Collagen type II solution extracted from supercritical carbon dioxide decellularized porcine cartilage: regenerative efficacy on post-traumatic osteoarthritis model

Osteoarthritis (OA) of the knee is a common degenerative articular disorder and is one of the main causes of pain and functional disability. Cartilage damage is frequently linked to elevated osteoarthritis incidence. Supercritical carbon dioxide (scCO2) decellularized cartilage graft produced from the porcine cartilage is an ideal candidate for cartilage tissue engineering. In the present study, we derived collagen type II (Col II) solution from the scCO2 decellularized porcine cartilage graft (dPCG) and compared its efficacy with hyaluronic acid (HA) in the surgical medial meniscectomy (MNX) induced post-traumatic osteoarthritis (PTOA) model. Dose-dependent attenuation of the OA (12.3 ± 0.8) progression was observed in the intra-articular administration of Col II solution (7.3 ± 1.2) which significantly decreased the MNX-induced OA symptoms similar to HA. The pain of the OA group (37.4 ± 2.7) was attenuated dose-dependently by Col II solution (45.9 ± 4.1) similar to HA (43.1 ± 3.5) as evaluated by a capacitance meter. Micro-CT depicted a dose-dependent attenuation of articular cartilage damage by the Col II solution similar to HA treatment. A significant (p < 0.001) dose-dependent elevation in the bone volume was also observed in Col II solution-treated OA animals. The protective competence of Col II solution on articular cartilage damage is due to its significant (p < 0.001) increase in the expression of type II collagen, aggrecan and SOX-9 similar to HA. To conclude, intra-articular administration of type II collagen solution and HA reestablished the injured cartilage and decreased osteoarthritis progression in the experimental PTOA model.

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)-1β, 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 GABA_A agonist, inhibits inflammatory response via activating GABA_A 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-1β, 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.

Supercritical carbon dioxide decellularized porcine cartilage graft with PRP attenuated OA progression and regenerated articular cartilage in ACLT-induced OA rats

Knee osteoarthritis (OA) is a common degenerative articular disorder and considered one of the primary causes of pain and functional disability. Knee OA is prevalent in 10% of men and 13% of women aged 60 years above. The study aims to use cartilage tissue engineering that combines the triads of decellularized porcine cartilage graft as "scaffold," plasma rich platelet (PRP) as "signal" and chondrocytes from rat as "cell" to attenuate ACLT-induced OA progression and regenerate the knee cartilage in rats. Decellularization of the porcine cartilage was characterized by hematoxylin and eosin, 4,6-Diamidino-2-phenylindole staining, scanning electron microscopy and residual DNA quantification. The protective effect of decellularized porcine cartilage graft (dPCG) was evaluated by intra-articular administration in surgically induced anterior cruciate ligament transection (ACLT) rat osteoarthritis (OA) model. Supercritical carbon dioxide technology completely decellularized the porcine cartilage. Intra-articular administration of dPCG with or without PRP significantly reduced the ACLT-induced OA symptoms and attenuated the OA progression. Pain-relief by dPCG with or without PRP was assessed by capacitance meter and improved articular cartilage damage in the rat knee was characterized by X-ray and micro-CT. Besides, the histological analysis depicted cartilage protection by dPCG with or without PRP. The repairation and attenuation effect by dPCG with or without PRP in the articular knee cartilage damage were also explored by safranin-O, type II collagen, aggrecan and SOX-9 immuno-staining. To conclude, intra-articular administration of dPCG with or without PRP is efficient in repairing the damaged cartilage in the experimental OA model.

Curative effect of sesame oil in a rat model of chronic kidney disease

AIM

Chronic kidney disease causes a progressive and irreversible loss of renal function. We investigated the curative effect of sesame oil, a natural, nutrient-rich, potent antioxidant, in a rat model of chronic kidney disease.

METHODS

Chronic kidney disease was induced by subcutaneously injecting uni-nephrectomized rats with deoxycorticosterone acetate (DOCA) and 1% NaCl [DOCA/salt] in drinking water. Four weeks later, the rats were gavaged with sesame oil (0.5 or 1 mL/kg per day) for 7 days. Renal injury, histopathological changes, hydroxyl radical, peroxynitrite, lipid peroxidation, Nrf2, osteopontin expression, and collagen were assessed 24 h after the last dose of sesame oil.

RESULTS

Blood urea nitrogen, creatinine, urine volume, and albuminuria were significantly higher in the DOCA/salt treated rats than in control rats. Sesame oil significantly decreased these four tested parameters in DOCA/salt treated rats. In addition, creatinine clearance rate and nuclear Nrf2 expression were significantly decreased in the DOCA/salt treated rats compared to control rats. Sesame oil significantly decreased hydroxyl radical, peroxynitrite level, lipid peroxidation, osteopontin, and renal collagen deposition, but increased creatinine clearance rate and nuclear Nrf2 expression in DOCA/salt treated rats.

CONCLUSION

We conclude that supplementation of sesame oil mitigates DOCA/salt induced chronic kidney disease in rats by activating Nrf2 and attenuating osteopontin expression and inhibiting renal fibrosis in rats.

1,4-Butanediol diglycidyl ether-cross-linked hyaluronan inhibits fibrosis in rat primary tenocytes by down-regulating autophagy modulation

Epidural fibrosis, an inevitable part of the postoperative healing process, is one of the important causes of failed back surgery syndrome after spinal surgery. The aim of this study was to examine the inhibitory effect of a novel material 1,4-butanediol diglycidyl ether-cross-linked hyaluronan (cHA) on fibrosis in primary tenocytes. cHA inhibited migration, cell proliferation, and suppressed the expression of fibronectin, but not transforming growth factor-β, in primary tenocytes. cHA significantly increased matrix metalloproteinase-3 but decreased collagen-1 and microtubule-associated protein light chain 3-II expression in a dose-dependent manner compared with control groups. We therefore concluded that suppressing autophagy activity may be involved in the anti-fibrotic effect of cHA in primary tenocytes. Further, cHA may have the potential for preventing epidural fibrosis and subsequent failed back syndrome in patients with laminectomy in the future.

Enteral sesame oil therapeutically relieves disease severity in rat experimental osteoarthritis

Background

Osteoarthritis (OA) is the most common cause of joint pain, affecting approximately 15% of the population. Recent studies indicate that quadriceps muscle weakness is directly involved in the pathogenesis of OA-associated joint pain. Oxidative stress plays an important role in skeletal muscle dysfunction. Sesame oil is a natural product with excellent antioxidative property. However, whether sesame oil can decrease OA-induced joint pain has never been investigated.

