Curcumin as a mild natural α‐glucosidase inhibitor: A study on its mechanism in vitro

Author(s):  
Yujia Liu ◽  
Jie Zhu ◽  
Jiamei Yu ◽  
Chen Xu ◽  
Zhang Shuyan ◽  
...  

Planta Medica ◽  
2021 ◽  
Author(s):  
Neil Miller ◽  
Elizabeth Joubert

AbstractPostprandial hyperglycemia is treated with the oral antidiabetic drug acarbose, an intestinal α-glucosidase inhibitor. Side effects of acarbose motivated a growing number of screening studies to identify novel α-glucosidase inhibitors derived from plant extracts and other natural sources. As “gold standard”, acarbose is frequently included as the reference standard to assess the potency of these candidate α-glucosidase inhibitors, with many outperforming acarbose by several orders of magnitude. The results are subsequently used to identify suitable compounds/products with strong potential for in vivo efficacy. However, most α-glucosidase inhibitor screening studies use enzyme preparations obtained from nonmammalian sources (typically Saccharomyces cerevisiae), despite strong evidence that inhibition data obtained using nonmammalian α-glucosidase may hold limited value in terms of identifying α-glucosidase inhibitors with actual in vivo hypoglycemic potential. The aim was to critically discuss the screening of novel α-glucosidase inhibitors from plant sources, emphasizing inconsistencies and pitfalls, specifically where acarbose was included as the reference standard. An assessment of the available literature emphasized the cruciality of stating the biological source of α-glucosidase in such screening studies to allow for unambiguous and rational interpretation of the data. The review also highlights the lack of a universally adopted screening assay for novel α-glucosidase inhibitors and the commercial availability of a standardized preparation of mammalian α-glucosidase.



2020 ◽  
Vol 11 ◽  
Author(s):  
Gitanjali Bhushan ◽  
Levina Lim ◽  
Ian Bird ◽  
Shubhada K. Chothe ◽  
Ruth H. Nissly ◽  
...  


2020 ◽  
Vol 104 ◽  
pp. 104277
Author(s):  
Maryam Aisyah Abdullah ◽  
Yu-Ri Lee ◽  
Siti Nurulhuda Mastuki ◽  
Sze Wei Leong ◽  
Wan Norhamidah Wan Ibrahim ◽  
...  


2018 ◽  
Vol 28 (3) ◽  
pp. 302-309 ◽  
Author(s):  
Sze Wei Leong ◽  
Faridah Abas ◽  
Kok Wai Lam ◽  
Khatijah Yusoff


ChemInform ◽  
2010 ◽  
Vol 24 (34) ◽  
pp. no-no
Author(s):  
J. R. BEHLING ◽  
A. L. CAMPBELL ◽  
K. A. BABIAK ◽  
J. S. NG ◽  
J. MEDICH ◽  
...  


2014 ◽  
Vol 62 (24) ◽  
pp. 5548-5554 ◽  
Author(s):  
Ming Liu ◽  
Hua Yin ◽  
Ge Liu ◽  
Jianjun Dong ◽  
Zhonghua Qian ◽  
...  


2021 ◽  
Vol 9 (Spl-2-ICOPMES_2020) ◽  
pp. S269-S273
Author(s):  
Rizky Rahmwaty Alami ◽  
◽  
Herlina Rante ◽  
Yulia Yusrini Djabir ◽  
◽  
...  

The purpose of this research was to determine the α-glucosidase enzyme inhibitory activity of Moringa oleifera plant samples collected from the three geographical areas viz., Saragi, Bacuhau, and Batumatongka of Southeast Sulawesi Indonesia. Ethanol extract of Moringa leaves was prepared by the maceration method using 95% ethanol. The estimation of α –glucosidase inhibitory activity of this extract was performed in vitro. The results of the study showed that ethanolic extract of three Moringa samples i.e. Sarangi, Bacuhau, and Batumatongka had the IC50value of 18.62, 10.18, 10.58 ppm, respectively while IC50value for the acarbose positive control was reported 11.54ppm. From the results of this study, it can be concluded that ethanolic extract of Moringa could inhibit α –glucosidase and this potential was similar to the commercial α –glucosidase inhibitor acarbose.



