scholarly journals In Vitro and In Vivo Effects of Norathyriol and Mangiferin on α-Glucosidase

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Zhi-Long Shi ◽  
Yi-Dan Liu ◽  
Yun-Yun Yuan ◽  
Da Song ◽  
Mei-Feng Qi ◽  
...  

Norathyriol is a metabolite of mangiferin. Mangiferin has been reported to inhibit α-glucosidase. To the best of our knowledge, no study has been conducted to determine or compare those two compounds on inhibiting α-glucosidase in vitro and in vivo by far. In this study, we determined the inhibitory activity of norathyriol and mangiferin on α-glucosidase in vitro and evaluated their antidiabetic effect in diabetic mice. The results showed that norathyriol inhibited α-glucosidase in a noncompetitive manner with an IC50 value of 3.12 μM, which is more potent than mangiferin (IC50 = 358.54 μM) and positive drug acarbose (IC50 = 479.2 μM) in the zymological experiment. Both of norathyriol and mangiferin caused significant (p<0.05) reduction in fasting blood glucose and the blood glucose levels at two hours after carbohydrate loading and it was interesting that mangiferin and norathyriol can make the decline of the blood glucose earlier than other groups ever including normal group in the starch tolerance test. However, norathyriol and mangiferin did not significantly influence carbohydrate absorption in the glucose tolerance test. Therefore, the antidiabetic effects of norathyriol and mangiferin might be associated with α-glucosidase, and norathyriol was more potent than mangiferin.

1983 ◽  
Vol 104 (4_Suppl) ◽  
pp. S11-S17
Author(s):  
Bengt Scherstén ◽  
Per-Olof Bitzén

ABSTRACT. The procedure for diagnosing diabetes mellitus when accompanied by classical symptoms is based on random blood glucose levels of 7 mmol/l or more. Problem of diagnosing diabetes in the asymptomatic subject remains difficult. A procedure based on fasting blood glucose levels below 5.5 mmol/l in normals and reproducible values at or above 7 mmol/l in diabetics is proposed. In cases with fasting blood glucose values between 5.5 and 7 mmol/l standardized oral glucose tolerance test is recommended. The diagnostic criteria for normality, impaired glucose tolerance and for diabetes are evaluated against the results of a 10–14 years prospective study.


2002 ◽  
Vol 30 (02n03) ◽  
pp. 187-194 ◽  
Author(s):  
Jing-Tian Xie ◽  
Han H. Aung ◽  
Ji An Wu ◽  
A. S. Attele ◽  
Jongbae Park

In this study, we evaluated antihyperglycemic effects of American ginseng berry extract in diabetic ob/ob mice. Animals received daily intraperitoneal (IP) injections of the extract 150 mg/kg for 12 days. On days 5 and 12, the extract-treated ob/ob mice had significantly lower fasting blood glucose levels compared to day 0 (both p < 0.05). Glucose tolerance improved significantly, which was shown by overall glucose excursion, calculated as area under the curve (AUC) during the two-hour IP glucose tolerance test. The AUC decreased by 31.8% on day 12 compared to day 0 (p < 0.01). In addition, after 12 days of the berry extract treatment, a significant reduction in body weight (p < 0.01 compared to day 0) and a significant increase in body temperature (p < 0.01 compared to day 0) was noticeable. Our results support in vivo antihyperglycemic and antiobese activity of American ginseng berry extract that may prove to be of clinical importance in the prevention and treatment of Type 2 diabetes.


2020 ◽  
Vol 10 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Morad Hebi ◽  
Mohamed Eddouks

Background: Corrigiola telephiifolia Pourr, is a perennial species, woody distributed throughout the north of Africa. This plant is used in traditional Mediterranean preparations and has many traditional uses especially treatment of diabetes. Aim/Methods: The current research was carried out to evaluate the antidiabetic effect of Aerial Parts of Aqueous Extract (APAE) of Corrigiola telephiifolia (C. telephiifolia) on both normal and streptozotocin (STZ)-induced diabetic rats treated at a dose of 5 mg/kg for fifteen days. Additionally, the histopathological changes in the liver, morphometric analysis, Oral Glucose Tolerance Test (OGTT) in normal rats and preliminary phytochemical screening for various components were realized. Results: Single oral administration of the APAE of C. telephiifolia (5mg/kg) showed no significant change in glycaemia of normal and STZ-induced diabetic rats. In contrast, repeated oral administration of C. telephiifolia reduced blood glucose levels from 4.11 ± 0.10 mmol/L to 3.16 ± 0.16 mmol/L (p<0.01) 15 days after administration in normal rats. Furthermore, blood glucose levels decreased from 17.84 ± 1.75mmol/L to 1.93 ± 0.33 mmol/L (p<0.0001) in STZ diabetic rats after fifteen days of treatment. According to the oral glucose tolerance test, C. telephiifolia (5 mg/kg) was shown to prevent significantly the increase in blood glucose levels in normal treated rats 30 min after glucose administration when compared to the control group. Also, the liver architecture of diabetic rats treated by C. telephiifolia was improved when compared with the liver architecture of untreated diabetic rats. Concerning the preliminary phytochemical screening of C. telephiifolia, several compounds have been found such as polyphenols, flavonoids, saponins, mucilage and terpenoids. Conclusion: The results show that the aqueous extract of C. telephiifolia possesses significant antihyperglycemic activity.


