Antidiabetic and in vitro antioxidant effects of hydromethanol extract of Paullinia pinnata root bark in alloxan-induced diabetic rat

Abstract Background The study evaluated phytochemical composition, antidiabetic, oral glucose tolerance test and in vitro antioxidant activities of hydromethanol extract of Paullinia pinnata root bark. Methods Cold maceration method was used in extract preparation and scavenging of 2,2-diphenyl-1-picrylhydrazyl radicals was used to evaluate antioxidant properties of the extract. Diabetes was induced with alloxan at the dose of 160 mg/kg. The antidiabetic activity of the extract was tested at doses of 50, 100 and 200 mg/kg, and glibenclamide was used as reference drug. Results Phytochemical analysis of the extract showed the presence of alkaloids, flavonoids, glycosides, tannins, saponins and terpenes/sterols. The extract produced a significant (p<0.05) time-dependent decrease in the fasting blood glucose (FBG) levels in the treated rats when compared with the distilled water treated rats, but did not produce dose-dependent effects. The extract 50, 100 and 200 mg/kg and glibenclamide (2 mg/kg) caused 83.62 %, 60.66 %, 47.77 % and 68.52 % reduction respectively in FBG at 6 h post-treatment while the distilled water (5 mL/kg) produced 8.12 % reduction in FBG at 6 h post treatment. The extract (50 mg/kg) and glibenclamide (2 mg/kg) produced a significant (p<0.05) oral glucose tolerance effect in both normoglycemic and diabetic rats. The extract produced concentration-dependent increase in antioxidant activity and had its optimum effect at 400 µg/mL concentration. Conclusions This study suggests that P. pinnata root bark has potent antidiabetic and antioxidant activities and also validates its use in folkloric medicine in the management of diabetes-related conditions.

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Characterization of the Antidiabetic Role ofParkinsonia aculeata(Caesalpineaceae)

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2011/692378 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 10

Author(s):

Ana Catarina Rezende Leite ◽

Tiago Gomes Araújo ◽

Bruno de Melo Carvalho ◽

Maria Bernadete Souza Maia ◽

Vera Lúcia de Menezes Lima

Keyword(s):

Glucose Tolerance ◽

Serum Triglyceride ◽

Diabetic Rats ◽

Epididymal Adipose Tissue ◽

Hepatic Glycogen ◽

Oral Glucose ◽

Phytochemical Analysis ◽

Oral Glucose Tolerance ◽

Urinary Glucose

This paper reports the characterization of the antidiabetic role of a hydroethanolic extract fromParkinsoniaaerial parts (HEPA), in normal and alloxan-induced diabetic rats, treated with HEPA (125 and 250 mg/kg; p.o.). Oral glucose tolerance test, acute oral toxicity test and preliminary phytochemical analyses were performed. The diabetic rats treated with HEPA showed a significant reduction in serum and urinary glucose, urinary urea and triglyceride levels, as compared to the diabetic untreated group. However, in the normal treated groups, a significant reduction was found only in serum triglyceride levels. In all treated diabetic groups, an improvement in hepatic glycogen was observed, as well as a decrease in liquid intake and urinary volume, and an enhancement in the weight of skeletal muscles (soleusandextensor digitorum longus), kidneys and epididymal adipose tissue. Nevertheless, body and liver weights were ameliorated only in the diabetic group treated with HEPA (250 mg/kg). Moreover, oral glucose tolerance was higher in animals treated with HEPA, while results also showed that HEPA could be considered toxicologically safe. Phytochemical analysis revealed the presence of tanins, flavonoids and steroids in HEPA. In conclusion,P. aculeatapresents an antidiabetic activity and other beneficial effects that ameliorate diabetes and associated complications.