1999 ◽  
Vol 342 (1) ◽  
pp. 153-161 ◽  
Author(s):  
Suresh K. JOSEPH ◽  
Darren BOEHNING ◽  
Shaila BOKKALA ◽  
Richard WATKINS ◽  
Johan WIDJAJA

A prominent labelled polypeptide having the same mobility as type-I inositol trisphosphate receptor (IP3R) was immunoprecipitated from WB-cell lysates by antibodies to calnexin, an ER integral membrane chaperone. The identity of this polypeptide was confirmed by re-immunoprecipitation of the radioactive polypeptides released from calnexin-antibody immunoprecipitates with type-I IP3R antibody. The interaction of calnexin with newly synthesized type-I IP3R was transient and inhibited by treatment of the cells with dithiothreitol or the glucosidase inhibitor N-methyldeoxynojirimicin. In similar experiments, there was no evidence for the binding of type-I IP3R to calreticulin, an ER luminal chaperone. Calnexin (but not calreticulin) associated with newly synthesized FLAG (DYKDDDDK epitope)-tagged type-III IP3R expressed in COS-7 cells. In order to further define the mechanism of interaction of nascent IP3R with chaperones, we have utilized an in vitro rabbit reticulocyte translation assay programmed with RNA templates encoding the six putative transmembrane (TM) domains of IP3Rs. In accordance with the known preference of calnexin for monoglucosylated oligosaccharide chains, calnexin antibody preferentially immunoprecipitated a proportion of glycosylated type-I translation product. Addition of glucosidase inhibitors prevented the association of calnexin with in vitro translated type-I TM construct. Using truncated RNA templates we found that calnexin did not associate with the first four TM domains but retained affinity for the construct encoding TM domains 5 and 6, which contains the glycosylation sites. We propose that calnexin is a key chaperone involved in the folding, assembly and oligomerization of newly synthesized IP3 receptors in the ER.



1987 ◽  
Vol 242 (1) ◽  
pp. 235-243 ◽  
Author(s):  
S W Mercer ◽  
D H Williamson

Depression of carbohydrate digestion by oral administration of acarbose, a glucosidase inhibitor, led to a 75% inhibition of the re-activation of lipogenesis in vivo in the mammary gland of 18 h-starved lactating rats refed with 5 g of chow diet. Rates of [1-14C]glucose incorporation in vitro into lipid and CO2 in mammary-gland acini isolated from refed animals were elevated compared with acini from starved rats, but acarbose treatment completely prevented this stimulation. Gastric intubation of glucose led to a large stimulation of lipogenesis in the mammary gland of starved lactating rats, similar to that induced by refeeding with chow diet; this was dependent on the amount of glucose given and the time elapsed between glucose administration and injection of 3H2O for the measurement of lipogenesis. The switch-on of lipogenesis in the mammary gland of starved lactating rats, by refeeding or by intubation of glucose, was associated with a decrease in the ratio of [glucose 6-phosphate]/[fructose 1,6-bisphosphate] in the gland, indicative of an increase in phosphofructokinase activity. A time-course study revealed that the ratio decreased rapidly over the first 30 min of chow refeeding, after which a large surge in lipogenesis was seen. Acarbose, given 25 min after the onset of refeeding, led to a stepwise increase in the ratio, in parallel with the observed decrease in lipogenic activity. It is concluded that the control of lipogenesis in the mammary gland is closely linked to the availability of dietary carbohydrate. An important site of regulation of lipogenesis in the gland appears to be at the level of phosphofructokinase. A possible role of insulin in the regulation of phosphofructokinase activity, and the acute modulation of insulin-sensitivity in the gland during the starved-refed transition, are discussed.



2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
F. Brindis ◽  
M. E. González-Trujano ◽  
M. González-Andrade ◽  
E. Aguirre-Hernández ◽  
R. Villalobos-Molina

Annona genus contains plants used in folk medicine for the treatment of diabetes. In the present study, an aqueous extract prepared fromAnnona macroprophyllata(Annonaceae, also known asA. diversifolia) leaves was evaluated on both the activity of yeastα-glucosidase (anin vitroassay) and sucrose tolerance in Wistar rats. The results have shown that the aqueous extract fromA. macroprophyllatainhibits the yeastα-glucosidase with an IC50 = 1.18 mg/mL, in a competitive manner with aKi= 0.97 mg/mL, a similar value to that of acarbose (Ki= 0.79 mg/mL). The inhibitory activity ofA. macroprophyllatawas reinforced by its antihyperglycemic effect, at doses of 100, 300, and 500 mg/kg in rats. Chromatographic analysis identified the flavonoids rutin and isoquercitrin in the most polar fractions ofA. macroprophyllatacrude extract, suggesting that these flavonoids are part of the active constituents in the plant. Our results support the use ofA. macroprophyllatain Mexican folk medicine to control postprandial glycemia in people with diabetes mellitus, involving active constituents of flavonoid nature.



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