Protective Effect Of Misoprostol Research Articles

The Protective Effect of Misoprostol on Dextran Sodium Sulphate-Induced Ulcerative Colitis Model in Rats

The Protective Effect of Misoprostol on Dextran Sodium Sulphate-Induced Ulcerative Colitis Model in Rats

The protective effect of misoprostol against doxorubicin induced liver injury

ABSTRACTWe investigated the potential hepatoprotective effects of misoprostol (MP) on doxorubicin (DOX) induced liver injury in rats using histology and biochemistry. We used 21 male Sprague-Dawley rats divided randomly into three groups: group 1, control; group 2, DOX; group 3, DOX + MP. The control group was injected intraperitoneally (i.p.) with 0.5 ml 0.9% w/v NaCl and given 1 ml 0.9% NaCl orally for 6 days. DOX was administered i.p. as a single dose of 20 mg/kg. MP, 0.2 mg/kg, was given orally for 6 days. Treatment with MP increased high density lipoprotein cholesterol levels and decreased serum alanine aminotransferase, aspartate aminotransferase, low density lipoprotein cholesterol, triglycerides and total cholesterol levels significantly in serum. Increased malondialdehyde level and decreased catalase, glutathione and superoxide dismutase levels caused by DOX were suppressed significantly in liver tissue by MP. DOX + MP reduced loss of body weight. Oxidative stress was decreased, antioxidant activity was increased and histopathological changes were reduced in the DOX + MP group compared to the DOX group. Liver injury caused by DOX was attenuated by MP treatment owing to the antioxidative and anti-apoptotic effects of MP, which might be useful for reducing the severity of DOX induced liver injury.

Abstract 164: Hypoxia-Induced Cardiomyocyte Mitophagy and Mitochondrial Permeability Transition are Inhibited by Bnip3 Phosphorylation

Bnip3 is a hypoxia-inducible initiator of cardiomyocyte cell death and has also been implicated as a mitochondrial receptor for the cellular mitophagy machinery. Previous work from our group demonstrates that the prostaglandin E1 analogue, misoprostol, prevents hypoxia-induced mitochondrial dysfunction and is a potent activator of PKA. We hypothesize that misoprostol alters the phosphorylation status of Bnip3, inhibiting its ability to induce cardiomyocyte mitophagy, mitochondrial dysfunction and cell death. Using a rodent model of neonatal hypoxia, in combination with rat primary ventricular neonatal cardiomyocytes (PVNC’s) and H9c2 cells, we assessed the effect of hypoxia and misoprostol drug treatments on mitochondrial function, mitophagy, and cell viability. In postnatal day 5 rats, hypoxia caused a 30% increase in the concentration of serum cardiac troponin-I, a clinically relevant marker for cardiomyocyte cell death, which was absent with the addition of misoprostol drug treatments (n=3). Using PVNC’s we further demonstrated that hypoxia reduced measures of mitochondrial function including membrane potential (47%) and maximal respiration (46%), which were restored back to control levels with the addition of misoprostol (p<0.01). Furthermore, hypoxia induced a 36% increase in mitophagy, concurrent with a 210% increase in mitochondrial permeability transition, both of which were reversed with misoprostol drug treatment (p<0.01). Using a combination of mass spectrometry and mutagenesis, we also show that PKA directly phosphorylates the transmembrane domain of Bnip3 to inhibit its function. Mechanistically, when the PKA phosphorylation site on Bnip3 was neutralized, the protective effect of misoprostol on mitochondrial membrane potential, mitophagy and permeability transition was lost. Taken together, these results demonstrate a foundational role for Bnip3 phosphorylation in the molecular regulation of cardiomyocyte mitochondrial dysfunction. These findings further identify a pharmacological mechanism, through PKA, which may ultimately be able to prevent hypoxia-induced myocardial injury.

Protective role of misoprostol against cisplatin-induced ototoxicity.

Cis-diammineedichloroplatinum (cisplatin) is a chemotherapeutic agent that is widely used in the treatment of many cancers. Nephrotoxicity, ototoxicity and neurotoxicity are dose-limiting adverse effects for cisplatin. The cellular and molecular mechanisms underlying cisplatin-induced ototoxicity aren't fully understood. It has been proposed that cisplatin primarily cause damage at the cochlea, outer hair cells in particular, leading to excessive production of free oxygen radicals in the organ of Corti, stria vascularis, spiral ligament, and spiral ganglionic cells. The cytotoxicity is associated with the generation of reactive oxygen species (ROS); thus, there is an increasing interest on antioxidants with an effort to discover the established protection against cisplatin-induced ototoxicity over time. Misoprostol (MP) has gained considerable interest as a reactive oxygen species scavenger in recent years. To best of our knowledge, there is no study about protective effect of MP, a prostaglandin E1 (PGE1) analogue, on cisplatin-induced ototoxicity. In our study, we show that protective effects of misoprostol on cisplatin-induced ototoxcity on rats.