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Preliminary Phytochemical Analysis of Extract of Spermadictyon suaveolens and its Effect on Oral Glucose Tolerance in Streptozotocin Induced Diabetic Rats

INTERNATIONAL JOURNAL OF TOXICOLOGICAL AND PHARMACOLOGICAL RESEARCH ◽

10.25258/ijtpr.v9i03.9076 ◽

2017 ◽

Vol 9 (03) ◽

Author(s):

Anuradha Vivekanand Phatak ◽

Kedar Sudhir Prabhavalkar

Keyword(s):

Glucose Tolerance ◽

Glucose Tolerance Test ◽

Tolerance Test ◽

Diabetic Rats ◽

Herbal Extract ◽

Oral Glucose ◽

Phytochemical Analysis ◽

Oral Glucose Tolerance ◽

Streptozotocin Diabetic Rats ◽

Fasted Rats

The preliminary phytochemical analysis of extract of Spermadictyon suaveolens was performed and its effect on oral glucose tolerance in streptozotocin induced diabetic rats studied. 1 week after the administration of streptozotocin, diabetic rats received herbal extract orally at dose 500 mg/kg body weight for 28 consecutive days. Oral glucose tolerance test was performed on overnight fasted rats on day 28. Blood samples were collected prior to glucose administration and at 30, 60, 90, 120 minutes after glucose loading and plasma glucose level was measured for all the samples. The preliminary phytochemical analysis of extract of roots of Spermadictyon suaveolens showed the presence of carbohydrates, flavonoids, glycosides, tannins and phenolic compounds. Extract of roots of Spermadictyon suaveolens improved oral glucose tolerance in streptozotocin induced diabetic rats.

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IN VITRO ANTIOXIDANT POTENTIALS AND HEPATOPROTECTIVE EFFECTS OF Asystasia vogeliana (BENTH) LEAF EXTRACTS AGAINST PARACETAMOL-INDUCED HEPATIC INJURY IN RATS

Journal of Experimental Biology and Agricultural Sciences ◽

10.18006/2020.8(6).839.848 ◽

2020 ◽

Vol 8 (6) ◽

pp. 839-848

Author(s):

Emeka Hillary Ugwuanyi ◽

◽

Chukwuneke Udem Samuel ◽

Ifeanyi Innocent Madubuinyi ◽

◽

...

Keyword(s):

Antioxidant Activities ◽

Radical Scavenging ◽

In Vitro Assays ◽

Distilled Water ◽

Leaf Extracts ◽

Group V ◽

Reference Drug ◽

Group I

This study was aimed to investigate the antioxidant potentials of methanol and petroleum ether leaf extracts of Asystasia vogeliana against paracetamol-induced liver injury in rats. For estimation of antioxidant potentials, in vitro radical scavenging assays were carried out using DPPH, FRAP, and ABTS. For in vivo study, twenty-five male Wistar rats weighing 100-120 g were randomized and assigned into 5 groups (I-V, n=5). Further, Paracetamol (PCM) at 2 g/kg was used to induce acute hepatotoxicity orally. Rats in group I received distilled water (10 ml/kg) only. While, the rats of groups II, III, and IV received MLEAV (200 mg/kg), PLEAV (200 mg/kg), and a standard hepatoprotective reference drug silymarin (25 mg/kg) respectively for 5 days before PCM induction. Rats in group V received distilled water for 5 days before PCM induction. Blood and liver samples were collected for hematology, serum biochemistry, and histopathology analyses using standard procedures. In vitro assays revealed that MLEAV showed significant (P < 0.05) increases in antioxidant activity compared with PLEAV. Further, significant (P < 0.05) reductions in the activities of ALT and ALP while a significant (P < 0.05) increases in the activity of antioxidant enzymes (CAT, SOD, and GPx) were reported in the group II and III compared with group V. There were also no observable lesions in their hepatocytes. Results of the study can be concluded that MLEAV elicited more in vitro and in vivo antioxidant activities than PLEAV, thus it protects the liver of rat from PCM-induced hepatotoxicity. Therefore, MLEAV could be used as a hepatoprotective agent for the clinical management of liver damage.

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Peptide-based GIP receptor inhibition exhibits modest metabolic changes in mice when administered either alone or combined with GLP-1 agonism

10.1101/822122 ◽

2019 ◽

Author(s):

Jason A. West ◽

Soumitra S. Ghosh ◽

David G. Parkes ◽

Anastasia Tsakmaki ◽

Rikke V. Grønlund ◽

...

