黄连总生物碱对糖尿病大鼠降血糖作用研究

目的：探讨黄连总生物碱对糖尿病大鼠的降血糖作用。方法：采用链脲佐菌素50 mg/kg诱导SD大鼠形成糖尿病模型,筛选糖尿病大鼠空腹血糖的禁食时间,考察黄连总生物碱给药68d对糖尿病大鼠血糖、糖化血清蛋白、肌酐、尿素氮的影响,并测定其肝、胃、肾脏器指数,评价黄连总生物碱对糖尿病大鼠的降血糖作用。结果：（1）选择白天禁食6 h为糖尿病大鼠的禁食时间。（2）与模型组比较,黄连总生物碱高剂量组（含黄连总生物碱578.7 mg/kg）可明显降低糖尿病大鼠空腹6 h血糖及糖化血清蛋白（P〈0.05）;黄连总生物碱低剂量组（含黄连总生物碱192.9 mg/kg）可显著降低谷胱甘肽-过氧化物酶（P〈0.01）。黄连总生物碱对糖尿病大鼠肌酐、超氧化物歧化酶、总胆固醇、甘油三酯及脏器指数总体上影响不明显（P〉0.05）。结论：黄连总生物碱对糖尿病大鼠有降血糖的作用。     

Modulatory effects of morin on hyperglycemia by attenuating the hepatic key enzymes of carbohydrate metabolism and β-cell function in streptozotocin-induced diabetic rats

The present study was aimed to evaluate the effect of morin on blood glucose, insulin level, hepatic glucose regulating enzyme activities and glycogen level in experimental diabetes. Diabetes mellitus was induced by a single intraperitoneal injection of streptozotocin (STZ) (50 mg/kg b.w.). Five days after STZ injection, diabetic rats received morin (25 and 50 mg/kg b.w.) orally for 30 days. Glibenclamide was used as reference drug. Morin treatment significantly reduced the blood glucose and improved the serum insulin levels. Further, a dose-dependent reduction in glucose-6-phosphatase and fructose-1,6-bisphosphatase was observed along with the increase in liver hexokinase and glucose-6-phosphate dehydrogenase activities. Morin supplement were found to be effective in preserving the normal histological appearance of pancreatic islets as well as to preserve insulin-positive β-cells in STZ-rats. Therefore, these findings suggest that morin displays beneficial effects in the treatment of diabetes, mediated through the regulation of carbohydrate metabolic enzyme activities.     

Effects of gatifloxacin on serum glucose concentration in normal and diabetic rats

To clarify the mechanisms of gatifloxacin (GFLX)-induced hypoglycemia and hyperglycemia, the effect of GFLX on serum glucose levels was investigated in normal and diabetic rats. Rats received an intravenous injection of GFLX and their arterial blood was sampled periodically. Diabetic rats were produced by the intraperitoneal injection of streptozotocin and nicotinamide. In normal rats, the serum glucose concentration was decreased by GFLX at 25 and 50 mg/kg, while it was elevated 0.25 h after the injection of 100 mg/kg of GFLX. Serum immunoreactive insulin (IRI) levels increased as the dose of GFLX increased. The serum epinephrine concentration rose rapidly after the injection of GFLX at 50 and 100 mg/kg. In diabetic rats, the serum glucose concentration was actually increased by GFLX at 50 mg/kg. The baseline concentration of IRI was lower and the degree of the elevation caused by GFLX was smaller in diabetic rats. Both diabetic and control rats showed an increase in the serum epinephrine concentration after the injection of 50 mg/kg of GFLX. In conclusion, GFLX-induced secretion of insulin and epinephrine would contribute to the abnormalities in glucose homeostasis. The response of serum glucose to GFLX may differ between diabetic and normal rats due to the alteration of insulin secretion.     

