Effect of telmisartan on the therapeutic efficacy of pitavastatin in high-fat diet induced dyslipidemic guinea pigs

Effects of telmisartan on metabolic syndrome components: a comprehensive review

Telmisartan is an antagonist of the angiotensin II receptor used in the management of hypertension (alone or in combination with other antihypertensive agents. It belongs to the drug class of angiotensin II receptor blockers (ARBs). Among drugs of this class, telmisartan shows particular pharmacologic properties, including a longer half-life than any other angiotensin II receptor blockers that bring higher and persistent antihypertensive activity. In hypertensive patients, telmisartan has superior efficacy than other antihypertensive drugs (losartan, valsartan, ramipril, atenolol, and perindopril) in controlling blood pressure, especially towards the end of the dosing interval. Telmisartan has a partial PPARγ-agonistic effect whilst does not have the safety concerns of full agonists of PPARγ receptors (thiazolidinediones). Moreover, telmisartan has an agonist activity on PPARα and PPARδ receptors and modulates the adipokine levels. Thus, telmisartan could be considered as a suitable alternative option, with multi-benefit for all components of metabolic syndrome including hypertension, diabetes mellitus, obesity, and hyperlipidemia. This review will highlight the role of telmisartan in metabolic syndrome and the main mechanisms of action of telmisartan are discussed and summarized. Many studies have demonstrated the useful properties of telmisartan in the prevention and improving of metabolic syndrome and this well-tolerated drug can be greatly proposed in the treatment of different components of metabolic syndrome. However, larger and long-duration studies are needed to confirm these findings in long-term observational studies and prospective trials and to determine the optimum dose of telmisartan in metabolic syndrome.

Anti-Diabetic Effect of Telmisartan Through its Partial PPARγ-Agonistic Activity

Telmisartan is an angiotensin II receptor antagonist, which selectively inhibits the angiotensin II type 1 receptor. Thus, it is widely used for hypertension management. Nowadays, telmisartan's effect on peroxisome proliferator-activated receptors (PPARs) is gaining wider attention. PPARs are ligand-activated transcription factors that belong to the nuclear hormone receptor superfamily. Telmisartan is reported to have a partial PPARγ-agonistic effect while avoiding the safety concerns found with full PPARγ agonists (thiazolidinediones). Telmisartan could be an alternative treatment option, with dual benefit for diabetes mellitus (DM) and hypertension. This review summarizes the anti-diabetic activity of telmisartan via its partial PPARγ-agonistic activity.

Simultaneous Determination of Telmisartan and Pitavastatin Calcium in Intestinal Perfusate by HPLC: Application to Intestinal Absorption Interaction Study

BACKGROUND

Hypertension and hypercholesterolemia are two main physiological risk factors of cardiovascular disease, and commonly occur in combination. Multicompound combination therapy is rational for the treatment of concurrent hypertension and hypercholesterolemia, while telmisartan and pitavastatin calcium can be used as a potential drug combination.

OBJECTIVE

The aim of this paper is to study the intestinal absorption and absorption interaction of telmisartan and pitavastatin calcium.

METHODS

An HPLC method was developed and validated to determine telmisartan and pitavastatin calcium in intestinal perfusate simultaneously. The in situ single-pass perfusion in rats was utilized to investigate the effects of concentrations, intestinal segment (duodenum, jejunum, ileum and colon) and co-administrated drugs on absorption.

RESULTS

The effective permeability coefficient and the absorption rate constant of telmisartan were higher in the duodenum as compared to other intestinal segments. However, the intestinal absorption of pitavastatin calcium was not segmental dependent. The effective permeability coefficient and absorption rate constant have no significant difference among three concentrations of telmisartan, pitavastatin calcium individually and their combination.

CONCLUSION

The results showed that telmisartan and pitavastatin calcium were transported passively, and telmisartan and pitavastatin calcium could be absorbed well in all intestinal segments. The intestinal absorption parameters revealed the absence of any intestinal absorption interaction when co-administered. Lay Summary: Co-administration of telmisartan and pitavastatin calcium can provide a potential therapeutic strategy for the treatment of concurrent hypertension and hypercholesterolemia. We are investigating the intestinal interaction of these two drugs in rats using the developed HPLC method and in situ single-pass perfusion technology. We will calculate some parameters after administrating two types of drugs either separately or together, which help reflect changes regarding intestinal absorption and penetration. Compared with telmisartan and pitavastatin calcium administrated separately, if parameters significantly change after co-administration, it proves the existence of the intestinal interactions. Moreover, the results might contribute to clinic drug monitoring.

Simultaneous determination of telmisartan and pitavastatin in rat plasma by UPLC-MS/MS: Application to pharmacokinetic interaction study

To investigate the pharmacokinetic (PK) interaction between telmisartan (Tel) and pitavastatin (Pit), a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometric assay method had been successfully established and fully validated for the simultaneous quantification of Tel and Pit in rat plasma. A simple protein precipitation procedure was adopted for the sample preparation with satisfactory extraction recovery for both analytes and the internal standard. The samples were chromatographed on an Inertsil ODS-3 C18 column (100mm×2.1mm, 2μm) using a mixture of acetonitrile and 10mM ammonium acetate containing 0.1% formic acid (60: 40, v/v) as the mobile phase at a flow rate of 0.4mL/min. The calibration curves obtained were linear (r>0.99) over the concentration range of 2-200ng/mL for Tel and 1-100ng/mL for Pit, respectively. The validated method was successfully applied to the PK study and the data did not reveal any evidence for the potential drug-drug interaction (DDI) between Tel and Pit. This information would provide the evidence for clinical rational use of Tel and Pit, and this study might be applied in therapeutic drug monitoring in patients receiving Tel/Pit combinations or single drug.

High-fat but not sucrose intake is essential for induction of dyslipidemia and non-alcoholic steatohepatitis in guinea pigs

Background

Non-alcoholic fatty liver disease (NAFLD) and dyslipidemia are closely related. Diet plays an important role in the progression of these diseases, but the role of specific dietary components is not completely understood. Therefore, we investigated the role of dietary sucrose and fat/cholesterol on the development of dyslipidemia and NAFLD.

Methods

Seventy female guinea pigs were block-randomized (based on weight) into five groups and fed a normal chow diet (control: 4 % fat), a very high-sucrose diet (vHS: 4 % fat, 25 % sucrose), a high-fat diet (HF: 20 % fat, 0.35 % cholesterol), a high-fat/high-sucrose diet (HFHS: 20 % fat, 15 % sucrose, 0.35 % cholesterol) or a high-fat/very high-sucrose diet (HFvHS: 20 % fat, 25 % sucrose, 0.35 % cholesterol) for 16 and 25 weeks.

Results

All three high-fat diets induced dyslipidemia with increased concentrations of plasma cholesterol (p < 0.0001), LDL-C (p < 0.0001) and VLDL-C (p < 0.05) compared to control and vHS. Contrary to this, plasma triglycerides were increased in control and vHS compared to high-fat fed animals (p < 0.01), while circulating levels of free fatty acids were even between groups. Histological evaluation of liver sections revealed non-alcoholic steatohepatitis (NASH) with progressive inflammation and bridging fibrosis in high-fat fed animals. Accordingly, hepatic triglycerides (p < 0.05) and cholesterol (p < 0.0001) was increased alongside elevated levels of alanine and aspartate aminotransferase (p < 0.01) compared to control and vHS.

Conclusion

Collectively, our results suggest that intake of fat and cholesterol, but not sucrose, are the main factors driving the development and progression of dyslipidemia and NAFLD/NASH.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-016-0110-1) contains supplementary material, which is available to authorized users.

Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease

We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.