Elucidation of anti-hyperglycemic activity of Psidium guajava L. leaves extract on streptozotocin induced neonatal diabetic Long-Evans rats.

BACKGROUND: Psidium guajava L (Guava) belongs to the Myrtaceae family and has been claimed to possess several pharmacological properties including antidiabetic. OBJECTIVE: This study was designed to evaluate the anti-hyperglycemic activity of P guajava L leaves aqueous extract on neonatal streptozotocin-induced type 2 diabetic model rats. METHODS: Streptozotocin was induced (90 mg/kg) intraperitoneally to 48 h old Long Evans rat pups. After three months, 18 male type-2 diabetic model rats were confirmed by OGTT (FG > 7 mmol/L). Therefore, experimental rats were divided into three groups 2) Diabetic water control (10 ml/kg), 3) Gliclazide treated (20 mg/kg), and 4) Extract treated group (1.25g/kg)] Six normal female rats comprised group 1 [Non-diabetic water control (10 ml/kg)]. All rats were treated orally with their respective treatment for 28 consecutive days. Blood samples were collected on 0 days (by tail cut method) and the end day (by cardiac puncture) of the experiment. The anti-hyperglycemic activity was evaluated by measuring fasting glucose, serum insulin, lipid profile, hepatic glycogen content, and intestinal glucose absorption by standard methods. RESULTS: The serum glucose level of extract treated group was decreased by 16% as well as significantly (p<0.05) increased the serum insulin level (M±SD, 0 day vs 28thday; 0.319 ± 0.110 vs 0.600 ± 0.348, µg/L). Moreover, the extract-treated group also significantly (p<0.05) enhanced liver glycogen content and inhibited glucose absorption from the upper intestine. Besides, a significant (p < 0.05) reduction of LDL-cholesterol level was found in the extract-treated group (M±SD, 55 ± 33 vs 14 ± 9, mg/dl) compared with baseline values where other groups did not show any statistically remarkable changes. CONCLUSION: Current study concludes that P guajava leaves aqueous extract enhances insulin secretion from pancreatic beta-cells and promotes glycogen synthesis in the liver. The extract also inhibits glucose absorption from the upper intestine and improves dyslipidemia to some extent. Therefore, possesses the potential for drug development against T2DM.

Phytochemical screening and antidiabetic effects of fruit rind of Momordica dioica roxb. on streptozocin induced type 2 diabetic rats.

Momordica dioica (M. dioica) is a gourd like blooming plant that is readily available in Bangladesh, requiring biological research to discover its therapeutic values. The goal of our research was to see if the ethanolic extract of this plant had any anti-hyperglycemic properties. Water, glibenclamide and M. dioica extracts were fed to Streptozocin induced type-2 diabetic rat models at a dose of 1.25 g/kg body weight (bw) for 28 days to see what kind of effects they had on serum glucose, insulin, liver glycogen and lipid contents. Except for the control group, all the groups followed a pattern of maintaining the body weight. The oral glucose tolerance test was observed to be improved in extract after 14 days of the experiment. When assessed with the control group, the M. dioica extract showed a significant (p = 0.0015) decrease in postprandial serum glucose level (M±SD, mmol/l, 13.23 ± 1.03 control Vs 11.47 ± 2.21 extract) at 120 min. The treatment of diabetic model rats with extract resulted in a 7% (p < 0.0001) reduction in serum cholesterol levels. While subsequent 28 days of treatment, insulin levels were found to be lowered in all groups (from 246.76 to 200.44 pg/dL; p < 0.0001 for standard and from 309.01 to 204.61 pg/dL; p < 0.0001 for sample). The results revealed that prolonged administration of M. dioica improved the glycemic and lipidemic state of type-2 diabetic rats, implying that more research is needed to identify the active ingredient (s).

In Vivo Toxicity Studies of Chitosan-Coated Cobalt Ferrite Nanocomplex for Its Application as MRI Contrast Dye.

