Cucumis sativus and Cucurbita maxima extract attenuate diabetes-induced hepatic and pancreatic injury in a rat model.

Diabetes is usually associated with oxidative stress that causes hepatic and pancreatic tissue injury. This work was carried out to evaluate the effect of Cucumis sativus and Cucurbita maxima methanol extracts on the streptozotocin-induced diabetic hepatic and pancreatic injury in rats. Diabetes was induced in seven equal groups of rats by a single intraperitoneal injection of streptozotocin (40 mg/kg), in addition to the non-diabetic control group. Two diabetic groups were treated with Cucumis sativus methanol extract and two were treated with Cucurbita maxima, each at 200 and 400 mg/kg for 21 days after streptozotocin-induced diabetes. Another diabetic group was treated with both Cucumis sativus and Cucurbita maxima at 200 mg/kg of each. Another group was treated with metformin (200 mg/kg orally). The plant extracts normalized serum liver enzymes activities, oxidative stress markers, and restored serum proteins and lipid profile. They also significantly reduced blood sugar to values comparable to non-diabetic rats. The hypoglycemic effect is also confirmed by the improvement of the immunohistochemical expression of insulin in ß-cells of islets of Langerhans. Hepatic and pancreatic protection was also confirmed by the improvement of the histopathological picture as compared to STZ-diabetic rats. The GC-MS analysis revealed the presence of 35 and 34 compounds in the methanol extract of cucumber and pumpkin, respectively. Finally, the methanol extract of cucumber and pumpkin could be beneficial acting synergistically in the protection of the liver and pancreas against diabetes-induced tissue damage.

Oligonol, a low-molecular-weight polyphenol derived from lychee peel, attenuates diabetes-induced pancreatic damage by inhibiting inflammatory responses via oxidative stress-dependent mitogen-activated protein kinase/nuclear factor-kappa B signaling.

This study investigated the effects of oligonol, a low-molecular-polyphenol derived from lychee peel, against diabetes-induced pancreatic damage via oxidative stress-induced inflammation. Oligonol was orally administered at 10 or 20 mg/kg body weight/day for 10 days to streptozotocin-induced diabetic rats, and the rats were compared with nondiabetic and diabetic control rats. The diabetic rats showed loss of body weight and increased pancreatic weight, and the oral administration of oligonol attenuated these parameters. Moreover, the administration of oligonol caused a significant decrease in the serum glucose level and a significant increase in the serum and pancreatic insulin and C-peptide levels in the diabetic rats. Oligonol also significantly reduced the enhanced levels of reactive oxygen species and 2-thiobarbituric acid reactive substance, which are oxidative stress biomarkers, in the serum and pancreas. Oligonol treatment reduced the overexpression of phospho-p38, phospho-ERK1/2, phospho-inhibitor of nuclear factor-kappa B (NF-κB), NF-κBp65, and NF-κBp65-induced inflammatory protein such as cyclooxygenase-2, inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin-6. Furthermore, oligonol treatment led to significantly attenuated histological damage in the pancreas. On the basis of these results, we conclude that a plausible mechanism of oligonol's antidiabetic action may be its antioxidative stress-related anti-inflammatory action.

Pancreatic function and histoarchitecture in Wistar rats following chronic exposure to Bushfire®: the mitigating role of zinc.

Objectives To assess the toxicopathologic effects of chronic exposure to the glyphosate-based herbicide Bushfire® on the pancreas of Wistar rats and the protective role of zinc. Methods We exposed the rats to daily doses of 14.4 to 750 mg/kg body weight of the glyphosate-based herbicide Bushfire® and to 50 or 100 mg/kg zinc, and measured blood glucose levels and serum insulin levels. Tissue samples were evaluated for histopathological alterations. Results Levels of both blood glucose and serum insulin increased in glyphosate-exposed rats, and moderate to severe degenerative changes were observed in both glandular pancreatic acinar cells and islets of Langerhans in all rats exposed to glyphosate. These effects were prevented by pretreatment with zinc. Conclusion Chronic exposure to glyphosate can alter pancreatic function and histoarchitecture, but zinc supplementation can mitigate these toxicopathologic effects.

