Antihyperlipidemic studies of newly synthesized phenolic derivatives: in silico and in vivo approaches

Bioassay-guided isolation and in silico study of antihyperlipidemic compounds from Onosma hispidum Wall

Isolation of bioactive compounds from plants and their therapeutic evaluation is crucial in the pursuit of novel phytochemicals and contributes an indispensable role in drug discovery and design. The literature has documented the hypolipidemic effect of numerous Onosma species. Taking that into consideration, the current study was designed to isolate, purify and evaluate the antihyperlipidemic potential of leaves of Onosma hispidum Wall. For the first time, the bioassay-guided isolation led to the separation of 3 compounds that were identified by spectroscopic techniques as o-phthalic acid bis-(2-ethyl decyl)-ester (1), bis (2-ethyloctyl) phthalate (2), and 1,2 benzenedicarboxylic acid bis(2-methyl heptyl) ester (3). Lipase inhibition assay was utilized to scrutinize the antihyperlipidemic potential of methanolic extract fractions and subsequently isolated compounds. Further, the isolated compounds were employed for in silico studies via molecular docking, molecular mechanics with generalized born and surface area solvation (MM-GBSA), and MD simulations with Pancreatic Lipase Colipase (PDB ID: 1LPB). Molecular docking and MM-GBSA of isolated compounds were employed to explain the mode of binding between the protein-ligand complex and binding free energy calculation, respectively. Since compound (3) displayed the best docking score of -6.689 kcal/mol as compared to orlistat -5.529 kcal/mol with PDB: 1LPB. So, it was chosen for MD simulations to evaluate ligand stability and flexibility of the complex which was validated by the fluctuation of α-carbon chain, root mean square deviation (RMSD), root mean square fluctuation (RMSF), and type of interactions involved which authenticated the in vitro lipase inhibitory potential. Overall, in silico and in vitro results validated that compound (3) could be exploited as a promising pancreatic lipase inhibitor.Communicated by Ramaswamy H. Sarma.

Drug repurposing by in silico prediction of cyclizine derivatives as antihyperlipemic agents

Cardiovascular diseases are the primary factor for increased mortality rates around the world. Atherosclerosis brought on by high serum cholesterol can result in coronary heart disease (CHD). The risk of CHD is markedly reduced by lowering serum cholesterol levels. Scientists across the world are inventing new treatment regimens for lowering blood lipid levels. In this work, we repurposed the already established drugs, i.e., cyclizine derivatives as antihyperlipidemic agents. The repurposing was done based on the similarity of the selected cyclizine derivatives with the already established antihyperlipidemic drug, fenofibrate. Computational studies were performed and the 16 cyclizine derivatives docked against PPAR. alpha scored higher than fenofibrate. Lifarizine and medibazine outperform fenofibrate inmmgbsa. Fenofibrate, etodroxizine, meclizine, and cinnarizine had similar mmgbsa scores. The ADME properties of these compounds were performed and from that etodroxizine and levocetirizine were found to have better properties. The computational studies were performed using the Schrodinger software, maestro 12.8. The "Protein Preparation Wizard" module in the Maestro panel was used to create the protein structure and OPLS4 force field was used for energy minimization. The maestro builder panel's "Ligprep", "Receptor Grid Generation" and "Ligand Docking" modules were then used to prepare ligands, receptor grids and to perform docking respectively. MMGBSA was performed on the "prime MMGBSA" segment. Using the "Qikprop" setting in the maestro panel, a number of ADMET properties were predicted, and the program was run in default mode using vsgb as the solvation model.

Cardioprotective effect of 2-methoxy phenol derivatives against oxidative stress-induced vascular complications: An integrated in vitro, in silico, and in vivo investigation

BACKGROUND

Oxidative stress and inflammation play crucial roles in macro/microvascular complications. Phenolic compounds and their derivatives show promise as therapeutic agents for diseases like cancer, metabolic disorders, and cardiovascular diseases. With their antioxidant and anti-inflammatory properties, these compounds hold potential for mitigating vascular complications and improving overall health.

METHODOLOGY

This study aimed to assess the therapeutic potential of five 2-methoxy phenol derivatives (T2, T5, T6, T7, and T8) as antioxidants, anti-inflammatory agents, and vasorelaxants using in vitro, in silico, and in vivo approaches.

