METHOD: Neonatal streptozotocin-induced non-obese type 2 diabetic rats were treated with a methanolic extract of EO (250 or 500 mg/kg) for 28 days, and blood glucose, serum insulin, and plasma antioxidant status were measured. Insulin and glucagon immunostaining and morphometry were performed in pancreatic section, and liver TBARS and GSH levels were measured. Additionally, EA was tested for glucose-stimulated insulin secretion and glucose tolerance test.
RESULTS: Treatment with EO extract resulted in a significant decrease in the fasting blood glucose in a dose- and time-dependent manner in the diabetic rats. It significantly increased serum insulin in the diabetic rats in a dose-dependent manner. Insulin-to-glucose ratio was also increased by EO treatment. Immunostaining of pancreas showed that EO250 increased β-cell size, but EO500 increased β-cells number in diabetic rats. EO significantly increased plasma total antioxidants and liver GSH and decreased liver TBARS. EA stimulated glucose-stimulated insulin secretion from isolated islets and decreased glucose intolerance in diabetic rats.
CONCLUSION: Ellagic acid in EO exerts anti-diabetic activity through the action on β-cells of pancreas that stimulates insulin secretion and decreases glucose intolerance.
METHODS: Streptozotocin-nicotinamide induced diabetic rats received oral VVSME for 28days. MI was induced by intraperitoneal injection of isoproterenol on last two days. Prior to sacrifice, blood was collected and fasting blood glucose (FBG), glycated hemoglobin (HbA1c), lipid profile and insulin levels were measured. Levels of serum cardiac injury marker (troponin-I and CK-MB) were determined and histopathological changes in the heart were observed following harvesting. Levels of oxidative stress (LPO, SOD, CAT, GPx and RAGE), inflammation (NF-κB, TNF-α, IL-1β and IL-6) and cardiac ATPases (Na(+)/K(+)-ATPase and Ca(2+)-ATPase) were determined in heart homogenates. LC-MS was used to identify constituents in the extracts.
RESULTS: Consumption of VVSME by diabetic rats with or without MI improved the metabolic profiles while decreased the cardiac injury marker levels with lesser myocardial damage observed. Additionally, VVSME consumption reduced the levels of LPO, RAGE, TNF-α, Iκκβ, NF-κβ, IL-1β and IL-6 while increased the levels of SOD, CAT, GPx, Na(+)/K(+)-ATPase and Ca(2+)-ATPase in the infarcted and non-infarcted heart of diabetic rats (p<0.05). LC-MS analysis revealed 17 major compounds in VVSME which might be responsible for the observed effects.
CONCLUSIONS: Consumption of VVSME by diabetics helps to ameliorate damage to the infarcted and non-infarcted myocardium by decreasing oxidative stress, inflammation and cardiac ATPases dysfunctions.
AIMS: To investigate P. niruri leaves aqueous extract (PN) effects on kidney functions, histopathological changes and levels of oxidative stress, inflammation, fibrosis, apoptosis and proliferation in DM.
METHODS: PN was orally administered to streptozotocin-nicotinamide-induced male diabetic rats for 28 days. At the end of the treatment, fasting blood glucose (FBG) and kidney functions were measured. Kidney somatic index, histopathological changes and levels of RAGE, Nrf2, oxidative stress markers (TBARS, SOD, CAT and GPx), inflammatory markers (NFkβ-p65, Ikk-β, TNF-α, IL-1β and IL-6), apoptosis markers (caspase-3, caspase-9 and Bax), fibrosis markers (TGF-β1, VEGF and FGF-1) and proliferative markers (PCNA and Ki-67) were determined by biochemical assays, qPCR, Western blotting, immunohistochemistry or immunofluorescence.
RESULTS: Administration of PN helps to maintain near normal FBG, creatinine clearance (CCr), blood urea nitrogen (BUN), BUN/Cr ratio, serum electrolytes, uric acid and urine protein levels in DM. Decreased RAGE, TBARS and increased Nrf2, SOD-1, CAT and GPx-1 were observed in PN-treated diabetic rat kidneys. Expression of inflammatory, fibrosis and apoptosis markers in the kidney reduced but expression of proliferative markers increased following PN treatment. Lesser histopathological changes were observed in the kidney of PN-treated diabetic rats.
CONCLUSION: PN helps to preserve near normal kidney function and prevents histopathological changes via ameliorating oxidative stress, inflammation, fibrosis and apoptosis while enhancing proliferation of the kidney in DM.
METHODS: Adult male rats with streptozotocin-nicotinamide-induced diabetes were given 50, 100 or 200 mg/kg body weight VVSEE orally for 28 days. At the end of the treatment, body weights were determined, and the blood was collected for analyses of fasting blood glucose, insulin and liver enzyme levels. Following sacrifice, livers were harvested and their wet weights and glycogen contents were measured. Histologic appearances of the livers were observed under light microscopy, and the expression and distribution of inflammatory, apoptosis and proliferative markers in the livers were identified by molecular biologic techniques.
RESULTS: Treatment of rats with diabetes by VVSEE attenuates decreased body weight, liver weight and liver glycogen content. Additionally, increases in fasting blood glucose levels and liver enzyme levels and decreases in serum insulin levels were ameliorated. Lesser histopathologic changes were also observed: decreased inflammation and apoptosis, as indicated by decreased levels of inflammatory markers (TNF-α, NF-Kβ, IKK-β, IL-6, IL-1β) and apoptosis markers (caspase-3, caspase-9 and Bax). VVSEE treatment induces increase in hepatocyte regeneration, as indicated by increased PCNA and Ki-67 distribution in the livers of rats with diabetes. Several molecules identified in VVSEE via gas chromatography mass spectrometry might contribute to these effects.
CONCLUSIONS: The anti-inflammatory, anti-apoptotic and pro-proliferative effects of VVSEE could account for its hepatoprotective actions in diabetes.
AIM OF STUDY: To investigate the potential protective effects of L. flavescens in pancreatic β cells through inhibition of apoptosis and autophagy cell death mechanisms in in vitro and in vivo models.
MATERIALS AND METHODS: L. flavescens leaves were extracted using solvent in increasing polarities: hexane, ethyl acetate, methanol and water. All extracts were tested for INS-1 β cells viability stimulated by streptozotocin (STZ). The extract which promotes the highest cell protective activity was further evaluated for insulin secretion, apoptosis and autophagy signaling pathways. Then, the acute toxicity of extract was carried out in SD rats according to OECD 423 guideline. The active extract was tested in diabetic rats where the pancreatic β islets were evaluated for insulin, apoptosis and autophagy protein.
RESULTS: The methanolic extract of L. flavescens (MELF) was found to increase INS-1 β cells viability and insulin secretion against STZ. In addition, MELF has been shown to inhibit INS-1 β cells apoptosis and autophagy activity. Notably, there was no toxicity observed in SD rats when administered with MELF. Furthermore, MELF exhibited anti-hyperglycemic activity in diabetic rats where apoptosis and autophagy protein expression was found to be suppressed in pancreatic β islets.
CONCLUSION: MELF was found to protect pancreatic β cells function from STZ-induced apoptosis and autophagy in in vitro and in vivo.