Objective

The aim of the present study was to examine the effect of sesame oil on OA-induced joint pain in rats.

Design

OA-associated joint pain in rats was induced by medial meniscal transection in rats. Sesame oil (0, 1, 2, or 4 ml/kg/day, orally) was given to rats 7 days after OA induction, while the parameters were determined 7 days after sesame oil administration.

Results

Daily sesame oil treatment for 7 days significantly decreased OA-associated joint pain. Sesame oil decreased muscular interleukin-6 and increased citrate synthase activity and myosin heavy chain IIa mRNA expression. Furthermore, sesame oil decreased muscular lipid peroxidation, nuclear Nrf2 protein expression, and reactive oxygen species generations as well as increased glutathione production and glutathione peroxidase activity in OA rats.

Conclusions

Sesame oil may relieve OA-associated joint pain by inhibiting quadriceps muscular oxidative stress, at least partially, in rats.

Sesamol ameliorates hypotension by modulating cytokines and PPAR-gamma in systemic inflammatory response

Sepsis is one of the major causes of death reported in intensive care units. Acute kidney injury (AKI) and hypotension are important in the pathogenesis and mortality of systemic inflammatory response (SIR). Sesamol delays mortality in sepsis; however, its effects on AKI and hypotension and the role of peroxisome proliferator-activated receptor-ɣ (PPAR-γ) activation have not been established. We investigated the effect of sesamol on SIR in cecal ligation and puncture (CLP)-induced acute kidney injury and lipopolysaccharide (LPS)-induced hypotension in rats. Sesamol was subcutaneously injected 1 h after SIR. Renal function (BUN and CRE) and proinflammatory mediators interleukin (IL)-1β and IL-6 were increased after CLP. Tumor necrosis factor (TNF)-α, IL-1β, IL-10, and nitrite production were significantly increased 6 h after LPS-induced hypotension (mean arterial pressure was significantly decreased). Sesamol significantly inhibited BUN, CRE, IL-1β, IL-6, and nitrite after CLP-induced acute renal injury. In addition, sesamol increased mean arterial pressure and IL-10, inhibited TNF-α and IL-1β, but did not affect nitrite production in LPS-induced hypotension. Sesamol increased PPAR-γ in the leucocytes and peritoneal macrophages in LPS-induced SIR. We conclude that sesamol regulates leucocyte and macrophage PPAR-γ-associated systemic cytokines expression, thereby ameliorates acute kidney injury and hypotension in rats.

Daily sesame oil supplement attenuates joint pain by inhibiting muscular oxidative stress in osteoarthritis rat model

Osteoarthritis (OA) is the most common form of arthritis, affecting approximately 15% of the population. The aim of this study was to evaluate the efficacy of sesame oil in controlling OA pain in rats. Rat joint pain was induced by medial meniscal transection in Sprague-Dawley rats and assessed by using hindlimb weight distribution method. Muscular oxidative stress was assessed by determining lipid peroxidation, reactive oxygen species and circulating antioxidants. Sesame oil significantly decreased joint pain compared with positive control group in a dose-dependent manner. Sesame oil decreased lipid peroxidation in muscle but not in serum. Further, sesame oil significantly decreased muscular superoxide anion and peroxynitrite generations but increased muscular glutathione and glutathione peroxidase levels. Further, sesame oil significantly increased nuclear factor erythroid-2-related factor (Nrf2) expression compared with positive control group. We concluded that daily sesame oil supplement may attenuate early joint pain by inhibiting Nrf2-associated muscular oxidative stress in OA rat model.

Oxidative stress participates in quadriceps muscle dysfunction during the initiation of osteoarthritis in rats

Osteoarthritis is the most common form of arthritis, affecting approximately 15% of the population. Quadriceps muscle weakness is one of the risk factors of osteoarthritis development. Oxidative stress has been reported to play an important role in the pathogenesis of various muscle dysfunction; however, whether it is involved in osteoarthritis-associated quadriceps muscle weakness has never been investigated. The aim of the present study is to examine the involvement of oxidative stress in quadriceps muscle dysfunction in the initiation of osteoarthritis in rats. Rat osteoarthritis was initiated by conducting meniscectomy (MNX). Quadriceps muscle dysfunction was evaluated by assessing muscular interleukin-6, citrate synthase activity, and myosin heavy chain IIa mRNA expression levels. Muscular oxidative stress was assessed by determining lipid peroxidation, Nrf2 expression, reactive oxygen species, and circulating antioxidants. Increased muscular interleukin-6 production as well as decreased citrate synthase activity and myosin heavy chain IIa mRNA expression were observed at 7 and 14 days after MNX. Biomarkers of oxidative stress were significantly increased after MNX. Muscular free radical counts were increased while glutathione and glutathione peroxidase expression were decreased in MNX-treated rats. We conclude that oxidative stress may be involved in the pathogenesis of muscle dysfunction in MNX-induced osteoarthritis.

Sleep deprivation-induced multi-organ injury: role of oxidative stress and inflammation

Sleep deprivation affects all aspects of health. Adverse health effects by sleep deviation are still underestimated and undervalued in clinical practice and, to a much greater extent in monitoring human health. We hypothesized that sleep deprivation-induced mild organ injuries; oxidative stress and inflammation might play a crucial role in inducing multi-organ injury. Male C57BL/6J mice (n = 6-7) were sleep-deprived for 0-72 h using a modified multiple platform boxes method. Blood and tissue were collected. Liver, heart, kidney, lung, and pancreatic injuries were evaluated using biochemical and histological analyses. Glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), total billirubin (TBIL), creatine phosphokinase (CPK), creatine phosphokinase-myocardial band (CKMB), lactic dehydrogenase (LDH), creatinine (CRE), and blood urea nitrogen (BUN) were assayed in blood. Malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 levels were measured. Histology revealed mild-to-moderate liver and lung injury in sleep-deprived mice. Sleep-deprived mice had significantly higher GOT, GPT, TBIL, CPK, CKMB, LDH, BUN, and α-amylase (AMYL) levels, which indicated liver, heart, kidney, and pancreatic injuries. Serum IL-1β at 24 h and IL-6 at 72 h were significantly higher in sleep-deprived than in control mice. Hepatic TNF-α and IL-1β were significantly higher, but IL-6 significantly lower in mice that had been sleep-deprived for 72 h. Sleep deprivation-mediated inflammation may be associated with mild to moderate multi-organ damage in mice. The implication of this study indicates sleep deprivation in humans may induce multi-organ injury that negatively affects cardiovascular and gastrointestinal health.