Effect of Misoprostol on Ultrastructural Changes of Renal Tissues in Cisplatin-Treated Adult Rats

Background: Cisplatin (CP) is one of the most effective antineoplastic drugs used for the treatment of various solid tumors. However, the nephrotoxic effect of CP limits its clinical use. The present study aimed to evaluate the possible protective effect of misoprostol (MP) against cisplatin-induced nephrotoxicity. Material & Methods: Twenty four male rats were randomly divided into four equal groups (control, cisplatintreated, misoprostol-treated and combined misoprostol and cisplatin-treated). Group II rats were treated with CP single i.p. dose of 7.5mg/kg on 5th day. Group III Rats were treated with oral MP at a dose of 200μg/kg/day for nine days. Group IV rats were treated with single oral dose of 200μg/kg/day MP for nine consecutive days and injected with CP single i.p. dose (7.5mg/kg) on 5th day. Body weight of rats was recorded on 1st, 3rd, 5th, 7th and 9th. days. On the 10th day, the rats were anesthetized by ether and scarified. Blood samples were obtained to determine creatinine and BUN levels. Body weight, Kidney weight & body weight/kidney weight ratio were calculated. Specimens of rats’ kidneys were prepared for both light and electron microscopic examinations.

Comparison of the protective effects of various antiulcer agents alone or in combination on indomethacin-induced gastric ulcers in rats

The aim of this study which was structured with the objective of determination of the optimum protective therapy against the long term NSAID therapy-induced ulcers was to compare the gastro-protective effects of various antiulcer drugs (ranitidine, omeprazole, bismuth and misoprostol) alone or in combination with each other in different doses on indomethacin-induced gastric ulcers in rats. In this experimental study the protective effect of misoprostol (100 μg/kg/day and 10 μg/kg/day i.g.), omeprazole (5 mg/kg/day and 1.5 mg/kg/day i.p.), ranitidine (40 mg/kg/day and 10 mg/kg/day i.p.), bismuth (70 mg/kg/day and 15 mg/kg/day i.g.), combinations of misoprostol (10 μg/kg/day i.g.) plus omeprazole (1.5mg/kg/day i.p.) and misoprostol (10 μg/kg/day i.g.) plus ranitidine (10 mg/kg/day i.p.) are investigated on indomethacin (50 mg/kg/day s.c.) induced gastric ulcers. Half an hour before indomethacin administration, each group received the above treatment regimens for 5 days. After 5-day treatment, the rats were sacrificed and histopathological and hematological examinations were performed. The following regimens were found to be effective in the prevention of indomethacin-induced gastric lesions: 100 μg/kg misoprostol, 10 μg/kg misoprostol, 5mg/kg omeprazole, combination of 10 μg/kg misoprostol plus 1.5 mg/kg omeprazole and 10 μg/kg misoprostol plus 10 mg/kg ranitidine. The prevention rates achieved by these treatments were 71.4%, 50%, 47.6%, 52.4% and 50%, respectively. As a result of this study, misoprostol and omeprazol were found to be effective in protection against NSAID-induced gastric problems; while, ranitidine and bismuth were not. Also, the combinations of these agents were not found to have additive or synergistic effects.

Prostaglandin analogue misoprostol attenuates neurotoxin 1-methyl-4-phenylpyridinium-induced mitochondrial damage and cell death in differentiated PC12 cells

Defects in mitochondrial function have been shown to participate in the induction of neuronal cell injury. The present study assessed the preventive effect of a prostaglandin E 1 analogue misoprostol against the toxicity of parkinsonian neurotoxin 1-methyl-4-phenylpyridinium (MPP +) with respect to the mitochondria-mediated cell death process and oxidative stress. MPP + induced the nuclear damage, the changes in the mitochondrial membrane permeability, the formation of reactive oxygen species and the depletion of GSH, which leads to cell death in differentiated PC12 cells. Misoprostol prevented the toxic effect of MPP +. Treatment with misoprostol significantly attenuated the MPP +-induced mitochondrial membrane permeability change that leads to the increase in pro-apoptotic Bax and Cytochrome c levels, and subsequent caspase-3 activation. The protective effect of misoprostol may be supported by the inhibitory effect of prostaglandin E 1 on the MPP + toxicity. Misoprostol significantly attenuated another parkinsonian neurotoxin rotenone-induced cell death. The results show that misoprostol may prevent the MPP + toxicity by suppressing the mitochondrial membrane permeability change that leads to the Cytochrome c release and caspase-3 activation. The preventive effect seems to be ascribed to the inhibitory effect on the formation of reactive oxygen species and depletion of GSH.

