N-Acetyl Cysteine Has Both Gastro-Protective and Anti-Inflammatory Effects in Experimental Rat Models: Its Gastro-Protective Effect Is Related to Its In Vivo and In Vitro Antioxidant Properties.

N-acetyl cysteine (NAC), a metabolite of sulphur-containing amino acid cysteine, is used as an antioxidant and a mucolytic agent. Therefore, we aimed to investigate anti-inflammatory and anti-ulcerative effects of NAC. We also intended to determine the relation between antiulcer effect of NAC and its antioxidant properties by biochemical evaluation. In this study a total of 15 rat groups (n = 6 per group) were used for inflammation and ulcer experiments. Anti-inflammatory effects of NAC have been investigated on six rat groups with carrageenan (CAR)-induced paw oedema model. Antiulcer effects of NAC have been investigated on 24 h fasted nine rat groups with IND-induced ulcer model in the presence of positive (LAN, RAN, FAM, and OMEP), negative (untreated IND group) and intact control groups. In biochemical analyses of stomach tissues; glutathione S-transferase (GST), catalase (CAT), myeloperoxidase (MPO), and superoxide dismutase (SOD) enzyme activities and lipid peroxidation (LPO) and the glutathione (GSH) levels were determined. All doses of NAC exerted significant anti-inflammatory effect; even the effect of 900 mg/kg NAC was similar with that of DIC and IND. In gastric tissues NAC administration decreased the level of LPO and activity of CAT, which were increased by IND. Furthermore, NAC increased the GSH level and SOD and GST activities, which decreased in ulcerous stomach tissues. Only MPO activity increased in both IND and NAC groups when compared to healthy rat group. We determined that NAC has both anti-inflammatory and anti-ulcerative effects.

Gastroprotective and Antioxidant Effects of Lobaria pulmonaria and Its Metabolite Rhizonyl Alcohol on Indomethacin-Induced Gastric Ulcer.

Two lichen metabolites, rhizonaldehyde (1) and rhizonyl alcohol (2), were isolated from the acetone extract of Lobaria pulmonaria by chromatographic methods, and their chemical structures were determined by UV/VIS, IR, and 1D- and 2D-NMR spectroscopic methods. The gastroprotective and in vivo antioxidant activities of extracts of L. pulmonaria and its metabolites, 1 and 2, were investigated in indomethacin-induced ulcer models in rats. The gastric lesions were significantly reduced by acetone, hexane, and CHCl3 extracts, with 75.3-41.5% inhibition. Rhizonyl alcohol (2) significantly reduced the gastric lesions with an inhibition rate of 84.6-42.8%, whereas rhizonaldehyde (1) significantly increased the gastric lesions. Antioxidant parameters and myeloperoxidase activities were also evaluated in the gastric tissues of the rats. Indomethacin caused oxidative stress, which resulted in lipid peroxidation in gastric tissues by decreasing the levels of the antioxidants as compared to healthy rat tissues. In contrast to indomethacin, all extracts and rhizonyl alcohol (2) caused a significant decrease in lipid peroxidation levels and an increase in antioxidant parameters, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase, and reduced glutathione in gastric tissues. The administration of rhizonyl alcohol (2) also resulted in a decrease in gastric myeloperoxidase activity increased by indomethacin. The gastroprotective effect of rhizonyl alcohol (2) can be attributed to its antioxidant properties and its suppressing effect on neutrophil infiltration into gastric tissues.

Alpha-lipoic acid protects against indomethacin-induced gastric oxidative toxicity by modulating antioxidant system.

Gastroprotective effects of α-lipoic acid (ALA) against oxidative gastric damage induced by indomethacin (IND) have been investigated. All doses (50, 75, 100, 150, 200, and 300 mg/kg body weight) of ALA reduced the ulcer index with 88.2% to 96.1% inhibition ratio. In biochemical analyses of stomach tissues, ALA administration decreased the level of lipid peroxidation (LPO) and activities of myeloperoxidase (MPO) and catalase (CAT) in gastric tissues, which were increased after IND application. ALA also increased the level of glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) that were decreased in gastric damaged stomach tissues. In conclusion, the gastroprotective effect of ALA could be attributed to its ameliorating effect on the antioxidant defense systems.

Anti-inflammatory and antinociceptive effects of salbutamol on acute and chronic models of inflammation in rats: involvement of an antioxidant mechanism.