2019 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Nur A. Setiani ◽  
Rika L. Anggriani ◽  
Anggi Restiasari

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycaemia. Functional food, such as kombucha tea, is widely used as complementary treatment for type 2 diabetes mellitus.  Kombucha tea is made through fermentation process of green or black tea using a microbial kombucha consortium (Acetobacter xylinum and several types of yeast). The aim of this study was to evaluate the effect of fermentation time of kombucha tea on its hypoglycaemic activity in rats. The green tea (Camellia sinensis) was fermented with kombucha consortium for 8, 14, and 21 days. Evaluation of hypoglycaemic activity was conducted using glucose tolerance test method. First, fasting blood glucose levels in rats were measured after 16 hours fasting.  Hyperglycaemic condition was induced by administering glucose 2 g/0.2 kg body weight. Blood glucose levels were measured again after 30 minutes. Subsequently, 5.5 ml of kombucha tea in various fermentation time was orally administered. Blood glucose levels were measured at 30, 60, 90, 120, 150 and 180 minutes after kombucha tea administration. The results revealed the average reduction of blood glucose were 18.16%, 33.64%, and 19.88% by kombucha tea fermented for 8, 14, and 21 days, respectively. In conclusion, kombucha tea fermented for 14 days is potential to be developed as a hypoglycaemic agent. Keywords: fermentation time, glucose level, hypoglycaemia, kombucha tea


2015 ◽  
Vol 10 (2) ◽  
pp. 326 ◽  
Author(s):  
Emordi Jonathan Emeka ◽  
Agbaje Esther Oluwatoyin ◽  
Oreagba Ibrahim Adekunle ◽  
Iribhogbe Osede Ignis

<p>The purpose of this study is to evaluate the hypoglycaemic properties and preliminary phytochemical screening of <em>Uveria chamae</em>. The hypoglycaemic properties of <em>Uveria chamae</em> was assessed on normoglycaemic rat that received single dose of the extract at 250 and 500 mg/kg body weight and blood glucose levels estimated at 2, 4, and 6 hours (single dose study). The hypoglycaemic property of the extract was also evaluated in normoglycemic rats by oral glucose tolerance test. Phytochemical screening of the extract for the presence of secondary metabolites was performed with standard methods. The extract showed a significant (p&lt;0.05) reduction in blood glucose levels at 2h and 6h compared to control.  The oral glucose tolerance test  result also showed a significant decrease (p&lt;0.05) in blood glucose levels . The study showed that the extract, <em>Uveria chamae</em> has hypoglycaemic properties which may be accounted for by the presence of the phytochemicals.</p><p> </p>


2019 ◽  
Vol 20 (6) ◽  
pp. 1517 ◽  
Author(s):  
Kai Wang ◽  
Yu Su ◽  
Yuting Liang ◽  
Yanhui Song ◽  
Liping Wang

Type 2 diabetes mellitus (T2DM) is associated with pancreatic β-cell dysfunction which can be induced by oxidative stress. Deuterohemin-βAla-His-Thr-Val-Glu-Lys (DhHP-6) is a microperoxidase mimetic that can scavenge reactive oxygen species (ROS) in vivo. In our previous studies, we demonstrated an increased stability of linear peptides upon their covalent attachment to porphyrins. In this study, we assessed the utility of DhHP-6 as an oral anti-diabetic drug in vitro and in vivo. DhHP-6 showed high resistance to proteolytic degradation in vitro and in vivo. The degraded DhHP-6 product in gastrointestinal (GI) fluid retained the enzymatic activity of DhHP-6, but displayed a higher permeability coefficient. DhHP-6 protected against the cell damage induced by H2O2 and promoted insulin secretion in INS-1 cells. In the T2DM model, DhHP-6 reduced blood glucose levels and facilitated the recovery of blood lipid disorders. DhHP-6 also mitigated both insulin resistance and glucose tolerance. Most importantly, DhHP-6 promoted the recovery of damaged pancreas islets. These findings suggest that DhHP-6 in physiological environments has high stability against enzymatic degradation and maintains enzymatic activity. As DhHP-6 lowered the fasting blood glucose levels of T2DM mice, it thus represents a promising candidate for oral administration and clinical therapy.


mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Rebecca J. Marshall ◽  
Pornthida Armart ◽  
Katina D. Hulme ◽  
Keng Yih Chew ◽  
Alexandra C. Brown ◽  
...  