Protective Effects of Glurenorm (Gliquidone) Treatment on the Liver Injury of Experimental Diabetes

Oxidative stress plays an important role in chronic complications of diabetes mellitus, and hence the regulation of free radicals is essential in the treatment of diabetes. The aim of the current study is to investigate the effect of glurenorm (10 mg/kg) on liver tissue in experimental diabetes. Diabetes was induced by intraperitoneal injection of 65 mg/kg streptozotocin. Glurenorm was administered to one diabetic and one control group separately, from days 14 to 42. On day 42, cardiac blood samples and liver tissue were taken from each rat. In diabetic rats, blood glucose, serum alkaline phosphatase and serum amino transferase activities, serum uric acid, serum sodium and potassium levels, liver nonenzymatic glycosylation, and lipid peroxidation increased, whereas body weight and liver glutathione levels decreased. The diabetic group given glurenorm blood glucose, serum alkaline phosphatase and aminotransferase activities, serum uric acid, sodium and potassium, liver nonenzymatic glycosylation, and lipid peroxidation levels decreased, and liver glutathione levels increased. As a result of all the biochemical findings obtained, it was concluded that glurenorm has a protective effect on damage of liver of streptozotocin-induced diabetes in rats.     

Protective effects of glurenorm (gliquidone) treatment on the liver injury of experimental diabetes

Oxidative stress plays an important role in chronic complications of diabetes mellitus, and hence the regulation of free radicals is essential in the treatment of diabetes. The aim of the current study is to investigate the effect of glurenorm (10 mg/kg) on liver tissue in experimental diabetes. Diabetes was induced by intraperitoneal injection of 65 mg/kg streptozotocin. Glurenorm was administered to one diabetic and one control group separately, from days 14 to 42. On day 42, cardiac blood samples and liver tissue were taken from each rat. In diabetic rats, blood glucose, serum alkaline phosphatase and serum amino transferase activities, serum uric acid, serum sodium and potassium levels, liver nonenzymatic glycosylation, and lipid peroxidation increased, whereas body weight and liver glutathione levels decreased. The diabetic group given glurenorm blood glucose, serum alkaline phosphatase and aminotransferase activities, serum uric acid, sodium and potassium, liver nonenzymatic glycosylation, and lipid peroxidation levels decreased, and liver glutathione levels increased. As a result of all the biochemical findings obtained, it was concluded that glurenorm has a protective effect on damage of liver of streptozotocin-induced diabetes in rats.     

Combined treatment with naringin and vitamin C ameliorates streptozotocin-induced diabetes in male Wistar rats

Diet and nutrition have substantial impact on reducing the incidence of diabetes mellitus, where oxidative stress is an important etiopathological factor. The combined protective role of low dose of naringin (15 mg kg(-1)) and vitamin C (25 mg kg(-1)) and high dose of naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) on streptozotocin (STZ)-induced toxicity was studied in male Wistar rats. To induce type II diabetes mellitus, rats were injected with STZ intraperitoneally at a dose of 45 mg kg(-1) body weight. STZ-induced diabetic rats showed significant increase in blood glucose, water intake, food intake and glycated hemoglobin and significant decrease in plasma insulin, total hemoglobin, body weight and liver glycogen. Diabetic rats also showed significant decrease in the activity of hexokinase and significant increase in the activities of glucose-6-phosphatase and fructose-1,6-bisphosphatase in liver and kidney. The levels of plasma thiobarbituric acid reactive substances, lipid hydroperoxides and vitamin E were elevated while the level of reduced glutathione was decreased in diabetic rats. Glycoprotein components such as hexose, hexosamine, fucose and sialic acid were increased in plasma, liver and kidney of diabetic rats. Oral administration of high doses of naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) to diabetic rats for a period of 21 days normalized all the above-mentioned biochemical parameters. The effect exerted by naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) was similar to the effect exerted by insulin (6 units kg(-1)). Thus, our study shows the antihyperglycemic and antioxidant effects of naringin and vitamin C in STZ-induced type II diabetes mellitus in rats.     

