Do desipramine and fluoxetine ameliorate the extent of colonic damage induced by acetic acid in rats?

The present study was aimed to compare the anti-inflammatory and antioxidant effects of two antidepressant drugs; desipramine and fluoxetine, administered in two different doses, on experimentally induced colitis in rats. Two doses for each drug [10, 20 mg/kg/d] were injected intraperitoneally in forty eight adult male albino rats for 2 weeks after induction of colitis by intra-colonic administration of 2ml 3% acetic acid. Several parameters including, macroscopic [ulcer score index], microscopic [histological] and biochemical such as myeloperoxidase [MPO], reduced glutathione [GSH], tumor necrosis factor alpha [TNF-alpha] and interleukin-1 Beta [IL-1beta] were measured using standard assay procedures. The study demonstrated that both desipramine and fluoxetine significantly attenuated the extent and the severity of the macroscopic and microscopic histological signs of cell damage. Both drugs significantly reduced tissue MPO activity in a dose dependent manner. Both desipramine and fluoxetine at either dose increased significantly the GSH in colonic tissue. On the contrary, both desipramine and fluoxetine significantly reduced TNF-alpha and IL-beta in a dose dependent manner. However, desipramine at the dose of 20 mg/kg produced more decrease in the level of TNF-alpha compared to the effect of the smaller dose, and on the contrary, fluoxetine at the dose of 10 mg/kg showed more decrease in the level of IL-beta compared to the effect of the larger dose. The available data indicate that both desipramine and fluoxetine have anti-inflammatory and antioxidants effects in experimentally induced colitis in rats opening the avenue to their possible protective role in patients with inflammatory bowel disease

Role of modulation of vascular endothelial growth factor and tumor necrosis factor-alpha in gastric ulcer healing in diabetic rats

To assess the role of modulation of vascular endothelial growth factor and tumor necrosis factor-alpha in gastric ulcer healing in streptozotocin [STZ]- induced diabetic rats. forty male rats were made diabetic by intraperitoneal [i.p] STZ infection and ten rats were injected i.p. by a single dose of saline and served as a control for group II Six weeks following STZ or saline injection, gastric ulcers were induced by serosal application of acetic acid. Three days after acetic acid application, rats were divided into: group I[normal control], group II [STZ-injected rats], groups III. IV and V [STZ-injected rats treated with insulin, insulin and phosphodiesterase [PDE] inhibitor [pentoxifylline] [PTX] and insulin and Hydroxymethylglutaryl Coenzyme A [HMG-CoA] reductase inhibitor [simvastatin] respectively, for seven days following acetic acid application. At the end of the experimental period, plasma glucose was measured. Gastric ulcer area as well as gastric tumor necrosis factor- alpha [TNF-alpha], vascular endothelial growth factor [VEGF] and haemoglobin [Hb] concentrations were determined. STZ-injection induced diabetes, evidenced by significant higher mean value in plasma glucose concentration in group II compared to that of the control group [I] Significant delay in ulcer healing could be observed, in the form of significant increase in gastric ulcer area in group II compared to the control group I. STZ-injection resulted in significant increase in gastric TNF-alpha as well as a significant decrease in gastric VEGF concentrations together with a significant decrease in gastric angiogenic response evidenced by a significant decrease in gastric Hb concentration in group II compared to the control group I. The use of insulin, as well as combinations of insulin and PTX or simvastatin caused a significant decrease in plasma glucose concentration as well as a significant increase in gastric ulcer healing [evidenced by a significant decrease in ulcer area], gastric VEGF and gastric Hb concentration as well as significant decrease in gastric TNF-alpha compared to group II. A significant difference in gastric ulcer area and gastric TNF-alpha could be observed between rat that received combinations of insulin and PTX or simvastatin compared to rats that received insulin only. A significant difference in gastric VEGF and Hb was also found between the group that received combination of insulin and simvastatin compared to the group that received insulin only. Experimental DM impairs ulcer healing, depending upon the increased release of proinflammatory cytokines [e.g. TNF-alpha] and the attenuation of angiogenesis Insulin reversed this impairment of ulcer healing in diabetic rats, mainly due to the enhancement of angiogenesis and reduction in expression of TNF-alpha in the ulcer area. Phosphodiesterase [PDE] inhibitor [pentoxifylline], via suppressing TNF-alpha and hydroxymethylglutaryl coenzyme A [HMG-CoA] reductase inhibitor [simvastatin]. via suppressing TNF-alpha and increasing VEGF, are beneficial in enhancing gastric ulcer healing. These findings support the notion that impairment of healing of gastric ulcers in DM results from impairment of angiogenic response of the gastric mucosa to injury together with upregulotion of gastric TNF-alpha and suggest the feasibility of a novel treatment strategy for patients in whom impairment of ulcer healing complication of DM

