ABSTRACT
Background: Traditional medicines with anti-diabetic effects are considered suitable supplements to treat diabetes. Among medicinal herbs, Stevia Rebaudiana Bertoni is famous for its sweet taste and beneficial effect in regulation of glucose. However, little is known about the exact mechanism of stevia in pancreatic tissue. Therefore, this study investigated the possible effects of stevia on pancreas in managing hyperglycemia seen in streptozotocin-induced Sprague-Dawley rats
Methods: Sprague-Dawley rats were divided into four groups including normoglycemic, diabetic and two more diabetic groups in which, one was treated with aquatic extract of stevia [400 mg/kg] and the other with pioglitazone [10 mg/kg] for the period of 28 days. After completion of the experimental duration, rats were dissected; blood samples and pancreas were further used for detecting biochemical and histopathological changes. FBS, TG, cholestrol, HDL, LDL, ALT and AST levels were measured in sera. Moreover, MDA [malondialdehyde] level, catalase activity, levels of insulin and PPARgamma mRNA expression were also measured in pancreatic tissue
Results: Aquatic extract of stevia significantly reduced the FBS, triglycerides, MDA, ALT, AST levels and normalized catalase activity in treated rats compared with diabetic rats [p<0.05]. In addition to this, stevia surprisingly, increased PPARgamma and insulin mRNA levels in treated rats [p<0.05]. Furthermore, stevia compensated for the histopathological damage in diabetic rats
Conclusion: It is concluded that stevia acts on pancreatic tissue to elevate the insulin level and exerts beneficial anti-hyperglycemic effects through the PPARgamma-dependent mechanism and stevia's antioxidant properties
ABSTRACT
Objective: Although much is known about estrogen and progesterone, their toxicity or protective effects on hepatocytes are yet to be fully understood. This study investigated the probable oxidant or antioxidant effects of estrogen and progesterone on HepG2 cell line in the presence or absence of H2O2
Methods: HepG2 cells were cultured with two concentrations of estrogen and progesterone [10PM and 1microM] and H2O2 [50 and 200 microM] separately, and in combination, for 24 hours. The effects of selected doses after MTT assay on: 1] cellular integrity, 2] GR and GPx activity, 3] cellular levels of GSH and 4] ALT and AST activities were assessed
Results: MTT assay showed toxic effect of 200 microM H2O2 on the cells. According to MTT results, 10nM and 1 microM doses of estrogen and progesterone and 1microM of each in combination, in the presence of 50 microM H2O2 were selected for the rest of the experiments. Incubation of the cells with H2O2 caused a remarkable decrease in GPx and GR activities as well as GSH level, and an increase in ALT and AST levels. However, treatment with estrogen attenuated further changes and estrogen in combination with progesterone led to a more pronounced amelioration of H2O2-induced toxicity
Conclusion: Our results demonstrated that while high level of oxidative stress is severely cytotoxic, estrogen and progesterone might significantly improve the antioxidant defense within hepatocytes which undergo a low-intensity oxidative exposure
ABSTRACT
Background: It has been proposed that oxidative stress may contribute to the development of testicular abnormalities in diabetes. Morus alba leaf extract [MAE] has hypoglycemic and antioxidant properties. We, therefore, explored the impact of the administration of MAE on steroidogenesis in diabetic rats
Methods: To address this hypothesis, we measured the serum level of glucose, insulin, and free testosterone [Ts] as well as oxidative stress parameters [including glutathione peroxidase, glutathione reductase, total antioxidant capacity, and malondialdehyde] in the testis of control, untreated and MAE-treated [1 g/day/kg] diabetic rats. In order to determine the likely mechanism of MAE action on Ts levels, we analyzed the quantitative mRNA expression level of the two key steroidogenic proteins, namely steroid acute regulatory protein [StAR] and P450 cholesterol side-chain cleavage enzyme [P450scc], by real-time PCR
Results: The MAE-treated diabetic rats had significantly decreased glucose levels and on the other hand increased insulin and free Ts levels than the untreated diabetic rats. In addition, the administration of MAE to the diabetic rats restored the oxidative stress parameters toward control. Induction of diabetes decreased testicular StAR mRNA expression by 66% and MAE treatment enhanced mRNA expression to the same level of the control group. However, the expression of P540scc was not significantly decreased in the diabetic group as compared to the control group
Conclusion: Our findings indicated t hat M AE significantly increased Ts production in the diabetic rats, probably through the induction of StAR mRNA expression levels. Administration of MAE to experimental models of diabetes can effectively attenuate oxidative stress-mediated testosterone depletion
ABSTRACT
Background: Hyperthyroidism is associated with liver oxidative stress causing liver dysfunction in many hyperthyroid patients. The hepatoprotective effect of Satureja Khuzestanica Essential Oil [SKEO], as herbal origin antioxidant and anti-inflammatory agent on the hyperthyroidism induced hepatotoxicity and oxidative stress is investigated
