Δ(9)-tetrahydrocannabinol protects cardiac tissue against endoplasmic reticulum and oxidative stresses, apoptosis, and inflammation in rats with hyperinsulinemia.

OBJECTIVES: In our study, we aimed to examine how δ(9)-tetrahydrocannabinol (THC) administration to hyperinsulinemia (HI) model rats would change endoplasmic reticulum stress (ERS), apoptosis, inflammation, and oxidative stress in cardiac tissue. METHODS: Rats were divided into four groups (n = 32): Control (C), THC, HI, and Treatment (Tre). Fructose (10%) in the drinking water was given to HI and Tre rats for 12 weeks. 1.5 mg/kg/d THC was given intraperitoneally to THC and Tre rats in the last 4 weeks of the experiment. The mRNA expressions of ERS and apoptosis markers in the cardiac tissue were detected. TNF-α concentration and oxidative stress were also analyzed. KEY FINDINGS: THC treatment in rats with HI ameliorated the overexpression of GRP-78, IRE1α, ATF6, ATF4, CHOP, Cas-12, Cas-8, Cas-9, and Cas-3 mRNAs, markers of ERS and apoptosis (P < .0001 for all). In addition, THC has been shown to reduce inflammation in the Tre group by causing a decrease in increased cardiac TNF-α levels (P < .01). Moreover, THC prevented cardiac tissue damage by regulating the degraded oxidative stress marker levels and antioxidant enzyme activities in HI. CONCLUSIONS: Our findings suggest that THC treatment in rats with HI exhibited a significant effect in ameliorating cardiac tissue damage by improving the antioxidant defense system, inflammation, apoptosis, ERS, and oxidative stress.

Chronic administration of delta9-tetrahydrocannabinol protects hyperinsulinemic gastric tissue in rats.

Hyperinsulinemia (HI) can result from some reasons such as an increase in basal/fasting circulating insulin and/or potentiation of postprandial insulin production. Diabetes mellitus (DM) is indirectly related to HI since it both causes and results from insulin resistance. Understanding the causes of HI and treating this is crucial for preventing DM. Previous research has shown that delta9-tetrahydrocannabinol (THC) has medicinal benefits. In light of this, the relationship between THC and oxidative stress, DNA repair mechanism, apoptosis, and its regulatory impact on appetite hormones in the gastric tissue of hyperinsulinemic rats has been investigated for the first time. Male rats (Spraque-Dawley, total = 32) were used, and they were randomly divided into the following groups (n = 8 in each group): control (CTRL), HI, THC administered control (THC, 1.5 mg/kg/day, during 4 weeks), and THC administered HI (HI + THC) groups. The number of poly (ADP-ribose) polymerase-1 and proliferating cell nuclear antigen (PCNA) and caspase-3 immunopositive cells in the HI group was significantly reduced compared to the CTRL group. The number of PCNA and caspase-9 immunopositive cells was significantly increased in the HI + THC group compared to the HI group. Obestatin immunopositive cell numbers in the HI + THC group were higher than in the HI and CTRL groups. The results show that THC administration may affect the regulation of appetite hormones and regeneration in the fundus of rats with HI. Glutathione (GSH) levels were higher in the HI + THC group than in the HI group. Both immunohistochemical and biochemical analyses revealed that THC promotes regeneration and regulates appetite hormones in hyperinsulinemic gastric tissues.

Influences of calorie restriction and lipopolysaccharide therapy on inflammation, cytokine response, and cell proliferation in pancreatic adenocarcinoma mouse model.

The study aimed to investigate the effects of lipopolysaccharide (LPS) alone and in combination with calorie restriction (CR) on the pancreatic tissues in C57BL/6 mice modeled with pancreatic ductal adenocarcinoma (PDAC). Forty male C57BL/6 mice (10-13 weeks old) were divided into five groups; LPS, LPS + CR, PDAC, PDAC + LPS, and PDAC + LPS + CR. Nuclear factor kappa B (NF-κß), interleukin-6 (IL-6), and c-Jun N-terminal kinases (JNK) mRNA expression levels were measured in pancreatic tissues. NF-κß, IL-6, JNK, and proliferating cell nuclear antigen (PCNA) peptide levels were determined by immunohistochemistry. Oxidative stress markers and antioxidant enzyme activities were determined spectrophotometrically. TH1/TH2 cytokine measurements were determined by a flow cytometer. It was detected that the number of PCNA immune + cells in the PDAC + LPS + CR group was significantly lower than in the PDAC and PDAC + LPS groups (p < 0.01, p < 0.05 respectively). PDAC + LPS + CR group's plasma interferon-gamma (IFN-γ), IL-6, IL-2, tumor necrosis factor-alpha, IL-3, and IL-4 levels were found to be significantly lower than the PDAC group (p < 0.01, p < 0.001, p < 0.01, p < 0.05, p < 0.01, and p < 0.05 respectively). According to our findings, the combination of low-dose LPS and 40% CR was found to be more effective in PDAC model mice.

