Safety of drugs commonly used to treat hypertension, dyslipidemia, and Type 2 diabetes (the metabolic syndrome): part 2

Development of an LC-MS/MS method for the quantitation of 55 compounds prescribed in combined cardiovascular therapy

This paper reports an LC-MS/MS method with positive electrospray ionization for the screening of commonly prescribed cardiovascular drugs in human plasma, including compounds with antihypertensive (57), antidiabetic (12), hypolipemiant (5), anticoagulant (2) and platelet anti-aggregation (2) effects. Sample treatment consisted of a simple protein precipitation with MeOH/0.1 M ZnSO₄ (4:1, v/v) solution after the addition of internal standard, followed by evaporation and reconstitution. Analytes separation was performed on a Polar-RP column (150 m x 2 mm, 4 μm) using a gradient elution of 15 min. The MS system was operated in MRM mode, monitoring one quantitation and one confirmation transition for each analyte. The recovery of the protein precipitation step ranged from 50 to 70% for most of the compounds, while some were considerably affected by matrix effects. Since several analytes fulfilled the linearity, accuracy and precision values required by the ICH guidelines, the method proved to be suitable for their quantitative analysis. The limits of quantitation varied from 0.38 to 9.1 μg/L and the limits of detection from 0.12 to 5.34 μg/L. The method showed to be suitable for the detection of plasma samples of patients under cardiovascular treatment with the studied drugs, and for 55 compounds reliable quantitative results could be obtained.

Anti-diabetic Activity of Triphala Fruit Extracts, Individually and in Combination, in a Rat Model of Insulin Resistance

We have investigated the possible antidiabetic properties of fruit extracts of Emblica officinalis Gaertn., Terminalia chebula Retz. and T. bellirica Roxb., individually and in combination (Triphala) in a high fructose diet induced rat model of insulin resistance. In the first part of the study, normal animals were studied for hypoglycemic activity. In the second part, animals were given a high fructose diet (HFD) for 40 days, for the last 20 days of which fruit extracts were also given. Body weight, fasting plasma glucose (FPG), and area under the curve (AUC) of the oral glucose tolerance test (OGTT) were assessed at the baseline, and at days 20 and 40. Fasting plasma insulin levels and the homeostasis model assessment (HOMA) resistance index were also assessed at baseline, 20 and 40 days. Fasting lipid levels were measured at the end of the study. During the first part of the investigation, in which extracts were given to normal animals, T. chebula showed significant hypoglycemic activity. During the second part of the study, in which the extracts were given to HFD fed rats, T. chebula caused a significant decrease in FPG and AUC. Emblica officinalis and Triphala caused a normalization of FPG. T. bellirica caused a reduction in AUC levels, but had no effect on FPG levels. T. bellirica caused a reduction in serum total cholesterol, triglyceride and low density lipoprotein levels. In conclusion, all three components of Triphala showed significant antidiabetic properties. T. bellirica, in addition, showed hypolipidemic activity.

Design and synthesis of novel antidiabetic agents

The synthesis and structure-activity relationships of a novel series of substituted quercetins that activates peroxisome proliferator-activated receptor gamma (PPARgamma) are reported. The PPARgamma agonistic activity of the most potent compound in this series is comparable to that of the thiazolidinedione-based antidiabetic drugs currently in clinical use.

Novel targets and therapeutic strategies for type 2 diabetes

The number of people diagnosed with type 2 diabetes mellitus (T2DM) is increasing at an alarming rate in western societies and has become a major health concern. During the past decade, studies using transgenic animals, gene transfer and pharmacological agents have yielded many data that have helped understand the molecular alterations characteristic of T2DM. This has opened the possibility for the development of potentially more-effective therapies, mainly focused on attenuating hepatic glucose production, enhancing glucose-dependent insulin secretion, enhancing the insulin signal transduction pathway, inhibiting lipolysis from the adipose tissue and promoting fatty acid oxidation.