Ethanol extract of mulberry leaves partially restores the composition of intestinal microbiota and strengthens liver glycogen fragility in type 2 diabetic rats.

BACKGROUND: Mulberry leaf as a traditional Chinese medicine is able to treat obesity, diabetes, and dyslipidemia. It is well known that diabetes leads to intestinal microbiota dysbiosis. It is also recently discovered that liver glycogen structure is impaired in diabetic animals. Since mulberry leaves are able to improve the diabetic conditions through reducing blood glucose level, it would be interesting to investigate whether they have any positive effects on intestinal microbiota and liver glycogen structure. METHODS: In this study, we first determined the bioactive components of ethanol extract of mulberry leaves via high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Murine animal models were divided into three groups, normal Sprague-Dawley (SD) rats, high-fat diet (HFD) and streptozotocin (STZ) induced type 2 diabetic rats, and HFD/STZ-induced rats administered with ethanol extract of mulberry leaves (200 mg/kg/day). Composition of intestinal microbiota was analyzed via metagenomics by sequencing the V3-V4 region of 16S rDNAs. Liver glycogen structure was characterized through size exclusion chromatography (SEC). Both Student's t-test and Tukey's test were used for statistical analysis. RESULTS: A group of type 2 diabetic rat models were successfully established. Intestinal microbiota analysis showed that ethanol extract of mulberry leaves could partially change intestinal microbiota back to normal conditions. In addition, liver glycogen was restored from fragile state to stable state through administration of ethanol extract of mulberry leaves. CONCLUSIONS: This study confirms that the ethanol extract of mulberry leaves (MLE) ameliorates intestinal microbiota dysbiosis and strengthens liver glycogen fragility in diabetic rats. These finding can be helpful in discovering the novel therapeutic targets with the help of further investigations.

Effect of nano yam polysaccharide on the blood glucose and blood lipid in rats.

Chinese yam is the dry rhizome of dioscoreaceae plant. Polysaccharide in yam is one of significant functional components, its pharmacological effects include glucose-lowering, lipid-lowering, anti-tumor, anti-oxidation and enhancing the immune. The effects of nano yam polysaccharide on the metabolism of blood glucose and blood lipid in model rats were systematically investigated in this study. The results showed that the diabetic rat model can been successfully induced by the peritoneal injection of 200mg/kg alloxan. The rats were fed with the high-fat diet for 30d, which could induce a model of hyperlipidemia rat successfully. After the model rats were fed with nano yam polysaccharide of 50mg/ml and 100mg/ml per day for 12d and 30d, respectively. For each nano yam polysaccharide group, the blood glucose level was significantly reduced, the glucose tolerance, glycogen and the content of C-peptide were improved in alloxan rats. Moreover, the symptom of one little and three more in diabetic rats was ameliorated and the contents of TC, TG and LDL-C in the serum for the high fat rats were significantly decreased.

Effects of Sideritis scardica Extract on Glucose Tolerance, Triglyceride Levels and Markers of Oxidative Stress in Ovariectomized Rats.

Menopause is characterized by deep metabolic disturbances, including decreased insulin sensitivity, adiposity, and changes in lipid profiles. Estrogen replacement therapy can partially reverse these changes, and while it is safe in most healthy postmenopausal women, there are still existing concerns regarding an increased risk for breast and endometrial cancer as well as a risk for cardiovascular and thromboembolic disease. Therefore, certain natural compounds with positive metabolic effects may be considered as a possible alternative or adjunctive treatment in patients not willing to take estrogens or patients with contraindications for estrogens. The aim of this study was to investigate the influence of Sideritis scardica (mountain tea) extract on metabolic disturbances induced by ovariectomy in rats. The study included 24 rats divided into three groups: ovariectomized rats treated with 200 mg/kg S. scardica extract for 24 weeks (n = 8), ovariectomized non-treated (n = 8), and Sham-operated (n = 8) rats. Food intake, weight gain, body composition, fasting glucose levels, response to oral glucose challenge, liver glycogen content, catalase activity, thiol groups, and malondialdehyde concentrations as well as AMP-activated protein kinase activity in liver cells were studied. Ovariectomized rats treated with S. scardica extract had lower blood triglycerides, reduced fasting glucose levels, as well lower glucose peaks after oral glucose challenge, increased liver glycogen content, and significantly higher catalase activity and thiol group concentration than non-treated ovariectomized rats. The ability of S. scardica extract to attenuate metabolic disturbances associated with ovariectomy was associated with the activation of AMP-activated protein kinase in liver cells.

