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Journal ArticleDOI

HPLC assisted chemobiological standardization of α-glucosidase-I enzyme inhibitory constituents from Piper longum Linn-An Indian medicinal plant

TL;DR: A reversed-phase high-performance liquid chromatography method was developed to quantify these active principles in the plant material, which can serve as an effective quality control tool.
About: This article is published in Journal of Ethnopharmacology.The article was published on 2006-12-06. It has received 40 citations till now.
Citations
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Journal ArticleDOI
TL;DR: The present review focuses on constituents isolated from different plants having α-glucosidase inhibitory potency along with IC50 values, which can retard the liberation of d-Glucose from dietary complex carbohydrates and delay glucose absorption, resulting in reduced postprandial plasma glucose levels and suppression of postpr andial hyperglycemia.
Abstract: Diabetes is a common metabolic disease characterized by abnormally high plasma glucose levels, leading to major complications, such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective managements of diabetes mellitus, in particular, non-insulin-dependent diabetes mellitus (NIDDM) to decrease postprandial hyperglycemia, is to retard the absorption of glucose by inhibition of carbohydrate hydrolyzing enzymes, such as α-glucosidase and α-amylase, in the digestive organs. α-Glucosidase is the key enzyme catalyzing the final step in the digestive process of carbohydrates. Hence, α-glucosidase inhibitors can retard the liberation of d-glucose from dietary complex carbohydrates and delay glucose absorption, resulting in reduced postprandial plasma glucose levels and suppression of postprandial hyperglycemia. In recent years, many efforts have been made to identify effective α-glucosidase inhibitors from natural sources in order to develop a physiologic functional food or lead compounds for use against diabetes. Many α-glucosidase inhibitors that are phytoconstituents, such as flavonoids, alkaloids, terpenoids,anthocyanins, glycosides, phenolic compounds, and so on, have been isolated from plants. In the present review, we focus on the constituents isolated from different plants having α-glucosidase inhibitory potency along with IC50 values.

550 citations

Journal ArticleDOI
TL;DR: In vivo studies demonstrated that A. paniculata extract significantly reduced peak blood glucose and area under curve in diabetic rats when challenged with oral administration of starch and sucrose, and indicates that AP extract can be considered as a potential candidate for the management of type 2 diabetes mellitus.
Abstract: There has been an enormous interest in the development of alternative medicines for type 2 diabetes, specifically screening for phytochemicals with the ability to delay or prevent glucose absorption. The goal of the present study was to provide in vitro evidence for potential inhibition of alpha-glucosidase and alpha-amylase enzymes, followed by a confirmatory in vivo study on rats to generate a stronger biochemical rationale for further studies on the ethanolic extract of Andrographis paniculata and andrographolide. The extract showed appreciable alpha-glucosidase inhibitory effect in a concentration-dependent manner (IC(50)=17.2+/-0.15 mg/ml) and a weak alpha-amylase inhibitory activity (IC(50)=50.9+/-0.17 mg/ml). Andrographolide demonstrated a similar (IC(50)=11.0+/-0.28 mg/ml) alpha-glucosidase and alpha-amylase inhibitory activity (IC(50)=11.3+/-0.29 mg/ml). The positive in vitro enzyme inhibition tests paved way for confirmatory in vivo studies. The in vivo studies demonstrated that A. paniculata extract significantly (P<0.05) reduced peak blood glucose and area under curve in diabetic rats when challenged with oral administration of starch and sucrose. Further, andrographolide also caused a significant (P<0.05) reduction in peak blood glucose and area under the curve in diabetic rats. Hence alpha-glucosidase inhibition may possibly be one of the mechanisms for the A. paniculata extract to exert antidiabetic activity and indicates that AP extract can be considered as a potential candidate for the management of type 2 diabetes mellitus.

309 citations


Additional excerpts

  • ..., 2002), pepper (Pullela et al., 2006), soy bean extracts, etc....

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Journal ArticleDOI
TL;DR: Despite traditional claims, insufficient scientific validation for the treatment of insomnia, dementia, epilepsy, rheumatoid arthritis, asthma, spleen disorder, puerperal fever and leprosy, necessitate future investigations in this direction.

80 citations

Journal ArticleDOI
TL;DR: Piplartine was isolated from Piper chaba, and was found to inhibit recombinant human ALR2 with an IC(50) of 160 μM, and a series of analogues have been synthesized by modification of the styryl/aromatic and heterocyclic ring functionalities of this natural product lead.

