Glucose-6-Phosphatase and α-Glucosidase Inhibitors from Smilax moranensis Roots Identified by Affinity-Directed Fractionation.

The ethanol/water-soluble extracts of the roots of Smilax moranensis M. Martens & Galeotti, Smilacaceae, which have been appreciated since pre-Hispanic times and traditionally used to treat type 2 diabetes in Mexico, were fractionated by the application of the affinity-directed method to identify glucose-6-phosphatase and α-glucosidase inhibitors. Mass spectrometry was used to identify the inhibitor as free ligands after released from the enzymatic complex by denaturing acidic conditions. The affinity study led to the identification of chlorogenic acid as a glucose-6-phosphatase inhibitor, which is the most abundant metabolite present in the analyzed crude drug. In addition, the affinity studies led to the identification of a flavonolignan glycoside as an α-glucosidase inhibitor. In silico analysis with α-glucosidase MAL12 from the yeast Saccharomyces cerevisiae allowed to determine the best conformational rearrangement for the α-glucosidase inhibitors. Graphical abstract. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s43450-020-00116-3.

Chronic hypoglycemic effect and phytochemical composition of Smilax moranensis roots

ABSTRACT Smilax moranensis M.Martens & Galeotti, Smilacaceae, root is a medicinal plant used among the Chatinos in Oaxaca, Mexico, to control type 2 diabetes. The objectives of the study were to isolate the bioactive compounds from the roots of Smilax and evaluate the chronic hypoglycemic effect of the ethanol-water extract. The main compounds were isolated from the methanolic extract via conventional phytochemical methods. The dried roots of S. moranensis were extracted with methanol and chromatographed on Sephadex LH 20. Fractions were chromatographed and purified on a silica gel chromatography column. The ethanol-water extract was orally administered to hyperglycemic rats for a period of 42 days, and glucose, glycated hemoglobin (HbA1c), and triacylglycerides were measured. Moreover, very-low-density lipoprotein was calculated. During the chemical investigation, three compounds were isolated and characterized, namely, 3-O-caffeoyl-quinic acid, 5-O-caffeoyl-quinic acid and trans-resveratrol, using various spectroscopic techniques. Animal experiments confirmed that the plant extract could control both the glucose and HbA1c levels. In conclusion, this study confirms that the roots of S. moranensis have hypoglycemic properties and suggests that the isolated compounds are potentially involved in this effect.

Phytochemical composition and chronic hypoglycemic effect of Rhizophora mangle cortex on STZ-NA-induced diabetic rats

ABSTRACT Type 2 diabetes is a major health problem in Mexico, as it is in other countries, is a chronic condition that develops when the body cannot produce enough insulin or cannot use it appropriately. Both insulin deficiency and insulin resistance lead to high blood glucose levels. In Mexico, people with diabetes are known to use the decoction of red mangrove (Rhizophora mangle L., Rhizophoraceae) bark to control blood glucose levels. Therefore, in this study, we sought to investigate the chronic hypoglycemic and hypolipidemic effects of R. mangle; we also elucidate some of the major phytochemical compounds of R. mangle. To analyze the hypoglycemic and hypolipidemic effects, we used rats with streptozotocin-nicotinamide-induced hyperglycemia; the rats were classified into four groups (six rats each), based on the treatment given, as follows: group 1, non-hyperglycemic control; group 2, hyperglycemic control; group 3, glibenclamide (5 mg/kg body weight); and group 4, Rhizophora ethanol-water extract (90 mg/kg). The extract or glibenclamide was orally administered, dissolved in 1.5 ml of physiological NaCl-solution, twice a day (in the morning and in the evening) over a period of 42 days. The methanolic extract was used to elucidate the main compounds present in R. mangle via conventional phytochemical methods, such as TLC, HLPC, UPLC-DAD-MS, and NMR. The following compounds were detected: cinchonains Ia and Ib, catechin-3-O-rhamnopyranoside, epicatechin, lyoniside, and nudiposide. The daily administration of Rhizophora ethanol-water extract, similar to the traditional usage to control type 2 diabetes, was shown to exert chronic hypoglycemic and hypolipidemic effects. This effect may be associated whit the constituents in the extract. These findings suggest that R. mangle and its constituents could be potentially used to treat type 2 diabetes.

Resistance-modifying Activity in Vinblastine-resistant Human Breast Cancer Cells by Oligosaccharides Obtained from Mucilage of Chia Seeds (Salvia hispanica).

The multidrug resistance (MDR) phenotype is considered as a major cause of the failure in cancer chemotherapy. The acquisition of MDR is usually mediated by the overexpression of drug efflux pumps of a P-glycoprotein. The development of compounds that mitigate the MDR phenotype by modulating the activity of these transport proteins is an important yet elusive target. Here, we screened the saponification and enzymatic degradation products from Salvia hispanica seed's mucilage to discover modulating compounds of the acquired resistance to chemotherapeutic in breast cancer cells. Preparative-scale recycling HPLC was used to purify the hydrolysis degradation products. All compounds were tested in eight different cancer cell lines and Vero cells. All compounds were noncytotoxic at the concentration tested against the drug-sensitive and multidrug-resistant cells (IC50  > 29.2 µM). For the all products, a moderate vinblastine-enhancing activity from 4.55-fold to 6.82-fold was observed. That could be significant from a therapeutic perspective. Copyright © 2017 John Wiley & Sons, Ltd.