Sarcopoterium spinosum extract improved insulin sensitivity in mice models of glucose intolerance and diabetes.

BACKGROUND: The glucose lowering properties of Sarcopoterium spinosum, a traditional medicinal plant, were previously validated by us using KK-Ay mice as a genetic model for type 2 diabetes (T2D). OBJECTIVE: To clarify the effects of Sarcopoterium spinosum extract (SSE) on diet-induced glucose intolerance and to investigate SSE effects on carbohydrate and lipid metabolism in target tissues of both high-fat-diet (HFD)-fed and KK-Ay mice. RESULTS: Mice were given SSE (70 mg/day) for 6 weeks. SSE improved glucose tolerance and insulin sensitivity in HFD-fed mice as was demonstrated previously in KK-Ay mice. Higher insulin sensitivity was validated by lower serum insulin and activation of the insulin signaling cascade in skeletal muscle and liver of SSE-treated mice in both models. H&E staining of the livers demonstrated lower severity of steatosis in SSE-treated mice. Several model-specific effects of SSE were observed-mRNA expression of proinflammatory genes and CD36 was reduced in SSE-treated KK-Ay mice. Hepatic mRNA expression of PEPCK was also reduced in SSE-treated KK-Ay mice, while other genes involved in carbohydrates and lipid metabolism were not affected. HFD-fed mice treated by SSE had elevated hepatic glycogen stores. Gluconeogenic gene expression was not affected, while GCK expression was increased. HFD-induced hepatic steatosis was not affected by SSE. However, while genes involved in lipid metabolism were downregulated by HFD, this was not found in HFD-fed mice given SSE, demonstrating an expression profile which is similar to that of standard diet-fed mice. CONCLUSION: Our study supports the insulin sensitizing activity of SSE and suggests that this extract might improve other manifestations of the metabolic syndrome.

Protective effect of sildenafil on liver injury induced by intestinal ischemia/reperfusion.

BACKGROUND: This study evaluated the protective effect of sildenafil on liver injury induced by intestinal ischemia-reperfusion. METHODS: Forty female Sprague Dawley rats were divided into 4 groups: sham-control (SC), ischemia (I), ischemia-reperfusion (IR), and ischemia-reperfusion+sildenafil (SIL; sildenafil gavaged at 50mg/kg before operating). A 2-h ischemia-reperfusion was performed by clamping the superior mesenteric artery. Liver function, plasma alanine (ALT) and aspartate (AST) aminotransferase, and intestinal and liver malondialdehyde (MDA) were measured at the end of the experiment. Intestinal and liver tissue damage was examined by histology. Liver samples were immunologically stained for endothelial nitric oxide synthase (eNOS) and proliferating cell nuclear antigen (PCNA). RESULTS: The ALT and AST levels were highest in the IR group and were lower in the SIL group (p<0.05). Intestinal MDA levels were statistically higher in the IR group than in the SC, I and SIL groups. Liver MDA levels were significantly higher in the IR group than in the I and SC groups (p<0.05) and higher than in the SIL group (p>0.05). Intestinal damage based on Chiu scoring was more severe in the IR than in the SIL group (p<0.05). Sildenafil reduced damage and also increased eNOS and PCNA immunoreactivity in liver tissue. CONCLUSIONS: Sildenafil shows a protective effect on intestinal ischemia-reperfusion-induced liver injury, possibly by decreasing vascular resistance through increased nitric oxide levels.

Priming the cow for lactation by rapeseed supplementation in the dry period.

High-producing dairy cows experience a sudden and significant increase in energy requirements due to the onset of milk production in early lactation. They mobilize body reserves, mainly adipose tissue, resulting in an increased risk of production decline and the development of health disorders. The objective of the present study was to investigate the effects of feeding oilseeds (rapeseed) during the dry period, thereby priming dairy cows for metabolism of body fat in early lactation. Forty-three Holstein dairy cows were used, 14 were primiparous and 29 were multiparous (≥2 nd lactation). In the dry period, 8 wk before expected calving until calving, the cows were fed either a diet with a high content of rapeseed in the total mixed ration (HF) or a standard total mixed ration with a low content of fat (CON). During the first 5 wk after calving, all the cows were fed a standard low fat lactation ration. The treatments were evaluated by performance and metabolic variables in blood and liver. The dry period diet had no effects on body weight and body condition score of the cows during the dry period and in early lactation. The daily yield of milk, protein, and lactose did not differ among treatments. However, the milk fat concentration was lower and the daily milk fat production tended to be lower for the cows fed the HF diet in the dry period compared with the cows fed the CON diet. The plasma content of nonesterified fatty acids, cholesterol, and phospholipids in the dry period was increased in the HF dry period diet compared with the CON diet. The lower plasma concentration of uric acid obtained prepartum for the cows fed the HF diet may indicate a lower rumen microbial protein synthesis. Postpartum, the plasma concentration of ß-hydroxybutyric acid tended to be lower for the cows fed the HF dry period diet. The liver content of triglycerides was lower and the liver content of glycogen was higher in early lactation among the cows fed the HF dry period diet compared with the cows fed the CON diet. Based on liver glycogen, triglyceride content, and blood ß-hydroxybutyric acid concentration, it could be argued that intake of oilseeds during the dry period is a positive strategy for priming dairy cows for fat metabolism in the following early lactation.