The possible role of ß-2 adrenergic receptors in modulation of inflammatory and nociceptive conditions suggests that the ß-2 adrenergic receptor agonist, salbutamol, may have beneficial anti-inflammatory and analgesic effects. Therefore, in this study, we induced inflammatory and nociceptive responses with carrageenan-induced paw edema or cotton-pellet-induced granuloma models, both of which result in oxidative stress. We hypothesized that salbutamol would prevent inflammatory and nociceptive responses by stimulating ß-2 adrenergic receptors and the prevention of generation of ROS during the acute inflammation process in rats. Both doses of salbutamol used in the study (1 and 2 mg/kg) effectively blocked the acute inflammation and inflammatory nociception induced by carrageenan. In the cotton-pellet-induced granuloma test, both doses of salbutamol also significantly decreased the weight of granuloma tissue on the cotton pellets when compared to the control. Anti-inflammatory and analgesic effects of salbutamol were found to be comparable with those of indomethacin. Salbutamol decreased myeloperoxidase (MPO) activity and lipid peroxidation (LPO) level and increased the activity of superoxide dismutase (SOD) and level of glutathione (GSH) during the acute phase of inflammation. In conclusion, salbutamol can decrease acute and chronic inflammation, possibly through the stimulation of ß-2 adrenergic receptors. This anti-inflammatory effect may be of significance in asthma treatment, where inflammation also takes part in the etiopathology. This study reveals that salbutamol has significant antioxidative effects, which at least partially explain its anti-inflammatory capabilities. These findings presented here may also shed light on the roles of ß-2 adrenergic receptors in inflammatory and hyperalgesic conditions.

The effects of montelukast on antioxidant enzymes and proinflammatory cytokines on the heart, liver, lungs, and kidneys in a rat model of cecal ligation and puncture-induced sepsis.

We investigated the potential protective effects of montelukast (MLK) on cecal ligation and puncture (CLP)-induced tissue injury in vital organs - liver, heart, kidneys, and especially lungs - through inhibition of the proinflammatory cytokine response and the generation of reactive oxygen species (ROS) in rats. The rat groups were (1) a 10-mg/kg MLK-treated CLP group; (2) a 20-mg/kg MLK-treated CLP group; (3) a 20-mg/kg MLK-treated, sham-operated group; (4) a CLP control group; and (5) a sham-operated control group. MLK treatment significantly decreased proinflammatory (tumor necrosis factor-alpha, interleukin-6) cytokine levels following CLP. The lipid peroxide level increased in the lung, heart, liver, and kidney tissues after CLP-induced sepsis, and myeloperoxidase activity increased in the lung, heart, and liver tissues. MLK attenuated this elevation in all tissues except the kidney, dose dependently. The glutathione levels and superoxide dismutase activity were significantly increased in the lung, liver, and kidney tissues after MLK treatment. MLK treatment after CLP also potentially reduced mortality. The lung and kidney tissues were the most protected by MLK under sepsis conditions. We can suggest that MLK reverses the systemic inflammatory reaction to polymicrobial sepsis and thereby reduces multiple organ failure.

Growth hormone reduces tissue damage in rat ovaries subjected to torsion and detorsion: biochemical and histopathologic evaluation.

OBJECTIVE: To evaluate the effects of growth hormone (GH) as an antioxidant and tissue-protective agent and analyse the biochemical and histopathological changes in rat ovaries due to experimental ischemia and ischemia/reperfusion injury. STUDY DESIGN: Forty-eight adult female rats were randomly divided into eight groups. In Group 1, a period of bilateral ovarian ischemia was applied. In Groups 2 and 3, 1 and 2 mg/kg of GH was administered, and 30 min later, bilateral ovarian ischemia was applied (after a 3-h period of ischemia, both ovaries were surgically removed). Group 4 received a 3-h period of ischemia followed by 3h of reperfusion. Groups 5 and 6 received 1 and 2 mg/kg of GH, respectively, 2.5 h after the induction of ischemia. At the end of a 3-h period of ischemia, bilateral vascular clips were removed, and 3h of reperfusion continued. Group 7 received a sham operation plus 2mg/kg of GH. Group 8 received a sham operation only. After the experiments, superoxide dismutase and myeloperoxidase activity and levels of glutathione and lipid peroxidation were determined, and histopathological changes were examined in all rat ovarian tissue. RESULTS: Ischemia and ischemia/reperfusion decreased superoxide dismutase activity and glutathione levels in ovarian tissue, but increased lipid peroxidation levels and myeloperoxidase activity significantly in comparison to the sham group. The 1 and 2 mg/kg doses of GH before ischemia and ischemia/reperfusion decreased lipid peroxidation levels and myeloperoxidase activity in the experimental groups. The administration of GH before ischemia and ischemia/reperfusion treatments also increased superoxide dismutase and glutathione levels. The histopathological findings also suggested a protective role of GH in ischemia/reperfusion injury. That is, ovarian tissues in the ischemia groups showed histopathological changes, such as haemorrhage, cell degeneration, and necrotic and apoptotic cells, but these changes in the GH groups were lesser. Moreover, in the ischemia/reperfusion groups, acute inflammatory processes--such as neutrophil adhesion and migration, apoptotic and degenerative cells, stromal oedema and haemorrhage--were present. However, the ovarian tissues of the IR+GH (1 mg) group had minimal apoptotic cells, and the IR+GH (2 mg) group had no apoptotic cells. In addition, the general ovarian histological structures of these groups were similar to those of the healthy control group. CONCLUSIONS: The administration of GH is protective against ischemia and/or ischemia/reperfusion-induced ovarian damage. This protective effect can be attributed to the antioxidant properties of GH.