RESULTS

Among all, T2 exhibited substantial antioxidant potential against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals with IC50 (27.97 µg/mL), nitric oxide (NO) radicals (IC50 = 34.36 µg/mL), hydroxyl (OH) radicals (IC50 = 34.83 µg/mL) and Iron chelation (IC50 = 24.32 µg/mL). Molecular docking analysis confirms that all derivatives, particularly T2, exhibit favorable binding energies with the target proteins, ACE (-7.7 Kcal/mol), ECE-1 (-7.9 Kcal/mol), and COX-1 (-7.8 Kcal/mol). All of the compounds demonstrated satisfactory physicochemical and pharmacokinetic characteristics, and showed minimal to no toxicity during in silico, in vitro, and in vivo assessments. In isolated aortic rings from Sprague Dawley rats, pre-contracted with high K+ (80 mM), T2 induced vasorelaxation in dose dependent manner and shifted calcium response curves to the right as compared to verapamil. T2 also showed substantial platelet aggregation inhibition in a dose dependent manner with IC50 21.29 µM. All derivatives except T7 exhibited significant conservation of endogenous antioxidants i.e. catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and reduced glutathione (GSH) and significantly suppressed serum levels of inflammatory markers i.e. nitric oxide (NO), peroxides (TBARS), interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2).

CONCLUSION

The study concludes that T2 has significant antioxidant potential and vasorelaxant effects with adequate pharmacokinetics, making it a promising lead compound for further molecular investigation in cardiovascular disorders.

Imine Derivatives of Benzoxazole Attenuate High-Fat Diet-Induced Hyperlipidemia by Modulation of Lipid-Regulating Genes

Purpose: Hyperlipidemia being the prominent risk factor of cardiovascular diseases and side effects associated with the current lipid-lowering drugs have attracted the interest of scientists in the quest for new alternatives. In view of the diverse pharmacological potentials of benzoxazole (BZX) compounds, this study was designed to evaluate the antihyperlipidemic activity of imine derivatives of BZX in high-fat diet (HFD)-fed rats. Methods: Hyperlipidemia was induced in Sprague-Dawley rats by using HFD for 28 days. On the 28th day, blood samples were collected, and animals having serum triglycerides (TG) greater than 400 mg/dL and total cholesterol (TC) greater than 280 mg/dL were selected for further study. Hyperlipidemic rats were daily treated with either a vehicle or simvastatin (SIM; 20 mg/kg) or BZX compounds (10, 20, and 30 mg/kg), for 12 consecutive days. After the specified time duration, hyperlipidemic biomarkers were evaluated in the blood samples of sacrificed rats. Liver samples were collected for histopathological and mRNA analyses. Binding affinities of BZX derivatives with different targets were assessed by molecular docking. Results: The present study revealed that the BZX derivatives dose-dependently reduced the serum levels of TC, TG, low-density lipoprotein, and very low-density lipoprotein along with improvement in high-density lipoprotein levels. Similarly, all the compounds reduced HFD-induced alanine transaminase and aspartate aminotransferase levels except BZX-4. Histopathology of liver samples demonstrated mild to moderate fatty changes upon treatment with BZX-1, BZX-2, and BZX-4. The hepatic architecture of the BZX-3-treated samples was close to normal, and only mild inflammation was witnessed in these samples. Moreover, all the compounds significantly increased superoxide dismutase and glutathione levels, indicating their antioxidant potentials. Gene expression data showed that BZX-1 and BZX-3 reduced lipid levels by inhibiting HMGCR, APOB, PCSK9, SRB1, and VCAM1 and via improving PPAR-α and APOE mRNA levels. BZX-2 demonstrated its antihyperlipidemic effects mainly due to inhibition of APOB, while BZX-4-mediated effects appeared to be due to attenuation of APOB, PCSK9, and SRB1. BZX derivatives displayed strong binding affinities with HMGCR, APOB, and VCAM1, which suggested that some of the interactions might be required for inhibition of these target proteins. Conclusions: Based on the current findings, it can be concluded that BZX derivatives exert their antihyperlipidemic effects via modulation of multiple lipid-regulating genes.

