Yunvjian decoction mitigates hyperglycemia in rats induced by a high-fat diet and streptozotocin via reducing oxidative stress in pancreatic beta cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Yunvjian (YNJ), a traditional Chinese herbal formula first reported in Jing Yue Quan Shu, is commonly used in the clinical treatment of type 2 diabetes mellitus (T2DM). However, the mechanism by which YNJ affects T2DM remains unclear. AIM OF THE STUDY: This study aimed to assess the therapeutic effects of YNJ on T2DM and explore the potential mechanism involved. MATERIALS AND METHODS: High-performance liquid chromatography (HPLC) was used to identify the chemical compounds of YNJ. The anti-T2DM effects of YNJ were observed in a high-fat diet/streptozotocin induced rat model. The type 2 diabetic rats were prepared as follows: rats were fed a high-fat diet for four weeks and then intraperitoneally injected with a low dose (30 mg/kg) of streptozotocin. YNJ and the positive control metformin were used in these experiments. Biochemical assays were implemented to determine the fasting blood glucose, glucose tolerance, insulin sensitivity, serum lipid levels, and oxidative stress index of the pancreas. Hematoxylin-eosin (H&E) staining was used to assess histopathological alterations in the pancreas. The mechanism by which YNJ affects T2DM was evaluated in INS-1 cells treated with glucose and high sodium palmitate. YNJ-supplemented serum was used in these experiments. Methyl thiazolyl tetrazolium assays, enzyme-linked immunosorbent assays, Nile red staining, flow cytometric analysis, and Western blotting were used to assess apoptosis, insulin secretion, lipid accumulation, reactive oxygen species production, and protein levels. RESULTS: Five major compounds were identified in YNJ. In high-fat diet/streptozotocin-induced diabetic rats, YNJ-M notably decreased fasting blood glucose and lipid levels; ameliorated glucose tolerance, insulin sensitivity, and islet morphology; reduced Malondialdehyde levels; and restored superoxide dismutase activity in the pancreatic islets. Furthermore, the effect of YNJ-M was significantly greater than that of YNJ-L, and YNJ-H had little effect on diabetic rats. In vitro experiments revealed that YNJ-supplemented serum (10%, 15%, and 20%) dramatically suppressed apoptosis, mitigated intracellular lipid accumulation and reduced intracellular oxidative stress levels in a dose-dependent manner. Additionally, YNJ-supplemented serum increased the protein expression of Nuclear factor erythroid 2-related factor 2, Heme oxygenase-1, and superoxide dismutase 1 and inhibited the protein expression of Kelch-like ECH-associated protein 1. CONCLUSION: YNJ ameliorates high-fat diet/streptozotocin induced experimental T2DM. The underlying mechanism involves reducing oxidative stress in pancreatic beta cells. The findings of this study provide scientific justification for the application of the traditional medicine YNJ in treating T2DM.

Antihyperglycemic and antihyperlipidemic effects of fruit extract of Hodgsonia heteroclita (Roxb.) Hook. f. & Thomson in diabetic mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Hodgsonia heteroclita has been known as an important traditionally consumed medicinal plant of North-East India known to have antidiabetic properties. This study aims to investigate the effects of the ethanolic fruit extract of Hodgsonia heteroclita against hyperglycemia and hyperlipidemia by using streptozotocin (STZ) treated diabetic mice. MATERIALS AND METHODS: The fruits of H. heteroclita were collected from the various parts of Kokrajhar district, Assam India (Geographic coordinates: 26°24'3.85″ N 90°16'22.30″ E). Basic morphological evaluations were carried out by the Botanical Survey of India, Eastern circle, Shillong, who also certified and identified the plant. Hexane, chloroform, and ethanolic extracts of the fruit of H. heteroclita were investigated for α-amylase inhibition assay as a rapid screening tool for examining anti-diabetic activity. The efficacy of ethanolic extract at a dose of 100, 200, and 300 mg/kg body weight was tested for 21 days in STZ-induced diabetic mice. The body weight, fasting plasma glucose and serum lipids, and hepatic glycogen levels were measured in experimental animals to examine the antihyperglycemic and antihyperlipidemic efficacy of the extract. Both HPTLC and LC-MS analysis was performed to examine the phyotochemicals present in the ethanolic extract of H. heteroclita. RESULTS: It has been observed that treatment with the ethanolic extract dose-dependently reduced the plasma glucose levels, total cholesterol, low density lipoprotein-cholesterol, very low-density lipoprotein-cholesterol, triglyceride, and increased the body weight, liver glycogens and high-density lipoprotein-cholesterol in STZ treated diabetic mice. HPTLC demonstrated the presence of triterpene compounds and LC-MS analysis revealed the presence Cucurbitacin I, Cucurbitacin E, and Kuguacin G as the triterpene phytoconstituents. CONCLUSION: The present study demonstrated that ethanolic fruit extract of H. heteroclita improved both glycemic and lipid parameters in mice model of diabetes.