Keyword(s):

Body Weight ◽

Food Intake ◽

Glucose Tolerance ◽

Mouse Model ◽

Metabolic Effects ◽

Oral Glucose ◽

Oral Glucose Tolerance ◽

Gip Receptor

ABSTRACTObjectiveCombinatorial gut hormone therapy is one of the more promising strategies for identifying improved treatments for metabolic disease. Many approaches combine the established benefits of glucagon-like peptide-1 (GLP-1) agonism with one or more additional molecules with the aim of improving metabolic outcomes. Recent attention has been drawn to the glucose-dependent insulinotropic polypeptide (GIP) system due to compelling pre-clinical evidence describing the metabolic benefits of antagonising the GIP receptor (GIPR). We rationalised that benefit might be accrued from combining GIPR antagonism with GLP-1 agonism. To this end we investigated the metabolic effects of co-administration of previously reported peptide-based GIPR antagonists with the GLP-1 agonist liraglutide.MethodsTwo GIPR peptide antagonists, GIPA-1 (mouse GIP(3-30)NH2) and GIPA-2 (NαAc-K10[γEγE-C16]-Arg18-hGIP(5–42)), were pharmacologically characterised in vitro in an assay measuring cAMP production in CHO-K1 cells overexpressing the mouse GIPR. These peptides were then characterised in vivo in lean mice for their effect on oral glucose tolerance, as well as their ability to antagonize exogenous GIP action. Finally, a mouse model of diet-induced obesity (DIO) was used to investigate the potential metabolic benefits of chronic dosing of peptide-based GIPR antagonists, alone or in combination with liraglutide.ResultsIn vitro, both GIPR peptides exhibited potent antagonistic properties, with GIPA-2 being the more potent of the two. Acute in vivo administration of GIPA-1 during an oral glucose tolerance test (OGTT) had negligible effects on glucose tolerance and circulated insulin in lean mice. In contrast, GIPA-2 impaired glucose tolerance and attenuated circulating insulin levels, with offsetting effects on glycemia noted with co-administration with exogenous mouse GIP, suggesting true antagonism via GIPA-2 at the GIP receptor. Chronic administration studies in a DIO mouse model showed expected effects of GLP-1 agonism (via liraglutide), lowering food intake, body weight, fasting blood glucose and plasma insulin concentrations while improving glucose sensitivity, whereas delivery of either GIPR antagonist alone had negligible effects on these parameters. Interestingly, chronic dual therapy with the GIPR antagonists and GLP-1 showed separation from single intervention arms though augmented insulin sensitizing effects (modestly lowering insulin and HOMA-IR) and lowering plasmas triglycerides and free-fatty acids, with more notable effects observed with GIPA-1 compared to GIPA-2.ConclusionWe conclude that, in contrast to the well-documented effects of GLP-1R agonism, systemic administration of peptide-based GIPR antagonists demonstrate minimal benefit on metabolic parameters in DIO mice, exhibiting no major effects on body weight, food intake and glycaemic parameters. However, the co-administration of both a GIPR antagonist together with a GLP1 agonist uncovers interesting synergistic and beneficial effects on measures of insulin sensitivity, circulating lipids and certain adipose stores that seem influenced by the degree or nature of GIP receptor antagonism.

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Abnormal preconception oral glucose tolerance test predicts an unfavorable pregnancy outcome after an in vitro fertilization cycle

Fertility and Sterility ◽

10.1016/j.fertnstert.2007.07.1289 ◽

2008 ◽

Vol 90 (3) ◽

pp. 613-618 ◽

Cited By ~ 9

Author(s):

H WEI ◽

R YOUNG ◽

I KUO ◽

C LIAW ◽

H CHIANG ◽

...

Keyword(s):

In Vitro Fertilization ◽

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Pregnancy Outcome ◽

Glucose Tolerance Test ◽

Tolerance Test ◽

Oral Glucose ◽

Oral Glucose Tolerance ◽

Vitro Fertilization

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In vitro antioxidant, hypoglycemic and oral glucose tolerance test of banana peels

Alexandria Journal of Medicine ◽

10.1016/j.ajme.2016.05.003 ◽

2017 ◽

Vol 53 (3) ◽

pp. 237-243 ◽

Cited By ~ 6

Author(s):

V.V. Navghare ◽

S.C. Dhawale

Keyword(s):

Glucose Tolerance ◽

Oral Glucose Tolerance Test ◽

Glucose Tolerance Test ◽

Tolerance Test ◽

Oral Glucose ◽

Oral Glucose Tolerance

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Antihyperglycemic Effect of Lavandula pedunculata: In Vivo, In Vitro and Ex Vivo Approaches

Pharmaceutics ◽

10.3390/pharmaceutics13122019 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2019

Author(s):

Salima Boutahiri ◽

Mohamed Bouhrim ◽

Chayma Abidi ◽

Hamza Mechchate ◽

Ali S. Alqahtani ◽

...