Anti-inflammatory potential of delta-9-tetrahydrocannabinol in hyperinsulinemia: an experimental study.

BACKGROUND: Hyperinsulinemia (HI) means that the amount of insulin in the blood is higher than normal and is often associated with type 2 diabetes. It is known that delta-9-tetrahydrocannabinol (THC) obtained from a medicinal plant, Cannabis sativa, has therapeutic effects on many diseases. OBJECTIVE: This study aimed to investigate the effects of THC on inflammatory and oxidant status in rat pancreas with HI. METHODS: Rats were divided into groups; Control, HI, THC and HI + THC. Each group consists of 8 animals. HI and HI + THC groups were given 10% fructose in the drinking water for 12 weeks. In the last four weeks of the experiment, 1.5 mg kg-1 THC was injected intraperitoneally daily into THC and HI + THC groups. The expression of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nuclear factor-kappa B (NF-κB) were detected. JNK/SAPK and Grap2/p38 levels, total antioxidant and oxidant capacities (TAC and TOC) were analyzed in the pancreas. RESULTS: Levels of IL-6, NF-κß, and TNF-α mRNA expression were higher in the pancreas with HI than in the control (p < 0.001 for all). THC treatment reduced the expression of IL-6, NF-κß, and TNF-α mRNAs in the HI + THC group compared to the HI group (p < 0.001 for all). TOC increased in the HI group compared to the control group (p < 0.001). However, THC treatment reduced TOC levels in the HI + THC group compared to the HI group (p < 0.001). CONCLUSION: According to the results, the THC treatment may regulate inflammation and TOC in rats with hyperinsulinemia. Thus, we can say that THC may have anti-inflammatory and antioxidant potential in metabolic disorders.

The relationship between ghrelin and inflammation in diabetic rat stomach.

BACKGROUND: Ghrelin is a hormone that regulates the digestive system, as well as has immunomodulating effects. The aim of this study is to explain effects of ghrelin on inflammation and oxidative stress parameters in the stomach. METHODS: Male Sprague Dawley rats 8-10 weeks old (n = 21) were randomly divided into three groups as control, type 2 diabetes (T2DM) and diabetes and given exogenous ghrelin (T2DM+Gh). The daily feed and water intake of the animals were measured. The levels of interleukin-6 (IL-6), interleukin-1ß (IL-1ß), tumor necrosis factor (TNF-α), and interleukin-10 (IL-10) mRNA in tissues were analyzed using RT-PCR technique. Ghrelin and nuclear factor-κß (NF-κß) peptides were detected by immunohistochemistry. RESULTS: T2DM group had a significant increase in water intake when compared to control group. T2DM group had significantly higher levels of IL-6, IL-1, and IL-10 mRNA expression than control group. IL-1ß and IL-10 mRNA expression were significantly lower in T2DM+Gh group than in T2DM group. In T2DM group, NF-κß was higher than in control group, but it was lower in T2DM+Gh group. In terms of oxidative stress, there were non-significant changes. CONCLUSION: According to our findings, exogenous ghrelin intake was found to be highly effective in reducing inflammation in stomach tissue with type 2 diabetes (Tab. 1, Fig. 3, Ref. 33). Text in PDF www.elis.sk Keywords: ghrelin, rat, type 2 diabetes, stomach, inflammation.

Aspartame induces cancer stem cell enrichment through p21, NICD and GLI1 in human PANC-1 pancreas adenocarcinoma cells.