Antihyperglycemic and antihyperlipidemic activities of ethanolic extract of Zygophyllum album in streptozotocin-induced diabetic mice.

Zygophyllum album has been mentioned in Tunisian system of folk medicine to be of value in the treatment of diabetes mellitus. The present study was designed to investigate the possible antihyperglycemic effects of ethanolic extracts of the whole plant of Z. album on blood glucose, plasma insulin, serum lipids and hepatic glycogen and metabolism enzymes of carbohydrate in streptozotocin (STZ)-induced diabetic mice. Administration of the ethanolic extract from plant (100 and 300 mg/kg body weight) for 14 days resulted in significant reduction in plasma glucose, cholesterol, triglycerides, low-density lipoprotein, very-low-density liprotein, hepatic glucokinase and glycogen in STZ diabetic mice. In addition to that, significant increase in plasma high-density lipoprotein, hepatic phosphofructokinase and glucose-6 phosphate dehydrogenase was observed in STZ diabetic mice. After administration of the ethanolic extract, the increased level of plasma insulin is not significant in diabetic mice. In conclusion, the present results showed that the ethanolic extract of Z. album possesses significant antihyperglycemic and antihyperlipidemic effects in experimental model of diabetes mellitus.

Antihyperglycemic potentials of a threatened plant, Helonias dioica: antioxidative stress responses and the signaling cascade.

Helonias dioica (HD) is a threatened species of herb growing in North America. It is used as a traditional medicine for treating various ailments particularly related to reproductive issues. The root is reported to contain approximately 10% of a saponin (chamaelirin; C(36)H(62)O(18)) apart from certain other fatty acids. As saponins are known to have hypoglycemic effects, we suspected its possible antihyperglycemic potentials. We injected intraperitoneally alloxan (ALX) at the dose of 200 mg/kg body weight (bw) to induce hyperglycemia in mice and tested possible hypoglycemic effects of HD in vivo by deploying two doses (100 and 200 mg/kg bw, respectively). We also tested its effects on the isolated pancreatic islets cells in vitro. We used various standard protocols like reactive oxygen species (ROS) generation and DNA damage, activities of biomarkers like catalase (CAT), superoxide dismutase (SOD), lipid peroxidase (LPO), reduced glutathione (GSH) of the pancreas tissue and glucokinase and glycogen content of the liver of hyperglycemic mice. With a mechanistic approach, we also tracked down the possible signaling pathway involved. We found an elevated level of ROS generation, LPO and overexpression of inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF-α), p38 Map kinase (p38 MAPK), nuclear factor (NF)-κß, interferon gamma (IFN-γ), cytochrome c, caspase 3, poly [ADP ribose] polymerase (PARP) and cyclo oxygenase 2 (COX2) in ALX-induced diabetic mouse. Treatment of hyperglycemic mice with both the doses of HD showed a significant decrease with respect to all these parameters of study. Thus, our results suggest that HD prevents ALX-induced islet cell damage and possesses antihyperglycemic and antioxidative potentials.

Chronic supplementation with shark liver oil for reducing tumor growth and cachexia in walker 256 tumor-bearing rats.

