The protective effect of muscimol against systemic inflammatory response in endotoxemic mice is independent of GABAergic and cholinergic receptors.

Systemic inflammatory response syndrome plays an important role in the development of sepsis. GABAergic and cholinergic pathways activation are considered important for inflammatory response regulation. Tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-12, IL-10, as well as inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) are important inflammatory mediators involved in the pathogenesis of sepsis. Muscimol, an active compound from the mushroom Amanita muscaria (L.) Lam., is a potent GABAA agonist, inhibits inflammatory response via activating GABAA receptor and vagus nerve. However, the effect of muscimol on lipopolysaccharide (LPS)-induced systemic inflammatory response is still unclear. Therefore, we studied the effects of muscimol on systemic inflammatory response and survival rate in endotoxemic mice. Mice endotoxemia was induced by LPS. Muscimol was given to mice or RAW264.7 cells 30 min before LPS (10 mg/kg, i.p., or 10 ng/mL, respectively). Mice received GABAergic and cholinergic receptor antagonists 30 min before muscimol and LPS. Muscimol decreased TNF-α, IL-1ß, IL-12, iNOS-derived NO, and increased IL-10 levels and survival rate after LPS treatment. Muscimol significantly decreased nuclear factor kappa B (NF-κB) activity, increased IκB expression, and decreased pIKK expression in LPS-treated RAW264.7 cells. GABAergic and cholinergic antagonists failed to reverse muscimol's protection in LPS-treated mice. In conclusion, muscimol protected against systemic inflammatory response in endotoxemic mice may be partially independent of GABAergic and cholinergic receptors.

Physical and psychological stress along with candle fumes induced-cardiopulmonary injury mimicking restaurant kitchen workers.

Restaurant kitchens are work areas where involve strict and hierarchal environments that promote opportunity for bullying and workplace aggression and violence. These physical and psychological stress and fumes ultimately trigger severe occupational stress by disrupting the body's homeostasis that might induce cardiopulmonary injury. The study aimed to investigate the physical and psychological stress and candle fumes on cardiopulmonary injury in an animal model mimicking a restaurant kitchen worker. Social disruption stress (SDR) mice were exposed to scented candle fumes (4.5 h/d, 5 d/wk) in an exposure chamber for 8 weeks. Exposure to burning scented candles failed to reduce serum corticosterone level and increased proinflammatory cytokines levels and NF-ƙB activity in the lung. In addition, burning scented candle fumes synergistically increased SDR-induced serum LDH, CPK, CKMB levels, proinflammatory cytokines production as well as NF-ƙB activation in the lung and heart. Further, cardiac HIF-1α and BNP levels were also increased. We conclude that the physical and psychological stress along with candle fumes might induce cardiopulmonary injury in mice. These results could be extrapolated to restaurant kitchen workers.

Beneficial effect of sesame oil on heavy metal toxicity.

Heavy metals become toxic when they are not metabolized by the body and accumulate in the soft tissue. Chelation therapy is mainly for the management of heavy metal-induced toxicity; however, it usually causes adverse effects or completely blocks the vital function of the particular metal chelated. Much attention has been paid to the development of chelating agents from natural sources to counteract lead- and iron-induced hepatic and renal damage. Sesame oil (a natural edible oil) and sesamol (an active antioxidant) are potently beneficial for treating lead- and iron-induced hepatic and renal toxicity and have no adverse effects. Sesame oil and sesamol significantly inhibit iron-induced lipid peroxidation by inhibiting the xanthine oxidase, nitric oxide, superoxide anion, and hydroxyl radical generation. In addition, sesame oil is a potent inhibitor of proinflammatory mediators, and it attenuates lead-induced hepatic damage by inhibiting nitric oxide, tumor necrosis factor-α, and interleukin-1ß levels. Because metal chelating therapy is associated with adverse effects, treating heavy metal toxicity in addition with sesame oil and sesamol may be better alternatives. This review deals with the possible use and beneficial effects of sesame oil and sesamol during heavy metal toxicity treatment.

Sesame oil accelerates healing of 2,4,6-trinitrobenzenesulfonic acid-induced acute colitis by attenuating inflammation and fibrosis.