Cobalt ferrite nanoparticle (CFN) has received attention in magnetic resonance imaging (MRI) as a promising contrast agent due to its higher saturation magnetization and magneto-crystalline anisotropy. However, the in vitro cytotoxicity of CFN has raised concern for its biomedical application as a diagnostic agent. The coating of CFN by a biocompatible polymer such as chitosan (CH) might lessen the biocompatibility concern. Therefore, in this study, we examined the applicability of chitosan-coated cobalt ferrite nanoparticle (CCN) as an MRI contrast dye and investigated its biocompatibility in vivo. Phantom MRI images revealed that the relaxivity of CCN was 121 (±8) mM-1s-1, indicating the potential of CCN as a T2-weighted contrast agent. A single intravenous (iv) administration of CCN (10 mg/kg) improved the contrast of magnetic-resonance-imaging-based angiography (MRA) and brain-MRI in male albino Wistar rats compared to the control. Furthermore, toxicity studies dependent on dose (1-20 mg/kg) and time (1-28 days) in male albino Wistar rats confirmed the in vivo biocompatibility of CCN. The physical, hematological, biochemical, and histopathological observation assured that a single iv injection of CCN up to 20 mg/kg was well adjusted with liver, kidney, heart, and brain functions. The findings of the current study consolidate CCN as a promising candidate for MRI contrast dye.

Glucose and lipid lowering effects of Enhydra fluctuans extract in cadmium treated normal and type-2 diabetic model rats.

BACKGROUND: Recent epidemiological and experimental studies suggest that cadmium and diabetes-related hyperglycemia may act synergistically to worsen metabolic regulation. The present study aims to evaluate the potential effects of Enhydra fluctuans extract in diabetes and dyslipidemia in cadmium (CdCl2) induced- normal and type 2 diabetic model rats. METHOD: Forty-eight Long-Evans rats were divided equally into the following six groups: Normal Control (N-C), Normal treated with CdCl2 (N-Cd), Normal treated with plant extract (N-P), Normal treated with both plant extract and CdCl2 (N-PCd), Diabetic treated with plant extract (DM-P) and Diabetic treated with both plant extract and CdCl2 (DM-PCd). Blood glucose and other biochemical parameters were estimated by the enzymatic colorimetric method. Histological analysis of liver and heart was done by the hematoxylin-eosin (H & E) method. RESULTS: Twenty-one days treatment of E. fluctuans extracts at a dose of 200 mg/kg significantly reduced blood glucose level in N-PCd and DM-PCd (p < 0.05), and DM-P (p < 0.01) group. The plant extract had no direct effects on total blood lipids but, it had beneficial effects on TG/HDL-C ratio in N-P and DM-PCd groups (p < 0.05). Cd induction significantly reduced body weight [(N-Cd, N-PCd, DM-PCd) (p < 0.01)], and induced liver [N-Cd (p < 0.05), N-PCd, p < 0.001] and renal impairment [N-Cd (p < 0.05)]. In bi-variate association, a significant positive correlation between serum glucose and SGPT (p < 0.05) as well as SGPT and TG/HDL ratio (p = 0.019) was found in DM-P and in the merged group. The histology of liver and heart showed severe damages including inflammation, nuclear pyknosis, loss of myocardial fibers, necrosis and fibrosis in the Cd treated groups compared to plant treated groups. CONCLUSION: E. fluctuans seems to have potent antihyperglycemic effects in diabetes and Cd toxicity along with partial antidyslipidemic properties in euglycemic and diabetic rats. Our study suggests a novel oral antihyperglycemic agent in the present environmental context.

Evidence of Toxoplasma gondii in Rodents from Bangladesh.