ABSTRACT People with diabetes are two times more likely to die from influenza than people with no underlying medical condition. The mechanisms underlying this susceptibility are poorly understood. In healthy individuals, small and short-lived postprandial peaks in blood glucose levels occur. In diabetes mellitus, these fluctuations become greater and more frequent. This glycemic variability is associated with oxidative stress and hyperinflammation. However, the contribution of glycemic variability to the pathogenesis of influenza A virus (IAV) has not been explored. Here, we used an in vitro model of the pulmonary epithelial-endothelial barrier and novel murine models to investigate the role of glycemic variability in influenza severity. In vitro, a history of glycemic variability significantly increased influenza-driven cell death and destruction of the epithelial-endothelial barrier. In vivo, influenza virus-infected mice with a history of glycemic variability lost significantly more body weight than mice with constant blood glucose levels. This increased disease severity was associated with markers of oxidative stress and hyperinflammation both in vitro and in vivo. Together, these results provide the first indication that glycemic variability may help drive the increased risk of severe influenza in people with diabetes mellitus. IMPORTANCE Every winter, people with diabetes are at increased risk of severe influenza. At present, the mechanisms that cause this increased susceptibility are unclear. Here, we show that the fluctuations in blood glucose levels common in people with diabetes are associated with severe influenza. These data suggest that glycemic stability could become a greater clinical priority for patients with diabetes during outbreaks of influenza.


2009 ◽  
Vol 296 (3) ◽  
pp. E473-E479 ◽  
Author(s):  
Yukihiro Fujita ◽  
Rhonda D. Wideman ◽  
Madeleine Speck ◽  
Ali Asadi ◽  
David S. King ◽  
...  

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are released during meals from endocrine cells located in the gut mucosa and stimulate insulin secretion from pancreatic β-cells in a glucose-dependent manner. Although the gut epithelium senses luminal sugars, the mechanism of sugar sensing and its downstream events coupled to the release of the incretin hormones are not clearly elucidated. Recently, it was reported that sucralose, a sweetener that activates the sweet receptors of taste buds, triggers incretin release from a murine enteroendocrine cell line in vitro. We confirmed that immunoreactivity of α-gustducin, a key G-coupled protein involved in taste sensing, is sometimes colocalized with GIP in rat duodenum. We investigated whether secretion of incretins in response to carbohydrates is mediated via taste receptors by feeding rats the sweet-tasting compounds saccharin, acesulfame potassium, d-tryptophan, sucralose, or stevia. Oral gavage of these sweeteners did not reduce the blood glucose excursion to a subsequent intraperitoneal glucose tolerance test. Neither oral sucralose nor oral stevia reduced blood glucose levels in Zucker diabetic fatty rats. Finally, whereas oral glucose increased plasma GIP levels ∼4-fold and GLP-1 levels ∼2.5-fold postadministration, none of the sweeteners tested significantly increased levels of these incretins. Collectively, our findings do not support the concept that release of incretins from enteroendocrine cells is triggered by carbohydrates via a pathway identical to the sensation of “sweet taste” in the tongue.


Author(s):  
Aymen Owais Ghauri ◽  
Saeed Ahmad ◽  
Tayyeba Rehman

AbstractBackgroundDiabetes is the one of the leading cause of morbidity and mortality. Traditionally phytotherapy is widely being used for diabetes treatment and highly valued. Citrus colocynthis has known anti-diabetic potential. However, anti-diabetic potential of hydro-ethanolic extract of C. colocynthis pulpy flesh with seeds is not reported yet.MethodsThe extract of C. colocynthis pulpy flesh with seeds was done by maceration method using 70% ethanol. To evaluate anti-diabetic and antioxidant potential of the seeded fruit in vitro, α-glucosidase and DPPH inhibition assays was done, respectively. In vivo study used streptozotocin (STZ) induced diabetes model of rats. Rats were randomized in five groups i. e. normal control, negative control, standard control, C. colocynthis 150 and 300 mg/kg. STZ was administered to all groups except normal control. After wards, plant extract and glibenclamide is continued for 14 days. Blood samples were collected from rat tail vein daily and from Cardiac puncture at the end of study. The blood glucose levels were monitored daily by using one-touch blood glucose monitoring system. The blood glucose level was monitored on 0, 1st, 5th, 8th, 11th, and 14th day of induction.ResultsHydro-ethanolic extract of C. colocynthis pulpy flesh with seeds was able to decolorize DPPH and therefore possess antioxidant potential, continuous administration for 14 days showed a marked decrease in serum glucose levels (p 0.01) it is found to be somewhat less effective as glibenclamide (standard control) (p 0.001). A time-dependent decrease in blood glucose levels was observed (351.3 ± 4 to 258 m/kg).ConclusionHydro-ethanolic extract of C. colocynthis pulpy flesh with seeds lowered the serum triglyceride and cholesterol levels in diabetic rats significantly as compared to negative control. The hypoglycemic effect of hydro-ethanolic extract of C. colocynthis pulpy flesh with seeds is may be due to α-glucosidase inhibition potential.


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