Neuroprotective role of vitamin B12 in streptozotocin-induced type 1 diabetic rats.

Chronic hyperglycemia-induced neuropathological changes include neuronal apoptosis, astrogliosis, decrease in neurotrophic support, impaired synaptic plasticity, and impaired protein quality control (PQC) system. Vitamin B12 is indispensable for neuronal development and brain function. Several studies reported the neuroprotective effect of B12 supplementation in diabetic patients. However, the underlying molecular basis for the neuroprotective effect of B12 supplementation in diabetes needs to be thoroughly investigated. Two-month-old Sprague-Dawley rats were randomly assigned into three groups: Control (CN), diabetes (D; induced with streptozotocin; STZ), and diabetic rats supplemented with vitamin B12 (DBS; vitamin B12; 50 µg/kg) for four months. At the end of 4 months of experimentation, the brain was dissected to collect the cerebral cortex (CC). The morphology of CC was investigated with H&E and Nissl body staining. Neuronal apoptosis was determined with TUNEL assay. The components of neurotrophic support, astrogliosis, synaptic plasticity, and PQC processes were investigated by immunoblotting and immunostaining methods. H& E, Nissl body, and TUNEL staining revealed that diabetes-induced neuronal apoptosis and degeneration. However, B12 supplementation ameliorated the diabetes-induced neuronal apoptosis. Further, B12 supplementation restored the markers of neurotrophic support (BDNF, NGF, and GDNF), and synaptic plasticity (SYP, and PSD-95) in diabetic rats. Interestingly, B12 supplementation also attenuated astrogliosis, ER stress, and ameliorated autophagy-related proteins in diabetic rats. Overall, these findings suggest that B12 acts as a neuroprotective agent by inhibiting the neuropathological changes in STZ-induced type 1 diabetes. Thus, B12 supplementation could produce beneficial outcomes including neuroprotective effects in diabetic patients.

Ginger Supplementation Attenuated Mitochondrial Fusion and Improved Skeletal Muscle Size in Type 2 Diabetic Rats.

BACKGROUND/AIM: Oxidative stress, regulated by SOD2 and mitochondrial dynamics, contributes to muscle atrophy in diabetes. Ginger root extract (GRE) reduces oxidative stress. However, its effect on oxidative stress, mitochondrial dynamics, and muscle atrophy is not known in the diabetic muscle. This study examined the effect of GRE on intramuscular oxidative stress, mitochondrial dynamics, and muscle size in diabetic rats. MATERIALS AND METHODS: Twenty-six male Sprague-Dawley rats were randomly divided into control diet (CON; n=10), high-fat diet with one dose of 35 mg/kg streptozotocin (HFD; n=9), and high-fat diet with one dose of 35 mg/kg streptozotocin and 0.75% w/w GRE (GRE; n=7) fed for seven weeks. Subsequently, the muscle was analyzed for cross-sectional area (CSA), H2O2 concentration, and DRP-1, MFN2, Parkin, PINK1, SOD2 mRNA. Additionally, the protein levels of SOD2, DRP-1, DRP-1ser616, LC3AB, MFN2, OPA1, Parkin, and PINK1 were analyzed. CSA, H2O2 concentration, and gene and protein expression levels were analyzed using a one-way ANOVA. Correlations among intramuscular H2O2, CSA, and SOD2 protein were assessed using Pearson's bivariate correlation test. RESULTS: In the soleus, the GRE group had a greater CSA and lower intramuscular H2O2 concentration compared to the HFD group. Compared to the HFD group, the GRE group had higher SOD2 and DRP-1 mRNA levels and lower MFN2 and total OPA1 protein levels. H2O2 concentration was negatively correlated with CSA and positively correlated with SOD2. CONCLUSION: GRE attenuated intramuscular H2O2, mitochondrial fusion, and muscle size loss. These findings suggest that GRE supplementation in diabetic rats reduces oxidative stress, which may contribute to muscle size preservation.