This study aimed to investigate the molecular effects of the common natural sugar glucose and artificial sweetener aspartame on cancer stem cell (CSC) population and cancer aggressiveness of PANC-1 human pancreas adenocarcinoma cells. According to our findings while aspartame exposure significantly increased the CSC population, high glucose had no effect on it. The epithelial-mesenchymal transition marker N-cadherin increased only in the aspartame group. The findings indicate that a high level of glucose exposure does not effect the invasion and migration of PANC-1 cells, while aspartame increases both of these aggressiveness criteria. The findings also suggest that a high concentration of glucose maintains CSC population through induction of nuclear Oct3/4 and differentiation to parental cells via increasing cytoplasmic c-myc. Aspartame exposure to PANC-1 cells activated AKT and deactivated GSK3ß by increasing levels of ROS and cytoplasmic Ca+2, respectively, through T1R2/T1R3 stimulation. Then p-GSK3ß(Ser9) boosted the CSC population by increasing pluripotency factors Oct3/4 and c-myc via NICD, GLI1 and p21. In the aspartame group, T1R1 silencing further increased the CSC population but decreased cell viability and suppressed the p21, NICD and GLI activation. The presence and amount of T1R subunits in the membrane fraction of PANC-1 cells are demonstrated for the first time in this study, as is the regulatory effect of T1R1's on CSC population. In conclusion, the present study demonstrated that long-term aspartame exposure increases CSC population and tumor cell aggressiveness through p21, NICD, GLI1. Moreover, while aspartame had no tumorigenic effect, it could potentially advance an existing tumor.

Oxidative stress and inflammatory response of ghrelin on myocardial and aortic tissues in insulin-resistant rats.

OBJECTIVES: This study was designed to clarify the effects of ghrelin on myocardial and aortic tissues in insulin-resistant rats. METHODS: Sprague-Dawley rats were divided into the following groups: control (Group 1), insulin resistance (IR, Group 2), ghrelin (Group 3) and IR+Ghrelin (Group 4) groups. Levels of HOMA-IR, fibronectin, hydroxyproline, collagen-1, collagen-3, matrix metalloproteinase-3, and matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1, and oxidative stress parameters as protein carbonyl (PCO), lipid hydroperoxides (LHPs), malondialdehyde, total thiol were determined in myocardial tissue. Expressions of IL-6, NF-κB and TNF-α mRNAs were detected by RT-qPCR. Aorta tissue was stained Masson trichrome. KEY FINDINGS: The HOMA-IR level decreased in the IR+Ghrelin group compared with the IR group (P < 0.001). The PCO and LHP concentrations were higher in the IR group compared with control rats (P < 0.05). The PCO level was reduced by ghrelin in the IR+Ghrelin group compared with the IR group (P < 0.001). Ghrelin treatment reduced the mRNA expression levels of IL-6, NF-κB and TNF-α in the IR+Ghrelin group compared with the IR group (P < 0.001). There was no difference among the groups in the histology of aortic tissue. CONCLUSIONS: Ghrelin, a regulator of appetite and energy homeostasis, may be effective in regulating oxidative stress and the inflammatory response when impaired by IR. Therefore, ghrelin may reduce the risks of myocardial dysfunction in IR.

Changes in the expression levels of CB1 and GLP-1R mRNAs and microRNAs 33a and 122 in the liver of type 2 diabetic rats treated with ghrelin.

The aim of the study is to clarify the effect of ghrelin treatment on the messenger RNA (mRNA) expression of the cannabinoid receptor 1 (Cnr1/CB1) and glucagon-like peptide 1 receptor (Glp1r/GLP-1R) as well as microRNAs (miR)-122 and miR-33a in the liver of rats with type 2 diabetes mellitus (T2DM). Adult Sprague-Dawley rats were divided into three groups: control (n = 7), T2DM (n = 7), and treatment (n = 7). Control animals received tap water. T2DM was induced by feeding 10% fructose in drinking water for 2 weeks followed by a single injection of streptozotocin (40 mg/kg, intraperitoneally [IP]). In the treatment group, diabetic rats were injected ghrelin (25 µg/kg, IP) for 14 days. Serum lipid profiles were evaluated, and mRNA expression levels of Cnr1 and Glp1r in the liver were detected using quantitative real-time polymerase chain reaction (RT-qPCR). In addition, miR-122 and miR-33a levels were measured using RT-qPCR. Serum triglycerides, low-density lipoprotein cholesterol, and very-low-density lipoprotein cholesterol significantly increased in the T2DM group compared with control rats but ghrelin treatment showed no effect on serum lipid levels. The mRNA expression levels of Cnr1 and Glp1r decreased in the T2DM group compared with the control group. These reductions were significantly increased in the T2DM group treated with ghrelin. Furthermore, the increase in miR-33a expression level was reduced in the treatment group compared to rats with T2DM. Our findings suggested that ghrelin treatment may alter the mRNA expression levels of CB1 and GLP-1R in the liver of rats with T2DM. The mRNA levels of Cnr1 and Glp1r may inversely correlate with the expression level of miR-33a but not miR-122.

