Synthesis and anti-hyperlipidemic evaluation of N‑(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives in Triton WR-1339-induced hyperlipidemic rats

Synthesis and in Vivo Lipid-Lowering Activity of Novel Imidazoles-5-carboxamide Derivatives in Triton-WR-1339-Induced Hyperlipidemic Wistar Rats

A new series of imidazole-5-carboxamide derivatives were prepared and tested for their anti-hyperlipidemic activity in Triton-WR-1339-induced hyperlipidemic Wistar rats. The purpose of this research was to improve benzophenone carboxamides water solubility maintaining at the same time the antihyperlipidemic activity. Compounds 4, 6, 10, and 11 were synthesized through a coupling reaction between imidazoles-5-carbonyl chloride and amino benzophenones. The tested animals (n=48) were divided into six groups: the first group (hyperlipidemic control group; HCG) received an intraperitoneal injection (i.p.) of (300 mg/kg) Triton WR-1339. The second group received i.p. injection of Triton WR-1339 followed by an intra-gastric administration of bezafibrate (100 mg/kg) (bezafibrate; BF). The third, fourth, fifth, and sixth groups received i.p. injection of Triton WR-1339 followed by an intra-gastric administration of (30 mg/kg) of compounds 4, 6, 10, and 11, respectively. At a dose of 30 mg/kg body weight compounds 4, 6, 10, and 11 significantly (p<0.0001) decreased the plasma level of triglyceride (TG), low-density lipoprotein (LDL) and total cholesterol (TC) levels after 18 h of treatment. Additionally, compounds 4, 6, 11 and bezafibrate (100 mg/kg) significantly (p<0.0001) increased the plasma level of high-density lipoprotein (HDL) levels, which is known for its preventive role against atherogenesis. These results demonstrate the possibility of pharmacokinetic properties improvement maintaining the biological and pharmacological profile of these compounds.

Pharmacological evaluation of Convolvulus pluricaulis as hypolipidaemic agent in Triton WR-1339-induced hyperlipidaemia in rats

Objective

The aim of the study was to evaluate the effect of Convolvulus pluricaulis (CP; C. pluricaulis) methanolic extract on Triton WR-1339-induced hyperlipidaemia in rats.

Methods

The study comprised of six groups namely normal control, experimental control and treatment groups (100, 200 and 400 mg/kg of C. pluricaulis, and 65 mg/kg of Fenofibrate). Hyperlipidaemia was induced by a single intraperitoneal injection of Triton WR-1339 400 mg/kg in rats. Parameters such as lipid profile, oxidative stress, histological analysis and atherogenic index were evaluated. The plant extract was further studied by HPLC and LCMS, for analyses of active phytochemicals.

Key findings

The result of the study showed that C. pluricaulis significantly decreased total cholesterol, triglycerides, LDL-c, MDA levels and atherogenic index while the levels of HDL-c and GSH were found to be raised. Plant extract at the dose of 400 mg had a consistent effect on all lipid profile parameters. Lower doses (100 and 200 mg) did not produce a statistically significant reduction in LDL-c. In addition, the protective effect of C. pluricaulis was confirmed by histological analysis. Further, the findings of the study were found to be comparable with fenofibrate.

Conclusions

Therefore, the present study suggests that C. pluricaulis has the potential for the treatment of hyperlipidaemia.

Synthesis of Novel Benzimidazole-2-carboxamide Derivatives and in Vivo Antihyperlipidemic Activity Evaluation

Hyperlipidemia is known as an elevation of plasma lipid components. It contributes significantly to atherosclerosis which is one of the most important causative factors in cardiovascular diseases. Agents that cause a dramatic decrease in serum lipid levels are of great value in the treatment of cardiovascular diseases. For this purpose, a new series of benzimidazole propyl carboxamide benzophenone derivatives have been synthesized (7, 8, and 9). These compounds were tested in vivo to evaluate their potential hypolipidemic activity using Triton WR-1339 induced hyperlipidemic rats. All the synthesized compounds have proved to be highly biologically active, with compound 9 being the most active derivative.