In silico approach for the development of phenolic derivatives as potential anti-angiogenic agents against lysyl oxidase-like 2 enzyme

Background

Lysyl oxidase-like 2 (LOXL2) has recently been explored as extremely pivotal protein involved in angiogenesis which results in metastasis of numerous types of cancers. Hence, LOXL2 is an exciting new target for drug development against tumor progression and its spread to distant organs. Newly synthesized derivatives of natural phenolic antioxidant guaiacol (T1 to T8) were evaluated for their potential as anti-angiogenic agents using in silico approach. The drug likeness properties and toxicity of the synthesized derivatives have also been determined. Active binding sites of LOXL2 protein were determined by online server DoGSiteScorer, and lead–target interactions and conformations of pose analysis were done by using AutoDock Vina and Discovery Studio 4.0. The GUSAR model was applied to find the toxicity and ADMET properties. On the other hand, the chemoinformatics prediction was also performed using online FAF Drug Server and Molinspiration online server.

Results

Lead molecules from T1 to T8 showed promising binding affinity values, especially T5 and T8 showed best fit in the binding pocket of target enzyme (binding energies − 7.9 and 8.0 kcal/Mol, respectively). The stability of docked complexes was further evaluated using molecular dynamic simulation studies using GROMACS force field, and both leads (T5 and T8) were found to be strongly bounded to the active binding sites. The ADMET results revealed that all experimental molecules were virtually nontoxic and showed compliance with rule of five.

Conclusion

The present work will further enable researchers to understand how computer-aided drug designing tools may help to expedite new drug discovery process in a minimum cost.

In silico interactions of statins with cell death-inducing DNA fragmentation factor-like effector A (CIDEA)

Statins are the low-density lipoproteins (LDL)-cholesterol-lowering drugs of first choice and are used to prevent the increased risk of cardiovascular and cerebrovascular diseases. Although some of their effects are well known, little is known about their ability to regulate other lipid-related proteins which control apoptotic mechanisms. The aim of this study was to explore whether statins can bind to cell death-inducing DNA fragmentation factor-like effector A (CIDEA), which might be a possible pleiotropic mechanism of action of these drugs on the modulation of apoptosis and lipid metabolism. The structures of statins were subjected to molecular docking and dynamics with the human CIDEA protein to investigate the interaction pattern and identify which residues are important. The docking results indicated that atorvastatin and rosuvastatin showed the best interaction energy (-8.51 and -8.04 kcal/mol, respectively) followed by fluvastatin (-7.39), pitavastatin (-6.5), lovastatin (-6.23), pravastatin (-6.04) and simvastatin (-5.29). Atorvastatin and rosuvastatin were further subjected to molecular dynamics at 50 ns with CIDEA and the results suggested that rosuvastatin-CIDEA complex had lower root-mean square deviation and root-mean square fluctuation when compared with atorvastatin-CIDEA. Since two arginine residues -ARG19 and ARG22-were identified to be common for the interaction with CIDEA, a single-point mutation was induced in these residues to determine whether they are important for binding interaction. Mutation of these two residues seemed to affect mostly the interaction of atorvastatin with CIDEA, suggesting that they are important for the binding and therefore indicate another possible metabolic mechanism of the pleiotropic effects of this statin.

Antihyperlipidemic effect of selected pyrimidine derivatives mediated through multiple pathways

Hyperlipidemia is worth-mentioning risk factor in quickly expanding atherosclerosis, myocardial infarction, and stroke. This study attempted to determine effectiveness of selected pyrimidine derivatives: 5-(3-Hydroxybenzylidene)-2, 4, 6(1H, 3H, 5H)-pyrimidinetrione (SR-5), 5-(4-Hydroxybenzylidene)-2, 4, 6(1H, 3H, 5H)-pyrimidinetrione (SR-8), 5-(3-Chlorobenzylidene)-2, 4, 6(1H, 3H, 5H)-pyrimidinetrione (SR-9), and 5-(4-Chlorobenzylidene)-2, 4, 6(1H, 3H, 5H)-pyrimidinetrione (SR-10) against hyperlipidemia. In silico results revealed that SR-5, SR-8, SR-9, and SR-10 exhibited high affinity with 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) possessing binding energy values of -8.2, -8.4, -8.6, and -9.5 Kcal/mol, respectively, and moderate (<-8 Kcal/mol) against other selected targets. In vivo findings showed that test drugs (25 and 50 mg/Kg) significantly decreased HFD rat total cholesterol, triglycerides, low-density lipoprotein, very-low-density lipoprotein, atherogenic index, coronary risk index, alkaline phosphatase, aspartate transaminase, alanine transaminase, and bilirubin and increased high-density lipoprotein (p < 0.05, p < 0.01, p < 0.001 vs HFD group). In animal liver tissues, SR-5, SR-8, SR-9, and SR-10 inhibited HMGCoA reductase enzyme, enhanced glutathione-s-transferase, reduced glutathione, catalase levels, improved cellular architecture in histopathological examination, and decreased expression of inflammatory markers: cyclo-oxygenase 2, tumor necrosis factor alpha, phosphorylated c-Jun N-terminal kinase, and phosphorylated-nuclear factor kappa B, evidenced in immunohistochemistry and enzyme-linked immunosorbent assay molecular investigations. This study indicates that SR-5, SR-8, SR-9, and SR-10 exhibit antihyperlipidemic action, mediated possibly through HMGCoA inhibition, hepatoprotection, antioxidant, and anti-inflammatory pathways.

