Inhibitory Activity of alpha-Amylase and alpha-Glucosidase by Plant Extracts from the Brazilian Cerrado
ABSTRACT Diabetes mellitus is the most common disease in the world. One therapeutic approach for treating diabetes is inhibition of α-amylase and α-glucosidase activities to reduce postprandial blood glucose levels. In vitro tests showed that several plant extracts from Brazilian cerrado species can inhibit the activity of α-amylase and α-glucosidase. The extracts of Eugenia dysenterica, Stryphnodendron adstringens, Pouteria caimito, Pouteria ramiflora, and Pouteria torta showed strong α-amylase and α-glucosidase inhibitory activity. Eugenia dysenterica, P. caimito, P. ramiflora, and P. torta aqueous extracts exerted the highest activity against α-amylase (IC₅₀) values of 14.93, 13.6, 7.08, and 5.67 µg/mL, respectively) and α-glucosidase (IC₅₀ values of 0.46, 2.58, 0.35, and 0.22 µg/mL, respectively). Stryphnodendron adstringens ethanol extract also exhibited inhibitory activity against both enzymes (IC₅₀) 1.86 µg/mL against α-amylase and 0.61 µg/mL against α-glucosidase). The results suggest that the activity of these cerrado plants on α-amylase and α-glucosidase represents a potential tool for development of new strategies for treatment of diabetes.
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ABSTRACT: Abstract It is well known that phytotherapy has grown in popularity in recent years. Because a drug cannot be administered without ensuring its effectiveness and safety, the standardization and regulation of phytotherapeutic drugs are required by the global market and governmental authorities. This article describes a simple and reliable high-performance liquid chromatography-diode array detection analysis method for the simultaneous detection of myricetin-3-O-β-D-galactopyranoside, myricetin-3-O-α-L-arabinopyranoside, and myricetin-3-O-α-L-rhaminopyranoside present in the hydroethanolic extract (ethanol/H2O, 7:3, v/v) of Pouteria torta. The mutagenic activity of the extract was evaluated on Salmonella typhimurium and by an in vivo micronucleus test on the peripheral blood cells of Swiss mice. The linearity, sensitivity, selectivity, repeatability, accuracy, and precision of the assay were evaluated. The analytical curves were linear and exhibited good repeatability (with a deviation of less than 5%) and demonstrated good recovery (within the 83-107% range). The results demonstrate that the hydroethanolic extract exhibited a mutagenic activity in both assays, suggesting caution in the use of this plant in folk medicine.Journal of Medicinal Food 07/2014; 17(10). DOI:10.1089/jmf.2013.0116 · 1.70 Impact Factor
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ABSTRACT: Schisandra chinensis (Turcz.) Baill. (SCTB) is a functional, economical and medicinal herb that has numerous medicinal and nutritional properties. The present study was carried out to investigate its inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase. The extracts and compounds isolated from petroleum ether (PE) extract were further tested for their PTP1B and α-glucosidase inhibitory activities. The data showed that the anti-diabetic activity of SCTB is attributable to the PE (IC50 = 1.77 ± 0.20 μg/mL) and EtOAc (IC50 = 1.04 ± 0.20 μg/mL) extracts as well as compounds 1 (IC50 = 2.36 ± 0.20 μM) and 4 (IC50 = 9.78 ± 0.10 μM) that were compared with the positive controls NaVO4 (IC50 = 22 ± 0.20 μM) and acarbose (IC50 = 2.10 ± 0.10 μg/mL), respectively. These results demonstrate that the stems of SCTB are useful as potential functional food ingredients for the prevention and treatment of type-2 diabetes.Journal of Functional Foods 07/2014; 9:264–270. DOI:10.1016/j.jff.2014.04.017 · 4.48 Impact Factor
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ABSTRACT: Abstract Publications linking hepatotoxicity to the use of herbal preparations are escalating. Herbal teas, Traditional Chinese Medicines (TCM) and dietary supplements have been shown to contain pyrrolizidine alkaloids (PAs). Acute PA toxicosis of the liver can result in sinusoidal-obstruction syndrome also known as veno-occlusive disease (VOD). This paper describes a sensitive and robust method for the detection of targeted PAs and their N-oxides (PANOs) in herbal products (selected herbal teas and TCMs) sourced within Ireland. The sample preparation includes a simple acidic extraction with clean-up via solid phase extraction (SPE). Sample extracts were accurately analysed by using LC-ESI-MS/MS applying for the first time a pentafluorophenyl (PFP) core-shell column to the chromatographic separation of PAs and PANOs. The method was validated for selectivity, taking into consideration matrix effects, specificity, linearity, precision and trueness. Limits of detection (LOD) and limits of quantitation (LOQ) were quantified for all PAs and PANOs ranging from 0.4 to 1.9 µg kg(-1) and 1.3 to 6.3 µg kg(-1), respectively. In this study 10 PAs and to 4 PANOs were targeted due to the fact that they are commercially available as reference standards. Therefore, this study can only report the levels of these PAs and PANOs analysed in the herbal teas and TCMs. The results reported represent the minimum levels of PAs and PANOs present in the samples analysed; commercially available herbal teas (n = 18) and Traditional Chinese Medicines (TCMs; n = 54). A total of 50% herbal teas and 78% Chinese medicines tested positive for one or more PAs and/or PANOs included within this study, ranging from 10 to 1733 and 13 to 3668 µg kg(-1), respectively.Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 03/2014; 31(5). DOI:10.1080/19440049.2014.900193 · 2.34 Impact Factor