The effects of delta-9-tetrahydrocannabinol on Krüppel-like factor-4 expression, redox homeostasis, and inflammation in the kidney of diabetic rat.

Diabetes mellitus is a complex, multifactorial disorder that is attributed to pancreatic ß cell dysfunction. Pancreatic ß cell dysfunction results in declining utilization of glucose by peripheral tissues as kidney and it leads to nephropathy. Excessive production and accumulation of free radicals and incapable antioxidant defense system lead to impaired redox status. Macromolecular damage may occur due to impaired redox status and also immune imbalance. Δ9-Tetrahydrocannabinol (THC) is the main active ingredient in cannabis. THC acts as an immunomodulator and an antioxidant agent. Our aim was to evaluate the effects of THC in the diabetic kidney. We analyzed macromolecular damage biomarkers as protein carbonyl (PCO), lipid hydroperoxide (LHP), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and antioxidant defense system biomarkers as thiol fractions (T-SH, NP-SH, P-SH) and Cu/Zn-superoxide dismutase activity for the antioxidative effects of THC. Furthermore, mRNA expression of Krüppel-like factor-4, secreted immunopositive cell number changes of interleukin-6, nuclear factor κß (NF-κß), and peroxisome proliferator-activated receptor-γ and tumor necrosis factor α (TNF-α) levels were analyzed for the immunomodulatory activity of THC. Diabetic rats showed significantly increased levels of PCO, LHP, MDA, and 8-OHdG when compared with controls (P < 0.05 for each parameter). THC significantly reduced the elevated levels of PCO and 8-OHdG (P < 0.05 for both parameters) and also LHP and MDA levels were insignificantly reduced by THC. Also, thiol fractions insignificantly increased in THC administered diabetic kidney when compared with diabetic rats. The NF-κß cell number significantly decreased in the diabetic rats treated with THC compared with the diabetic group. According to our data, THC has ameliorative effects on the impaired redox status of diabetic kidney and also it acts as an immunomodulator. Therefore, THC might be used as a therapeutic agent for diabetic kidneys but its usage in the healthy kidney may show adverse effects.

The effects of antioxidant combination on indomethacin-induced gastric mucosal injury in rats.

The aim of this study is an investigation the protective effects of vitamin C (Vit C), vitamin E (Vit E), ß-carotene, sodium selenate combination in indomethacin-induced gastric mucosal damage in rats. Rats were divided into 6 groups. Group I: Intact animals (control). Group II: Control animals receiving Vit C (100 mg/kg/day), Vit E (100 mg/kg/day), ß-carotene (15 mg/kg/day) and sodium selenate (0.2 mg/kg/day) for 3 days. Group III: Animals receiving 25 mg/kg indomethacin. Group IV: Animals receiving Vit C, Vit E, ß-carotene and sodium selenate (in same doses) for 3 days 2 h before the administration of indomethacin. Group V: Animals receiving ranitidine (150 mg/kg) for 3 days. Group VI: Animals receiving ranitidine for 3 days 2 h before to the administration of indomethacin (in same dose and time). The administration of indomethacin caused a decrease in the levels of glutathione, mucus, hexosamine and in the activities of glutathione-S-transferase, sodium-potassium ATPase, thromboplastic activity and an increase in the aspartate and alanine amino transferase, alkaline phosphatase, catalase, lactate dehydrogenase, myeloperoxidase activities and sialic acid, lipid peroxidation and protein carbonyl levels.  Stomach caspase-8 immun+ cell numbers showed a slight increase while caspase-9 immun+ cell numbers reduced in indomethacin given group compared to control animals. Our results findings suggest that the combination of Vit C, Vit E, ß-carotene, sodium selenate and ranitidine has a protective effect on indomethacin-induced gastric mucosal injury of rats.