Role of the trace metals, selenium and zinc, in pilocarpine-induced epilepsy in rats

Excitotoxic brain lesions, such as epilepsy, lead to increasing destruction of neurons, in the course of few hours after the insult. The deadly cascade of events possibly involves detrimental actions by free radicals, proinflammatory cytokines and the activation of pro-apoptotic transcription factors, which finally result in neuronal destruction. Several reports suggest that the level of some trace elements play a vital role in seizure conditions to prevail. The aim of the present study was to assess the possible modulatory role of the trace elements, selenium and zinc on pilocarpine-induced epilepsy in rats.The study was carried out on 40 male albino rats, weighing 150-200 grams that were divided into the following groups each of 10 rats: Group I: control rats that received intraperitoneal [i.p.] saline, Group II: pilocarpine induced epilepsy, Group 111: selenium pretreated for 3 weeks before pilocarpine injection and Group IV: zinc pretreated for 3 weeks before pilocarpine injection. The seizure latency and severity for each rat was recorded. Twenty four hours following pilocarpine injection, rats were exsanguinated and the following parameters were determined: cerebral caspase-3 activity [as a marker of apoptosis], interleukin-lbeta [IL-ljB], reduced glutathione [GSH] and malondialdehyde [MDA] concentrations, serum neuron specific enolase[NSE] concentration [as a marker of brain injury].Intraperitoneal injection of pilocarpine in rats resulted in progression to limbic seizures with progressing behavioural scores at various time intervals [recorded every 30 minutes up to 2 hours]. Latency to forelimb clonus was 51.86 +/- 1.89 min. The results of the present study demonstrated significantly increased cerebral MDA concentration together with significant decrease in cerebral GSH concentration in non-treated pilocarpine injected rats compared to normal control rats. A significant increase in cerebral caspase-3 activity, and in cerebral 1L-1/beta as well as in serum NSE concentrations could be observed in non-treated pilocarpine-injected rats compared to normal control rats. Pretreatment with selenium or zinc reduced the severity of pilocarpine- induced seizures. In addition, both trace elements decreased the latency to attain the forelimb clonus [score 4]. A significant decrease in cerebral MDA and IL-1/beta, serum NSE concentrations could be observed in selenium and zinc-treated rats compared to non-treated pilocarpine-injected rats. A significant' increase in cerebral GSH concentration was observed in zinc-treated, but not in selenium-treated ones.The results of the present study confirm the role of the trace elements, selenium and zinc, in mitigating epilepsy. Further human studies to evaluate the role of trace elements in epilepsy are recommended. Furthermore, since antiepileptic drugs [AEDs] are reported to induce zinc and selenium deficiency,thus combining these trace elements with AEDs are worthy to be evaluated

Role of rosiglitazone and pravastalin in freund's adjuvant arthritis and mixed-type hypersensitivity in rats