Methods: Adult male sprague dawley rats were divided into categories of; control [group C], hyperthyroid [group H], hyperthyroid with olive oil [group H+O], hyperthyroid with vitamin E [group H+E], hyperthyroid with SKEO [group H+S], combination of hyperthyroid with vitamin E and SKEO [group H+S+E]. Hepatoprotective and antioxidant properties of SKEO with or without vitamin E in hyperthyroid rats were then investigated
Results: Serum Aspartate Transaminase [AST] and Alanine Transaminase [ALT] activities reduced significantly in H+O, H+E, H+S and H+S+E groups in comparison with hyperthyroid rats. Enzymes activities returned to normal in H+S+E group. Hepatic Malondialdehyde [MDA] was reduced in H+E, H+S and H+S+E groups in comparison with hyperthyroid rats. The most significant MDA reduction was in the H+S+E group. Glutathione Peroxidase [GPx] and Glutathione Reductase [GR] activities increased in H+E, H+S and H+S+E groups in comparison with group H. The largest increment in GPx and GR activities were in the H+S+E group. Glutathione level did not change in any group in comparison with the control group
Conclusion: Administration of SKEO has hepatoprotective effect in hyperthyroid rats and is more effective when used in combination with vitamin E
ABSTRACT
OBJECTIVE: Combined oral contraceptives (COCs) have some adverse effects on the serum lipid profile. Because hyperlipidemia is one of the risk factors in cardiovascular diseases, lipid abnormalities should be evaluated in women consuming COCs. Vitamins E and C are known to have beneficial effects on serum lipid profiles. Therefore, in this study, we evaluated the effects of vitamins E and C on serum lipids in women using COCs. METHODS: The study compared changes in lipid parameters with and without vitamin therapy in women consuming COCs compared to those of a control group (40 non-contraceptive users or NCU) for 4 weeks. Total cholesterol and triglyceride, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels along with HDL/LDL ratios were measured for all participants. RESULTS: COC users experienced significantly higher increases in the levels of triglycerides and LDL than non-users (p<0.05). However, no significant differences were noted in the total cholesterol and HDL levels. In the treated COC group receiving vitamins E and C, the HDL level and the HDL/LDL ratio increased and the LDL and triglycerides levels decreased significantly compared with those of the other groups. CONCLUSION: The results of our study indicate that supplementation with antioxidant vitamins E and C restores a normal lipid profile in COC users.
Subject(s)
Female , Humans , Cardiovascular Diseases , Cholesterol , Contraceptives, Oral , Contraceptives, Oral, Combined , Hyperlipidemias , Lipoproteins , Risk Factors , Triglycerides , VitaminsABSTRACT
Combination of glycation and oxidation is associated with diabetes mellitus. The aim of this study was to clarify the effect of glycated proteins in presence of transition metal ions on production of reactive oxygen species [ROS] in rat hepatocyte suspension. Glycated albumin was prepared by incubation of bovine serum albumin with 100 mM glucose in 0.3 M phosphate buffer at 37°C for 2, 4, and 6 weeks. The prepared rat liver cell suspension was treated with glycated albumin in presence of either Fe[+++] or Cu[++] ions. Produced malone-dialdehyde was measured as an indicator of ROS and of cell injury. The results showed Fe[+++] and Cu[++] ions increase the ROS production in presence of glycated albumin [p<0.01]. All prepared glycated albumin showed cytotoxicity in rat hepatocytes suspension in the presence of cupric and ferric ions, and this injury was dependent to metal ion concentration. Higher degree of glycation showed higher effect on ROS production [P<0.01] Comparing the effect of Fe[+++] and Cu[++], cupric ion had higher cytotoxic effect [p<0.01]. Conclusion: These results indicated that hepatocytes may be damaged by ROS which are produced by the interaction of the glycated albumin and transition metal ion
Subject(s)
Animals, Laboratory , Metals , Ions , Transition Elements , Hepatocytes , Rats, Wistar , Reactive Oxygen SpeciesABSTRACT
Aqueous extract of Teucrium polium has been used traditionally as an antidiabetic agent in many Iranian provinces. The goal of this study was to investigate the hypoglycemic effect and histopathological changes in the liver following the ingestion of an extract of T. polium in streptozocin-induced diabetic rats. An aqueous extract of Teucrium polium was fed intra-esophageally to healthy and streptozocin-induced diabetic rats for several days. Serum glucose levels of the case group were measured daily and compared to those of the healthy control. At the end of the extract ingestion period, parts of the animal liver were excised, fixed in formalin and studied histologically. Treatment of diabetic animals with the aqueous extract resulted in a significant decrease [p<0.001] in the serum glucose level after 24h, which reached those of the normoglycemic animals in 8 days. Liver sections from T. polium-treated rats showed marked cytoplasmic hydropic changes in 1/3 to 2/3 of the liver lobule in perivenular and midzonal areas. Apoptopic bodies were also noted in the perivenular zone and Kupffer cells increased in number. Nuclear enlargement with anisonucleosis and prominence of 1 or 2 nucleoli suggestive of regenerative changes were also observed. Although the aqueous extract of T. polium has strong hypoglycemic properties in experimental animals, human application should be discouraged