We investigated the effect of chronic supplementation with shark liver oil (SLO), an antitumor supplement source of n-3 fatty acids and 1-O-alkylglycerols, alone and combined with coconut fat (CF), a source of saturated fatty acids, on Walker 256 tumor growth and cachexia. Male rats were supplemented daily and orally with SLO and/or CF (1 g per kg body weight) for 7 wk. After 7 wk, 50% of animals were subcutaneously inoculated with 3 × 10(7) Walker 256 tumor cells. After 14 days, the rats were killed, the tumors were removed for lipid peroxidation measurement, and blood was collected for glycemia, triacylglycerolemia, and lacticidemia evaluation. Liver samples were obtained for glycogen measurement. Unlike CF, supplementation with SLO promoted gain in body weight, reduction of tumor weight, and maintained glycemia, triacylglycerolemia, lacticidemia, and liver glycogen content to values similar to non-tumor-bearing rats. Combined supplementation of SLO with CF also showed a reversion of cachexia with gain in body mass, reduction of lacticidemia, maintaining the liver glycogen store, and reduction in tumor weight. SLO, alone or combined with CF, promoted increase of tumor lipid peroxidation. In conclusion, SLO supplemented chronically, alone or associated with CF, was able to reduce tumor growth and cachexia.

Solidago chilensis Meyen hydroalcoholic extract reduces JNK/IκB pathway activation and ameliorates insulin resistance in diet-induced obesity mice.

Hydroalcoholic extract of Solidago chilensis (Sc) is employed in popular medicine to treat inflammatory disease. The low-grade proinflammatory state and the activation of serine/threonine kinases in adipose tissue, like c-jun kinase (JNK) and IKK, and transcription factors, have an important role in obesity-associated insulin resistance. The aim of this study was to further investigate the effects of the Sc extract on glucose homeostasis in diet-induced obesity mice. Male Swiss mice were randomized to three groups: a control group (C) fed with standard laboratory chow; a group with an experimental high-fat diet (HFD); and a group fed with a high-fat (45% kcal from fat) diet + extract of Sc (via intraperitoneal, 3 mg/kg) (ScHFD). The dietary treatment lasted for eight weeks. Subsequently, the expression and phosphorylation of proteins of interest in the liver, hypothalamus and skeletal muscle were evaluated by Western blot analysis. Body weight, epididymal fat pad mass and liver triglycerides were higher in HFD than in control mice, but these parameters were reduced by intraperitoneal administration of the extracts (3 mg/kg) to the HFD group. AKT phosphorylation stimulated by insulin in the liver, hypothalamus and skeletal muscle was higher in ScHFD as compared with HFD mice. Additionally, liver expression of phosphoenolpyruvate carboxykinase (PEPCK) and fatty acid synthase were lower in ScHFD as compared with HFD mice. Nuclear factor κB, p-IκB and p-JNK levels were higher in HFD when compared with control mice, but they were lowered by treatment with extract (ScHFD). In addition, in db/db mice, Sc extract also improved liver AKT phosphorylation stimulated by insulin and reduced PEPCK expression. The data presented herein show that Sc improves AKT activation. This effect may be promoted by reduction of the proinflammatory pathway in the liver and hypothalamus. Therefore, systemic action of the Sc components may contribute to improve obesity-associated pathophysiology.

Effects of Teucrium polium spp. capitatum flavonoids on the lipid and carbohydrate metabolism in rats.

CONTEXT: The main objective of the study was to investigate the biochemical mechanism of the antidiabetic activities of the dry extracts of Teucrium polium L. ssp. capitatum (L.) Arcangeli (Lamiaceae), from Republic of Macedonia, traditionally used to treat diabetes. MATERIALS AND METHODS: Aerial parts of the plant were extracted in alcohol and freeze- or spray-dried, analyzed by high performance liquid chromatography (HPLC) and examined for insulinotropic effect in INS-1E cells in vitro. Their effect on blood glucose, lipids and carbohydrate-related enzymes was tested in normo- and streptozotocin hyperglycemic rats. RESULTS AND DISCUSSION: HPLC analyses revealed several flavonoids: luteolin, apigenin, cirsiliol, diosmetin, cirsimaritin and cirsilineol as both free aglycons and glycosides. The extract and mixture of commercial flavonoids showed a distinct insulinotropic effect on INS-1E cells at 500 µg/ml. Intragastric (i.g.) administration of identical doses of the extract (125 mg/kg) in both normo- and hyperglycemic rats was more efficient in lowering the blood glucose than intraperitoneal injection (35% vs. 24% reduction) with highest effect (50% reduction) 8 h after administration. After 10 days of treatment, the magnitude of the effect was comparable to i.g. administration of 2.5 mg/kg of glibenclamide (38% reduction). No effect was seen on blood lipid profiles. In OGTT (oral glucose tolerance test), the extract lowered blood glucose levels by ~35%. The treatment reduced hepatic glycogen and tended to normalize the activity of gluconeogenic enzymes. CONCLUSION: The results demonstrate that examined plant extracts contain flavonoids with insulinotropic and antihyperglycemic effects.