The protective effects of Δ9 -tetrahydrocannabinol against inflammation and oxidative stress in rat liver with fructose-induced hyperinsulinemia.

OBJECTIVES: A large amount of fructose is metabolized in the liver and causes hepatic functional damage. Δ9 -tetrahydrocannabinol (THC) is known as a therapeutic agent for clinical and experimental applications. The study aims to investigate the effects of THC treatment on inflammation, lipid profiles and oxidative stress in rat liver with hyperinsulinemia. METHODS: Sprague-Dawley rats were divided into groups: control, fructose (10% fructose in drinking water for 12 weeks), THC (1.5 mg/kg/day for the last 4 weeks, intraperitoneally) and fructose+THC groups. Biochemical parameters were measured spectrophotometrically. ELISA method was used for insulin measurement. Apoptosis and inflammation markers were detected by the streptavidin-biotin peroxidase method. KEY FINDINGS: The consumptions of food and fluid are inversely proportional to fructose and non-fructose groups. Insulin levels were the highest in fructose group. The reduced glutathione-S-transferase level significantly increased in fructose + THC group compared with fructose group. Total cholesterol level in the fructose + THC group was higher than the fructose group. Caspase-3 and NF-κß immunopositive cell numbers increased in fructose + THC rats compared with fructose group. The number of IL-6 immunopositive cell decreased in fructose + THC group compared with fructose group. CONCLUSIONS: According to the result, long-term and low-dose THC administration may reduce hyperinsulinemia and inflammation in rats to some extent.

Dipeptidyl peptidase-4 inhibition prevents cell death via extrinsic and intrinsic apoptotic pathways in rat pancreas with insulin resistance.

The study aims to evaluate the effect of saxagliptin, a specific inhibitor of dipeptidyl peptidase-4 enzymes, on body weight gain, lipid profiles, and cell death through apoptosis in rats with insulin resistance (IR). Male adult Sprague-Dawley rats (n = 32) were divided into 4 groups: control (Ctrl), IR, saxagliptin control, and IR treated with saxagliptin(IR + S). Insulin resistance was induced by 10% fructose in the drinking water for 8 weeks. Saxagliptin (10 mg/kg/day) was administrated by oral gavage for 2 weeks. Biochemical parameters were measured spectrophotometrically. Peptides were determined by the streptavidin-biotin-peroxidase method. Although the amount of food and liquid consumed are inversely proportional, the calories received are almost equal between both Ctrl and IR groups, as well as IR and IR + S groups. Increased homeostasis model assessment for insulin resistance, HOMA-ß, triglycerides, and very low-density lipoprotein in the IR group were comparatively decreased by saxagliptin administration. The area percentage of caspase-3 and apoptotic peptidase activating factor-1 immunopositive cells in the IR + S group decreased compared with the IR group. Similarly, the percentages of caspase-8 and -9 immunopositive cells in the IR group were higher than the IR + S group. It was observed that the percentage of poly (ADP-ribose) polymerase-1 immunopositive cells was increased in the IR + S group compared with the IR group. Thus, saxagliptin may prevent IR-induced apoptotic cell death and regulate impaired homeostasis model assessment for insulin resistance and serum lipid levels.

CB-1R and GLP-1R gene expressions and oxidative stress in the liver of diabetic rats treated with sitagliptin.

BACKGROUND: Type 2 diabetes is a major health problem affecting millions of people. Controlled eating and regular physical activity are important for the management of type 2 diabetes. Dipeptidyl peptidase-4 enzyme (DPP-4) inhibitor sitagliptin is a potent agent for the treatment of type-2 diabetes. The aim of this study was to examine the effects of sitagliptin on the liver of rats with streptozotocin (STZ)-induced diabetes, in terms of (i) the expression levels of the cannabinoid 1 receptor (CB-1R) and glucagon-like peptide 1 receptor (GLP-1R), (ii) alterations in the number and localization of these peptides, and (iii) changes in histological and oxidative damage. METHODS: Thirty-two neonatal (two-day-old) rats, which were divided into four groups, were treated with saline (control), sitagliptin (control; 1.5mg/kg/day for 15 days starting from day 5 of the experimental period), STZ (diabetes; 100mg/kg single dose), STZ+sitagliptin (diabetes+sitagliptin). After 20 days, hepatic tissues were obtained from rats. RESULTS: The expressions of GLP-1R and CB-1R mRNA increased approximately 1.89- and 2.94-fold, respectively, in the diabetes+sitagliptin group as compared to the diabetic group. Additionally the number of GLP-1R immunopositive cells decreased and CB-1R immunopositive cells increased in comparison to the diabetic group; however, this was not statistically significant. Glutathione levels increased, but malondialdehyde and protein carbonyl levels decreased in the diabetes+sitagliptin group more than the diabetic group. CONCLUSION: Our findings indicate that sitagliptin treatment regulates GLP-1R and CB-1R gene expressions, which are associated with appetite regulation in diabetic rat, and may decrease oxidative stress and liver tissue damage.