Ethanolic extract of fenugreek seeds moderates dimethoate-induced pancreatic damage in male rats.

Dimethoate is a widely used organophosphate insecticide known to be toxic to the pancreas. The aim of this study is to detect the possible protective effects of the fenugreek seed ethanolic extract on the biochemical, histological, and ultra-structural abnormalities induced by dimethoate chronic exposure in the pancreas of adult male rats. The study was conducted on 50 adult male albino rats that were divided equally into 5 groups: (group I) negative control, (group II) vehicle control group, (group III) fenugreek-treated group that was given 400 mg/kg ethanolic fenugreek seed extract once daily, (group IV) dimethoate group received 20 mg/kg/day dimethoate, and (group V) dimethoate- + fenugreek-treated group received a combination of dimethoate and fenugreek in the same previous doses. Dimethoate treatment caused a significant increase in serum glucose, amylase, and lipase levels and a significant decrease in serum insulin. A significant increase in lipid peroxidation and pro-fibrotic cytokine (TGF-ß1) together with a significant reduction of the antioxidant {reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD)} activities and the anti-inflammatory (IL-4) in pancreatic tissues was also recorded. There was a histological and ultra-structural evidence of pancreatic acinar and islet cell injury. The recorded abnormalities were reversed in dimethoate+fenugreek treated group indicating that fenugreek ethanolic extract can serve as an antidote for dimethoate-induced pancreatic insult.

Possible involvement of iNOS and TNF-α in nutritional intervention against nicotine-induced pancreatic islet cell damage.

Nicotine is the more abundant and most significant components of cigarette smoke. Epidemiological evidence strongly suggests an association between cigarette smoking and pancreatic injury. Although effects of smoking on endocrine pancreas are still controversial Here, we examined the impact and underlying mechanisms of action of folic acid and vitamin B12 on nicotine induced damage in pancreatic islets of rats. Male Wistar rats were treated with nicotine (3mg/kg body weight/day, intraperitonealy) with or without folic acid (36µg/kg body weight/day, orally) and vitamin B12 (0.63µg/kg body weight/day, orally) for 21days. Supplementation with folic acid and vitamin B12 suppressed the nicotine induced changes in HbA1c, insulin, TNF-α, IL-6, generation of reactive oxygen species, and attenuated the changes in markers of oxidative stress. Moreover, folic acid and vitamin B12 also counteracted the increased expression of protein and mRNA contents of TNF-α and iNOS produced by nicotine. Further, folic acid and vitamin B12 in combination limits the nicotine induced changes in cell cycle and excessive apoptosis of the pancreatic ß-cells and also successfully blunted the nicotine induced alteration in loss of mitochondrial membrane potential. In conclusion, data demonstrate that folic acid and vitamin B12 may be possible nutritional intervention against cellular oxidative stress, which is a critical step in nicotine-mediated islet injury, and improves islet cell functional status by scavenging free radicals and by inhibiting the generation of pro-inflammatory mediators.

Protective Effects of Intralipid and Caffeic Acid Phenethyl Ester (CAPE) on Hepatotoxicity and Pancreatic Injury Caused by Dichlorvos in Rats.

The present study was aimed to the investigate the protective effects of caffeic acid phenethyl ester (CAPE) and intralipid (IL) on hepatotoxicity and pancreatic injury caused by acute dichlorvos (D) intoxication in rats. Forty-eight Wistar rats were randomly divided into seven groups each containing seven rats except control groups. The groups included control, D, CAPE, IL, D + CAPE, D + IL, and D + CAPE + IL. Total antioxidant status and total oxidative stress levels were measured by automated colorimetric assay. Tissues were evaluated using hematoxylin and eosin (H&E) staining. Tissues were analyzed with hematoxylin and eosin by using standard protocols. Also, Bcl-2, Bax and caspase-3 were evaluated by immunohistochemical method in liver tissue. Total oxidant status in control, CAPE, and IL groups were significantly lower, and total antioxidant status in the D + CAPE, D + IL, and D + IL + CAPE groups were significantly higher compared to the D group. CAPE and IL treatment decreased the apoptotic and mitotic cell count in liver tissue. Parenchymal necrosis caused by dichlorvos is observed in pancreas tissues of rats. Mild congestion and edema formation occurred in pancreas tissues following D + CAPE and D + IL therapies. These results indicate that CAPE and IL have the potential to decrease oxidative stress and hepatic and pancreatic injuries caused by acute dichlorvos intoxication. These drugs can be considered as a new method for supportive and protective therapy against pesticide intoxication.