Protective effect of Stevia on diabetic induced testicular damage: an immunohistochemical and ultrastructural study.

OBJECTIVE: Diabetes mellitus (DM) has been considered a major problem because of its related complications and growing incidence worldwide. Testicular dysfunction has become a predominant diabetic complication characterized by impaired reproductive function and testicular damage. Stevia rebaudiana Bertoni has been known for its antioxidant effect on diabetes, inflammation, and obesity. The current study investigates the protective effect of Stevia on diabetic-induced testicular injury. MATERIALS AND METHODS: Sprague Dawley adult male rats were divided into three groups: the control group, the diabetic group, and the diabetic + Stevia group, type 2 diabetes is induced by a high-fat diet (HFD) and a single dose of 35 mg/kg streptozotocin injection. The effects of Stevia were evaluated regarding biochemical, oxidative stress, histopathological and ultrastructural changes, and immunohistochemical expression of vascular endothelial growth factor (VEGF), vascular cell adhesion molecule-1 (VCAM-1), receptor-interacting serine/threonine-protein kinase 1 (RIPK 1), and caspase 3. RESULTS: Stevia extract attenuated the diabetic-induced oxidative stress, restored the testicular architecture, and decreased testicular damage, inflammation, necroptosis, and apoptosis by upregulating VEGF and downregulating VCAM 1, RIPK 1, and caspase 3. CONCLUSIONS: The current study highlights the importance of Stevia as an antioxidant anti-inflammatory that ameliorates diabetic-induced testicular injury by modulating oxidative stress, inflammation, necroptosis, and apoptosis.

Chromium Picolinate Protects against Testicular Damage in STZ-Induced Diabetic Rats via Anti-Inflammation, Anti-Oxidation, Inhibiting Apoptosis, and Regulating the TGF-ß1/Smad Pathway.

Chromium picolinate (CP) is an organic compound that has long been used to treat diabetes. Our previous studies found CP could relieve diabetic nephropathy. Thus, we speculate that it might have a positive effect on diabetic testicular injury. In this study, a diabetic rat model was established, and then the rats were treated with CP for 8 weeks. We found that the levels of blood glucose, food, and water intake were reduced, and body weight was enhanced in diabetic rats after CP supplementation. Meanwhile, in CP treatment groups, the levels of male hormone and sperm parameters were improved, the pathological structure of the testicular tissue was repaired, and testicular fibrosis was inhibited. In addition, CP reduced the levels of serum inflammatory cytokines, and decreased oxidative stress and apoptosis in the testicular tissue. In conclusion, CP could ameliorate testicular damage in diabetic rats, as well as being a potential testicle-protective nutrient in the future to prevent the testicular damage caused by diabetes.

Impacts of trelagliptin and remogliflozin alone and in combination with Alpha Lipoic Acid on cardiac function in streptozotocin-induced diabetes mellitus in rats.

This study investigated the effects of trelagliptin and remogliflozin, alone and in combination with alpha lipoic acid (ALA), on cardiac biomarkers in diabetic cardiomyopathy (DCM). We aimed to assess the management of glucotoxicity consequences in streptozotocin-induced diabetic rats by measuring serum levels of pharmacologically active endogenous ligands. Forty-eight male rats were divided into different treatment groups, including negative control, positive control, and four experimental groups. After inducing diabetes, the rats were treated for 28 days, and serum levels of biomarkers associated with oxidative stress (malondialdehyde and thioredoxin-interacting protein), inflammation (nuclear factor NF-kappa-B p105 and lipoprotein-associated phospholipase A2), and myopathy (neprilysin and high selective cardiac troponin T) were measured. Immunohistochemical analysis of heart cells was also performed. The results showed that inducing hyperglycemia increased serum glucose levels and biomarkers associated with DCM. However, all treatment groups exhibited a significant decrease in these biomarkers and an increase in insulin levels compared to the diabetic control group. The groups receiving combination therapy with ALA showed greater improvements in cardiac biomarkers compared to the individual treatments. The immunohistochemical analysis supported these findings by demonstrating a reduction in the percentage area of cathepsin B, a protein involved in DCM pathophysiology. In conclusion, supplementing the base treatments with ALA showed promise in enhancing cardiac biomarkers associated with DCM. The combination of trelagliptin, remogliflozin, and ALA may have additional clinical value in managing DCM by targeting oxidative stress, inflammation, and glucotoxicity. However, further research is needed to validate these findings and explore their potential clinical applications.