Recent studies have shown that peroxisome proliferator- activated receptor- gamma [PPAR gamma] may participate in control of inflammation, especially in modulating the production of inflammatory mediators. Similarly, the cholesterol lowering drugs, statins, have been found to exhibit anti-inflammatory properties that are beyond their lipid lowering effects. The present study was conducted to investigate the effect of a PPAR gamma agonist [rosiglitazone] and a statin [pravastatin] on immunologically mediated chronic inflammation. Two models were chosen, namely, Freund's adjuvant arthritis [FA] and mixed- type hypersensitivity [MH] in rats. The effect of these drugs was assessed on the basis of biochemical markers in blood and / or inflammatory exudate. The investigated drugs were given orally daily during the course of inflammation development. The results of the present study demonstrated that, in either model, rosiglitazone and pravastatin reduced the elevated serum and exudate [local] leukotriene B[4] [LTB[4]] and interleukine-6 [IL-6] levels. The anti-inflammatory effect of these drugs was also accompanied by reduction or normalization of elevated systemic and or local levels of lipid peroxide [LP], superoxide dismutase [SOD], and reduced glutathione [GSH]. It could be concluded that long-term treatment with rosiglitazone or pravastatin confers a good anti-inflammatory activity against arthritis in rat, leading to improvement of the oxidative stress induced by the arthritic insult. The reparative effect of these drugs could be mediated via reduction of LTB[4] and IL-6

possible reno- and vascufoprotective of drugs that inhibit the renin angiotensin system in diabetic rats

Aim: The renin angiotensin system [RAS] plays an important role in the development of diabetic renovascular pathology characteristic of diabetic nephropathy [DN]. Through inhibition of RAS by different mechanisms, angiotensin-converting enzyme inhibitors [ACEIs] and angiotensin II type 1 receptor blockers [ARBs] could slow the progression of diabetic renovascular disease. Thus, the present study was undertaken to test the hypothesis that a combination of an ACEI [fosinopril] and an ARB [candesartan] could exert additive reno- and vasculoprotective effects in uninephrectomized [UNE], streptozotocin [STZ] -induced diabetic rats. Material and Fifty male albino rats weighing 150-200 g were used in the present study. Rats were divided into five groups [each of ten rats]; ten rats of them were taken as normal sham-operated group. The remaining forty rats were subjected to left unilateral nephrectomy and then three weeks later, diabetes was induced by a single intravenous injection of STZ. The UNE STZ - diabetic rats were further subdivided into: control rats that were given no additional treatment but insulin s.c., UNE STZ -diabetic rats treated with fosinopril in addition to insulin for 16 weeks, UNE STZ - diabetic rats treated with candesartan in addition to insulin for 16 weeks and the fifth group was UNE STZ -diabetic rats treated with a combination of fosinopril and candesartan in addition to insulin for 16 weeks. UNE STZ - diabetic rats exhibited the characteristic features of diabetic renal disease including increased BP, plasma creatinine [PCr], urinary albumin excretion [UAE], kidney weight [KW], BG and glycosylated hemoglobin [HbAIc] together with decreased urinary creatinine [UCr] and creatinine clearance [CrCI]. Furthermore, control rats showed significant elevations in plasma transforming growth factor-beta 1 [TGF-D 1] and in renal malondialdehyde [MDA] associated with significant reduction in renal reduced glutathione [GSH]. Edothalial dysfunction [ED] of renal arteries isolated from STZ-diabetic rats, evidenced by a significant decrease in percentage of maximal relaxation in response to acetylcholine [ACH], has been also demonstrated. Oral administration of fosinopril or candesartan for 16 weeks in UNE STZ diabetic rats produced significant decreases in KW,BP, PCr,UAE, plasma TGED1 and renal MDA concentration together with significant increase in UCr, CrC 1 and renal GSH concentration. Vasculoprotective effect of fosinopril and candesartan has been also found, evidenced by a significant increase in the percentage of maximal relaxation in response to Ach in renal arteries isolated from UNR STZ-diabetic rats treated with fosinopril or candesartan Treatment of UNE diabetic rats with a combination of an ACEI [Fosinopril] and an ARB [candesartan] improved most of the estimated biochemical parameters as well as BP more significantly than either drug alone, but the combination of both drugs did not result in a significant difference in the percentage of maximal relaxation in response to Ach in renal arteries compared to either drug given alone. Conclusions: the results of the present study demonstrated that ACEIs and ARBs have a comparable degree of reno- and vasculoprotection in UNE STZ- induced diabetic rats Moreover, the present study demonstrated an additive renoprotective effect of combination therapy with ACEIs and ARBs over monotherapy with either class alone

Role of peroxisome proliferator activated receptor [PPAR] agonists in experimental liver fibrosis in rats