Effect of melatonin supplementation on plasma glucose and liver glycogen levels in rats subjected to acute swimming exercise.

The aim of the present study is to examine how melatonin supplementation affects plasma glucose and liver glycogen levels in rats subjected to acute swimming exercise. Sprague-Dawley species thirty adult male rats were allocated to 3 groups with equal number of animals: general control group which was not subjected to any procedure (Group 1), the group subjected to a 30-minute acute swimming exercise (Group 2), and the group subjected to a 30-minute acute swimming exercise after intraperitoneal (i.p.) melatonin supplementation (3 mg/kg/day) for 4 weeks (Group 3). Blood samples collected from the experimental animals by decapitation method were analyzed in terms of plasma glucose, and glycogen levels were determined in liver tissue samples by histological method. The highest plasma glucose levels were obtained in group 2 (p < 0.05). Plasma glucose levels in groups 1 and 3 were not different. Mean liver glycogen level in group 3 was significantly higher than those in the other groups (p < 0.01), while there was no significant difference between group 1 and group 2 in terms of this parameter. Results of the study demonstrate that melatonin supplementation can have a protective effect on liver glycogen reserves in rats subjected to acute swimming exercise.

Leucas cephalotes regulates carbohydrate and lipid metabolism and improves antioxidant status in IDDM and NIDDM rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Leucas cephalotes (Roth.) Spreng. (Laminaceae) is an ayurvedic traditional medicinal plant used in India, Nepal and Pakistan to treat several ailments including diabetes. AIM OF THE STUDY: The aim of the present study is to investigate the antidiabetic, antihyperlipaemic and antioxidant activities of Leucas cephalotes for its purported use in diabetes. MATERIALS AND METHODS: The ethanol extract of leaves of Leucas cephalotes was administered (150, 300 and 450 mg kg(-1)bw) to diabetes induced (IDDM and NIDDM) rats and carbohydrate, lipid, antioxidant, urea and creatinine profiles were assessed. RESULTS: All the three doses of extract decreased plasma glucose and lipid profiles and, improved the antioxidant status of both types of diabetic rats. The extract administration improved hepatic glycogen content and hexokinase activity, decreased glucose-6-phosphatase activity, blood urea, creatinine contents and decreased lipid peroxidation in diabetic rats. Of the three doses used, 450 mg kg(-1)bw dose was found to be more potent in its effects comparable to those of glibenclamide and metformin. CONCLUSION: Leucas cephalotes regulates both carbohydrate and lipid metabolism and, improves body antioxidant defense systems in both types of diabetes.

Effects of long-term mildronate treatment on cardiac and liver functions in rats.

Mildronate is a cardioprotective drug that improves cardiac function during ischaemia and functions by lowering l-carnitine concentration in body tissues and modulating myocardial energy metabolism. The aim of the present study was to characterise cardiovascular function and liver condition after long-term mildronate treatment in rats. In addition, changes in the plasma lipid profile, along with changes in the concentration of mildronate, l-carnitine and gamma-butyrobetaine were monitored in the rat tissues. Wistar rats were perorally treated daily with a mildronate dose of either 100, 200 or 400 mg/kg for 4, 8 or 12 weeks. The l-carnitine-lowering effect of mildronate was dose-dependent. However, the carnitine levels reached a plateau after about four weeks of treatment. During the additional weeks of treatment, the carnitine levels were not considerably changed. The obtained results provide evidence that even a high dose of mildronate does not alter cardiovascular parameters and the function of isolated rat hearts. Furthermore, the histological evaluation of liver tissue cryosections and measurement of biochemical markers of hepatic toxicity showed that all the measured values were within the normal reference range. Our results provide evidence that long-term mildronate administration induces significant changes in carnitine homeostasis, but it is not associated with cardiac impairment or disturbances in liver function.

Effect of garlic (Allium sativum) on nickel II or chromium VI induced alterations of glucose homeostasis and hepatic antioxidant status under sub-chronic exposure conditions.