Oxidative stress in liver of streptozotocin-induced diabetic mice fed a high-fat diet: A treatment role of Artemisia annua L.

Objective. The aim of this study was the investigation of a treatment role of Artemisia annua L. (AA) on liver dysfunction and oxidative stress in high-fat diet/streptozotocin-induced diabetic (HFD/STZ) mice. Methods. Sixty mice were divided into 12 groups including control, untreated diabetic, and treated diabetic ones with metformin (250 mg/kg), and doses of 100, 200, and 400 mg/kg of water (hot and cold) and alcoholic (methanol) extracts of AA. Type 2 diabetes mellitus (T2DM) was induced in mice by high-fat diet for 8 weeks and STZ injection in experimental animals. After treatment with doses of 100, 200 or 400 mg/kg of AA extracts in HFD/STZ diabetic mice for 4 weeks, oxidative stress markers such as malondialdehyde (MDA), glutathione (GSH), and free radicals (ROS) were determined in the liver tissue in all groups. Results. Diabetic mice treated with metformin and AA extracts showed a significant decrease in ROS and MDA concentrations and a notable increase in GSH level in the liver. Effectiveness of higher doses of AA extracts (200 and 400 mg/kg), especially in hot-water and alcoholic ones, were similar to and/or even more effective than metformin. Conclusion. Therapeutic effects of AA on liver dysfunction showed that antioxidant activity of hot-water and alcoholic AA extracts were similar or higher than of metformin.

Compare the effectiveness of extracorporeal shockwave and hyperbaric oxygen therapy on enhancing wound healing in a streptozotocin-induced diabetic rodent model.

Studies have revealed that both extracorporeal shock-wave therapy (ESWT) and hyperbaric oxygen therapy (HBOT) can accelerate wound healing. This study aimed to compare the effectiveness of ESWT and HBOT in enhancing diabetic wound healing. A dorsal skin defect in a streptozotocin-induced diabetes rodent model was used. Postoperative wound healing was assessed once every 3 days. Histologic examination was performed with hematoxylin and eosin staining. Proliferation marker protein Ki-67 (Ki-67), endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and 8-hydroxy-2-deoxyguanosine (8-OHdG) were evaluated with immunohistochemical (IHC) staining. The wound area was significantly reduced in the ESWT and HBOT groups compared to that in the diabetic controls. However, the wound healing time was significantly increased in the HBOT group compared to the ESWT group. Histological findings showed a statistical increase in neovascularization and suppression of the inflammatory response by both HBOT and ESWT compared to the controls. IHC staining revealed a significant increase in Ki-67, VEGF, and eNOS but suppressed 8-OHdG expression in the ESWT group compared to the HBOT group. ESWT facilitated diabetic wound healing more effectively than HBOT by suppressing the inflammatory response and enhancing cellular proliferation and neovascularization and tissue regeneration.

Protective Properties of Spheroidal Taxifolin Form in Streptozotocin-Induced Diabetic Rats.

One of the key factors in the pathogenesis of diabetes and its complications is oxidative stress. To inhibit this process, antioxidants may be helpful. Herein, we focused on the protective properties of taxifolin spheroidal form (TS) in the streptozotocin rat model of diabetes mellitus. After 4 weeks of treatment with TS, the fasting blood glucose level of the diabetic animals decreased by 12% compared with the level right after the injection of streptozotocin. While the feed intake in the untreated diabetic rats increased by 5.3% compared with the healthy group, the TS-treated group showed a pronounced 15.3% decrease. Therapeutic administration of TS has a protective effect on the pancreas and the liver against the cytotoxic action of streptozotocin. The plasma antioxidant capacity of all diabetic groups appeared to be approximately 15% lower than in healthy rats with no significant difference between the TS-treated and untreated diabetic animals. Apparently, this can be attributed to taxifolin and plasma proteins binding. These data demonstrate the potential of TS in antidiabetic therapy.

Effect of madecassoside in reducing oxidative stress and blood glucose in streptozotocin-nicotinamide-induced diabetes in rats.