Asiatic acid mitigates hyperglycemia and reduces islet fibrosis in Goto-Kakizaki rat, a spontaneous type 2 diabetic animal model.

The Goto-Kakizaki (GK) rat is a spontaneous type 2 diabetic animal model, which is characterized by a progressive loss of beta islet cells with fibrosis. In the present study, the hypoglycemic effect of asiatic acid (AA) in GK rats was examined. GK rats receiving AA at a daily dose of 25 mg·kg(-1) for four weeks showed a significant reduction in blood glucose levels. Age-matched normal Wistar rats were given 0.5% sodium carboxymethyl cellulose (CMC-Na) solution for the same periods and used as control. Compared to the normal Wistar rats, GK rats treated with AA showed improvement in insulin resistance partially through decreasing glucose level (P < 0.01) and insulin level (P < 0.05). Furthermore, the results of immunohistochemistry indicate that AA treatment reduced islet fibrosis in GK rats. Fibronectin, a key protein related to islet fibrosis, was over-expressed in GK rats, which was reversed significantly by AA treatment (P < 0.05). These findings suggest that AA has a beneficial effect on lowering blood glucose levels in GK rats and improves fibrosis of islets in diabetes, which may play a role in the prevention of islets dysfunction.

Carbon tetrachloride-induced lipid peroxidation and hyperglycemia in rat: a novel study.

Launaea procumbens methanol extract (LPME) was evaluated against carbon tetrachloride (CCl4)-induced pancreatic oxidative damage and hyperglycemia in rats. Various doses of the extract were administered to rats after 48 h of CCl4 treatment (3 ml/kg bodyweight (bw); intraperitoneally, 20% CCl4/olive oil) twice a week for 4 weeks. Coadministration of various concentrations of LPME (100, 150 and 200 mg/kg) ameliorated the toxicity of CCl4 and reversed the serum level of enzymes (amylase and lipase), glucose and hormone (insulin). The extract was able to reduce thiobarbituric acid reactive substance but increased the glutathione contents in pancreatic tissue. Depletion of antioxidant enzyme activities (catalase, peroxidase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase and glutathione-S-reductase) and DNA damages induced with CCl4 were restored by LPME supplement. It is suggested that LPME effectively protects the liver against the CCl4-induced oxidative damage in rats, possibly through antioxidant and/or free radical scavenging effects of flavonoids and phenolic compounds in the extract.

Effect of maternal use of flaxseed oil during pregnancy and lactation on glucose metabolism and pancreas histomorphometry of male offspring from diabetic rats.

AIM: Investigate if the maternal use of flaxseed oil prevents pancreatic alterations in the offspring of diabetic mothers. METHODS: Diabetes was induced in female wistar rats (n=12) by a high-fat diet and low-dose of streptozotocin. After the confirmation of the diabetes (glucose >300 mg/dL), rats were mated and once pregnancy was confirmed, they were allocated into three groups (n=6): high-fat group (HFG); flaxseed oil group (FOG); and control group (CG) (nondiabetic rats). At weaning, male offspring (n=12/group) received a standard chow diet. The animals were euthanized in two phases: at 100 and at 180 days, (n=6/group). The pancreas was collected for histomorphometric and immunohistochemistry analysis. RESULTS: HFG showed hypertrophy of pancreatic islets at 100 and at 180 days (p<0.0001), while the FOG offspring had islets with smaller diameters compared to HFG at both phases of sacrifice (p<0.0001). HFG had a lower percentage of small islets when compared to CG and FOG, which had a higher percentage when compared to HFG (p=0.0053) at 100 days. At 180 days HFG showed higher percentage of larger islets (p=0.00137) and lower percentage of smaller islets (p=0.00112), when compared to FOG. HFG showed lower islet insulin immunodensity at 100 days (p<0.0001) and 180 days (p<0.0001), whereas FOG was similar to CG (p<0.0001) at 100 days and higher at 180 days (p<0.0001). CONCLUSIONS: Flaxseed oil reduced the damage caused by maternal hyperglycemia, promoting normal pancreas histomorphometry and ß cell mass.