BACKGROUND: Sesame oil is a component of traditional health food in Asian countries. Acute colitis is a form of inflammatory bowel disease (IBD) with chronic inflammatory disorder of the bowel. The precise etiology of IBD remains unknown, but it is believed that an abnormal host response to endogenous antigens causes initial tissue injury with amplification of the immune response. We investigated the protective effect of sesame oil against 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced acute colitis in rats. METHODS: Rats were intracolonically instilled with TNBS (120 mg/kg) using a cannula to induce colitis and then orally gavaged with sesame oil (4 mL/kg for 7 days) to attenuate TNBS-induced acute colitis. The acute colitis activity index (ACAI) was assessed using the colon weight/length ratio (mg/cm), thickness, extension of lesion, diarrhea, and macroscopic and microscopic damage scores. In addition, the degree of inflammation, mucins, and fibrosis was assessed by measuring mast cells, CD68(+) cells, neutral mucin, acidic mucin, collagen, and laminin on day 8 after inducing acute colitis. RESULTS: All tested parameters except neutral mucins were significantly higher in TNBS-induced acute colitis. Sesame oil significantly decreased the degree of inflammation, fibrosis, and acidic mucin and increased neutral mucin. CONCLUSION: We conclude that sesame oil accelerates the healing of an inflamed colon by inhibiting inflammation, acidic mucin, and fibrosis in TNBS-induced acute colitis in rats.

Role of flavin-containing-monooxygenase-dependent neutrophil activation in thioacetamide-induced hepatic inflammation in rats.

Thioacetamide is widely used in industry and is known to be one of the most potent hepatotoxicants in experimental animals. We investigated the involvement of flavin-containing monooxygenase (FMO)-dependent hepatic-neutrophil activation and the release of proinflammatory mediators in thioacetamide-induced hepatic injury in rats. Thioacetamide (100 mg/kg, intraperitoneally) increased, within 12 h, hepatic serum aspartate transferase and alanine transferase levels, tumor necrosis factor-α production, interleukin-1ß and nitrite levels, and myeloperoxidase activity. Rabbit anti-neutrophil serum markedly inhibited all thioacetamide-altered parameters. In addition, FMO-competitive inhibitor methimazole reduced thioacetamide-induced myeloperoxidase activity, hepatic tumor necrosis factor-α, interleukin-1ß, nitrite, inducible nitric oxide synthase, and hepatic damage in thioacetamide-treated rats. Thus, we conclude that FMO-dependent hepatic neutrophil activation initiates the release of proinflammatory mediators in thioacetamide-treated rats.

Therapeutic sesamol attenuates monocrotaline-induced sinusoidal obstruction syndrome in rats by inhibiting matrix metalloproteinase-9.

We investigated the therapeutic effect of sesamol against monocrotaline-induced sinusoidal obstruction syndrome (SOS) in rats. Male Sprague-Dawley rats were gavaged with a single dose of monocrotaline (90 mg/kg) to induce SOS. Sesamol (5, 10, 20, and 40 mg/kg) was subcutaneously injected 24 h after monocrotaline treatment. Control rats were given saline only. Aspartate transaminase, alanine transaminase, mast cells, CD 68(+) Kupffer cells, neutrophils, myeloperoxidase, matrix metalloproteinase-9 (MMP-9), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), laminin, and collagen were assessed 48 h after monocrotaline treatment. All tested parameters, except for TIMP-1, laminin, and collagen, were significantly higher in monocrotaline-treated rats than in control rats, and, except for TIMP-1, laminin, and collagen, significantly lower in sesamol-treated rats than in monocrotaline-treated rats. In addition, liver pathology revealed that sesamol offered significant protection against SOS. We conclude that a single dose of sesamol therapeutically attenuated SOS by decreasing the recruitment of inflammatory cells, downregulating MMP-9, and upregulating TIMP-1 expression.

Anti-hepatotoxic effects of 3,4-methylenedioxyphenol and N-acetylcysteine in acutely acetaminophen-overdosed mice.

3,4-Methylenedioxyphenol (sesamol) is effective against acetaminophen-induced liver injury in rats. Whether sesamol's anti-hepatotoxic effect is comparable to that of N-acetylcysteine has never been studied. We investigated the anti-hepatotoxic effects of sesamol and N-acetylcysteine on acetaminophen-induced hepatotoxicity in mice. Equimolar doses (1 mmol/kg) of sesamol and N-acetylcysteine significantly inhibited acetaminophen (300 mg/kg)-increased serum aspartate transaminase and alanine transaminase levels 6 h post-administration. Sesamol and N-acetylcysteine maintained hepatic glutathione levels and inhibited lipid peroxidation. Moreover, the combination of sesamol and N-acetylcysteine antagonistically inhibited sesamol's protection against acetaminophen-induced liver injury. We conclude that the protective effect of sesamol against acetaminophen-induced liver damage is comparable to that of N-acetylcysteine by maintaining glutathione levels and inhibiting lipid peroxidation in mice.

17ß-Estradiol protects against acetaminophen-overdose-induced acute oxidative hepatic damage and increases the survival rate in mice.