α-Lipoic acid has anti-inflammatory and anti-oxidative properties: an experimental study in rats with carrageenan-induced acute and cotton pellet-induced chronic inflammations.

α-Lipoic acid (ALA) has been termed the 'ideal' antioxidant, a readily absorbed and bioavailable compound capable of scavenging a number of free radicals, and it has been used for treating diseases in which oxidative stress plays a major role. The present study was designed to gain a better understanding for the positive effects of ALA on the models of acute and chronic inflammation in rats, and also determine its anti-oxidative potency. In an acute model, three doses of ALA (50, 100 and 200 mg/kg) and one dose of indomethacin (25 mg/kg) or diclofenac (25 mg/kg) were administered to rats by oral administration. The paw volumes of the animals were calculated plethysmometrically, and 0·1 ml of 1 % carrageenan (CAR) was injected into the hind paw of each animal 1 h after oral drug administration. The change in paw volume was detected as five replicates every 60 min by plethysmometry. In particular, we investigated the activities of catalase, superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), inducible NO synthase (iNOS) and myeloperoxidase (MPx), and the amounts of lipid peroxidation (LPO) or total GSH in the paw tissues of CAR-injected rats. We showed that ALA exhibited anti-inflammatory effects on both acute and chronic inflammations, and a strongly anti-oxidative potency on linoleic acid oxidation. Moreover, the administration of CAR induced oedema in the paws. ALA significantly inhibited the ability of CAR to induce: (1) the degree of acute inflammation, (2) the rise in MPx activity, (3) the increases of GST and iNOS activities and the amount of LPO and (4) the decreases of GPx, GR and SOD activities and the amount of GSH. In conclusion, these results suggest that the anti-inflammatory properties of ALA, which has a strong anti-oxidative potency, could be related to its positive effects on the antioxidant system in a variety of tissues in rats.

Beneficial effects of vegetable oils (corn, olive and sunflower oils) and alpha-tocopherol on anti-inflammatory and gastrointestinal profiles of indomethacin in rats.

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin are widely used in the treatment of inflammation, fever and pain. However, NSAIDs cause gastric damage as a major adverse reaction. In this study, the effects of vegetable oils (corn, olive and sunflower oils) and alpha-tocopherol on anti-inflammatory and gastrointestinal profiles of indomethacin were evaluated in rats. Results showed that indomethacin given with sunflower, corn and olive oils reduced paw edema induced by carrageenan by 79.5%, 74.0% and 60.5%, whereas individual indomethacin and diclofenac reduced paw edema by 56.2% and 50.7%, respectively. Furthermore, it has been found that the vegetable oils possess significant anti-inflammatory effect against paw edema when given alone. These results showed that the vegetable oils have beneficial effects on reduction paw edema induced by carrageenan. Besides, the administration of indomethacin together with the vegetable oils and alpha-tocopherol did not cause a statistically significant gastric damage in rats (P>0.05). However, indomethacin caused statistically significant gastric lesions as compared with untreated rats (P<0.05). Moreover, it was also found that the effects of the vegetable oils and alpha-tocopherol improved the levels of antioxidant defense systems in rat stomach tissues against oxidative damage. These results suggest that indomethacin as well as other NSAIDs do not have any adverse effect on the gastrointestinal tract when they are used together with vegetable oils and vitamin E or as the preparations of the oils.