Rodents contribute to the life cycle of the protozoan parasite Toxoplasma gondii as an intermediate host and key prey animal of cats, the definitive host. As there is limited scientific knowledge available about the incidence and prevalence of T. gondii in commensal rodents in many Asian countries, we tested rodents from a commercial rice mill and eight local villages in Bangladesh for the presence of T. gondii DNA using rodent brain material preserved in ethanol. Overall, 10 of 296 (3.4%) rodent samples tested positive for Toxoplasma DNA. Our results indicate that rodents present in food production and food storage facilities may carry T. gondii.

Oyster mushroom functions as an anti-hyperglycaemic through phosphorylation of AMPK and increased expression of GLUT4 in type 2 diabetic model rats.

OBJECTIVES: Traditionally, mushrooms have been used to reduce hyperglycaemia. However, the mechanism underlying this effect has not yet been explored. AMP-activated protein kinase (AMPK) is known to reduce hyperglycaemia through an insulin-independent pathway. This study aimed to observe the effect of oyster mushroom powder (OMP) on phosphorylation of AMPK (p-AMPK) and expression of GLUT4 mRNA in diabetic model rats. METHODS: Long-Evans rats were used to develop type 2 diabetic model rats through intraperitoneal induction of streptozotocin (STZ). OMP was supplemented at 5% with the usual feed of rats for 8 consecutive weeks. Then, the rats were sacrificed. RNA was extracted by the TRIzol reagent, and proteins were extracted from different tissues with RIPA lysis buffer. Expression of GLUT4 mRNA was measured through cDNA-PCR techniques, and p-AMPK was detected using western blotting. The band intensities of the PCR products and proteins were measured using Image J software. RESULTS: Supplementation of OMP for 8 weeks resulted in a reduction of the serum glucose level in STZ-induced, type 2 diabetic model rats. The levels of p-AMPK, as a ratio relative to ß-actin, increased in the muscle and adipose tissues of mushroom-treated type 2 diabetic model rats, compared to those in control diabetic model rats. Expression of GLUT4, as a ratio relative to GAPDH, increased significantly in both the muscle and adipose tissues of mushroom-treated diabetic rats. CONCLUSION: Oyster mushroom may decrease hyperglycaemia through increased p-AMPK and also expression of GLUT4 in the muscle and adipose tissues.

Effect of aqueous extract of Aegle marmelos fruit and leaf on glycemic, insulinemic and lipidemic status of type 2 diabetic model rats.

BackgroundAegle marmelos is a popular fruit plant in the Indian subcontinent, various parts of which are traditionally used against various illnesses including diabetes mellitus (DM). However, the underlying mechanisms of the antidiabetic effects of the plant are not clear, especially in type 2 DM. The present study was undertaken to investigate the effect of aqueous extracts of A. marmelos fruits (AMFE) and leaves (AMLE) on glycemic, lipidemic, insulinemic, insulin resistance and ß-cell functional status of type 2 diabetic model rats. Methods An interventional study was designed using 20 type 2 diabetic rats. Type 2 DM was induced in Long Evans rats by a single intra-peritoneal injection of streptozotocin (90 mg/kg body weight) to 48 h old pups. Three months after induction of diabetes, the rats were divided into three independent groups: water-treated control group (n=6), AMLE-treated group (n=7) and AMFE-treated group (n=7). The rats were fed with extracts or water for 21 consecutive days and blood samples were collected at days 0 and 21 after an overnight fast. Data were expressed as mean±SD and analyzed by paired t-test or ANOVA as appropriate. Results There were significantly lower blood glucose values in AMLE and AMFE groups at Endpoint compared to Baseline (mmol/l, mean±SD, Baseline vs. Endpoint, 7.04±1.0 vs. 6.06±0.92; p=0.032 and 7.04±0.97 vs. 5.87±0.93; p=0.047). There were also significantly lower serum insulin levels in AMLE and AMFE groups at Endpoint compared to Baseline (µIU/mL, mean±SD, Baseline vs. Endpoint, 14.02±5.48 vs. 7.57±2.90; p=0.026 and 11.54±4.83 vs. 6.58±4.36; p=0.008). Insulin resistance (HOMA-IR) was significantly improved both in AMLE and AMFE groups at Endpoint compared to Baseline (mean±SD, Baseline vs. Endpoint, 4.22±1.68 vs. 2.05±0.90; p=0.021 and 3.69±1.79 vs. 1.69±1.61; p=0.013). However, ß-cell function or lipid profile did not show any significant alteration at Endpoint compared to Baseline in AMLE and AMFE groups. Conclusions Aqueous extracts of A. marmelos leaf and fruit have hypoglycemic property which seem to be mediated by lowering of insulin resistance. These findings highlight the therapeutic potential of the extracts of A. marmelos in human type 2 DM and provides strong impetus for further studies.