Therapeutic effects of sesame oil on monosodium urate crystal-induced acute inflammatory response in rats

Sesame oil has been used in traditional Taiwanese medicine to relieve the inflammatory pain in people with joint inflammation, toothache, scrapes, and cuts. However, scientific evidence related to the effectiveness or action mechanism of sesame oil on relief of pain and inflammation has not been examined experimentally. Here, we investigated the therapeutic effect of sesame oil on monosodium urate monohydrate (MSU) crystal-induced acute inflammatory response in rats. Air pouch, a pseudosynovial cavity, was established by injecting 24 mL of filtered sterile air subcutaneously in the backs of the rats. At day 0, inflammation in air pouch was induced by injecting MSU crystal (5 mg/rat, suspended in sterilized phosphate buffered saline, pH 7.4), while sesame oil (0, 1, 2, or 4 mL/kg, orally) was given 6 h after MSU crystal injection. Parameters in lavage and skin tissue from the air pouches were assessed 6 h after sesame oil was given. Sesame oil decreased MSU crystal-induced total cell counts, tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 levels in lavage and pouch tissue. Sesame oil significantly decreased leukocyte and neutrophil counts in lavage compared with MSU crystal alone group. Sesame oil decreased activated mast cell counts in skin tissue in MSU crystal-treated rats. Sesame oil significantly decreased nuclear factor (NF)-κB activity and IL-4 level in isolated mast cells from rats treated with MSU crystal. Furthermore, sesame oil decreased lavage complement proteins C3a and C5a levels in MSU crystal-treated rats. In conclusion, sesame oil shows a potent therapeutic effect against MSU crystal-induced acute inflammatory response in rats.

Sesame oil mitigates nutritional steatohepatitis via attenuation of oxidative stress and inflammation: a tale of two-hit hypothesis

Nonalcoholic fatty liver disease, the most common chronic liver disorder worldwide, comprises conditions from steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. NASH is associated with an increased risk of hepatocellular carcinoma. Sesame oil, a healthful food, increases resistance to oxidative stress, inflammation and protects against multiple organ injury in various animal models. We investigated the protective effect of sesame oil against nutritional steatohepatitis in mice. C57BL/6 J mice were fed with methionine-choline deficient (MCD) diet for 28 days to induce NASH. Sesame oil (1 and 2 ml/kg) was treated from 22nd to 28th day. Body weight, steatosis, triglycerides, aspartate transaminase, alanine transaminase, nitric oxide, malondialdehyde, tumor necrosis factor-α, interlukin-6, interleukin-1β, leptin, and transforming growth factor-β1 (TGF-β1) were assessed after 28 days. All tested parameters were higher in MCD-fed mice than in normal control mice. Mice fed with MCD diet for 4 weeks showed severe liver injury with steatosis, oxidative stress, and necrotic inflammation. In sesame-oil-treated mice, all tested parameters were significantly attenuated compared with MCD-alone mice. Sesame oil inhibited oxidative stress, inflammatory cytokines, leptin, and TGF-β1 in MCD-fed mice. In addition, histological analysis showed that sesame oil provided significant protection against fibrotic collagen. We conclude that sesame oil protects against steatohepatitic fibrosis by decreasing oxidative stress, inflammatory cytokines, leptin and TGF-β1.

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-1β 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.

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.

Ostensibly ineffectual doses of cadmium and lipopolysaccharide causes liver damage in rats

Various hepatotoxicants co-treated with lipopolysaccharide (LPS) have the potential to cause severe hepatic damage. Whether co-treatment with ostensibly ineffectual (without effect on customary clinical liver function tests, such as aspartate aminotransferase and alanine aminotransferase) doses of cadmium (Cd) and LPS cause liver damage is still unknown. We examined the effects of treating ostensibly ineffectual doses of Cd and LPS on liver dysfunction as well as on liver histopathology. We injected rats with saline only, Cd only, LPS only, or a single ostensibly ineffectual dose of Cd (100 μg/kg body weight) plus LPS (0.1 mg/kg body weight). After 6 h, the rats were killed and their liver damage was assessed. Co-treated with ostensibly ineffectual doses of Cd and LPS had higher levels of aspartate aminotransferase and alanine aminotransferase, hepatic lipid peroxidation, peroxynitrite, nitrite, and interleukin-1β (IL-1β), but lower levels of hepatic metallothionein (MT) than did that treated with saline only, Cd only, and LPS only. Histopathological analysis of Cd only and LPS only showed apparent liver damage, but Cd plus LPS showed marked hepatic damage. We conclude that co-treating the rats with ostensibly ineffectual doses of Cd and LPS is hepatotoxic. Cd promotes LPS-initiated oxidative-stress-associated liver damage by increasing IL-1β and decreasing MT levels in rats.

Roles of histamine receptors and oxyradicals in aggravation of acid-induced gastric haemorrhagic ulcers in endotoxaemic rats

We clarified the roles of histamine H(1)-, H(2)-, H(3)-receptors and oxyradicals in the exacerbation of acid-induced gastric haemorrhage and stomach ulcer in endotoxaemic rats by measuring changes in gastric mucosal glutathione concentrations, lipid peroxide generation and histamine levels as well as in luminal electrolytes and haemoglobin contents. Stomach ulcers were evaluated by morphological and histological examination. Rats were deprived of food for 24 h, and challenged intravenously with lipopolysaccharide (LPS, 3 mg/kg) at 0, 12, 18 and 24 h after withdrawal of food. Control rats received saline only. Gastric truncal vagotomy was performed and followed by irrigation for 3 h with an acid solution containing 100 mmol/L HC1 and 54 mmol/L NaCl. The augmentation of mucosal permeability to electrolytes (acid back-diffusion), haemoglobin contents and lipid peroxide levels as well as the lowered mucosal glutathione concentrations were dependent on the duration of LPS intoxication. Serious damage of corpus mucosal cells was observed in acid-perfused stomachs of LPS rats. Intraperitoneal diphenhydramine, an H(1)-receptor antagonist, or ranitidine, an H(2)-receptor blocker, caused dose-dependent inhibition of these ulcerogenic factors. Antioxidants, including ascorbate and sodium benzoate, also were effective in inhibition. Moreover, intraperitoneal R-(alpha)-methylhistamine, an H(3)-receptor agonist, produced elimination, while thioperamide, an H(3)-receptor antagonist, and exogenous histamine elevated mucosal histamine concentrations and haemorrhagic ulcers in LPS rats. It is concluded that gastric haemorrhage and stomach ulcers produced by acid solution in LPS-treated rats are modulated by oxyradicals and histamine H(1)-, H(2)- and H(3)-receptors.