Effect of Withania somnifera on insulin sensitivity in non-insulin-dependent diabetes mellitus rats

We investigated the effect of an aqueous extract of Withania somnifera (WS) on insulin sensitivity in non-insulin-dependent diabetes mellitus (NIDDM) rats. NIDDM was induced by single intraperitoneal injection of streptozotocin (100 mg/kg) to 2 days old rat pups. WS (200 and 400 mg/kg) was administered orally once a day for 5 weeks after the animals were confirmed diabetic (i.e. 75 days after streptozotocin injection). A group of citrate control rats (group I) were also maintained that has received citrate buffer on the second day of their birth. A significant increase in blood glucose, glycosylated haemoglobin (HbA(1)c) and serum insulin levels were observed in NIDDM control rats. Treatment with WS reduced the elevated levels of blood glucose, HbA(1)c and insulin in the NIDDM rats. An oral glucose tolerance test was also performed in the same groups, in which we found a significant improvement in glucose tolerance in the rats treated with WS. The insulin sensitivity was assessed for both peripheral insulin resistance and hepatic insulin resistance. WS treatment significantly improved insulin sensitivity index (K(ITT)) that was significantly decreased in NIDDM control rats. There was significant rise in homeostasis model assessment of insulin resistance (HOMA-R) in NIDDM control rats whereas WS treatment significantly prevented the rise in HOMA-R in NIDDM-treated rats. Our data suggest that aqueous extract of WS normalizes hyperglycemia in NIDDM rats by improving insulin sensitivity.     

Antidiabetic effect of Phlomis anisodonta: effects on hepatic cells lipid peroxidation and antioxidant enzymes in experimental diabetes.

The present study investigated the effects of aerial parts of Phlomis anisodonta methanolic extract (PAE) on streptozotocin (STZ)-induced diabetic rats by measuring fasting blood glucose, serum insulin, change in body weight, ferric reducing antioxidant power (FRAP), lipid peroxidation (LPO), and liver antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Male Wistar rats were randomly divided into six groups of six animals. Treatment of diabetic rats with oral administration of PAE at doses of 100, 200 and 400 mg kg(-1) for 10 days resulted in a significant reduction in fasting blood glucose, and an increase in serum insulin levels in comparison with diabetic control group. PAE also protected rats from STZ-induced loss in body weight. Hepatic FRAP increased and LPO in diabetic rats decreased after treatment by PAE at doses of 200 and 400 mg kg(-1). PAE-treated diabetic rats at three doses indicated a significant increase in hepatic SOD, CAT, and GPx activities. These results suggest that PAE is beneficial in the control of diabetes by reduction of blood glucose and increasing insulin levels and combating oxidative stress by activation of hepatic antioxidant enzymes.     

双(α-呋喃甲酸)氧钒对糖尿病大鼠血糖的调节作用

目的研究双(α-呋喃甲酸)氧钒(VO-FA)对正常大鼠及链脲佐霉素(STZ)性糖尿病大鼠的降糖作用。方法以STZ诱导大鼠糖尿病模型。观察VO-FA灌胃给药后，对血糖、糖化血红蛋白、糖原和血清胰岛素等的影响。结果VO-FA ig两周后，剂量依赖性地降低STZ性糖尿病动物的血糖水平，但对正常动物的血糖无影响。VO-FA 56.8 mg·kg^-1可降低正常动物血清胰岛素水平，加倍剂量尚能降低STZ性糖尿病大鼠的血清胰岛素水平。此外，VO-FA 能降低糖尿病大鼠的糖化血红蛋白，明显改善糖耐量，增加肌糖原和肝糖原的含量，并呈现出量效关系，但对正常动物则没有影响。结论VO-FA可以改善糖尿病动物的糖代谢，而不影响正常动物的血糖水平。     

Geraniol,a natural monoterpene,ameliorates hyperglycemia by attenuating the key enzymes of carbohydrate metabolism in streptozotocin-induced diabetic rats

Context: Geraniol, an acyclic monoterpene alcohol is found in medicinal plants, is used traditionally for several medical purposes including diabetes.