Differential radioprotective effects of misoprostol in DNA repaircell proficient and-deficient or radiosensitive systems

The protective effects of misoprostol (MP), an analogue of prostaglandin E, on X-ray-induced chromosomal aber1 rations, were studied in normal or mutant Chinese hamster cell lines grown as spheroids in vitro and on cell-killing in stem-cell spermatogonia of a mutant (scid) mouse strain or its wild-type. The mutant hamster cell lines chosen for this purpose are known to be either hypersensitive to the killing effects of X-rays and/or deficient in the repair of DNA double-strand breaks. The scid mice are deficient in the repair of DNA double-strand breaks. The results show that MP manifests varying degrees of radioprotection in all these systems, but the magnitude of these effects in the mutants is markedly reduced compared to their respective wild-type counterparts. These findings suggest a link between ionizing radiation sensitivity, DNA double-strand break repair capability and MP-mediated radioprotection.

CO-STIMULATORY EFFECTS OF MISOPROSTOL AND DICLOFENAC ON GLYCOSAMINOGLYCAN SYNTHESIS IN HUMAN CARTILAGE EXPLANTS AND THEIR THERAPEUTIC RELEVANCE

Misoprostol, a prostaglandin E(1) analog, is currently available to manage ulcer disease, being used predominantly in the prophylaxis of nonsteroidal anti-inflammatory drug (NSAID)-induced ulceration, a serious side effect of anti-inflammatory therapy in arthritis. The protective effects of misoprostol have now also been shown to extend to cartilage in a series of experiment using an ex vivo system employing normal human and osteoarthritis (OA) cartilage. Misoprostol reproducibly reverses inhibition of proteoglycan synthesis induced by interleukin-1 and certain NSAIDs, and also stimulates synthesis in OA cartilage. The article reviews these findings and also presents the results obtained in a study of 20 OA cartilages in which synergy was demonstrated between misoprostol (at 50 ng/ml) and diclofenac (0.3 &mgr;g/ml) in preventing proteoglycan synthesis. Diclofenac on its own is unusual amongst NSAIDs in exerting virtually no deleterious effect on cartilage. The synergy with misoprostol is of clinical interest in view of the recent introduction of a misoprostol/diclofenac combination product (Arthrotec), the intention of which was to provide antiinflammatory efficacy with a reduced incidence of GI damage. The implications of these cartilage experiments is that such a combination may also offer improvements in the management of the arthritic process in OA, and methods whereby this would be assessed clinically are discussed.

The Prostaglandin E 1 Analog, Misoprostol, a Normal Tissue Protector, Does Not Protect Four Murine Tumors In Vivo from Radiation Injury

The clinical development of radioprotectors, such as misoprostol, to protect normal tissue during cancer treatment must proceed with the assurance that tumors are not protected similarly or significantly. To provide data on this critical question, radiation-induced growth delay with or without the presence of misoprostol was measured in four murine tumors grown in the flanks of mice: the Lewis lung carcinoma, M-5076 ovarian sarcoma, FSA and NFSA. The effect of misoprostol on the tumor control dose (TCD50) of radiation was measured in FSA-bearing mice with or without prior treatment with the nonsteroidal anti-inflammatory agent, indomethacin. Misoprostol did not influence the in vivo growth of any of the four tumors, nor did it protect any of the tumors from radiation-induced growth delay. Likewise, there was no increase in the radiation TCD50 to treat the FSA in vivo in control or indomethacin-treated tumor-bearing mice. To measure any possible influence of tumor burden on the protective effect of misoprostol on normal tissue in mice, the protective effect of misoprostol on the survival of intestinal clonogenic cells was measured in M-5076-bearing mice and found to be the same as in non-tumor-bearing mice. These data suggest that misoprostol protects normal tissue in mice without protecting at least four experimental murine tumors. The data support the contention that misoprostol can achieve therapeutic gain by protecting normal tissues without protecting tumors.

Microvascular changes in liver after ischemia-reperfusion injury. Protection with misoprostol.