Emerging strategies of targeting lipoprotein lipase for metabolic and cardiovascular diseases

Although statins and other pharmacological approaches have improved the management of lipid abnormalities, there exists a need for newer treatment modalities especially for the management of hypertriglyceridemia. Lipoprotein lipase (LPL), by promoting hydrolytic cleavage of the triglyceride core of lipoproteins, is a crucial node in the management of plasma lipid levels. Although LPL expression and activity modulation is observed as a pleiotropic action of some the commonly used lipid lowering drugs, the deliberate development of drugs targeting LPL has not occurred yet. In this review, we present the biology of LPL, highlight the LPL modulation property of currently used drugs and review the novel emerging approaches to target LPL.

Lipid lowering activity of novel N-(benzoylphenyl)pyridine-3-carboxamide derivatives in Triton WR-1339-induced hyperlipidemic rats

CONTEXT

Dyslipidemia is a major risk factor for the development of cardiovascular diseases. Many dyslipidemic patients do not achieve their target lipid levels with the currently available medications, and most of them may experience many side effects.

OBJECTIVE

The present work aimed toward identifying a new class of novel nicotinic acid-carboxamide derivatives as promising antihyperlipidemic compounds.

MATERIALS AND METHODS

Six novel N-(benzoylphenyl)pyridine-3-carboxamide derivatives were synthesized using acid chloride pathways. All structures were confirmed using ¹H-NMR, ¹³C-NMR, IR, and HRMS. The evaluation of biological activity was conducted using Triton WR-1339-induced hyperlipidemic rats model.

RESULTS

This study revealed that some of the newly synthesized novel N-(benzoylphenyl)pyridine-3-carboxamide derivatives mainly C4 and C6 possessed significant antihyperlipidemic activities on lipid components TG and TC (p value <0.05).

DISCUSSION AND CONCLUSION

This research opens the door for new potential antihyperlipidemic compounds derived from nicotinic acid that need further optimization of their biological activities.

Structure-activity relationships for lipoprotein lipase agonists that lower plasma triglycerides in vivo

The risk of cardiovascular events increases in individuals with elevated plasma triglyceride (TG) levels, therefore advocating the need for efficient TG-lowering drugs. In the blood circulation, TG levels are regulated by lipoprotein lipase (LPL), an unstable enzyme that is only active as a non-covalently associated homodimer. We recently reported on a N-phenylphthalimide derivative (1) that stabilizes LPL in vitro, and moderately lowers triglycerides in vivo (Biochem. Biophys. Res. Commun.2014, 450, 1063). Herein, we establish structure-activity relationships of 51 N-phenylphthalimide analogs of the screening hit 1. In vitro evaluation highlighted that modifications on the phthalimide moiety were not tolerated and that lipophilic substituents on the central phenyl ring were functionally essential. The substitution pattern on the central phenyl ring also proved important to stabilize LPL. However, in vitro testing demonstrated rapid degradation of the phthalimide fragment in plasma which was addressed by replacing the phthalimide scaffold with other heterocyclic fragments. The in vitro potency was retained or improved and substance 80 proved stable in plasma and efficiently lowered plasma TGs in vivo.

Triglyceride-lowering agents

This review is the first attempt at systematization of the literature data on the structures and activities of triglyceride-lowering agents which used in medical practice or are in development. The effects and mechanisms of action of statins, squalene synthase inhibitors, fibrates, PPARα and PPARα/γ agonists, nicotinic acid, omega-3 fatty acids and some other molecular targets were considered. Unfortunately, to date, harmless and effective triglyceride-lowering drug still does not exist and there is still need for development of better triglyceride-lowering agents.