Sesame oil accelerates kidney healing following gentamicin-induced kidney injury in rats

BACKGROUND/AIMS

We investigated the therapeutic effect of a single dose of sesame oil against gentamicin-induced renal damage in rats.

METHODS

Experimental rats were subcutaneously injected with gentamicin (100 mg/kg/day for 7 days) to induce renal injury. Sesame oil (1, 2 or 4 ml/kg) was given orally 24 h after the last dose of gentamicin. Control rats were treated with saline only. Renal injury, histopathological examination, histochemical staining, osteopontin expression, superoxide anion, nitric oxide, peroxynitrite radical and lipid peroxidation were assessed 24 h after sesame oil administration.

RESULTS

Serum blood urea nitrogen and creatinine as well as renal osteopontin expression, superoxide anion, nitric oxide, peroxynitrite radical and lipid peroxidation levels were higher in gentamicin-treated rats than in control rats. Sesame oil significantly decreased all the tested parameters compared with gentamicin-alone rats. Furthermore, histopathological and histochemical staining showed that renal tubules had recovered and regenerated in the sesame oil-treated rats.

CONCLUSION

We hypothesize that a single dose of sesame oil inhibits oxidative stress to shorten the recovery period and allow the regeneration of renal tubules after the onset of gentamicin-induced renal injury in rats.

Sesamol down-regulates the lipopolysaccharide-induced inflammatory response by inhibiting nuclear factor-kappa B activation

We examined the effects of sesamol on the lipopolysaccharide (LPS)-induced inflammatory response. Sesamol inhibited serum tumor necrosis factor (TNF)-α, interleukin (IL)-1β and nitrite production in LPS-treated mice, and inhibited LPS-induced inducible nitric oxide synthase expression in mouse leukocytes. Sesamol also down-regulated TNF-α, IL-1β, and nitrite production as well as inducible nitric oxide synthase expression in LPS-treated RAW 264.7 cells. Further, sesamol inhibited LPS-induced nuclear factor (NF)-κB translocation and inhibitor (I)κB-α phosphorylation in RAW 264.7 cells. By inhibiting TNF-α, IL-1β, and nitrite levels, and interfering with the NFκB pathway, sesamol down-regulated the LPS-initiated inflammatory response.

The non-peptide chemical 3,4-methylenedioxyphenol blocked lipopolysaccharide (LPS) from binding to LPS-binding protein and inhibited pro-inflammatory cytokines

After binding to lipopolysaccharide (LPS)-binding protein, LPS is transferred to CD14 and then to the MD2—Toll-like receptor 4 complex, which results in the progression of sepsis. We investigated how 3,4-methylenedioxyphenol (sesamol), an inexpensive natural product in sesame seeds, affects the binding of LPS and LPS-binding protein and the release of pro-inflammatory cytokines. Sesamol: (i) dose-dependently inhibited LPS from binding to LPS binding protein; (ii) significantly decreased the release of tumor necrosis factor-α and interleukin-1β in LPS-challenged peritoneal macrophages in medium and in the serum of LPS-challenged rats; and (iii) significantly reduced the mortality rate in mice given a lethal dose of LPS. We hypothesize that sesamol blocks LPS from binding to LPS-binding protein and inhibits the release of pro-inflammatory cytokines, both of which are associated with a decrease of mortality in endotoxemia.

Effect of sesame oil on acidified ethanol-induced gastric mucosal injury in rats

BACKGROUND

Exposure of gastric mucosa to concentrated ethanol induces acute gastritis. Gastric mucosal lipid peroxidation plays a significant role in the pathogenesis of ethanol-induced gastric mucosal lesions. The aim of this study was to investigate the effect of sesame oil on acidified ethanol-induced gastric mucosal damage in rats.

METHODS

We performed gastric bilateral vagotomy in rats. A small incision on forestomach was made and stomach content was expelled. Normal artificial gastric acid (54 mM NaCl plus 100 mM HCl) or acidified ethanol (30% ethanol plus 150 mM HCl) was instilled into the stomach. Gastric lipid peroxidation, glutathione, and nitric oxide levels were measured 3 hours after acidified ethanol administration.

RESULTS

Acidified ethanol caused mucosal ulceration, luminal hemorrhage, lipid peroxidation, and a lower level of mucosal glutathione and nitric oxide production. Pretreatment of sesame oil, but not mineral oil, significantly decreased acidified ethanol-induced mucosal ulcer formation and luminal hemorrhage. Sesame oil reduced mucosal lipid peroxidation, as well as glutathione and nitric oxide production in acidified ethanol-treated stomachs. Furthermore, both sesame oil and mineral oil did not affect serum ethanol concentration in acidified ethanol-treated rats.

CONCLUSION

Sesame oil attenuates acidified ethanol-induced gastric mucosal injury by reducing oxidative stress in rats.

Sesame oil does not show accumulatively enhanced protection against oxidative stress-associated hepatic injury in septic rats

BACKGROUND

Sepsis is one of the major causes of death reported in intensive care units. A daily supplement of sesame oil for 1 week significantly attenuates oxidative stress-associated hepatic injury in septic rats. However, the excess intake of sesame oil may be associated with a health risk. This study investigates the effect of accumulative sesame oil on oxidative stress-associated hepatic injury after cecal ligation and puncture in rats.

METHODS

Sesame oil was administered daily (4 mL/kg/d, orally) to rats, and the total intake of sesame oil ranged from 0 (control) to 140 mL/kg before cecal ligation and puncture in 9 groups of rats. Oxidative stress was examined by determining the levels of lipid peroxidation and glutathione. Hepatic injury was evaluated by measuring serum levels of aspartate aminotransferase and alkaline phosphatase.

RESULTS

Rats that received sesame oil for 4 and 5 weeks had a lower body weight gain compared with those that received saline. Lipid peroxidation was decreased in the 20-mL/kg and 28-mL/kg groups, but it was increased in the 140-mL/kg group compared with the control group. Glutathione levels were increased in the < or =28-mL/kg groups compared with the control group. Serum levels of aspartate aminotransferase and alkaline phosphatase were reduced in the < or =28-mL/kg groups compared with the control group.