Emblica officinalis improves glycemic status and oxidative stress in STZ induced type 2 diabetic model rats.

OBJECTIVE: To evaluate the antidiabetic and antioxidant potential of Emblica officinalis (E. officinalis) fruit on normal and type 2 diabetic rats. METHODS: Type 2 diabetes was induced into the male Long-Evans rats. The rats were divided into nine groups including control groups receiving water, type 2 diabetic controls, type 2 diabetic rats treated with glibenclamide (T2GT) and type 2 diabetic rats treated with aqueous extract of fruit pulp of E. officinalis. They were fed orally for 8 weeks with a single feeding. Blood was collected by cutting the tail tip on 0 and 28 days and by decapitation on 56 day. Packed red blood cells and serum were used for evaluating different biochemical parameters. RESULTS: Four weeks administration of aqueous extract of E. officinalis improved oral glucose tolerance in type 2 rats and after 8 weeks it caused significant (P<0.007) reduction in fasting serum glucose level compared to 0 day. Triglycerides decreased by 14% but there was no significant change in serum ALT, creatinine, cholesterol and insulin level in any group. Furthermore, reduced erythrocyte malondialdehyde level showed no significant change (P<0.07) but reduced glutathione content was found to be increased significantly (P<0.05). CONCLUSIONS: The aqueous extract of E. officinalis has a promising antidiabetic and antioxidant properties and may be considered for further clinical studies in drug development.

In vitro antioxidant effects of Aloe barbadensis Miller extracts and the potential role of these extracts as antidiabetic and antilipidemic agents on streptozotocin-induced type 2 diabetic model rats.

In this study, the total phenolic and flavonoid contents, the 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging ability and the ferric reducing power (FRAP) of Aloe vera were measured to determine the antioxidant activity of this species. The in vivo antidiabetic effects of the plant were also investigated using streptozotocin-induced type 2 diabetic model rats that were divided into five groups based on the treatment received: (1) water (WC); (2) glibenclamide; (3) concentrated gel extract (Gel-C); (4) ethanol (80%) gel extract (Gel-Et); and (5) ethanol (80%) skin extract of Aloe vera (Skin-Et). Skin-Et, which contained the highest level of total phenolics (62.37 ± 1.34 mg(gallic acid)/kg) and flavonoids (20.83 ± 0.77 mg/kg), exhibited the highest scavenging activity (85.01 ± 0.52%) and the greatest reducing power (185.98 ± 0.41 µM), indicating that the skin contained the highest level of antioxidants. The oral consumption of Gel-Et for 4 weeks a caused significant reduction in the fasting serum glucose levels of the rats. The rats in the Gel-C-, Gel-Et- and Skin-Et-treated groups experienced a reduction in their total cholesterol levels by 11%, 17% and 25%, respectively and a reduction in their LDL cholesterol levels by 45%, 3% and 69%, respectively. The in vivo experimental antioxidant parameter MDA is strongly correlated with the in vitro antioxidant parameters of flavonoids and polyphenols, namely the DPPH and FRAP values (r = 0.94, 0.92, 0.93, 0.90), thus confirming the antioxidant potential of the Aloe vera extracts.