OBJECTIVES: Madecassoside (MAD) is a triterpenoid constituent of Centella asiatica (L.) Urb., an ethnomedical tropical plant, extracts of which were shown to reduce blood glucose in experimental diabetes. This study examines MAD for its anti-hyperglycaemic effects and tests the hypothesis that it reduces the blood glucose in experimentally induced diabetic rats by protecting the ß-cells. METHODS: Diabetes was induced using streptozotocin (60 mg/kg, i.v.) followed by nicotinamide (210 mg/kg, intraperitoneal (i.p.)). MAD (50 mg/kg) was administered orally for 4 weeks, commencing 15 days after induction of diabetes; resveratrol (10 mg/kg) was used as a positive control. Fasting blood glucose, plasma insulin, HbA1c, liver and lipid parameters were measured, along with antioxidant enzymes and malondialdehyde as an index of lipid peroxidation; histological and immunohistochemical studies were also undertaken. KEY FINDINGS: MAD normalized the elevated fasting blood glucose levels. This was associated with increased plasma insulin concentrations. MAD alleviated oxidative stress by improving enzymatic antioxidants and reducing lipid peroxidation. Histopathological examination showed significant recovery of islet structural degeneration and an increased area of islets. Immunohistochemical staining showed increased insulin content in islets of MAD-treated rats. CONCLUSIONS: The results demonstrate an antidiabetic effect of MAD associated with preservation of ß-cell structure and function.

Neuroprotective effects of terpenoids against streptozotocin-nicotinamide-induced diabetic rats: An in silico, in vitro and in vivo study.

The present study focused to determine the neuroprotective effects of terpenoids in streptozotocin & nicotinamide-induced type-2 diabetes in rats. The in silico studies were carried out for 68 terpenoids using AutoDock 4.2. The in vitro cholinestrerase, α-amylase enzyme inhibitory assays were perfomed using standard procedures. For in vivo neuroprotective studies, male wistar rats were separated into five groups and each group comprised of six animals. Treatment groups were received low dose and high dose α-Bisabolol 100 and 200 mg/kg respectively, and the standard groups received rivastigmine 2 mg/kg, p.o. and metformin group 100 mg/kg, p.o. for 30 consecutive days. Administration of streptozotocin (45 mg/kg, i.p.) and nicotinamide (110 mg/kg, i.p.)-induced the type 2 diabetes in all groups except the control. The behavioural assessments such as Morris water maze, and open field test were performed and biochemical parameters such as acetylcholinesterase levels and enzymatic antioxidants and reduced glutathione level were estimated from brain homogenates. Treatment of diabetic rats with α-Bisabolol was lowered blood glucose level, improved spatial recognition memory in behavioural assessments in a concentration dependent manner. It can be concluded that α-Bisabolol could act as a potential drug candidate in the management of diabetic Alzheimer's disease.

The Hypoglycemic and Hypolipidemic Effects of Polyphenol-Rich Strawberry Juice on Diabetic Rats.

Obesity and diabetes are some of the most important modern health problems requiring simple preventative or palliative measures using dietary means. This study investigated the impact of strawberry juice on diabetic rats. Diabetes was induced in rats using a single intraperitoneal injection of 50 mg/kg streptozotocin (STZ). Fifty male rats were divided into five groups: normal control (NC), strawberry juice only (S), diabetic control (DC), and two diabetic groups treated with strawberry juice (DC + S) or metformin (DC + met). Rats were administered a single dose of both strawberry juice and oral metformin, and biochemical and histological analyses were conducted. The experiment was conducted in compliance with the Ethics Committee's regulations for the care and utilization of animals, microorganisms, and living cell cultures in education and scientific research at the Faculty of Agriculture, Minia University (MU/FA/006/12/22). Treatment of diabetic rats with strawberry juice led to a significant decrease in blood glucose. Insulin levels were also significantly increased, while lipid profiles were lowered in the diabetic rats treated with strawberry juice. Carbohydrate metabolism enzymes and antioxidant enzyme activities in the treated rats were restored to normal levels, and the levels of lipid peroxidation and proinflammatory cytokines were notably reduced. The microstructure of pancreatic and liver cells in diabetic rats was also improved with strawberry juice treatment. In addition, HPLC analysis revealed that strawberry juice was rich in flavonoids and phenolic compounds and exhibited potent antioxidant activity. These findings suggest that strawberry juice has considerable hypoglycemic and hypolipidemic effects on rats with diabetes which may be used in human after further investigations.