Antihypercholesterolemic and Antioxidative Potential of an Extract of the Plant, Piper betle, and Its Active Constituent, Eugenol, in Triton WR-1339-Induced Hypercholesterolemia in Experimental Rats

Hypercholesterolemia is a dominant risk factor for atherosclerosis and cardiovascular diseases. In the present study, the putative antihypercholesterolemic and antioxidative properties of an ethanolic extract of Piper betle and of its active constituent, eugenol, were evaluated in experimental hypercholesterolemia induced by a single intraperitoneal injection of Triton WR-1339 (300 mg/kg b.wt) in Wistar rats. Saline-treated hypercholesterolemic rats revealed significantly higher mean blood/serum levels of glucose, total cholesterol, triglycerides, low density and very low density lipoprotein cholesterol, and of serum hepatic marker enzymes; in addition, significantly lower mean serum levels of high density lipoprotein cholesterol and significantly lower mean activities of enzymatic antioxidants and nonenzymatic antioxidants were noted in hepatic tissue samples from saline-treated hypercholesterolemic rats, compared to controls. However, in hypercholesterolemic rats receiving the Piper betle extract (500 mg/kg b.wt) or eugenol (5 mg/kg b.wt) for seven days orally, all these parameters were significantly better than those in saline-treated hypercholesterolemic rats. The hypercholesterolemia-ameliorating effect was better defined in eugenol-treated than in Piper betle extract-treated rats, being as effective as that of the standard lipid-lowering drug, lovastatin (10 mg/kg b.wt). These results suggest that eugenol, an active constituent of the Piper betle extract, possesses antihypercholesterolemic and other activities in experimental hypercholesterolemic Wistar rats.

The pharmacological effects of novel 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamide derivatives on plasma lipid profile of Triton-WR-1339-induced Wistar rats

A novel series of 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamides (3c-3g) were synthesized. The present study was undertaken to investigate the possible antihyperlipidemic effect of these novel compounds on hyperlipidemic rats. Hyperlipidemia was induced by a single intraperitoneal injection of Triton WR-1339 (300 mg/kg). The tested animals were divided into normal control (NCG), hyperlipidemic control (HCG), compounds 3c-, 3d-, 3e-, 3f-, 3g- and bezafibrate (BF)-treated groups. At a dose of 15 mg/kg, compounds 3c-3g and BF (100 mg/kg) significantly (p < 0.0001) reduced elevated plasma triglycerides levels after 12 and 24 h compared to the hyperlipidemic control group. However, only compounds 3e and 3g obviously showed a significant (p < 0.0001) reduction in plasma total cholesterol levels after 12 and 24 h. Moreover, high-density lipoprotein cholesterol levels were significantly increased in all treated groups. The current study demonstrates that 5-fluoro-N-(9,10-dihydro-9,10-dioxoanthracen-8-yl)-1H-indole-2-carboxamides (3c-3g) have a definite antihyperlipidemic potential and these beneficial activities may contribute to their cardioprotective and antiatherosclerotic role.

Antihyperlipidemic properties of novel N-(benzoylphenyl)-5-substituted-1H-indole-2-carboxamides in Triton WR-1339-induced hyperlipidemic rats

In the search for new potential antihyperlipidemic agents, the present study focuses on the synthesis of novel N-(benzoylphenyl)-5-substituted-1H-indole-2-carboxamides (compounds 8-12, 15, 16, 18) and investigating their antihyperlipidemic activity using Triton WR-1339-induced hyperlipidemic rats as an experimental model. Hyperlipidemia was developed by intraperitoneal injection of Triton WR-1339 (250 mg/kg body weight). The tested animals were divided into normal control (NCG), hyperlipidemic (HG), compound 8, 9, 15, 16, 18- and bezafibrate treated groups. At a dose of 15 mg/kg body weight, compounds 9, 16, 18 and bezafibrate (100 mg/kg) significantly (p < 0.0001) reduced elevated plasma triglycerides levels after 12 h compared to the hyperlipidemic control group. However, only the group treated with compounds 9, 16 and 18 showed an obviously significant (p < 0.001) reduction in plasma total cholesterol levels after 12 h compared to the hyperlipidemic control group. Moreover, high density lipoprotein-cholesterol levels were significantly (p < 0.0001) increased in all treated groups after 12 h compared to the hyperlipidemic control group, except for compounds 8 and 15 which revealed inactive. It is therefore reasonable to assume that compounds 9, 16 and 18 may have potential in the treatment of hyperlipidemia.