69 citations

Journal ArticleDOI
TL;DR: Chabamide H (1), I (2), J (3), K (4) and 11 known compounds were determined on the basis of the comprehensive spectroscopic techniques (IR, Mass, and NMR) as discussed by the authors.

62 citations

References
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Journal ArticleDOI

2,029 citations

Journal ArticleDOI
TL;DR: Luteolin inhibited alpha-glucosidase by 36% at the concentration of 0.5 mg/ml and was stronger than acarbose, the most widely prescribed drug, in inhibitory potency, suggesting that it has the possibility to effectively suppress postprandial hyperglycemia in patients with non-insulin dependent diabetes mellitus.
Abstract: Twenty-one naturally occurring flavonoids were tested for inhibitory activities against alpha-glucosidase (EC 3.2.1.20) and alpha-amylase (EC 3.2.1.1). Luteolin, amentoflavone, luteolin 7-O-glucoside, and daidzein were the strongest inhibitors among the compounds tested. Luteolin inhibited alpha-glucosidase by 36% at the concentration of 0.5 mg/ml and was stronger than acarbose, the most widely prescribed drug, in inhibitory potency, suggesting that it has the possibility to effectively suppress postprandial hyperglycemia in patients with non-insulin dependent diabetes mellitus. Luteolin also inhibited alpha-amylase effectively although it was less potent than acarbose. The clinical value of luteolin needs to be further evaluated.

581 citations

Journal ArticleDOI
TL;DR: It is shown that in MDBK cells alpha-glucosidase inhibitors prevented the formation and secretion of infectious bovine viral diarrhea virus and data is presented showing that NN-DNJ, compared with NB- DNJ, exhibits a prolonged retention in liver in vivo.
Abstract: One function of N-linked glycans is to assist in the folding of glycoproteins by mediating interactions of the lectin-like chaperone proteins calnexin and calreticulin with nascent glycoproteins. These interactions can be prevented by inhibitors of the alpha-glucosidases, such as N-butyl-deoxynojirimycin (NB-DNJ) and N-nonyl-DNJ (NN-DNJ), and this causes some proteins to be misfolded and retained within the endoplasmic reticulum (ER). We have shown previously that the NN-DNJ-induced misfolding of one of the hepatitis B virus (HBV) envelope glycoproteins prevents the formation and secretion of virus in vitro and that this inhibitor alters glycosylation and reduces the viral levels in an animal model of chronic HBV infection. This led us to investigate the effect of glucosidase inhibitors on another ER-budding virus, bovine viral diarrhea virus, a tissue culture surrogate of human hepatitis C virus (HCV). Here we show that in MDBK cells alpha-glucosidase inhibitors prevented the formation and secretion of infectious bovine viral diarrhea virus. Data also are presented showing that NN-DNJ, compared with NB-DNJ, exhibits a prolonged retention in liver in vivo. Because viral secretion is selectively hypersensitive to glucosidase inhibition relative to the secretion of cellular proteins, the possibility that glucosidase inhibitors could be used as broad-based antiviral hepatitis agents is discussed. A single drug against HBV, HCV, and, possibly, HDV, which together chronically infect more than 400 million people worldwide, would be of great therapeutic value.

323 citations

Journal ArticleDOI
TL;DR: N‐Linked oligosaccharides play many roles in the fate and functions of glycoproteins and may be useful therapeutics for many viruses, especially those which bud from the endoplasmic reticulum (where protein folding takes place).

272 citations

Journal ArticleDOI
TL;DR: Inhibition of α-glucosidase-mediated N-linked oligosaccharide trimming may prevent the assembly of DEN virus by affecting the early stages of envelope glycoprotein processing.
Abstract: We report that endoplasmic reticulum alpha-glucosidase inhibitors have antiviral effects on dengue (DEN) virus. We found that glucosidase inhibition strongly affects productive folding pathways of the envelope glycoproteins prM (the intracellular glycosylated precursor of M [membrane protein]) and E (envelope protein): the proper folding of prM bearing unprocessed N-linked oligosaccharide is inefficient, and this causes delayed formation of prME heterodimer. The complexes formed between incompletely folded prM and E appear to be unstable, leading to a nonproductive pathway. Inhibition of alpha-glucosidase-mediated N-linked oligosaccharide trimming may thus prevent the assembly of DEN virus by affecting the early stages of envelope glycoprotein processing.

211 citations