Platycodin D inhibits HFD/STZ-induced diabetic nephropathy via inflammatory and apoptotic signaling pathways in C57BL/6 mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The dried root of Platycodon grandiflorum (Jacq.) A.DC. (PG) is a traditional herb used in Asian countries and is widely used in formulas for the treatment of diabetes. Platycodin D (PD) is one of the most important components of PG. AIM OF THE STUDY: This study aimed to investigate the improvement effects and regulatory mechanisms of PD on kidney injury in a high-fat diet (HFD) combined with streptozotocin (STZ)-induced diabetic nephropathy (DN). MATERIALS AND METHODS: Model mice were treated with oral gavage of the PD (2.5, 5 mg/kg) for 8 weeks. Determination of serum lipid and renal function-related indexes creatinine (CRE), and blood urea nitrogen (BUN) levels in mice, and histopathological section analysis of kidney. Molecular docking and molecular dynamics were utilized to study the binding ability of PD to target NF-κB and apoptosis signaling pathway-related proteins. Moreover, Western blot was used to test the expressions of NF-κB and apoptosis-related proteins. Vitro experiments were performed to validate the related mechanisms using RAW264.7 cells and HK2 cells cultured by high glucose. RESULTS: In vivo experiments, the administration of PD (2.5 and 5.0 mg/kg) reduced fasting blood glucose (FBG) and homeostasis model assessment of insulin resistance (HOMA-IR) levels in DN mice, while lipid levels and renal function were significantly improved. Furthermore, PD significantly inhibited the development of DN in the model mice by regulating NF-κB and apoptotic signaling pathways, reduced the abnormal elevation of serum inflammatory factors TNF-α and IL-1ß, and repaired renal cell apoptosis. In vitro experiments, NF-κB inhibitor ammonium pyrrolidine dithiocarbamate (PDTC) was used to confirm that PD can alleviate high glucose-induced inflammation in RAW264.7 cells and inhibit the release of inflammatory factors. And in HK2 cell experiments, it was verified that PD can inhibit ROS generation, reduce the loss of JC-1 and suppress HK2 cell injury by regulating NF-κB and apoptotic pathways. CONCLUSIONS: These data suggested that PD has the potential to prevent and treat DN and is a promising natural nephroprotective agent.

Protective Effects of Hemp (Cannabis sativa) Root Extracts against Insulin-Deficient Diabetes Mellitus In Mice.

The pharmacological potential of industrial hemp (Cannabis sativa) has been widely studied. However, the majority of studies have focused on cannabidiol, isolated from the inflorescence and leaf of the plant. In the present study, we evaluated the anti-diabetic potential of hemp root water (HWE) and ethanol extracts (HEE) in streptozotocin (STZ)-induced insulin-deficient diabetic mice. The administration of HWE and HEE ameliorated hyperglycemia and improved glucose homeostasis and islet function in STZ-treated mice (p < 0.05). HWE and HEE suppressed ß-cell apoptosis and cytokine-induced inflammatory signaling in the pancreas (p < 0.05). Moreover, HWE and HEE normalized insulin-signaling defects in skeletal muscles and apoptotic response in the liver and kidney induced by STZ (p < 0.05). Gas chromatography-mass spectrometry analysis of HWE and HEE showed possible active compounds which might be responsible for the observed anti-diabetic potential. These findings indicate the possible mechanisms by which hemp root extracts protect mice against insulin-deficient diabetes, and support the need for further studies geared towards the application of hemp root as a novel bioactive material.

[Effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on proteomics and autophagy in mice with type 2 diabetes mellitus induced by high-fat diet coupled with streptozotocin].