Acetaminophen overdose causes acute liver injury or even death in both humans and experimental animals. We investigated the effect of 17ß-estradiol against acetaminophen-induced acute liver injury and mortality in mice. Male mice were given acetaminophen (p-acetamidophenol; 300 mg/kg; orally) to induce acute liver injury. Acetaminophen significantly increased the levels of aspartate transaminase, alanine transaminase, myeloperoxidase, lipid peroxidation, and glutathione reductase, but it decreased superoxide dismutase, catalase, and glutathione. In addition, acetaminophen-induced mortality began 4h post-treatment, and all mice died within 9h. 17ß-Estradiol (200 µg/kg; i.p.) protected against acetaminophen-induced oxidative hepatic damage by inhibiting neutrophil infiltration and stimulating the antioxidant defense system. However, 17ß-estradiol did not affect acetaminophen-induced glutathione depletion or increased glutathione reductase activity. We conclude that 17ß-estradiol specifically attenuates acute hepatic damage and decreases mortality in acetaminophen-overdosed male mice.

Effects of sesame oil against after the onset of acetaminophen-induced acute hepatic injury in rats.

BACKGROUND: Acetaminophen (APAP) is a safe and effective analgesic and antipyretic when used at therapeutic levels. However, an acute or cumulative overdose can cause severe liver injury with the potential to progress to liver failure in humans and experimental animals. Much attention has been paid to the development of an antioxidant that protects against APAP-induced acute hepatic injury. Hence, we aimed to investigate the effect of sesame oil against after the onset of acute hepatic injury in APAP-overdosed rats. METHODS: Male Wistar rats were first given 2 oral doses (1,000 mg/kg each) of APAP (at 0 and 24 hours) and then 1 oral dose of sesame oil (8 mL/kg at 24 hours). RESULTS: After 48 hours, APAP increased aspartate and alanine aminotransferase levels in the rats' serum and centrilobular necrosis in liver tissue. In addition, APAP significantly decreased the rats' glutathione levels and mitochondrial aconitase activity, but increased superoxide anion, hydroxyl radical, and lipid peroxidation levels. Oral sesame oil (8 mL/kg, given at 24 hours) reversed all APAP-altered parameters and protected the rats against APAP-induced acute liver injury. CONCLUSION: We hypothesize that sesame oil acts as a useful agent that maintains intracellular glutathione levels and inhibits reactive oxygen species, thereby protecting rats against after the onset of APAP-induced acute oxidative liver injury.

The protective effect of sesamol against mitochondrial oxidative stress and hepatic injury in acetaminophen-overdosed rats.

An acetaminophen (APAP) overdose induces oxidative stress and acute hepatic injury or even death. We investigated the prophylactic effect of sesamol (SM) on mitochondrial oxidative stress, hydroxyl-radical-generated lipid peroxidation, and hepatic injury in APAP-overdosed rats. Six male Wistar rats (APAP group) were given only oral APAP (1,000 mg/kg) to induce mitochondrial oxidative-stress-associated hepatic injury, and another six (ASM group) were given the same dose of oral APAP, and then, immediately afterward, were injected with SM (10 mg/kg, i.p.), to assess its prophylactic effects. In the APAP group, APAP had significantly increased the levels of 1) serum aspartate transaminase and alanine transaminase, 2) centrilobular necrosis, 3) ferrous ions, 4) hydrogen peroxide, 5) hydroxyl radicals, and 6) lipid peroxidation, and decreased 7) mitochondrial aconitase activity in the rats' liver tissue 24 h later. In the ASM group, SM had prevented significant rises in the levels of 1) to 6) and a significant decrease (7). Therefore, we hypothesize that the protective effect of SM in APAP-overdosed rats is associated with maintaining the mitochondrial aconitase activity, ferrous ions (Fe2+), and hydrogen peroxide levels and inhibiting hydroxyl-radical-associated lipid peroxidation and hepatic injury.

Effect of sesame oil against acetaminophen-induced acute oxidative hepatic damage in rats.

Acetaminophen (APAP) overdose causes acute liver injury or even death in both humans and experimental animals. We investigated the effect of sesame oil on APAP-induced acute liver injury. Male Wistar rats were given APAP (1,000 mg/kg; orally) to induce acute liver injury. Acetaminophen significantly increased aspartate transaminase, alanine transaminase, lipid peroxidation, and superoxide anion and hydroxyl radical generation levels; it also induced glutathione depletion. Sesame oil (8 mL/kg; orally) did not alter the gastric absorption of APAP, but it inhibited all the parameters altered by APAP and protected the rats against APAP-induced acute liver injury. We hypothesize that sesame oil maintained the intracellular glutathione levels, reduced reactive oxygen species levels, and inhibited lipid peroxidation in rats with APAP-induced acute liver injury.