The ligand-dependent transcription factors, peroxisome proliferator-activated receptors [PPARs] are expressed in hepatic stellate cells [HSCs], which are the cells reported to play a central role in liver fibrosis. It has been reported that the transcriptional activity of PPAR gamma and alpha is reduced during activation of HSCs. The aim of the present study was to evaluate whether oral administration of pioglitazone [alpha PPAR gamma ligand], and bezafibrate [alpha PPAR alpha ligand], might retard liver fibrosis in rats. Fifty male albino rats weighing 150-200 g were used in the present study. Rats were divided into five groups, each often rats. Group I, injected intraperitonealy [i.p.] by thioacetamide [TAA]. Group II, injected i.p. by saline. Groups III and IV, treated with bezafibrate and pioglitazone respectively, orally starting from the first day of TAA administration. Group V, served as a control group for groups III and IV. The duration of the study was six weeks. Administration of TAA to rats for six weeks resulted in significant increases in portal pressure, serum cytokines [tumor necrosis factor-alpha TNF-alpha and transforming growth factor-beta 1 TGF-beta 1], hepatic hydroxyproline [HPO], and serum aspartate aminotransferase [AST] and alanine aminotransferase [ALT] associated with a significant decrease in hepatic glycogen concentration. On the other hand, the two PPAR ligands, pioglitazone and bezafibrate, produced a significant decrease in portal pressure, a significant decrease in serum TNF-alpha and TGF-beta 1, a significant improvement in all the estimated parameters of liver function, as well as a significant decrease in hepatic HPO concentration in rats that received the drugs for six weeks compared to the control untreated rats. The results of the present study demonstrated that the PPAR agonists, pioglitazone and bezafibrate were effective in preventing the fibrogenic process via modulating the action of the cytokines TNF-alpha and TGF- beta1. Further studies on humans are needed in order to assess the clinical use of PPAR agonists in patients with liver fibrosis

study on some pharmacologic manipulations of diet-induced obesity in rats

Aim: Obesity is a major health problem that represents an energy imbalance associated with complications, including cardiovascular disease, diabetes, and an increased mortality rate. The aim of the present work was to study some pharmacological manipulations of diet-induced obesity [DIO] in rats. Subjects and The study was conducted on 60 adult male albino rats that were divided into two groups; the DIO group fed high-calorie diet [HCD] [n=48] and the normal control group [n=12] fed normal laboratory diet. After 8 weeks, DIO rats were subdivided into four subgroups [each of 12 rats] that received the lipase inhibitor [orlistat], or the PPAR-gamma agonist [rosiglitazone], or the beta3-agonist [trecadrine] or a vehicle orally for 3 weeks. After the specified period, the following obesity variables were recorded: body weight, obesity index, food intake and rectal temperature. Blood samples were withdrawn for determination of serum metabolic parameters: glucose, triglycerides [TG], free fatty acids [FFA], leptin and insulin levels. Rats were sacrificed; and the remaining obesity variables were measured: retroperitoneal and interscapular fat as well as liver weight. The use of a HCD for 8 weeks resulted in a significant increase in all the measured obesity variables [except for rectal temperature] together with a significant increase in all the measured serum parameters as compared to rats that received normal laboratory diet. Orlistat administration for 3 weeks caused a significant decrease in all obesity variables with no significant change in food intake. A significant decrease in serum TG, FFA, insulin and leptin levels was also evident. Rosiglitazone-treated rats exhibited a significant decrease in liver weight together with a significant increase in fat pads weight and rectal temperature. Trecadrine produced significant reduction in obesity variables except for interscapular fat weight and rectal temperature that were significantly increased. Significant improvements in all serum metabolic parameters were noted with rosiglitazone and trecadrine treatment. Conclusions: From the current study, it can be concluded that lipase inhibitors and beta 3 agonists are effective in reducing body weight, while PPAR-gamma agonists are effective in improving insulin sensitivity and lipid abnormalities and so are rather effective as an adjuvant therapy to control the subsequent metabolic derangements relevant to obesity. Extrapolating these findings, especially the role of beta3-agonists, awaits further human trials before recommending it as a standard antiobesity drug