Objectives: The present study evaluates the antihyperglycemic potential of geraniol on key enzymes of carbohydrate metabolism in streptozotocin (STZ)-induced diabetic rats.

Materials and methods: Diabetes was induced in experimental rats, by a single intraperitoneal (i.p) injection of STZ [40?mg/kg body weight (b.w.)]. Different doses of geraniol (100, 200 and 400?mg/kg b.w.) and glyclazide (5?mg/kg b.w.) were administrated orally to diabetic rats for 45?days. Body weight, food intake, plasma glucose, insulin, blood haemoglobin (Hb), glycosylated haemoglobin (HbA_1c), hepatic glucose metabolic enzymes and glycogen were examined.

Results: The LD₅₀ value of geraniol is 3600?mg/kg b.w. at oral administration in rats. Administration of geraniol in a dose-dependent manner (100, 200, 400?mg/kg b.w.) and glyclazide (5?mg/kg b.w.) for 45?days significantly improved the levels of insulin, Hb and decreased plasma glucose, HbA_1C in diabetic-treated rats. Geraniol at its effective dose (200?mg/kg b.w.) ameliorated the altered activities of carbohydrate metabolic enzymes near normal effects compared with two other doses (100 and 400?mg/kg b.w.). Geraniol treatment to diabetic rats improved hepatic glycogen content suggesting its anti-hyperglycemic potential. Geraniol supplement was found to preserve the normal histological appearance of hepatic cells and pancreatic β-cells in diabetic rats.

Discussion and conclusions: The present findings suggest that geraniol can potentially ameliorate key enzymes of glucose metabolism in experimental diabetes even though clinical studies used to evaluate this possibility are warranted.     

小剂量阿司匹林对糖尿病大鼠胰腺功能和凋亡相关蛋白的研究

目的研究小剂量阿司匹林对糖尿病大鼠胰腺功能和凋亡相关蛋白的影响。方法雄性SD大鼠,尾静脉注射链脲佐菌素30mg/kg,造成1型糖尿病动物模型,随机分为糖尿病模型组和9 mg/kg阿司匹林治疗组(ASA治疗组),每组8只,另选8只健康雄性大鼠为正常对照组。各组大鼠灌服给药12周后,检测各组大鼠空腹血糖、血清胰岛素水平,免疫组化法检测分析Caspase-3、Bax和Bcl-2的表达情况。结果与正常对照组比较,糖尿病模型组大鼠空腹血糖提高、血清胰岛素水平降低,胰岛素抵抗指数升高;胰腺组织Caspase-3、Bax表达增强,Bcl-2的表达减弱,Bcl-2/Bax比值降低;ASA治疗组大鼠,血糖减低,胰岛素提高,减低Caspase-3、Bax表达,提升Bcl-2的表达,并明显提高Bcl-2/Bax比值。结论小剂量阿司匹林对糖尿病大鼠胰岛素分泌功能有保护作用,可能与调节胰腺细胞凋亡相关蛋白表达有关。     

Effects of selenium on the serum glucose and insulin levels in diabetic rats]

We investigated the effects of selenium (Se) on the serum glucose and insulin levels in rats with diabetes induced by streptozotocin (STZ, 75 mg/kg, i.p.) and pancreatectomized rats. Moreover, the direct action of Se on insulin release from the isolated pancreatic islets using a slight diabetic rat was studied. The following results were obtained: 1) Selenite at a dose of 173 micrograms/kg (78.9 micrograms/kg of Se base equivalent) drastically reduced the very high level of serum glucose in acute diabetic rats within 5 to 30 min after treatment. During this time period, the insulin level in the serum showed an increasing tendency. 2) The high serum glucose level in chronic diabetic rats returned to the original level with injection of selenite for 4 days, once a day. However, Se did not elicit a significant increase in serum insulin level. 3) Although there was a tendency for the serum glucose level to decrease when selenite was administered into pancreatectomized rats, no secretion of insulin into the serum was observed. 4) Insulin release from isolated pancreatic islets was dose-dependently accelerated by the addition of selenite. These data present the new finding that Se reduced the high level of serum glucose in diabetic rats.     