Keyword(s):

Glucose Tolerance ◽

Aqueous Extract ◽

Digestive Enzymes ◽

Ex Vivo ◽

Glucose Absorption ◽

Oral Glucose ◽

Oral Glucose Tolerance ◽

Antihyperglycemic Effect

Lavandula pedunculata (Mill.) Cav. (LP) is one of lavender species traditionally used in Morocco to prevent or cure diabetes, alone or in the form of polyherbal preparations (PHP). Therefore, the primary objective of this study was to test the antihyperglycemic effect of the aqueous extract of LP, alone and in combination with Punica granatum L. (PG) and Trigonella foenum-graecum L. (FGK). The secondary objective was to explore some mechanisms of action on the digestive functions. The antihyperglycemic effect of the aqueous extract of LP, alone and in combination with PG and FGK, was studied in vivo using an oral glucose tolerance test (OGTT). In addition, LP extract was tested on the activities of some digestive enzymes (pancreatic α-amylase and intestinal α-glucosidase) in vitro and on the intestinal absorption of glucose ex vivo using a short-circuit current (Isc) technique. Acute and chronic oral administration of LP aqueous extract reduced the peak of the glucose concentration (30 min, p < 0.01) and the area under the curve (AUC, p < 0.01). The effect of LP + PG was at the same amplitude to that of the positive control Metformin (MET). LP aqueous extract inhibited the pancreatic α-amylase with an IC50 almost identical to acarbose (0.44 ± 0.05 mg/mL and 0.36 ± 0.02 mg/mL, respectively), as well as the intestinal α-glucosidase, (IC50 = 131 ± 20 µg/mL) and the intestinal glucose absorption (IC50 = 81.28 ± 4.01 µg/mL) in concentration-dependent manners. LP aqueous extract exhibited potent actions on hyperglycemia, with an inhibition on digestive enzymes and glucose absorption. In addition, the combination with PG and FGK enhanced oral glucose tolerance in rats. These findings back up the traditional use of LP in type 2 diabetes treatment and the effectiveness of the alternative and combinative poly-phytotherapy (ACPP).

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Effects of Uraemic Serum, Urea, Creatinine and Methylguanidine on Glucose Metabolism

Clinical Science ◽

10.1042/cs0420395 ◽

1972 ◽

Vol 42 (4) ◽

pp. 395-404 ◽

Cited By ~ 27

Author(s):

P. L. Balestri ◽

P. Rindi ◽

M. Biagini ◽

S. Giovannetti

Keyword(s):

Glucose Tolerance ◽

Glucose Uptake ◽

Fasting Blood Glucose ◽

Inhibitory Effect ◽

Oral Glucose ◽

Oral Glucose Tolerance ◽

Intravenous Glucose ◽

Diabetic Dogs ◽

Diaphragm In Vitro

1. Uptake of glucose by the rat diaphragm in vitro and utilization of glucose by human erythrocytes were inhibited by urea, creatinine and, to an even greater extent, by urea plus creatinine. Guanidine, methylguanidine and guanidinoacetic acid individually had a small enhancing effect on glucose uptake and utilization but collectively there may be an additive effect. Urate, p-cresol and p-cresylsulphate had no appreciable effects. 2. Dialysis of uraemic patients greatly decreased, or abolished, the inhibitory effect of their sera on glucose uptake by hemidiaphragms. 3. Administration of urea or creatinine lowered the oral glucose tolerance of patients with moderately impaired renal function. 4. In ten normal dogs intravenous glucose tolerance curves were unchanged during methylguanidine administration, whereas in five dogs oral glucose tolerance curves became flattened. 5. Fasting blood glucose of five alloxan-diabetic dogs was decreased during administration of methylguanidine and increased again when administration was discontinued.

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