Intraperitoneal co-administration of thymosin alpha-1 ameliorates streptozotocin-induced pancreatic lesions and diabetes in C57BL/6 mice.

We investigated the effects of the in vivo administration of thymosin alpha-1 (Talpha-1) on streptozotocin (STZ)-induced pancreatic lesions and diabetes. Mice were randomly divided into four experimental groups: normoglycemic control, STZ-treated, STZ plus 0.1 microg/kg body weight/day Talpha-1-treated, and STZ plus 1 microg/kg/day Talpha-1-treated. Blood glucose was assayed periodically, and serum insulin was determined at the end of the experiment using the ELISA Kit. Aldehyde fuchsin staining was used for histopathological examination of the pancreas. Parameters for oxidative stress were measured with pancreatic malondialdehyde (MDA) level, glutathione (GSH) content and enzymatic activities of superoxide dismutase and catalase. Fourteen days after the initiation of Talpha-1 treatment and up to day 35 when the treatment was stopped, both of the two STZ and Talpha-1-co-treated mouse groups had significant lower levels of blood glucose than the STZ-treated but Talpha-1-untreated mice, although both remained higher than that of the normoglycemic controls. At the end of the Talpha-1 treatment, the serum insulin level for STZ-treated mice receiving 1 microg/kg/day Talpha-1 for 35 days was 2-fold (P<0.001) as much as that of the Talpha-1-untreated STZ-diabetic mice, although not completely restored to the normal level. Pancreatic aldehyde fuchsin staining showed that STZ treatment caused significant pancreatitis, islet atrophy, and a significant reduction in the number of pancreatic beta cells. These histological lesions, however, were significantly alleviated by 1 microg/kg/day Talpha-1 treatment for 35 days. Furthermore, compared with the Talpha-1- untreated STZ-diabetic mice, the pancreatic GSH level of the 1 microg/kg/day Talpha-1-treated STZ-induced mice was 1.92-fold that of the untreated STZ-induced mice (P<0.01), whereas the pancreatic MDA level was only 81.9% that of the untreated STZ-diabetic mice (P<0.05). Together these results demonstrate that co-administration of Talpha-1 leads to significant protection against STZ-induced pancreatic damage and diabetes, and part of the protection might be achieved through enhancing pancreatic antioxidative capability.

Effects of Salvia miltiorrhiza on intercellular adhesion molecule 1 protein expression in the lungs of rats with severe acute pancreatitis or obstructive jaundice.

OBJECTIVE: The objective of the study was to observe the effects of Salvia miltiorrhiza on intercellular adhesion molecule 1 (ICAM-1) protein expression in the lungs of rats with severe acute pancreatitis (SAP) or obstructive jaundice (OJ). METHODS: A total of 288 rats were used for SAP- and OJ-associated experiments. The rats were randomly divided into sham-operated, model control, and treated group. According to the difference of time points after operation, the SAP rats of each group were subdivided into 3-, 6-, and 12-hour groups, whereas the OJ rats were divided into 7-, 14-, 21-, and 28-day groups. The contents of interleukin (IL) 6, IL-18, nitric oxide, malondialdehyde, and superoxide dismutase in serum were determined, and pathological changes and ICAM-1 protein expression in the lungs were observed. RESULTS: Compared with the respective model control groups, in treated groups of SAP and OJ rats, the numbers of dead rats declined; serum superoxide dismutase content significantly increased, and serum IL-18, IL-6, and malondialdehyde contents were significantly decreased; the positive staining intensity of ICAM-1 protein in the lungs decreased significantly (P < 0.05, P < 0.01, or P < 0.001); and pathological changes in the lungs were relieved. CONCLUSIONS: Salvia miltiorrhiza plays a positive role in the protection of the lungs of SAP and OJ rats.