Garlic (Allium sativum) has a profound effect in reducing plasma glucose and increasing serum insulin in diabetic rats. We studied the effect of a garlic extract on nickel- or chromium-induced alteration of plasma glucose and hepatic glycogen levels and anti-oxidant status in rats. Adult male albino rats (n=36) divided into six groups of six animals each were treated as follows: Group I, untreated controls; Group II, fresh aqueous homogenate of garlic; Group III, nickel sulfate; Group IV, nickel sulfate + garlic; Group V, potassium dichromate; Group VI, potassium dichromate + garlic. In Groups IV and VI, the simultaneous administration of garlic abrogated a significant nickel- or chromium-induced increase in plasma glucose and decrease in liver glycogen. Nickel and chromium alone also increased lipid peroxide (LPO) and decreased glutathione levels, as well as the activity of superoxide dismutase (SOD), catalase, and glutathione peroxidase. Simultaneous garlic administration significantly reduced the LPO level and remarkably improved SOD activity. Hence, we postulate that the administration of garlic can prevent nickel II- or chromium VI-induced alterations in blood glucose homeostasis while exerting a hepatoprotective effect on glycogen levels and antioxidant status in male albino rats.

Effects of water extract and crude polysaccharides from Liriope spicata var. prolifera on InsR/IRS-1/PI3K pathway and glucose metabolism in mice.

AIM OF THE STUDY: The present study was designed to investigate the effects of water extract (WE) and crude polysaccharides (CPs) from the tuberous root of Liriope spicata var. prolifer on the InsR/IRS-1/PI3K pathway and glucose metabolism in type 2 diabetic mice. MATERIALS AND METHODS: WE and CPs were administered orally at different doses (200 and 100mg/kg body weight) to streptozotocin (STZ)-induced type 2 diabetic male BABL/c mice, respectively. After 4 weeks of administration, immunohistochemistry and western blot were applied to detect the expression levels of insulin receptor-alpha (InsR-alpha), insulin receptor substrate-1 (IRS-1) and phosphatidylinositol 3-kinase (PI3K) in renal tissues of mice. Moreover, the hepatic glycogen content, glucokinase (GK) and glucose-6-phosphatase (G6Pase) activities were measured to investigate the effect of WE and CPs on glucose metabolism. RESULTS: Compared with diabetic control, greater immunostaining for InsR-alpha, IRS-1 and PI3K was present in the tubulointerstitial regions of WE and CPS groups in renal tissues and the expression levels of these three signal molecules from WE and CPs groups were significantly increased; the glycogen content and GK activity from WE and CPs groups in liver were significantly increased, yet the G6Pase activity was significantly lower. CONCLUSIONS: It is demonstrated that WE and CPs can ameliorate insulin signaling transduction and glucose metabolism, as a result, lessen IR and hyperglycemia eventually. So, this study has provided more powerful evidences for Liriope spicata var. prolifer to be a potential hypoglycemic agent and insulin sensitizer.

Oral administration of Eucalyptus globulus extract reduces the alloxan-induced oxidative stress in rats.

In light of evidence that some complications of diabetes mellitus may be caused or exacerbated by an oxidative stress, the putative protective effect of Eucalyptus globulus, a medicinal plant, was investigated in alloxan-diabetic rats. E. globulus extract was given in drinking water for 15 days at a daily dose equivalent to 130 mg dry leaves/kg of body weight. Lipids peroxidation level and activities of catalase, superoxide-dismutase and glutathione peroxidase were then measured in liver and kidney. Under our experimental conditions, eucalyptus extract was found to significantly reduce the blood glucose level in diabetic animals but failed to restore the liver glycogen level, whereas insulin lowered blood glucose and restored liver glycogen to high concentration. Our results suggest that the antihyperglycemic action of eucalyptus extract is not exerted via the stimulation of insulin secretion but rather unveil a proper effect of the extract involving the enhancement of peripheral glucose uptake. In addition, eucalyptus extract appears to exert an antioxidative activity demonstrated (1) by the increase of catalase, superoxide-dismutase and gluthatione-peroxidase activities in liver and kidney, and (2) a lowering of lipids peroxidation level in these organs. In conclusion, the present study indicates that extract of E. globulus, administered per os, could be used with some profit in diabetic patients.

Diabetic therapeutic effects of ethyl acetate fraction from the roots of Musa paradisiaca and seeds of Eugenia jambolana in streptozotocin-induced male diabetic rats.