To compare the pancreatic proteomics and autophagy between Rehmanniae Radix-and Rehmanniae Radix Praeparata-treated mice with type 2 diabetes mellitus(T2DM). The T2DM mouse model was established by high-fat diet coupled with streptozotocin(STZ, intraperitoneal injection, 100 mg·kg~(-1), once a day for three consecutive days). The mice were then randomly assigned into a control group, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) catalpol groups, low-(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix Praeparata groups, low-(150 mg·kg~(-1)) and high-dose(300 mg·kg~(-1)) 5-hydroxymethyl furfuraldehyde(5-HMF) groups, and a metformin(250 mg·kg~(-1)) group. In addition, a normal group was also set and each group included 8 mice. The pancreas was collected after four weeks of administration and proteomics tools were employed to study the effects of Rehmanniae Radix and Rehmanniae Radix Praeparata on protein expression in the pancreas of T2DM mice. The expression levels of proteins involved in autophagy, inflammation, and oxidative stress response in the pancreatic tissues of T2DM mice were determined by western blotting, immunohistochemical assay, and transmission electron microscopy. The results showed that the differential proteins between the model group and Rehmanniae Radix/Rehmanniae Radix Prae-parata group were enriched in 7 KEGG pathways, such as autophagy-animal, which indicated that the 7 pathways may be associated with T2DM. Compared with the control group, drug administration significantly up-regulated the expression levels of beclin1 and phosphorylated mammalian target of rapamycin(p-mTOR)/mTOR and down-regulated those of the inflammation indicators, Toll-like receptor-4(TLR4) and Nod-like receptor protein 3(NLRP3), in the pancreas of T2DM mice, and Rehmanniae Radix showed better performance. In addition, the expression levels of inducible nitric oxide synthase(iNOS), nuclear factor erythroid 2-related factor 2(Nrf2), and heine oxygenase-1(HO-1) in the pancreas of T2DM mice were down-regulated after drug administration, and Rehmanniae Radix Praeparata demonstrated better performance. The results indicate that both Rehmanniae Radix and Rehmanniae Radix Praeparata can alleviate the inflammatory symptoms, reduce oxidative stress response, and increase the autophagy level in the pancreas of T2DM mice, while they exert the effect on different autophagy pathways.

Ameliorative effect of Arabic gum Acacia and mori extracts in streptozotocin-induced diabetic rats: implications of Cas-3 and TGF-ß.

OBJECTIVE: Arabic gum Acacia (AG) is rich in fiber which improves lipid metabolism besides its antioxidant effect. Folium mori (FM) is a widely used herb due to its immunomodulatory, antimicrobial, and antioxidant activity. In the current study, we explore the antidiabetic, anti-inflammatory, as well as antioxidant activities of AG and FM in Streptozotocin (STZ), induced diabetic rats. MATERIALS AND METHODS: STZ diabetic rats were orally administrated with metformin and/or a combination of AG and FM for 4 weeks. Glycemic levels, Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), cholesterol, triglycerides, urea, and creatinine were determined. Malondialdehyde (MDA), glutathione peroxidase (GPx), and Superoxide dismutase (SOD) were also evaluated. Gene expression and profile as well as immunohistopathological were also evaluated. RESULTS: The results elicited no toxicological profile of both AG and FM. Plasma glucose level was decreased starting from 1st week to 4th week; besides, there was an improvement in glycated hemoglobin, insulin, and fructosamine. Liver and kidney damage markers were decreased in both AG and FM-treated rats. A significant increase in the antioxidant defense system and a decrease in oxidative stress markers were also observed. Gene expression analysis in brain tissues revealed a significant decrease in Interleukin beta 1 (IL-ß1), Caspase 3 (Cas-3), and Transforming growth factor beta (TGF-ß). CONCLUSIONS: Oral treatment of metformin with AG and FM in STZ-injected rats could ameliorate protective pathways and can be one of the promising oral anti-diabetic herbal agents.

Melatonin protects retinal tissue damage in streptozotocin-induced aged rats.

OBJECTIVES: The aim of this study was to investigate how melatonin administration affects retinal oxidative damage and retinal SIRT1 gene activation in diabetic elderly female rat model. METHODS: 16-months-old female rats were used in the study. A total of 24 rats were divided into 4 groups in equal numbers: Group 1. Control, Group 2. Control + Melatonin, Group 3. Diabetes, Group 4. Diabetes + Melatonin. In group 3 and 4 rats, diabetes was induced by intraperitoneal (IP) injection of streptozotocin. Groups 2 and 4 were given ip melatonin for 4 weeks. SIRT-1 gene expression was determined by PCR method and GSH and MDA levels by ELISA in retinal tissue samples taken from animals sacrificed under general anesthesia. RESULTS: In our study, the highest retinal SIRT1 expression values were obtained in the diabetes + melatonin (G4) group. The retinal SIRT1 expression values of the diabetes group (G3) were lower than group 4 and higher than the general control (G1) and control + melatonin (G2) groups. Again in our study, the highest retinal MDA values were obtained in the diabetes group (G3). The highest retinal GSH values were obtained in the Diabetes + melatonin group (G4). CONCLUSION: The results of our study showed that melatonin supplementation has a protective effect on retinal tissue in a diabetic elderly female rat model. This protective effect of melatonin supplementation occurs by increasing both retinal antioxidant activity and retinal SIRT1 gene expression.