Evaluation of Δ(9)-tetrahydrocannabinol metabolites and oxidative stress in type 2 diabetic rats.

OBJECTIVES: The object of the study is to examine the effects of Δ(9)-tetrahydrocannabinol (THC) against oxidative stress in the blood and excretion of THC metabolites in urine of type 2 diabetic rats. MATERIALS AND METHODS: The control (n=8), THC control (n=6), diabetes (n=8) and diabetes + THC (n=7) groups were created. Type 2 diabetes was induced by nicotinamide (NA, 85 mg/kg) + streptozotocin (STZ, 65 mg/kg). THC was administered intraperitoneally for seven days. The glutathione (GSH) level in erythrocytes and malondialdehyde (MDA) level, superoxide dismutase (SOD) and catalase (CAT) enzyme activities in plasma were measured. THC metabolites were analyzed in urine. RESULTS: The results showed that the erythrocyte GSH levels were significantly increased (P<0.05), but plasma MDA levels were non-significantly decreased in diabetes group treated with THC when compared with the diabetes group. The CAT activity was non-significantly reduced and SOD was significantly increased (P<0.01) in the plasma of diabetes induced by THC in comparison with the diabetic group. The excretion of THC metabolites was higher in the urine of diabetes + THC rats as compared to the THC control rats. CONCLUSION: These findings highlight that THC treatment may attenuate slightly the oxidative stress in diabetic rats. The excretion rate of THC may vary in the type 2 diabetes mellitus status.

The effects of silibin administration for different time periods on mouse liver with Ehrlich ascites carcinoma.

BACKGROUND: Ehrlich ascites carcinoma is the one of the animal cancer models having high malignancy and rapid growth resistance. Silibin has reported to be an antioxidant in previous studies. We aimed to investigate the effects of silibin on mouse liver with Ehrlich ascites tumor (EAT) cells in different time periods. METHODS: Balb/c mice were divided into five groups. Group I (Control): The saline buffer (sb) was injected intraperitoneally (ip) to the mice for 15 days. Group II (Silibin): 150mg/kg silibin was injected ip for 15 days. Group III (Ehrlich): 2×10(5) cells were transferred from the donor mouse to healthy mice on first day. Group IV (Ehrlich+Silibin): Silibin was given between 5th and 15th days to mice inoculated with EAT. Group V (Silibin+Ehrlich): Silibin was injected for 15 days after EAT cells. The liver sections were stained with matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9), caspase 3, caspase 8, and proliferating cell nuclear antigen (PCNA) antibodies by the streptavidin-biotin-peroxidase technique. Biochemical analysis and Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method were performed in the liver. RESULTS: Superoxide dismutase levels of liver increased in Ehrlich+Silibin group compared with Ehrlich group. Malondialdehyde levels significantly decreased in Silibin+Ehrlich group compared with Ehrlich+Silibin. MMP-2 and MMP-9 immunopositive cells increased in Silibin+Ehrlich compared with Ehrlich group. Caspase 3 and TUNEL signals significantly increased in Silibin+Ehrlich group compared with Ehrlich group. PCNA positive signals significantly increased in Ehrlich+Silibin group compared with Ehrlich group. CONCLUSION: According to our findings, we suggest that silibin treatment after EAT cells inoculation has more effective than concurrently EAT and silibin treatment.

Immunohistochemical, apoptotic and biochemical changes by dipeptidyl peptidase-4 inhibitor-sitagliptin in type-2 diabetic rats.