CONCLUSION

Sesame oil does not demonstrate accumulatively enhanced protection against oxidative stress-associated hepatic injury after cecal ligation and puncture in rats.

The prophylactic protective effect of sesamol against ferric-nitrilotriacetate-induced acute renal injury in mice

The aim of this study was to examine the prophylactic protective effects of 3,4-methylenedioxyphenol (sesamol) on ferric-nitrilotriacetate (Fe-NTA)-induced acute renal damage in mice. We induced acute renal injury in mice by treating them with 4 mg/kg of Fe-NTA for 3h. We used blood biochemistry, creatinine clearance, and histological examinations to assess renal function. With a high-performance chemiluminescence analyzer, we also determined the hydroxyl radical and superoxide anion levels (free radicals) generated. Renal xanthine oxidase activities were also assessed. Sesamol inhibited Fe-NTA-induced acute renal injury, renal lipid peroxidation, the levels of renal hydroxyl radical and superoxide anion generated, and the activity of xanthine oxidase in mice. Therefore, we concluded that sesamol protected mice against Fe-NTA-induced oxidative-stress-associated acute renal injury by at least partially inhibiting the production of reactive oxygen species.

THE EFFECT OF SESAMOL ON SYSTEMIC OXIDATIVE STRESS AND HEPATIC DYSFUNCTION IN ACUTELY IRON-INTOXICATED MICE

This study investigated the effect of sesamol (3,4-methylenedioxyphenol) on systemic oxidative stress and hepatic function in acutely iron-intoxicated mice. Sesamol reduced the levels of lipid peroxidation, hydroxyl radical, iron production and superoxide anion generation, and xanthine oxidase activity in iron-intoxicated mice. In addition, sesamol decreased the serum levels of aspartate aminotransferase and alanine aminotransferase, and ameliorated iron-intoxication-induced histological changes in the liver. In summary, sesamol might attenuate systemic oxidative stress by reducing xanthine oxidase and improving hepatic function in iron-intoxicated mice.

SESAME OIL PROTECTS AGAINST LEAD-PLUS-LIPOPOLYSACCHARIDE-INDUCED ACUTE HEPATIC INJURY

Lead (Pb) increases lipopolysaccharide (LPS)-induced tumor necrosis factor alpha, which causes liver damage. In this study, we investigated the effect of sesame oil on Pb-plus-LPS (Pb + LPS)-induced acute liver damage in mice. Mice were given sesame oil (8 mL/kg orally) just after Pb acetate (10 mmol/kg i.p.) plus LPS (5 mg/kg i.p.). Aspartate aminotransferase, alanine aminotransferase, tumor necrosis factor-alpha, interleukin-1beta, nitric oxide, and inducible nitric oxide synthase levels were examined. Sesame oil significantly decreased serum aspartate aminotransferase and alanine aminotransferase levels in Pb + LPS-stimulated mice. Sesame oil reduced Pb + LPS-induced tumor necrosis factor-alpha, interleukin-1beta, and nitric oxide production in serum and liver tissue. Furthermore, sesame oil decreased inducible nitric oxide synthase expression in leukocytes and liver tissue in Pb + LPS-treated mice. We hypothesize that the inhibition of proinflammatory cytokines and nitric oxide might be involved in sesame oil-associated protection against Pb + LPS-induced acute hepatic injury in mice.

SESAME OIL ATTENUATES CISPLATIN-INDUCED HEPATIC AND RENAL INJURIES BY INHIBITING NITRIC OXIDE-ASSOCIATED LIPID PEROXIDATION IN MICE

Although cisplatin (cis-diamminedichloroplatinum) is an effective drug for the treatment of several solid tumors and has been used therapeutically for decades, several cisplatin-induced side effects have limited its therapeutic dosage in clinical studies. Our aim was to examine the effect of sesame oil on cisplatin-induced hepatic and renal injuries in mice (8-week-old female SPF C57BL/6) given subcutaneous cisplatin (0, 5, 10, or 20 mg/kg). Hepatic and renal functions, lipid peroxidation (LPO) levels, and reactive oxygen free radicals were evaluated 3 days after cisplatin administration, and tumor volumes were recorded 0, 3, 6, and 9 days after cisplatin administration. Sesame oil (i) potently attenuated cisplatin-associated hepatic and renal injuries; (ii) decreased cisplatin-initiated LPO as well as the production of hydroxyl radical, peroxynitrite, and nitrite in blood and tissue; and (iii) did not affect the antitumor capacity exerted by cisplatin in mice with melanoma. We suggest that sesame oil attenuates cisplatin-induced hepatic and renal damage by at least partially inhibiting nitric oxide-associated LPO in mice. Sesame oil might be a new approach for preventing cisplatin-induced multiple organ injury during the treatment of tumors.

SESAME OIL ATTENUATES ACUTE IRON-INDUCED LIPID PEROXIDATION-ASSOCIATED HEPATIC DAMAGE IN MICE

Acute iron intoxication from the accidental ingestion of iron-containing preparations is one important cause of death in children. The aim of this study was to investigate the protective effect of sesame oil on acute iron-induced lipid peroxidation (LPO) and hepatic injury in mice. Acute iron intoxication was induced by giving ferric nitrilotriacetate to mice. Hepatic function was assessed using blood biochemistry. Free radicals were determined using a high-performance chemiluminescence analyzer. Ferric nitrilotriacetate increased serum ferrous (Fe) and LPO levels, and induced acute hepatic injury. Sesame oil (a) dose-dependently decreased acute iron-induced LPO and hepatic injury, (b) reduced acute iron-associated hydroxyl radical and superoxide anion generation, and (c) inhibited the activity of xanthine oxidase in acute iron intoxication. Thus, sesame oil might ameliorate LPO and acute hepatic injury by inhibiting xanthine oxidase-initiated superoxide anion generation, thereby reducing hydroxyl radical production, at least partially, in acutely iron-intoxicated mice.