The folklore medicine of primitive people has been greatly appreciated for centuries. Many researchers study the curative efficiency and mode of action of various medicinal plants. Serum glucose level, lipid profile, glucose tolerance, hepatic and muscle glycogen contents as well as the activities of hepatic hexokinase and glucose-6-phosphatase recovered significantly after oral administration of ethyl acetate fractions of Eugenia jambolana (E. jambolana) or Musa paradisiaca (M. paradisiaca) in separate (E. jambolana L.: 200 mg/kg of body weight and M. paradisiaca: 100 mg/kg of body weight) or combined form for 90 days (twice a day through gavage) to streptozotocin-induced diabetic rats. The loss in body weight of diabetic animals was reversed and serum levels of insulin as well as C-peptide, which were found to be reduced in diabetic rats, increased significantly after oral administration of the fractions. A histological study of the rats' pancreas revealed that after 90 days of oral treatment with the plant fractions in separate or combined form, the size and volume of pancreatic islets in diabetic treated rats increased significantly compared with the diabetic control group. Treatment of diabetic rats with the combined dose (300 mg/kg of body weight) of plant fractions (200 mg E. jambolana and 100 mg M. paradisiaca) was found to be more effective than treatment with the individual fraction. The doses of E. jambolana and M. paradisiaca selected for this study are the optimum antihyperglycemic doses of the plant fractions, which were determined after conducting a dose-dependent study at various dose levels (50-500 mg/kg) in our pilot experiments. The plant fractions were found to be free from metabolic toxicity. Through HPTLC finger printing, three different compounds were noted in the ethyl acetate fraction of E. jambolana L. and eight different compounds in the ethyl acetate fraction of M. paradisiaca L.

Effects of dietary onion (Allium cepa L.) in a high-fat diet streptozotocin-induced diabetes rodent model.

BACKGROUND/AIMS: The present study was conducted to investigate the effects of two dietary doses of freeze-dried onion powder on diabetes-related symptoms in a high-fat (HF) diet streptozotocin (STZ)-induced diabetes rat model. METHODS: Five-week-old male Sprague-Dawley rats were fed a HF diet for 2 weeks and then randomly divided into 4 groups as follows: HF control (HFC), diabetic control (DBC), onion low (ONL; 0.5%) and onion high (ONH; 2.0%). Diabetes was induced by an intraperitoneal injection of STZ (40 mg/kg body weight) in all groups except the HFC group. RESULTS: After 4 weeks on the experimental diets, fasting blood glucose levels for both onion-fed groups were higher than in the DBC and HFC groups, albeit only significantly so (p < 0.05) in the ONL group. Serum insulin concentrations and insulin resistance were dose-dependently increased (however, not significantly so) in the onion-fed groups compared to the DBC group. Pancreatic beta-cell function and liver glycogen concentrations were nonsignificantly higher in the DBC and ONH groups compared to the ONL group. Additionally, the ONH group had significantly higher lipid concentrations (except for high-density lipoprotein cholesterol) compared to all other groups. The ONL group showed a similar hyperlipidemic trend, however to a lesser extent, with only triglycerides significantly differing from those of the DBC and HFC groups. CONCLUSION: The results suggest that the HF onion diet may increase insulin secretion and consequently insulin resistance in a dose-dependent manner, resulting in a worsened hyperglycemic and hyperlipidemic diabetic state. We conclude that higher dietary fat may impair the antidiabetic effects of dietary onion intake as has been previously reported.

Avaliação do perfil lipídico, glicêmico, conteúdo de glicogênio hepático ecardíaco em ratos diabéticos suplementados com farinha de casca de maracujá (Passiflora edulis) / Assessment of the profile of lipids, glucose, liver and heart glucogen, in diabetic mice supplemented withpassion-fruit rind flour (Passiflora edulis) / Evaluación del perfil de lípidos, glucosa, contenido de glicógeno hepático y cardíaco, en ratones diabéticoscomplementados con harina de cáscara de maracuyá (Pasiflora edulis)

A ingestão de fibras alimentares está associada a redução do risco das complicações do diabetes mellitus, caracterizado pelos níveis elevados de glicose sangüínea. Com base nisto, o presente estudo propôs verificar o efeito da suplementação com farinha de casca de maracujá (Passiflora edulis) sobre os níveis plasmáticos de glicose, triglicérides, colesterol total e frações, e conteúdo de glicogênio hepático e cardíaco de ratos diabéticos. Utilizou-se 25 ratos, divididos em 5 grupos (n=5): grupo controle (GI) e grupo diabético (GII) que receberam ração comercial, dois grupos diabéticos tratados com ração suplementada com farinha de maracujá nas concentrações de 50 (GIII) e 100% (GIV) da dose correspondente à ingestão diária recomendada (IDR) de fibras, e grupo GV com ração suplementadacom 150% da IDR. Após o tratamento, coletou-se o plasma sangüíneo para análise dos parâmetros bioquímicos. No fígado e no coração, dosou-se o conteúdo de glicogênio. Em relação aos níveis lipídicos, não houve diferença significativa entre os grupos. A glicemia do GIII (137,60 ± 10,24 mg/dL)e GIV (153,60 ± 14,99 mg/dL) foi reduzida quando comparada ao GII (399,20 ± 37,21 mg/dL). O teor de glicogênio hepático e cardíaco, respectivamente, em GIII (22,91 ± 7,78 mg/g e 0,65 ± 0,09 mg/g)e GIV (28,29 ± 7,99 mg/g e 2,1 ± 0,19 mg/g) aumentou significativamente em relação ao GI (7,0 ± 4,71mg/g e 0,12 ± 0,01 mg/g), p<0,05. Conclui-se que a utilização da farinha de casca de maracujá nas concentrações de 50 e 100% da IDR foi efetiva para controle glicêmico e aumento do glicogênio hepático e cardíaco, não sendo efetiva na diminuição de lipídios plasmáticos no período de estudo.

