Potent α-amylase inhibitory activity of Indian Ayurvedic medicinal plants

Abstract

BackgroundIndian medicinal plants used in the Ayurvedic traditional system to treat diabetes are a valuable source of novel anti-diabetic agents. Pancreatic α-amylase inhibitors offer an effective strategy to lower the levels of post-prandial hyperglycemia via control of starch breakdown. In this study, seventeen Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for α-amylase inhibition, in order to assess and evaluate their inhibitory potential on PPA (porcine pancreatic α-amylase). Preliminary phytochemical analysis of the lead extracts was performed in order to determine the probable constituents.MethodsAnalysis of the 126 extracts, obtained from 17 plants (Aloe vera (L.) Burm.f., Adansonia digitata L., Allium sativum L., Casia fistula L., Catharanthus roseus (L.) G. Don., Cinnamomum verum Persl., Coccinia grandis (L.) Voigt., Linum usitatisumum L., Mangifera indica L., Morus alba L., Nerium oleander L., Ocimum tenuiflorum L., Piper nigrum L., Terminalia chebula Retz., Tinospora cordifolia (Willd.) Miers., Trigonella foenum-graceum L., Zingiber officinale Rosc.) for PPA inhibition was initially performed qualitatively by starch-iodine colour assay. The lead extracts were further quantified with respect to PPA inhibition using the chromogenic DNSA (3, 5-dinitrosalicylic acid) method. Phytochemical constituents of the extracts exhibiting≥ 50% inhibition were analysed qualitatively as well as by GC-MS (Gas chromatography-Mass spectrometry).ResultsOf the 126 extracts obtained from 17 plants, 17 extracts exhibited PPA inhibitory potential to varying degrees (10%-60.5%) while 4 extracts showed low inhibition (< 10%). However, strong porcine pancreatic amylase inhibitory activity (> 50%) was obtained with 3 isopropanol extracts. All these 3 extracts exhibited concentration dependent inhibition with IC50 values, viz., seeds of Linum usitatisumum (540 μgml-1), leaves of Morus alba (1440 μgml-1) and Ocimum tenuiflorum (8.9 μgml-1). Acarbose as the standard inhibitor exhibited an IC50 (half maximal inhibitory concentration)value of 10.2 μgml-1. Phytochemical analysis revealed the presence of alkaloids, tannins, cardiac glycosides, flavonoids, saponins and steroids with the major phytoconstituents being identified by GC-MS.ConclusionsThis study endorses the use of these plants for further studies to determine their potential for type 2 diabetes management. Results suggests that extracts of Linum usitatisumum, Morus alba and Ocimum tenuiflorum act effectively as PPA inhibitors leading to a reduction in starch hydrolysis and hence eventually to lowered glucose levels.

Comparative Analysis of Nutritional and Bioactive Properties of Aerial Parts of Snake Gourd (Trichosanthes cucumerinaLinn.)

“…The assay was performed according to Sudha et al [17] with slight modifications. The assay mixture consisted of 50  μ L of α -amylase from porcine pancreas (A3176 SIGMA) in phosphate buffer (PBS) (0.02 M; 6.7 mM NaCl; pH 6.9) and 50  μ L plant extracts in different concentrations ranging from 5 to 25 mg/mL.…”

“…Starch-iodine assay was carried out as described by Sudha et al [17] with slight modifications. Assay reaction was initiated by adding 40  μ L of PBS, 40  μ L of plant extracts in different concentrations (5–25 mg/mL), and 40  μ L of enzyme in PBS into microplate wells.…”

Antidiabetic and hypolipidemic activities of hydroethanolic root extract of Uvaria chamae in streptozotocin induced diabetic albino rats

“…It is one of the oldest diseases of mankind that affects millions of people worldwide [3]. The number of people living with the disease is expected to double with major impact on the population of the developing countries due to increased rate of industrialization [3, 4]. It is a major risk factor for the development of cardiovascular disease [5].…”

Biosynthesis Of Bimetallic Au-Ag Nanoparticles Using Ocimum Basilicum (L.) With Antidiabetic And Antimicrobial Properties

“…The enzyme activity of human pancreatic α-amylase (HPA) and α-glucosidase in the small intestine correlates to an increase in postprandial glucose levels. After a mixed carbohydrate diet pancreatic α-amylase catalyzes the initial step in hydrolysis of starch to a mixture of smaller oligosaccharides comprising of maltose, maltotriose, and a number of α-(l-6) and α-(1-4) oligoglucans that are finally converted to monosaccharides by α-glucosidase and further degraded to glucose [56]. Liberated glucose is absorbed by the gut, enters the bloodstream and results in a high blood glucose level [25].…”