Antihyperglycemic activity and antidiabetic effect of methyl caffeate isolated from Solanum torvum Swartz. fruit in streptozotocin induced diabetic rats

Natural remedies from medicinal plants are considered to be effective and safe alternatives to treat diabetes mellitus. Solanum torvum Swartz. fruit is widely used in the traditional system of medicine to treat diabetes. In the present study methyl caffeate, isolated from S. torvum fruit, was screened for its efficacy in controlling diabetes in animal models. Antihyperglycemic effect of methyl caffeate was studied in normal glucose-fed rats. The effects of oral administration of methyl caffeate (10, 20 and 40 mg/kg) for 28 days on body weight, fasting blood glucose, plasma insulin, hemoglobin, glycated hemoglobin, total protein, hepatic glycogen and carbohydrate metabolism enzymes in streptozotocin induced diabetic rats were investigated. Histological observations in the pancreas and GLUT4 expression in skeletal muscles were also studied. Methyl caffeate at 40 mg/kg significantly prevented the increase in blood glucose level after glucose administration at 60 min in comparison to the hyperglycemic control group. In streptozotocin induced diabetic rats, methyl caffeate produced significant reduction in blood glucose and increased body weight. The levels and/or activities of other biochemical parameters were near normal due to treatment with methyl caffeate. Methyl caffeate treated diabetic rats showed upregulation of GLUT4 and regeneration of β-cells in the pancreas. These results substantiated that methyl caffeate possessed hypoglycemic effect, and it could be developed into a potent oral antidiabetic drug.     

Antidiabetic activity of alcoholic stem extract of Gymnema montanum in streptozotocin-induced diabetic rats

In the present study, the effect of alcoholic stem extract of Gymnema montanum (GMSt) on blood glucose, plasma insulin, and carbohydrate metabolic enzymes were studied in experimental diabetes. Diabetes mellitus was induced by a single intraperitoneal injection of STZ (60 mg/kg bw). Five days after STZ induction, diabetic rats received GMSt orally at the doses of 25, 50, 100 and 200 mg/kg daily for 3 weeks. Graded doses of stem extract showed a significant reduction in blood glucose levels and improvement in plasma insulin levels. The effect was more pronounced in 100 and 200 mg/kg than 50 mg/kg. GMSt showed significant increase in hexokinase, Glucose-6-phosphate dehydrogenase and glycogen content in liver of diabetic rats while there was significant reduction in the levels of glucose-6-phosphatase and fructose-1,6-bisphosphatase. The present study clearly indicated significant antidiabetic effect with the stem extract of G. montanum and lends support for its traditional usage.     

Antihyperglycemic effect of biochanin A, a soy isoflavone, on streptozotocin-diabetic rats

The study was designed to investigate the antihyperglycemic effect of biochanin A on streptozotocin-diabetic rats. Diabetes was induced in adult male albino rats of the Wistar strain, weighing 180-200 g, by administration of streptozotocin (40 mg/kg of body weight) intraperitoneally. Diabetic rats showed increase in plasma glucose and glycosylated hemoglobin and a decrease in plasma insulin and hemoglobin. Activities of gluconeogenic enzymes such as glucose 6-phosphatase, fructose 1,6-bisphosphatase increased and glucokinase, glucose 6-phosphate dehydrogenase decreased in the liver of diabetic rats along with glycogen. Oral administration of biochanin A (10mg/kg body weight) or glibenclamide (600 μg/kg body weight) in 0.5% dimethyl sulfoxide, for 45 days, prevented the above changes and improved towards normality. In addition, protection against body weight loss of diabetic animals by biochanin A was also observed. No significant effect was observed in normal rats treated with biochanin A (10mg/kg bodyweight). These results showed that biochanin A has potential antihyperglycemic activity at a dose of 10mg/kg bodyweight in streptozotocin induced diabetic rats.     