Sesamol delays mortality and attenuates hepatic injury after cecal ligation and puncture in rats: role of oxidative stress

Sesame oil potently protects rats against sepsis, and sesamol appears to be the protective ingredient in sesame oil. The aims of the present study were to examine the effects of sesamol on mortality and reactive oxygen species-associated liver injury in Wistar rats with cecal-ligation-and-puncture-induced sepsis (septic rats). After sepsis was induced, sesamol was administered every 6 h. The survival rate was determined during the ensuing 48 h. Hepatic injury was assessed using blood biochemistry and histological examination. Hepatic oxidative stress was assessed by determining the levels of liver lipid peroxidation, hydroxyl radical, and superoxide anion generation, and nitric oxide production 12 h after cecal ligation and puncture. Inducible nitric oxide synthase expression was also determined. Sesamol delayed mortality and attenuated hepatic injury in septic rats. Hepatic lipid peroxidation, hydroxyl radical, and superoxide anion levels were significantly lower in sesamol-treated septic rats. Furthermore, sesamol inhibited the production of nitrite and the expression of inducible nitric oxide synthase in the liver in septic rats. Therefore, sesamol may delay mortality and attenuate oxidative stress-associated liver injury by inhibiting the production of nitric oxide, at least partially, in septic rats.

ATTENUATION OF ENDOTOXIN-INDUCED OXIDATIVE STRESS AND MULTIPLE ORGAN INJURY BY 3,4-METHYLENEDIOXYPHENOL IN RATS

Endotoxin is a potent inducer of lipid peroxidation (LPO), which is associated with the development of endotoxemia. 3,4-Methylenedioxyphenol (sesamol) is one of the sesame oil lignans with a high anti-LPO effect. Whether sesamol can attenuate endotoxin-induced LPO and multiple organ injury is unknown. After a dose response for sesamol in endotoxin-challenged rats was established, experiments were conducted to assess its effects on hydroxyl radical, peroxynitrite, and superoxide anion counts, activities of superoxide dismutase, catalase, and glutathione peroxidase, as well as the production of nitric oxide (NO) and the expression of inducible NO synthase. In addition, the effects of sesamol on endotoxin-induced hepatic and renal injuries were assessed. Sesamol (a) dose dependently reduced serum LPO inendotoxin-challenged rats, (b) decreased hydroxyl radical and peroxynitrite, but not superoxide anion counts, (c)increased the activities of superoxide dismutase, catalase, and glutathione peroxidase in endotoxin-treated rats, (d)reduced NO production and inducible NO synthase expression, and (e) attenuated hepatic and renal injuries induced by endotoxin in rats. We concluded that sesamol might protect against organ injury by decreasing NO-associated LPO in endotoxemic rats.

Effects of topical sesame oil on oxidative stress in rats

OBJECTIVE

To assess the effects of topical sesame oil on systemic oxidative stress in rats.

DESIGN

Oxidative stress was induced with lipopolysaccharide and assessed by determining serum lipid peroxidation, superoxide anion, and hydroxyl radical levels. The levels of 3 circulating antioxidants--superoxide dismutase, catalase, and glutathione--also were determined.

RESULTS

Topical sesame oil significantly reduced lipid peroxidation, superoxide anion, and hydroxyl radical levels after lipopolysaccharide administration. However, sesame oil did not affect the 3 circulating antioxidants. Further, sesame oil decreased the activity of xanthine oxidase and nitric oxide production in lipopolysaccharide-treated rats.

CONCLUSION

Sesame oil given topically might attenuate oxidative stress by inhibiting the production of xanthine oxidase and nitric oxide in rats.

EFFECT OF SESAME OIL ON OXIDATIVE-STRESS-ASSOCIATED RENAL INJURY IN ENDOTOXEMIC RATS: INVOLVEMENT OF NITRIC OXIDE AND PROINFLAMMATORY CYTOKINES

This study aimed to investigate the effect of sesame oil on oxidative stress-associated renal injury induced by lipopolysaccharide in rats. The effects of sesame oil on renal injury, oxidative stress, hydroxyl radical, superoxide anion, nitric oxide, and proinflammatory cytokines were assessed after a lipopolysaccharide challenge. Sesame oil attenuated lipopolysaccharide-induced renal injury, decreased lipid peroxidation, increased the activities of superoxide dismutase, catalase, and glutathione peroxidase, reduced hydroxyl radical generation and nitric oxide production, and had no effect on superoxide anion generation in lipopolysaccharide-challenged rats. In addition, sesame oil significantly decreased tumor necrosis factor-alpha and interleukin 1beta production 1 and 6 h, respectively, after lipopolysaccharide administration in mice. Thus, sesame oil attenuates oxidative stress-associated renal injury via reduction of the production of nitric oxide and the generation of proinflammatory cytokines in endotoxemic rats.

Epinephrine protects against severe acute gastric bleeding in rats: role of nitric oxide and glutathione

The aim of this study was to examine the effect of the systemic administration of epinephrine against severe acute gastric bleeding in rats. Epinephrine decreased gastric hemorrhage not only before but also after lipopolysaccharide-induced severe acute gastric bleeding. Epinephrine ameliorated severe gastric hemorrhage and decreased gastric mucosal lipid peroxidation through alpha- and beta-adrenoceptors. Epinephrine modulated alpha-adrenoceptors to increase the levels of gastric mucosal nitric oxide and glutathione. Nitric oxide synthase inhibitors potently reversed the effects of epinephrine on gastric mucosal glutathione. Thus, epinephrine might act through alpha-adrenoceptors to increase the levels of gastric mucosal nitric oxide and glutathione and thus protect against severe acute gastric bleeding in rats.

EFFECTS OF SESAME OIL ON OXIDATIVE STRESS AFTER THE ONSET OF SEPSIS IN RATS

The aim of this study was to investigate effects of sesame oil on oxidative stress after the onset of sepsis in rats. Effects of sesame oil on lipid peroxidation, superoxide anion, superoxide dismutase, catalase, glutathione, and nitrite after the onset of endotoxin intoxication were determined. To further examine the protective effect of sesame oil on sepsis, a mortality study was also conduced in cecal ligation and puncture-induced sepsis in rats. Sesame oil was given orally 6 h after endotoxin administration and cecal ligation and puncture, and parameters were then measured in another 6 h. Data demonstrated that a single dose of sesame oil reduced lipid peroxidation 6 h after endotoxin intoxication. Superoxide anion counts were decreased, glutathione levels were increased, and activities of superoxide dismutase and catalase, as well as nitrite levels, were not altered in lipopolysaccharide plus sesame oil-treated groups compared with lipopolysaccharide-treated groups. Furthermore, sesame oil given 6 h after cecal ligation and puncture significantly increased survival rate. Thus, we suggested that sesame oil could be used as a potent antioxidant to reduce oxidative stress after the onset of sepsis in rats.