Rosa canina L. improves learning and memory-associated cognitive impairment by regulating glucose levels and reducing hippocampal insulin resistance in high-fat diet/streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Recent studies claim that Type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) overlap in several common pathological pathways which from neuronal damage to impaired memory performance. It is known that the use of Rosa canina L. (R. canina) as medicine in folk medicine dates back to ancient times and is used in the treatment of nervous diseases in Persian medicine. However, the effect of R. canina on diabetes-related cognitive decline and memory impairment has not yet been studied. AIM OF THE STUDY: We evaluated the impact of T2DM on AD-like alterations and examined the molecular mechanism of a possible effect of R. canina on cognitive alterations in diabetic rats. MATERIALS&METHODS: R. canina ethanol extract was obtained by maceration method. This study was performed with male Sprague-Dawley rats fed with a high-fat diet (HFD) for 8 weeks, low-dose streptozotocin (STZ; 35 mg/kg IP) injection for 4 weeks, and R. canina (250 mg/kg; per oral) and metformin (400 mg/kg; per oral) administration for 4 weeks. The weight and blood glucose of rats were measured weekly. To evaluate glucose tolerance area under the curve (AUC) was calculated by performing an oral glucose tolerance test. Then the rats were subjected to behavioural tests, and their hippocampus and cortex tissues were obtained for biochemical and morphological analyses. RESULTS: R. canina could manage glucose responsiveness by reducing post-prandial blood glucose levels, preventing weight loss, and raising serum insulin levels in T2DM-induced rats. Behavioural tests showed that R. canina significantly improves diabetes-related cognitive decline in recall and long-term memory. Treatment with R. canina significantly reversed HFD/STZ-induced increases in insulin, amyloid-ß, amyloid precursor protein levels, and acetylcholinesterase activity in the prefrontal cortex and hippocampus. Furthermore, histological analyzes revealed the protection of R. canina against neuronal disruption in the cortical and hippocampal CA3 region caused by chronic hyperglycemia. CONCLUSION: Analyzed collectively, these results suggest that R. canina can correct T2DM-related cognitive decline may be attributed to insulin pathway modulation, prevention of amyloid deposition, and increased cholinergic transmission.

Potential therapeutic effect of medium chain triglyceride oil in ameliorating diabetic liver injury in a streptozotocin-induced diabetic murine model.

OBJECTIVE: Diabetes mellitus is one of the most commonly arising endocrine conditions. The disorder gives rise to enduring damage to a number of body tissues and viscera as a result of related macrovascular and microvascular complications. In patients who are unable to maintain their nutritional status independently, medium-chain triglyceride (MCT) oil is frequently added as a supplement to parenteral nutrition. The aim of the present research is to establish whether MCT oil has a therapeutic influence on the hepatic damage occurring in male albino rats as a result of streptozotocin (STZ)-induced diabetes. MATERIALS AND METHODS: 24 male albino rats were randomized into four cohorts, i.e., controls, STZ-diabetic, metformin-treated and MCT oil-treated. The rodents were fed a high-fat diet for 14 days; a low dose of intraperitoneal STZ was then administered in order to induce diabetes. The rats were subsequently treated for 4 weeks with metformin or MCT oil. Analysis included an appraisal of liver histology and biochemical indices, i.e., fasting blood glucose (FBG), hepatic enzymes and glutathione (GSH), the latter obtained from hepatic tissue homogenate. RESULTS: A rise in FBG and hepatic enzymes was observed, but in the STZ-diabetic cohort, hepatic GSH levels were diminished. Treatment with either metformin or MCT oil led to a decline in FBG and hepatic enzyme titers whereas GSH concentrations increased. Liver histology findings were notable amongst rodents within control, STZ-diabetic and metformin-treated groups. The majority of histological changes were resolved following therapy with MCT oil. CONCLUSIONS: The anti-diabetic and antioxidant characteristics of MCT oil have been substantiated by this work. MCT oil led to a reversal of the hepatic histological changes seen in STZ-induced diabetes in rats.