本草消渴丹对2型糖尿病大鼠血糖和血清胰岛素含量的影响

目的:研究本草消渴丹对2型糖尿病大鼠血糖和血清胰岛素含量的影响。方法:选择高脂、高糖饲料加小剂量链脲佐素(STZ,25mg·kg-1腹腔注射)复制大鼠2型糖尿病模型,分别以本草消渴丹和二甲双胍进行干预,检测空腹血糖。治疗4周后测大鼠空腹血糖、血清胰岛素含量以及大鼠体质量变化。结果:本草消渴丹能显著降低2型糖尿病大鼠血糖含量和胰岛素含量且具有显著缓解体质量增长缓慢的作用。结论:本草消渴丹治疗糖尿病的机制之一是缓解血清胰岛素抵抗。     

Hypoglycemic effect of Hypoxis hemerocallidea corm (African potato) aqueous extract in rats

Diabetes mellitus has been recognized as a clinical syndrome since ancient times, and remains a crippling global health problem today. It is a group of heterogeneous, autoimmune, hormonal and metabolic disorders, often accompanied by hypertension, hyperlipidemia and obesity. Current estimates suggest that approximately 150 million people worldwide suffer from diabetes mellitus. The present study was undertaken to examine the hypoglycemic effect of aqueous extract of Hypoxis hemerocallidea (family: Hypoxidaceae) corm (locally known as "African Potato") in normal (normoglycemic) and in streptozotocin (STZ)-treated, diabetic rats. Young adult, male Wistar rats weighing 250-300 g were used. Diabetes mellitus was induced in the group of diabetic test rats by intraperitoneal injections of STZ (90 mg/kg). In one set of experiments, graded doses of the aqueous extract of African Potato (100-800 mg/kg p.o.) were administered to 12-h fasted normal and diabetic rats. In another set of experiments, 800 mg/kg of African potato extract, a dose of the plant extract that produced maximal hypoglycemic effects in fasted normal and diabetic rats in our pilot experiments, was used. The hypoglycemic effect of this single dose was compared with those of insulin (5 micro U/kg s.c.) and glibenclamide (5 mg/kg p.o.) in 12-h fasted normal and diabetic rats. Following acute treatment, relatively moderate to high doses of African potato extract (100-800 mg/kg p.o.) produced dose-dependent, significant reductions (p < 0.05-0.001) in the blood glucose concentrations of fasted normal and diabetic rats. Similarly, insulin (5 micro U/kg s. c.) and glibenclamide (5 mg/kg p.o.) produced significant reductions (p < 0.01-0.001) in the blood glucose concentrations of the fasted normal and diabetic rats. At a dose of 800 mg/kg, the plant extract caused 30.20% and 48.54% reductions in the blood glucose concentrations of fasted normal and STZ-treated diabetic rats, respectively. While it is likely that the hypoglycemic effect of the plant extract is largely due to its phytosterols and/or sterolin content, the exact mechanism of its hypoglycemic action is still obscure and will have to await further studies. However, the results of this experimental animal study indicate that African potato possesses hypoglycemic activity; and thus lends credence to the suggested folkloric use of the herb in the control and/or management of adult-onset, type 2 diabetes mellitus in some communities of South Africa.     

Antidiabetic properties of the alcoholic extract of Sphaeranthus indicus in streptozotocin-nicotinamide diabetic rats

We have investigated the possible antihyperglycaemic effects of Sphaeranthus indicus extract in rats rendered diabetic by nicotinamide (120 mgkg(-1) i.p.) and streptozotocin (STZ) (60 mgkg(-1) i.p). Fasting plasma glucose levels, serum insulin levels, serum lipid profiles, magnesium levels, glycosylated haemoglobin, changes in body weight and liver glycogen levels were evaluated in normal and diabetic rats. Oral administration of S. indicus for 15 days resulted in significant decrease in blood glucose levels and increases in hepatic glycogen and plasma insulin levels. Fasting normal rats treated with the alcoholic extract of S. indicus showed significant improvement in oral glucose tolerance test. Glibenclamide was used as a reference standard. The findings demonstrate that the alcoholic S. indicus extract may be useful in the treatment of diabetes.     