BACKGROUND: Diabetes is a major public health problem that is rapidly increasing in prevalence. In this study, the effects of sitagliptin, a dipeptidyl peptidase-4 inhibitor, were examined on newborn diabetic rat model. METHODS: Wistar albino newborn rats were divided into control (Ctrl), sitagliptin (Sit), diabetic and diabetic+Sit groups. On the second day after the birth, 100mg/kg streptozotocin (STZ) was administered intraperitoneally in a single dose to induce type-2 diabetes in rats. The Sit and diabetic+Sit groups were administered sitagliptin (1.5mg/kg subcutaneous) as of the day 5 for 15 days. The pancreas sections were stained with insulin (INS), glucagon (GLU), somatostatin (SS), glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-1 receptor (GLP-1R) antibodies by the streptavidin-biotin peroxidase technique. The TUNEL method for apoptosis and biochemical analysis were performed in the pancreas and serum, respectively. RESULTS: Body weight and blood glucose levels showed significant differences among all groups on days 11 and 20. In diabetic rats following treatment with sitagliptin, the area percentage of INS immunopositive cells increased while the area percentage of SS immunopositive cells decreased, insignificantly. A significant increase was observed on the area percentage of GLU, GLP-1 and GLP-1R immunopositive cells in the diabetic+Sit group when compared to the diabetic group. The area percentage of apoptotic cells was the same among all groups. While serum glutathione and malondialdehyde levels demonstrated insignificant alterations, the catalase and superoxide dismutase activity significantly changed among four groups. CONCLUSION: According to our findings, sitagliptin may be a useful therapeutic agent to a certain extent of type-2 diabetic condition.

The role of ghrelin on apoptosis, cell proliferation and oxidant-antioxidant system in the liver of neonatal diabetic rats.

Ghrelin is a multifunctional peptide hormone which stimulates appetite and regulates glucose metabolism and adipogenesis. The purpose of this study was to investigate whether ghrelin has protective effects in the liver of streptozocin (STZ) diabetic rats or not. Wistar-type neonatal rats were divided into four groups: I. Controls, II. Ghrelin administrated controls, III. STZ-diabetic rats, and IV. Ghrelin administrated diabetic rats. On the second day after birth, 100 mg/kg STZ was administered intraperitoneally in a single dose to induce diabetes in rats. 100 µg/kg/day ghrelin was administrated to rats subcutaneously for 4 weeks. Ghrelin administration improved histopathologic changes in STZ-diabetic liver. Obestatin immunoreactivity has been shown in livers of neonatal rats. The immunoreactivity of obestatin increased in diabetic rats and a decline was observed in ghrelin administrated diabetic rats. Caspase 8 and 3 immunoreactivities increased in diabetic rats; however, ghrelin administration differently affected caspases 8 and 3 immunoreactivities. Proliferating cell nuclear antigen immunoreactivities decreased in diabetic rats and in ghrelin administrated diabetic rats. Serum alanine (P < 0.05) and aspartate transaminase (P < 0.0001) and serum alkaline phosphatase (P < 0.0001) activities were decreased in ghrelin administrated diabetic rats compared to the diabetic rats. Gamma glutamyl transferase activity (P < 0.001) decreased in ghrelin administrated diabetic rats compared to the diabetic rats. The response of antioxidants including glutathione levels, catalase and superoxide dismutase activities were altered in ghrelin administrated diabetic rats. Our findings indicate that ghrelin administration affects hepatic functions in neonatal diabetic rats and might be considered as a therapeutic agent.

Oxidative stress and cannabinoid receptor expression in type-2 diabetic rat pancreas following treatment with Δ9-THC.