Morphological changes in the hepatic microvasculature were studied in experimentally induced ischemia-reperfusion injury in the rat using a vascular casting technique. Partial hepatic ischemia was induced for 90 min followed by 24 hr reperfusion. Microvascular casting was performed after 24 hr reperfusion by either intraarterial or intravenous infusion of acrylic resin (Mercox). After corrosion of the tissue, the cast was examined by scanning electron microscopy. Casts of normal livers showed good patency with no evidence of unfilled areas. The mean diameter of sinusoids was 14 +/- 3 microns with those in zone 1 slightly smaller than those in zone 3. Liver casts from rats subjected to ischemia and reperfusion resulted in gross disruption of normal architecture. The common characteristics seen in both prograde and retrograde casts were clusters of closed sinusoids around zones 2 and 3 of the liver acini, which resulted in cavities of various sizes. Varicosities were observed in some areas. The mean diameter of sinusoids in areas of patent microvascular structure (10 +/- 2 microns) was significantly smaller compared to those in normal livers (P < 0.001). Misoprostol given at 1 min before reperfusion markedly reduced the microvascular injury. The hepatic microvascular was generally intact with mild focal unfilled areas. The majority of the sinusoids were of normal size and no clusters of blind ending sinusoids were detected. The present study shows that hepatic ischemia-reperfusion results in extensive microvascular injury in the liver. The protective effects of misoprostol against this injury may occur at the vascular level.

Misoprostol: new frontiers; benefits beyond the gastrointestinal tract.

Recent findings suggest that the protective role that misoprostol exerts in the gastrointestinal tract against nonsteroidal anti-inflammatory drug (NSAID) damage may be extended to a variety of other tissues and other noxious stimuli including those mediated by molecules such as interleukin 1 (IL-1), tumor necrosis factor (TNF), and endotoxin. The protective effects of misoprostol outside the gastrointestinal tract may involve prevention of triggering activities that would otherwise initiate a sequence of tissue damaging events. If this capacity of misoprostol to maintain homeostasis in a variety of settings is recognized, a cohesive pattern of action emerges. Numerous studies have shown that misoprostol is likely to act as a regulator within various cascades of immunological regulatory events. The in vitro and in vivo experimental data described in this paper suggest that the events which trigger episodes of pain and inflammation may be controllable by the administration of misoprostol. Mitigation of adverse effects of certain NSAIDs on renal function and cartilage metabolism has also been observed. Demonstration of this latter phenomenon in the clinical setting will greatly benefit the patient if it is shown to modify the arthritis disease process. The therapeutic applications of misoprostol beyond the gastrointestinal tract appear to be among the most interesting of therapeutic advances offered by any class of compound in the next decade. Because of the inflammatory and pain processes associated with arthritis disease progression, particular emphasis and confirmation through further clinical study should be placed on the potential effect of misoprostol on chondroprotection and synergy with NSAIDs.

Protective Effects of Misoprostol on Carbon Tetrachloride-Induced Liver Damage in the Rat

Effects of misoprostol on histologic and biochemical alterations caused by CCl4 were investigated in the rat. Misoprostol protected against CCl4-induced liver injury. A close correlation occurred between biochemical data and morphological changes. This hepatoprotective effect was observed only when misoprostol was given 30 min before CCl4.

Protective Effect of Misoprostol, a Synthetic Prostaglandin E1, Analog, on Cerulein-Induced Acute Pancreatitis in Rats

This study was performed to assess the effects of misoprostol, a synthetic prostaglandin E1 analog, on cerulein-induced pancreatitis. Per group of 10 each, male Wistar rats received either cerulein (2.5 micrograms/kg/h subcutaneously), cerulein and misoprostol (500 micrograms/kg intraperitoneally at 0 and 4 h), or saline. Rats were killed 6 h after the first injection. Misoprostol treatment significantly reduced interstitial edema and acinar cell lesions induced by hyperstimulation. Pancreatic amylase and chymotrypsin contents were increased by cerulein and returned towards control levels in the misoprostol-treated group. The lysosomal volume density and the pancreatic beta-D-glucuronidase activity were significantly increased after hyperstimulation. The two parameters were significantly reduced by misoprostol. A protective effect of misoprostol against lesions induced by cerulein hyperstimulation would be a consequence of a lysosomal stabilizating effect.