Ellagic acid inhibits pancreatic fibrosis in male Wistar Bonn/Kobori rats.

The key pathological features of chronic pancreatitis are chronic inflammation, acinar atrophy, and pancreatic fibrosis. We have previously shown that ellagic acid, a plant-derived polyphenol found in fruits and nuts, inhibited activation of pancreatic stellate cells, a major profibrogenic cell type in the pancreas, in vitro. Here we examined whether ellagic acid inhibited the development of pancreatic fibrosis in vivo. Ellagic acid was administered orally in the diet to ten-week-old male Wistar Bonn/Kobori rats, an experimental model of spontaneous chronic pancreatitis, for ten weeks. Ellagic acid (100 mg/kg body weight/day) attenuated pancreatic inflammation and fibrosis. The protective effects were confirmed by an increase in pancreatic weight and decreases in myeloperoxidase activity (an index of neutrophil infiltration), collagen content, transforming growth factor-beta1 expression, and the number of alpha-smooth muscle actin-positive cells (activated pancreatic stellate cells) and ED-1-positive cells (macrophages/monocytes). Ellagic acid inhibited the production of reactive oxygen species in pancreatic stellate cells in response to transforming growth factor-beta1 or platelet-derived growth factor. Our results suggest that ellagic acid might be a candidate for treatment of chronic pancreatitis.

Protective effect of Hachimi-jio-gan against the development of pancreatic fibrosis and oxidative damage in Otsuka Long-Evans Tokushima Fatty rats.

In our previous study, the polyherbal drug Hachimi-jio-gan was reported to possess a protective effect against the progression of diabetic nephropathy by attenuating glucose toxicity and renal damage with a type 2 diabetic model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Based on these findings, this study was undertaken to reveal the effect of Hachimi-jio-gan on pancreatic damage focusing on fibrosis and oxidative stress in type 2 diabetes. OLETF rats were orally administered Hachimi-jio-gan for 32 weeks, and we assessed the changes in the serum glucose level every 8 weeks, as well as those of body weight, and food and water consumption every 4 weeks. In addition, pancreatic wet weight, insulin content, and Western blot analyses of transforming growth factor-beta(1), fibronectin, and nuclear factor-kappaB-related inflammatory enzymes, such as inducible nitric oxide synthesis and cyclooxygenase-2, were also performed in the pancreas. As a consequence, long-term treatment with Hachimi-jio-gan had a hypoglycemic effect, reducing pancreatic atrophy and fibrosis, and ameliorating the oxidative status. Therefore, this may provide evidence that Hachimi-jio-gan is a therapeutic target for preventing the development of pancreatic damage concomitant with hyperglycemia in type 2 diabetes.

Attenuation of microvascular reperfusion injury in rat pancreas transplantation by L-arginine.

BACKGROUND: Despite improving results, exocrine complications remain a major challenge in clinical pancreas transplantation. The etiology of posttransplantation pancreatitis relates almost certainly to cold ischemia/reperfusion-induced microvascular injury with an imbalance of vasoconstricting and vasodilating mediators due to endothelial dysfunction. We therefore studied the effectiveness of a nitric oxide donor on postischemic microvascular reperfusion injury after pancreas transplantation. METHODS: Heterotopic isogeneic pancreaticoduodenal transplantation was performed in spontaneously breathing, chloralhydrate-anesthetized Sprague Dawley rats after 16 hr (n=5) of cold storage of the graft in 4 degrees C histidine-tryptophane-ketoglutarate solution. An additional five animals received L-arginine immediately before (50 mg/kg i.v.) and during the first 30 min of reperfusion (100 mg/kg i.v.). Five animals that did not undergo transplantation served as controls. Intravital fluorescence microscopy was used for analysis of functional capillary density, capillary diameters, and capillary red blood cell velocity in exocrine pancreatic tissue during 120 min of reperfusion. Histology served for quantitative assessment of inflammatory response (leukocytic tissue infiltration) and endothelial disintegration (edema formation). RESULTS: In L-arginine-treated animals, functional capillary density of exocrine tissue of pancreatic grafts was found slightly higher after 30 and 60 min, and significantly higher after 120 min of postischemic reperfusion compared with untreated pancreatic grafts. This was accompanied by a significant increase of capillary diameters. In parallel, pancreatic histology revealed significant attenuation of both leukocytic tissue infiltration and edema formation in the L-arginine-treated animals when compared with the nontreated controls. CONCLUSIONS: Besides reduction of leukocyte-dependent microvascular injury, L-arginine improves postischemic microvascular reperfusion, supposedly by capillary dilatation. Thus, our results suggest that supplement of nitric oxide during reperfusion is effective in attenuating exocrine microvascular reperfusion injury.