Hypoglycaemic and antioxidant activities of Ficus racemosa Linn. fruits.

The effects of Ficus racemosa Linn. fruit extract and fraction on fasting serum glucose levels of normal, type 1 and type 2 diabetic model rats are presented. The aqueous 80% EtOH extract and its water soluble fraction of F. racemosa fruit did not show any serum glucose lowering effect on non-diabetic and type 2 diabetic rats at the fasting condition, whereas the extract showed significant hypoglycaemic effect on the type 1 diabetic model rats. Both the extract and fraction were consistently active in both non-diabetic and types 1 and 2 diabetic model rats when fed simultaneously with glucose load. On the contrary, they were ineffective in lowering blood glucose levels when fed 30 min prior to glucose load. The 1-BuOH soluble part of the ethanol extract exhibited significant antioxidant activity in DPPH free radical scavenging assay. 3-O-(E)-Caffeoyl quinate (1) was isolated for the first time from this plant, which also showed significant antioxidant activity.

Insulin secretory actions of extracts of Asparagus racemosus root in perfused pancreas, isolated islets and clonal pancreatic beta-cells.

Asparagus racemosus root has previously been reported to reduce blood glucose in rats and rabbits. In the present study, the effects of the ethanol extract and five partition fractions of the root of A. racemosus were evaluated on insulin secretion together with exploration of their mechanisms of action. The ethanol extract and each of the hexane, chloroform and ethyl acetate partition fractions concentration-dependently stimulated insulin secretion in isolated perfused rat pancreas, isolated rat islet cells and clonal beta-cells. The stimulatory effects of the ethanol extract, hexane, chloroform and ethyl acetate partition fractions were potentiated by glucose, 3-isobutyl-1-methyl xanthine IBMX, tolbutamide and depolarizing concentration of KCl. Inhibition of A. racemosus-induced insulin release was observed with diazoxide and verapamil. Ethanol extract and five fractions increased intracellular Ca(2+), consistent with the observed abolition of insulin secretory effects under Ca(2+) -free conditions. These findings reveal that constituents of A. racemosus root extracts have wide-ranging stimulatory effects on physiological insulinotropic pathways. Future work assessing the use of this plant as a source of active components may provide new opportunities for diabetes therapy.

Antidiabetic activity of Caesalpinia bonducella F. in chronic type 2 diabetic model in Long-Evans rats and evaluation of insulin secretagogue property of its fractions on isolated islets.

Caesalpinia bonducella F., is a shrub widely distributed throughout the coastal region of India and is ethnically used by the tribal people of Andaman and Nicober Island as a remedy of symptoms of diabetes mellitus. This ethnic report prompted the detail investigation of hypoglycemic activity of Caesalpinia bonducella seeds, initially on physiological hyperglycemic model and then on type 1 and type 2 sub-acute diabetic animal models which has already been reported. Evaluation of different extracts from Caesalpinia bonducella in chronic type 2 diabetic model alongwith insulin secretagogue activity of five fractions isolated from the Caesalpinia bonducella seed kernel are presented in this paper. Both the aqueous and ethanolic extracts showed potent hypoglycemic activity in chronic type 2 diabetic model. Two fractions BM 169 and BM 170 B could increase secretion of insulin from isolated islets.

Advanced studies on the hypoglycemic effect of Caesalpinia bonducella F. in type 1 and 2 diabetes in Long Evans rats.

Caesalpinia bonducella, widely distributed throughout the coastal region of India and used ethnically by the tribal people of India for controlling blood sugar was earlier reported by us to possess hypoglycemic activity in animal model. This prompted us to undertake a detail study with the aqueous and ethanolic extracts of the seeds of this plant in both type 1 and 2 diabetes mellitus in Long Evans rats. Significant blood sugar lowering effect (P < 0.05) of C. bonducella was observed in type 2 diabetic model. Special emphasis was given on the mechanistic study by gut absorption of glucose and liver glycogen.