The objectives of study were (a) to determine alteration of feeding, glucose level and oxidative stress and (b) to investigate expression and localization of cannabinoid receptors in type-2 diabetic rat pancreas treated with Δ(9)-tetrahydrocannabinol (Δ(9)-THC). Rats were randomly divided into four groups: control, Δ(9)-THC, diabetes and diabetes + Δ(9)-THC groups. Diabetic rats were treated with a single dose of nicotinamide (85 mg/kg) 15 min before injection of streptozotocin (65 mg/kg). Δ(9)-THC was administered intraperitoneally at 3 mg/kg/day for 7 days. Body weights and blood glucose level of rats in all groups were measured on days 0, 7, 14 and 21. On day 15 after the Δ(9)-THC injections, pancreatic tissues were removed. Blood glucose levels and body weights of diabetic rats treated with Δ(9)-THC did not show statistically significant changes when compared with the diabetic animals on days 7, 14 and 21. Treatment with Δ(9)-THC significantly increased pancreas glutathione levels, enzyme activities of superoxide dismutase and catalase in diabetes compared with non-treatment diabetes group. The cannabinoid 1 receptor was found in islets, whereas the cannabinoid 2 receptor was found in pancreatic ducts. Their localization in cells was both nuclear and cytoplasmic. We can suggest that Δ(9) -THC may be an important agent for the treatment of oxidative damages induced by diabetes. However, it must be supported with anti-hyperglycaemic agents. Furthermore, the present study for the first time emphasizes that Δ(9)-THC may improve pancreatic cells via cannabinoid receptors in diabetes. The aim of present study was to elucidate the effects of Δ(9)-THC, a natural cannabinoid receptor agonist, on the expression and localization of cannabinoid receptors, and oxidative stress statue in type-2 diabetic rat pancreas. Results demonstrate that the cannabinoid receptors are presented in both Langerhans islets and duct regions. The curative effects of Δ(9)-THC can be occurred via activation of cannabinoid receptors in diabetic rat pancreas. Moreover, it may provide a protective effect against oxidative damage induced by diabetes. Thus, it is suggested that Δ(9)-THC can be a candidate for therapeutic alternatives of diabetes symptoms.

Biochemical and immunohistochemical changes in delta-9-tetrahydrocannabinol-treated type 2 diabetic rats.

The regulation of glucose, lipid metabolism and immunoreactivities of insulin and glucagon peptides by delta-9-tetrahydrocannabinol (Δ(9)-THC) in diabetes were examined in an experimental rat model. Male Sprague-Dawley rats were divided into four groups: (1) control, (2) Δ(9)-THC treated, (3) diabetic, and (4) diabetic+Δ(9)-THC. The type 2 diabetic rat model was established by intraperitoneal (i.p.) injection of nicotinamide (85 mg/kg body weight) followed after 15 min by i.p. injection of streptozotocin (STZ) at 65 mg/kg of body weight. Δ(9)-THC and Δ(9)-THC treated diabetic groups received 3mg/kg/day of Δ(9)-THC for 7 days. The immunolocalization of insulin and glucagon peptides was investigated in the pancreas using a streptavidin-biotin-peroxidase technique. High density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), very low density lipoprotein cholesterol (VLDL), triglycerides (TG), total cholesterol (TC) and total protein (TP) levels were measured in serum. Total islet area percent of insulin immunoreactive cells slightly changed in diabetic+Δ(9)-THC rats compared to diabetic animals. However, the area percent of glucagon immunoreactive cells showed a decrease in diabetic+Δ(9)-THC rats compared to that of diabetic animals alone. Serum TC, HDL and LDL levels of diabetes+Δ(9)-THC group showed a decrease compared to the diabetic group. These results indicate that Δ(9)-THC may serve a protective role against hyperlipidemia and hyperglycemia in diabetic rats.

Regulation of oxidative stress and somatostatin, cholecystokinin, apelin gene expressions by ghrelin in stomach of newborn diabetic rats.

The aim of the study was to determine whether ghrelin treatment has a protective effect on gene expression and biochemical changes in the stomach of newborn streptozotocin (STZ) induced diabetic rats. In this study, four groups of Wistar rats were used: control, ghrelin control, diabetic and diabetic+ghrelin. The rats were sacrificed after four weeks of treatment for diabetes. The gene expressions of: somatostatin, cholecystokinin, apelin and the altered active caspase-3, active caspase-8, proliferating cell nuclear antigen, were investigated in the pyloric region of the stomach and antioxidant parameters were measured in all the stomach. Although ghrelin treatment to diabetic rats lowered the stomach lipid peroxidation levels, the stomach glutathione levels were increased. Exogenous ghrelin caused an increased activities of stomach catalase, superoxide dismutase, glutathione reductase and glutathione peroxidase in diabetic rats. Numbers of somatostatin, cholecystokinin and proliferating cell nuclear antigen immunoreactive cells decreased in the diabetic+ghrelin group compared to the diabetic group. Apelin mRNA expressions were remarkably less in the diabetic+ghrelin rats than in diabetic rats. The results may indicate that ghrelin treatment has a protective effect to some extent on the diabetic rats. This protection is possibly accomplished through the antioxidant activity of ghrelin observed in type 2 diabetes. Consequently exogenous ghrelin may be a candidate for therapeutic treatment of diabetes.