Effects of glutamine-enriched parenteral nutrition on the exocrine pancreas.

Total parenteral nutrition (TPN) is associated with intestinal and pancreatic atrophy and pancreatic exocrine insufficiency. Recent investigations have demonstrated that the addition of glutamine to intravenous feedings attenuates TPN-associated intestinal atrophy. However, the effect of glutamine-supplemented intravenous feedings on the pancreas of intact animals is unknown. This study compared the effects of an intravenous infusion of a 2% glutamine-enriched diet (GLN) with an isonitrogenous, isocaloric diet without glutamine (CONT) on the composition and structure of the exocrine pancreas in laboratory rats with and without a 60% small bowel resection. In nonresected, TPN-fed animals, pancreatic weight was significantly increased in the GLN group when compared to CONT (645 +/- 33 g vs 554 +/- 20 g, p less than 0.05). Nonresected GLN animals also had increased pancreatic DNA (3.82 +/- 0.19 mg vs 2.91 +/- 0.49 mg, p less than 0.005) and protein contents (93.0 +/- 5.9 mg vs 76.6 +/- 7.0 mg, p = 0.08) compared to control. Similar significant increases in pancreatic weight, DNA, and protein were observed in intestinally resected animals fed the glutamine diet. When data from CONT and GLN animals were pooled and analyzed together, glutamine significantly increased total pancreatic trypsinogen and lipase contents (p less than 0.05). The increase in trypsinogen in resected GLN animals was significantly greater than in CONT animals (283 +/- 22 vs 139 +/- 23, p less than 0.005). Biochemical and morphometric observations demonstrated that the trophic effects of glutamine on the exocrine pancreas were manifest by acinar hyperplasia and not hypertrophy. Glutamine appears to be an important nutrient for pancreatic exocrine tissue during TPN.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of selenium on certain hepatotoxic and pancreotoxic manifestations of subacute cadmium administration.

Administration of cadmium chloride (1.0 mg/kg s.c.) to rats, twice a day for 7 days, significantly stimulated the activities of hepatic pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose 1,6-diphosphatase and glucose 6-phosphatase, markedly increased the concentration of hepatic cyclic adenosine monophosphate and circulating blood glucose and significantly reduced serum insulin levels. Furthermore, subacute exposure to cadmium induced glucose intolerance that was associated with a decreased pancreatic secretory activity as evidenced by lowered insulinogenic indices and marked inhibition of phentolamine-stimulated insulin release. In contrast to cadmium, administration of selenium dioxide (2 X 1.0 mg/kg/day s.c., 7 days) failed to alter significantly the activities of gluconeogenic enzymes, hepatic cyclic adenosine monophosphate, blood glucose or serum insulin levels, glucose tolerance or the pancreatic secretory activity. However, administration of selenium concurrently with cadmium completely prevented the cadmium-induced increases of hepatic gluconeogenic enzymes. Treatment with selenium ameliorated the cadmium-induced hyperglycemia, hypoinsulinemia, glucose intolerance and the suppression of pancreatic secretory activity, whereas it failed to alter significantly the cadmium-induced elevation of hepatic cyclic AMP levels. Data provide evidence suggesting that subacute exposure to cadmium alters several parameters of carbohydrate metabolism and suppresses pancreatic secretory activity and that administration of selenium alone is without any appreciable effect on the above parameters. However, administration of selenium concurrently with cadmium prevents, to varying degrees, several of the cadmium-induced metabolic and functional changes.