The intake of alimentary fibers is associated to the reduction of the risk of complications with diabetes mellitus, which is characterized by high glucose levels in the blood. Based upon this,the present study aimed to check the effect of supplementation with passion fruit rind flour (Pasiflora edulis) on the glucose plasmatic levels, triglycerides, cholesterol total and fractions, and the hepatic and heart glucogen in diabetic mice. Twenty five mice were used, divided into 5 groups (n=5): control group (GI) and diabetic group (GII) which received commercial ration,two diabetic groups which received ration supplemented with passion fruit flour, 50% (GIII) and100% (GIV) concentrations of the recommended dose of daily fiber intake (RDI), and group(GV) having ration supplemented with 150% of the RDI. After the treatment, blood plasma was collected for the analysis of the biochemical parameters. The content of glucogen in the liver and the heart was quantified. In relation to the lipidic levels no significant difference was found among groups. The glucose level in GIII (137.60 + 10.24 mg/dL) and in GIV (153.60 + 14.99 mg/dL) was reduced when compared to GII (399.20 + 37.21 mg/dL). The level of hepatic and heart glucogen was significantly increased in GIII (22.91 + 7.71 mg/g and 0.65 + 0.09 mg/g) and GVI (28.29 + 7.99 mg/g) when compared to GI (7.0 + 4.71 mg/g and 0.12 + 0.01 mg/g), p<0.05. It was concluded that the use of flour from passion fruit rind in the concentrations of 50% and 100% was effective on the control of blood glucose and the increase of hepatic and heart glucogen, not being effective on the reduction of plasmatic lipids during the period of study.

La ingestión de fibras alimentares está asociada a la reducción del riesgo de complicaciones de la diabetes mellitus, caracterizada por elevados niveles de glucosa en la sangre. Con base en esto, el presente estudio se propuso verificar el efecto de la complementación con harina de cáscara de maracuyá (Pasiflora edulis) sobre los niveles plasmáticos de glucosa, triglicéridos, colesterol total y fracciones, y contenido de glicógeno hepático y cardíaco en ratones diabéticos. Se utilizaron 25 ratones, divididos en 5 grupos (n=5): grupo de controle (GI) y grupo diabético (GII) que recibieron ración comercial, dos grupos diabéticos tratados con ración complementada con harina de maracuyá, en las concentraciones de 50% (GIII) y 100% (IV) de la dosis correspondiente a la ingestión diaria recomendada (IDR) de fibras, y grupo (GV) con ración complementada con 150% de la IDR. Tras el tratamiento se colectó el plasma de la sangre para el análisis de los parámetros bioquímicos. En el hígado y en el corazón se ha dosificado el contenido de glicógeno. Con relación a los niveles lípidos no hubo diferencia significativa entre los grupos. La glicemia del GIII (137,60 + 10,24 mg/dL) y GIV (153,60 + 14,99 mg/dL)se ha reducido cuando comparada con GII (399,20 + 37,21 mg/dL). El contenido de glicógenohepático y cardíaco, respectivamente, en GIII (22,91 + 7,78 mg/g y 0,65 + 0,09 mg/g) y GIV(28,29 + 7,99 mg/g y 2,1 + 0,19 mg/g) ha aumentado significativamente con relación al GI (7,0+ 4,71 mg/g), p<0,05. Se ha concluido que la utilización de la harina de cáscara de maracuyá,en las concentraciones de 50% y 100% de la IDR, fue efectiva para el control de la glucosa y del aumento del glicógeno hepático y cardíaco, no resultando efectivo en la reducción de lípidos plasmáticos durante el periodo del estudio.