Involvement of nitric oxide in gastric protection of epinephrine in endotoxin intoxication in rats

Reduction in blood pressure may cause gastric mucosal hypoxia and injury during endotoxin intoxication. Epinephrine is found to increase gastric mucosal perfusion while managing hypotension. Nitric oxide plays an important role in regulating gastric mucosal perfusion and maintaining gastric integrity. The aim of this study was to investigate the involvement of nitric oxide in the gastric protection of epinephrine by determining gastric mucosal lipid peroxidation, ulceration, and hemorrhage levels in endotoxin intoxication in rats. Epinephrine significantly increased gastric mucosal nitrite levels, decreased gastric mucosal lipid peroxidation levels, and ameliorated gastric ulceration and hemorrhage in endotoxin-treated rats. Furthermore, nitric oxide synthase inhibitors potently reversed the effects of epinephrine on gastric mucosa in endotoxin-treated rats. It was suggested that nitric oxide might be involved in the protective effect of epinephrine on gastric mucosal injury in endotoxin intoxication in rats.

BICUCULLINE METHIODIDE ATTENUATES HEPATIC INJURY AND DECREASES MORTALITY IN SEPTIC RATS: ROLE OF CYTOKINES

Bicuculline methiodide attenuates inflammation by inhibiting the production of proinflammatory cytokines, such as tumor necrosis factor-alpha, and by increasing the production of the anti-inflammatory cytokine interleukin-10, both of which play important roles in the pathogenesis of sepsis. The aim of this study was to examine the effects of bicuculline methiodide on sepsis in the cecal ligation and puncture septic-rat model. Cytokine production was measured by enzyme-linked immunosorbent assay. Oxidative stress was assessed by determining serum lipid peroxidation and nitrite levels. Hepatic injury was evaluated by determining the levels of serum aspartate aminotransferase, alkaline phosphatase, and total bilirubin. Mortality was recorded within 24 h. Bicuculline methiodide potently decreased the production of tumor necrosis factor-alpha and interleukin-1beta but increased interleukin-10 in serum. Bicuculline methiodide significantly decreased serum lipid peroxidation and nitrite levels. Further, bicuculline methiodide attenuated hepatic injury and reduced mortality after cecal ligation and puncture. Therefore, the alteration of cytokine production may be involved in the effects of bicuculline methiodide on hepatic injury and mortality in septic rats.

Effect of GABAA receptor antagonist bicuculline methiodide on hypotension in endotoxin-intoxicated rats

Gamma-aminobutyric acid (GABA) receptor plays an important regulatory role in human and animal blood pressure; however, whether a GABAergic mechanism is involved in endotoxin intoxication-associated hypotension has never been reported. In vivo effect of the GABA(A) receptor antagonist bicuculline methiodide (BMI) on mean arterial pressure (MAP), heart rate (HR), and serum nitrite levels were investigated in endotoxin (lipopolysaccharide; LPS)-treated rats. BMI increased MAP and decreased HR in LPS-stimulated rats. DOAV ([deamino-Pen, O-Me-Tyr, Arg3]-vasopressin), an arginine vasopressin (AVP) antagonist, reversed the hemodynamic improvement resulted from BMI in LPS-intoxicated rats. Based on a two-factor (BMI treatment by LPS dose) factorial design, BMI reduced the serum nitrite production induced by LPS. DOAV plus BMI, however, did not affect the serum nitrite level in LPS-intoxicated rats. Thus, GABA receptor antagonist BMI might attenuate hypotension in endotoxin intoxication in rats.

EFFECTS OF SESAME OIL ON OXIDATIVE STRESS AND HEPATIC INJURY AFTER CECAL LIGATION AND PUNCTURE IN RATS

Oxidative stress is known to be involved in the development of organ failure and death in sepsis. Sesame oil attenuates oxidative stress induced by endotoxin; however, whether sesame oil is still effective in rats with sepsis has never been investigated. The aim of the present study was to determine the effect of sesame oil on oxidative stress-associated hepatic injury in cecal ligation and puncture-induced rats with sepsis. We examined the effect of sesame oil (4 mL/kg daily for 1 week) on lipid peroxidation, hydroxyl radical, superoxide anion, and nitrite levels in rats with sepsis. In addition, hepatic injury was also assessed by blood biochemistry. Sesame oil significantly decreased lipid peroxidation and serum nitrite levels, but affected neither superoxide anion nor hydroxyl radical in cecal ligation and puncture-treated rats. Furthermore, sesame oil significantly attenuated cecal ligation and puncture-induced hepatic injury in rats. Nevertheless, oxidative stress and hepatic injury were not affected by corn oil or mineral oil in rats with sepsis. Thus, attenuation of oxidative stress and hepatic injury may be associated with inhibition of nitric oxide in sesame oil-associated protection in rats with sepsis.

Parenteral sesame oil attenuates oxidative stress after endotoxin intoxication in rats

Sesame oil is regarded as a daily nutritional supplement to increase cell resistance to lipid peroxidation. The aims of this study were to examine the effects of parenteral sesame oil on oxidative stress and hepatic disorder induced by lipopolysaccharide and to determine the defense mechanisms involved in sesame oil-associated anti-oxidative effects in rats. Oxidative stress was induced by lipopolysaccharide (5 mg/kg, intraperitoneally) and assessed by determination of lipid peroxidation. Sesame oil (8 ml/kg, subcutaneously) was given 3 h after lipopolysaccharide, and lipid peroxide levels, hydroxyl radical, superoxide anion, the enzyme activities of superoxide dismutase and catalase as well as the levels of glutathione and nitrite were examined 6 h after lipopolysaccharide. Hepatic function was assessed by determining the activities of serum aspartate aminotransferase and alkaline phosphatase. Sesame oil reduced lipid peroxidation and hydroxyl radical, but failed to affect superoxide anion. Superoxide dismutase and catalase were increased, but glutathione was not affected, and the levels of nitrite were reduced. Further, sesame oil-treated groups showed attenuated hepatic disorder in lipopolysaccharide-treated rats. Thus, parenteral sesame oil can be used to attenuate oxidative stress and relieve hepatic disorder after lipopolysaccharide intoxication in rats.

Sesame oil protects against lipopolysaccharide-stimulated oxidative stress in rats

OBJECTIVE

The aim of this study was to determine the effects and the defense mechanisms of sesame oil on lipopolysaccharide-induced oxidative stress in rats.

DESIGN

Laboratory in vivo study of the effect of sesame oil on lipid peroxide, superoxide anion, superoxide dismutase, catalase, glutathione, and nitrite concentrations. To assess the effect of sesame oil on hepatic function, we determined serum aspartate aminotransferase, total bilirubin, and liver histology.