Treatment with cyclohexenonic long-chain fatty alcohol reverses diabetes-induced tracheal dysfunction in the rat

In this study, we tried to elucidate the effect of cyclohexenonic long-chain fatty alcohol (N-hexacosanol) on tracheal dysfunction in diabetic rats. Diabetes was induced in 8-week-old male Sprague-Dawley rats by administering an intraperitoneal injection of 50 mg/kg streptozotocin. Non-diabetic control rats received an injection of citrate-phosphate buffer alone. Four weeks after the induction of diabetes, rats were randomly divided into 5 groups: age-matched non-diabetic control rats (group A); 4-week diabetic rats without N-hexacosanol treatment (group B); diabetic rats treated with vehicle (group C), and diabetic rats treated with N-hexacosanol at a dose of 2 or 8 mg/kg i.p. every day for the following 4 weeks (group D and group E, respectively; n = 6-8 animals in each group). Serum glucose and insulin levels were determined, as were the contractile responses induced by carbachol and 100 mmol/l KCl. The participation of M(2) and M(3) receptors was investigated in the trachea by real-time polymerase chain reaction (PCR), hematoxylin and eosin (HE) and immunohistochemical staining. Hypertrophy of airway smooth muscle was observed in diabetic rats, and was ameliorated by treatment with N-hexacosanol. Treatment with either 2 or 8 mg/kg N-hexacosanol did not alter diabetic rat status, i.e., body weight, serum glucose or serum insulin levels, but it significantly reversed the decrease in tracheal wall thickness and diabetes-induced hypercontractility in the rat trachea. In the immunohistochemical studies, muscarinic M(2) and M(3) receptors were expressed in the airway smooth muscle, the elastic fibers, the fibroblast and the surface of epithelium, and these expressions were not altered by either induction of diabetes or N-hexacosanol treatment. The expression of M(3) muscarinic receptor mRNAs in the trachea tended to be increased by the induction of diabetes and normalized when treated with N-hexacosanol. Our data indicate that N-hexacosanol could reverse diabetes-induced hypercontractility in the rat trachea.     

Tinospora cordifolia attenuates oxidative stress and distorted carbohydrate metabolism in experimentally induced type 2 diabetes in rats

Diabetes is a chronic metabolic disorder affecting a vast number of people worldwide. Oxidative stress is the causative agent amplifying diabetic complications in various organs by generating noxious amount of free radicals. A huge interest always exists in exploring nutraceuticals from plant materials to replace synthetic drugs in order to overcome their adverse effects and also for economic reasons. The anti-diabetic efficiency of a medicinal plant, Tinospora cordifolia (TC) was studied in experimentally induced type 2 diabetes in Sprague-Dawley rats. Diabetes was induced by a combination of high fat diet (HFD) for a period of 10 weeks followed by intraperitoneal injection of streptozotocin (STZ, 35 mg/kg of body weight). Oral treatment of TC (100 and 200 mg/kg body weight) for 14 days regulated blood glucose, provoked insulin secretion and also suppressed oxidative stress marker, thiobarbituric acid reactive substances (TBARS), formation and restored cellular defence anti-oxidant markers including superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione (GSH), in liver. Treatment with TC (100 and 200 mg/kg) also inhibited glucose 6-phosphatase and fructose 1,6-diphosphatase (p < 0.001); and restored glycogen content in liver (p < 0.005), which was also studied by histopathological staining with periodic acid-Schiff stain. In conclusion, the traditional plant Tinospora cordifolia mediates its anti-diabetic potential through mitigating oxidative stress, promoting insulin secretion and also by inhibiting gluconeogenesis and glycogenolysis, thereby regulating blood glucose.