Macroscopic and microscopic analysis of ethanol and nicotine damage to rat gastric mucosa after treatment with misoprostol and omeprazole

We compared the protective effects of misoprostol, a prostaglandin El derivative with both acid-inhibitory and cytoprotective actions, to omeprazole which possesses potent acid-inhibitory activity only on the injury to rat gastric mucosa induced by ethanol alone, and ethanol combined with nicotine, which was given to rats 25 μg/ml tap H2O for ten days before experiment. Assessment of macroscopic and microscopic mucosal damage were made in rats treated with ethanol and nicotine alone, or in combination with varied doses of Misoprostol, and Omeprazole topically The ulcer index was measured by the total area of macroscopic hemorrhagic necrosis in the glandular stomach. Microscopic examination of the tissue taken from the non-necrotic lesion areas of each rat stomach was carried out in order to determine the extent and depth of mucosal damage. The depth of mucosal damage was classified as O-damage; I-damage, II-damage and III-damage based on standardized criteria. In rats challenged with ethanol alone, the ulcer index, the total area of damaged gastric mucosa, and III damage in the non-necrotic lesion area of stomach were significantly lower in rats treated with all doses of misoprostol and high doses of Omeprazole vs low doses of Omeprazole and control (p Conclusion Misoprostol protects ethanol and nicotine induced mucosal injury better than omeprazole and control This indicates that cytoprotective action rather than acid-inhibition is more important in offering mucosal protection.

Protective Effect of Misoprostol, A Synthetic Prostaglandin E, Analog, on Experimental Pancreatitis Induced by Pancreatic Duct Ligation in Rat

This study was performed to assess the effects of misoprostol (M), a synthetic prostaglandin E1 analog, on experimental pancreatitis in rat. Pancreatitis was induced by ligation of the main pancreatic duct of 3-month-old male Wistar rats. Pancreatic lesions were observed at 6, 12, 24, 48, and 96 h after pancreatic duct ligation (PDL). A time of 48 h was chosen to evaluate M treatment. M was injected intraperitoneally (500 micrograms/kg every 4 h) between time 0 and 48 h after PDL. Stereological analysis was performed on light and electron microscopy. Total pancreatic amylase and chymotrypsin concentrations were determined. Four groups of five rats were studied: sham operated (SO), M without PDL (PG), duct ligation without M (DL), and duct ligation with M (DLPG). Edema, dedifferentiation of pancreatic acinar cells, and heterogeneous distribution of zymogen granule diameters observed after PDL were significantly decreased by M in the DLPG group. Enzyme concentrations were also decreased by M in the DLPG group. Enzyme concentrations were also decreased by M both in normal (PG) and duct ligated rats (DL). M has protective effects against pancreatic lesions induced by PDL. In this model, the protective effect of M may be due to a blockade of the autodigestive secretions of the pancreatic acinar cells.

Protection by misoprostol against naproxen-induced gastric mucosal damage

The protective effect of misoprostol against naproxen-induced gastric mucosal damage was the subject of a double-blind, randomized, parallel-group study. Thirty-two healthy subjects were treated with naproxen 500 mg twice daily and either misoprostol 200 μg or matching placebo twice daily for seven days. Gastroscopy was performed before and after the treatment period and the mucosa was assessed for erosive and petechial lesions according to a predetermined scoring scheme. Of 25 evaluable subjects, 12 were treated with misoprostol and 13 were treated with placebo. The mean overall endoscopic score was 1.24 ± 0.09 with placebo and 0.26 ± 0.07 with misoprostol. The difference, 0.98, was highly significant (p <0.001), with 95 percent confidence limits of 0.74 to 1.22. All subjects in the placebo group had higher mean scores than any in the misoprostol group. The scores for erosive and bleeding lesions in the antrum and corpus/fundus of the stomach were all reduced by administration of misoprostol. In conclusion, the results clearly demonstrate that misoprostol protects the gastric mucosa of humans against naproxen-induced damage.

Gastric mucosal damage in sepsis--effects of pretreatment with a synthetic prostaglandin E1 analogue.

An experimental model was used which includes intragastric instillation of 80 mM HCl and 0.6 ml bile/kg followed by intravenous infusion of live E coli in cats for up to three hours. This procedure regularly induces gastric mucosal ulcerations. Mucosal blood flow was measured by microspheres before, early, and late in sepsis. Total gastric blood flow was recorded electromagnetically. Mucosal regeneration capacity as reflected by the RNA/DNA ratio was measured. Misoprostol (a PGE1 analogue) was infused iv (5 micrograms/kg X h) or given locally in the stomach (10 micrograms/kg) before bacteriemia. Misoprostol did not influence the haemodynamic response to bacteria. The gastric mucosal damage was assessed either as an index representative for the entire corpus-fundus region or as the number of areas with intact surface epithelium within the series. Misoprostol iv protected the mucosa from ulceration compared with untreated septic controls while misoprostol intragastrically significantly reduced the number of damaged areas only. Topical misoprostol increased total gastric and mucosal blood flows early in sepsis compared to iv or no pretreatment while no difference was seen during late sepsis. The protective effect of misoprostol was thus not dependent on increased gastric mucosal blood flow. Nor was it mediated through effects on mucosal nucleic acid concentrations or ratio.