SETTING

University laboratory.

SUBJECTS

Male SPF Wistar rats.

INTERVENTIONS

Blood testing, administration of oils, and liver biopsies.

MEASUREMENTS AND MAIN RESULTS

Oxidative stress induced by lipopolysaccharide (5 mg/kg, intraperitoneally) was assessed by determination of lipid peroxidation. Sesame oil was given orally immediately after lipopolysaccharide administration, and lipid peroxidation concentrations were determined. The reactive oxygen species superoxide anion was measured by chemiluminescence analyzer. The enzyme activities of superoxide dismutase and catalase and the concentrations of glutathione and nitrite also were determined. Hepatic injury was evaluated by determining the concentrations of serum aspartate aminotransferase and total bilirubin and by liver histologic examination. Sesame oil significantly reduced lipid peroxidation but failed to affect nitrite concentrations in lipopolysaccharide-treated rats. Superoxide anion counts were decreased, and glutathione, but not superoxide dismutase or catalase, was increased in sesame oil-treated groups with lipopolysaccharide-induced oxidative stress. Only sesame oil-treated groups, but not corn oil- or mineral oil-treated groups, showed attenuated hepatic disorder induced by lipopolysaccharide. In addition, sesame oil given 6 hrs after lipopolysaccharide also attenuated lipid peroxidation and hepatic disorder. Furthermore, sesame oil given immediately or 6 hrs after lipopolysaccharide administration significantly reduced morphologic changes induced by lipopolysaccharide.

CONCLUSION

A single dose of sesame oil may attenuate oxidative stress and subsequently relieve hepatic disorder in endotoxemic rats.

The elucidation of epinephrine as an antihypotensive agent in abamectin intoxication

Abamectin (ABM) has been used in some suicidal attempt cases in recent years. ABM-intoxicated patients demonstrate low mean arterial pressure (MAP) and commonly treated with catecholamine to burst MAPs in their intensive cares. This investigation examined roles of epinephrine on MAP, heart rate (HR), and therein baroreflex sensitivity (BRS = HR/MAP) during ABM intoxication in rats. Oral application of ABM (20 mg/kg) induced an increase in HR and BRS accompanied by a decrease in MAP. These effects, except for on BRS, were abolished by concomitant epinephrine injection [100 microg/ kg, subcutaneously (s.c.)]. ABM also induced an increase in serum nitric oxide levels, which was partly antagonized by epinephrine. In summary, oral application of ABM induced a decrease in MAP. Administration of epinephrine sustained the normal range of MAP via nitric oxide regulation, but it has no effect on BRS due to the synchronous changes of MAP and HR in ABM-intoxicated rats.

Abamectin attenuates gastric mucosal damage induced by ethanol through activation of vagus nerve in rats

Some type A gamma-aminobutyric acid (GABA(A)) receptor agonists are effective in protecting against the formation of stomach lesions induced by ethanol. Natural product abamectin, one of the existing GABA(A) receptor agonists, might protect against the development of gastric ulcers induced by ethanol. We investigated the protective effect of abamectin against the formation of gastric mucosal lesions induced by ethanol in rats. Abamectin (3 mg/kg, p.o.) was given to rats 1 h before administration of ethanol [4 ml of a 30% (volume/volume) solution]. Mucosal lipid peroxidation (LPO), nitric oxide (NO) levels, and ulcer index were measured 3 h after gastric surgery (vagotomy vs. sham vagotomy) in treated versus control subjects. Abamectin attenuated ethanol-induced gastric ulceration, decreased LPO regeneration, and increased NO production in the gastric mucosa of rats in the sham vagotomy group. However, this protective effect of abamectin against ethanol-induced gastric lesions was not observed in rats in the group that underwent vagotomy. These results support the suggestion that administration of abamectin ameliorated the ethanol-induced gastric mucosal injury through elevation of NO production. Activation of the vagus nerve may be involved in the abamectin-associated gastric protection against the effects of ethanol in rats.

Sesame oil attenuates multiple organ failure and increases survival rate during endotoxemia in rats

OBJECTIVE

To investigate the effects and the possible mechanism of sesame oil on multiple organ failure induced by lipopolysaccharide in rats.

DESIGN

Laboratory in vivo study of the effects of sesame oil on serum aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, total bilirubin, blood urea nitrogen, creatinine, lipid peroxide, and nitric oxide concentrations. To assess the effect of sesame oil on xanthine oxidase, serum uric acid was measured. Furthermore, lipid peroxide concentrations in liver and kidney were determined.

SETTING

University laboratory.

SUBJECTS

Male Wistar rats.

INTERVENTIONS

Blood testing.

MEASUREMENT AND MAIN RESULTS

Serum aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, total bilirubin, blood urea nitrogen, creatinine, and uric acid concentrations were determined. Lipid peroxide was analyzed by using a commercial kit. Nitric oxide production was estimated by Griess reaction. Sesame oil ameliorated hepatic and renal damage in a dose-dependent manner and increased animal survival in lipopolysaccharide-treated rats. Sesame oil decreased lipid peroxide concentration in serum but not in liver and kidney. Serum nitrite production was unaffected by sesame oil ingestion. Furthermore, the activity of xanthine oxidase was reduced by sesame oil in lipopolysaccharide-challenged rats.

CONCLUSION

Sesame oil ameliorated multiple organ failure and mortality via its inhibition of xanthine oxidase in lipopolysaccharide-dosed rats. Xanthine oxidase may play a critical role in sesame oil-associated organ protection during endotoxemia in rats.

Abamectin effects on aspartate aminotransferase and nitric oxide in rats

Abamectin is widely used as an insecticide and an anthelmintic. A previous report indicated that abamectin was used to commit suicide and led to death in Taiwan. This investigation focused on the toxicological effects of abamectin on serum aspartate aminotransferase (AST) and nitrate/nitrite (NO) levels in rats. After rats were gavaged with abamectin ranging from 1 to 20 mg/kg/body weight, AST and NO levels were examined within 12 h. AST and NO levels were elevated in abamectin-dosed rats in a dose-dependent manner. The least increase of AST corresponded to the highest enhancement of NO release at 6 h. A negative correlation coefficient (r=-0.55) between AST and NO was found. Both NG-nitro-L-arginine-methyl ester and aminoguanidine, inhibitors of nitric oxide synthase, increased the AST level induced by abamectin. These findings suggest that NO may be involved in the alteration of AST release induced by abamectin in rats.