glucose and lipid metabolic profiles is notably ameliorated when MSM is supplemented. These data suggest that MSM has beneficial effects on multiple metabolic dysfunctions, including hyperglycemia, hyperinsulinemia, insulin resistance, and inflammation. Thus, MSM could be the therapeutic option for the treatment of obesity-related metabolic disorders such as type 2 diabetes and fatty liver diseases.

Methylsulfonylmethane inhibits NLRP3 inflammasome activation

Methylsulfonylmethane (MSM) is an organosulfur compound and the health benefits associated with MSM include inflammation. Although MSM has been shown to have various physiological effects, no study has yet focused on inflammasome activation. The inflammasome is a multiprotein complex that serves as a platform for caspase 1-dependent proteolytic maturation and secretion of interleukin-1β (IL-1β). In this study, we tested the effect of MSM on inflammasome activation using mouse and human macrophages. In our results, MSM significantly attenuated NLRP3 inflammasome activation in lipopolysaccharide-primed macrophages, although it had no effect on NLCR4 or AIM2 inflammasome activation. Extracts of MSM-enriched vegetables presented the same inhibitory effect on NLRP3 inflammasome activation as MSM. MSM also attenuated the transcriptional expression of IL-1α, IL-1β, IL-6, and NLRP3. Taken together, these results show that MSM has anti-inflammatory characteristics, interrupts NLRP3 inflammasome activation, and inhibits pro-cytokine expression. We further confirmed the intracellular mechanism of MSM in relation to NLRP3 inflammasome activation, followed by comparison with that of DMSO. Both chemicals showed a synergic effect on anti-NLRP3 activation and attenuated production of mitochondrial reactive oxygen species (ROS). Thus, MSM is a selective inhibitor of NLRP3 inflammasome activation and can be developed as a supplement to control several metabolic disorders.

Identification of a metabolic biomarker panel in rats for prediction of acute and idiosyncratic hepatotoxicity

It has been estimated that 10% of acute liver failure is due to “idiosyncratic hepatotoxicity”. The inability to identify such compounds with classical preclinical markers of hepatotoxicity has driven the need to discover a mechanism-based biomarker panel for hepatotoxicity. Seven compounds were included in this study: two overt hepatotoxicants (acetaminophen and carbon tetrachloride), two idiosyncratic hepatotoxicants (felbamate and dantrolene), and three non-hepatotoxicants (meloxicam, penicillin and metformin). Male Sprague–Dawley rats were orally gavaged with a single dose of vehicle, low dose or high dose of the compounds. At 6 h and 24 h post-dosing, blood was collected for metabolomics and clinical chemistry analyses, while organs were collected for histopathology analysis. Forty-one metabolites from previous hepatotoxicity studies were semi-quantified and were used to build models to predict hepatotoxicity. The selected metabolites were involved in various pathways, which have been noted to be linked to the underlying mechanisms of hepatotoxicity. PLS models based on all 41 metabolite or smaller subsets of 6 (6 h), 7 (24 h) and 20 (6 h and 24 h) metabolites resulted in models with an accuracy of at least 97.4% for the hold-out test set and 100% for training sets. When applied to the external test sets, the PLS models predicted that 1 of 9 rats at both 6 h and 24 h treated with idiosyncratic liver toxicants was exposed to a hepatotoxic chemical. In conclusion, the biomarker panel might provide information that along with other endpoint data (e.g., transcriptomics and proteomics) may diagnose acute and idiosyncratic hepatotoxicity in a clinical setting.

Acute enteral manganese intoxication with hepatic failure due to ingestion of a joint supplement overdose

Manganese is a ubiquitous, essential trace element and a common ingredient of joint supplement tablets. Little information is known about the inherent toxic potential if ingested at higher doses. A 5-year-old female spayed Pug dog presented for evaluation of vomiting and ataxia after accidental ingestion of approximately 100 joint supplement tablets. The dog developed acute hepatic failure and was euthanized 6 days after presentation due to progression of the disease. Necropsy showed severe acute hepatic necrosis. Liver and kidney samples were submitted for toxicology analysis, results of which showed severely elevated manganese concentrations in the liver and kidneys.

Diminution of hepatic response to 7, 12-dimethylbenz(α)anthracene by ethyl acetate fraction of Acacia catechu willd. through modulation of xenobiotic and anti-oxidative enzymes in rats

BACKGROUND

Liver is the primary metabolizing site of body and is prone to damage by exogenous as well as endogenous intoxicants. Polycyclic aromatic hydrocarbons such as 7, 12- dimethylbenz(α)anthracene (DMBA) is an exogenous hepatotoxin, which is well known for modulating phase I, II and anti-oxidative enzymes of liver. Plants contain plethora of polyphenolic compounds which can reverse the damaging effect of various xenobiotics. The present study investigated protective role of the ethyl acetate fraction of Acacia catechu Willd. (EAF) against DMBA induced alteration in hepatic metabolizing and anti-oxidative enzymes in rats.

METHODOLOGY AND PRINCIPAL FINDINGS

The rats were subjected to hepatic damage by treating with DMBA for 7 weeks on alternative days and treatment schedule was terminated at the end of 14 weeks. The rats were euthanized at the end of protocol and livers were homogenized. The liver homogenates were used to analyse phase I (NADPH-cytochrome P450 reducatse, NADH-cytochrome b5 reductase, cytochrome P420, cytochrome b5), phase II (glutathione-S-transferase, DT diaphorase and γ-Glutamyl transpeptidase) and antioxidative enzymes (catalase, superoxide dismutase, ascorbate peroxidase, glutathione reductase, guiacol peroxidase and lactate dehydrogenase). Furthermore, other oxidative stress parameters (thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes and reduced glutathione) and liver marker enzymes (serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and alkaline phosphatase) were also studied. The DMBA induced significant changes in activity of hepatic enzymes that was reversed by treatment with three dose levels of EAF.

CONCLUSION

It is concluded that EAF affords hepato-protection against DMBA in rats through modulation of phase I, II and anti-oxidative enzymes.