Tissue distribution and molecular docking research on the active components of Bidens bipinnata L. against hyperlipidemia

Bidens bipinnata L. is a folk medicinal plant in China that shows significant antihyperlipidemia effectiveness. However, studies of the underlying mechanism study are lacking. In order to explore the potential action sites and the underlying mechanism of treating hyperlipidemic, this work undertook tissue distribution and molecular docking research on the markers of B. bipinnata L., which were obtained through serum pharmacochemistry and network database retrieval. The results showed that seven compounds (gallic acid, protocatechuic acid, rutin, hyperoside, bipinnate polyacetylenicloside, luteolin and quercetin) were screened out as markers. Owing to the diversity of chemical structures, they exhibited an inconsistent trend in tissue distribution. However, all of them had high levels in the liver and no specific distribution in other tissues. More interestingly, seven proteins-HMGCR (1HWK), NR3C1 (4P6W), CYP1A2 (2HI4), RXRA (4PP3), CES1 (1MX1), HSD11B1 (2RBE) and CYP1A1 (4I8V)-showed significant binding affinity with three or more markers, suggesting that they may be the target proteins of B. bipinnata L. This study preliminarily sheds light on the tissue distribution and targets of B. bipinnata L., providing some useful information on the underlying mechanisms of the antihyperlipidemia effect.

Inhibition of human 3-hydroxy-3-methylglutaryl CoA reductase by peptides leading to cholesterol homeostasis through SREBP2 pathway in HepG2 cells

In mammalian cells, human 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), a rate-limiting endoplasmic reticulum (ER) bonded enzyme, plays a central role in the cholesterol homeostasis via the negative feedback mechanism. The present study indicates that the interactions of novel peptides with the catalytic domain of HMGCR, provides an alternative therapeutic candidate for reducing cholesterol. The potential natural origin of HMGCR peptide inhibitors were filtered from the peptide library using the molecular docking, which revealed three strong candidates for inhibition. This information was used for synthesizing peptides, which were evaluated for inhibition against HMGCR. The stronger docking interactions were confirmed by experimental dissociation constant (K_D) values of 9.1 × 10^-9 M, 1.4 × 10^-8 M and 1.2 × 10^-8 M for peptides NALEPDNRIESEGG (Pep-1), NALEPDNRIES (Pep-2) and PFVKSEPIPETNNE (Pep-3) respectively. The immunological based interactions show a strong evidence of peptide-HMGCR complexes. The LDL uptake showed enhancements after treatments with peptides in the extracellular environment of HepG2 cells, which was further, corroborated through increase in the immunofluorescence signal of the localized LDL-R protein expression on the cell membrane. The results showed that the mRNA and protein expression of transcription factors were significantly up-regulated showing regulation of cholesterol biosynthesis in peptide treated HepG2 cells. The binding of transcription factors, sterol regulatory element (SRE) and cAMP-response element (CRE) on HMGCR promotor further confirms the cholesterol biosynthesis regulation. All the above results suggested a key role of peptide/s in alleviating cholesterol accumulation in tissue via inhibition of rate-limiting HMGCR enzyme.

Hypolipidemic effect of novel 2,5-bis(4-hydroxybenzylidenamino)-1,3,4-thiadiazole as potential peroxisome proliferation-activated receptor-α agonist in acute hyperlipidemic rat model

The development of new antihyperlipidemic agents with higher potency and lower side effects is of high priority. In this study, 1,3,4 thiadiazole Schiff base derivatives were synthesized as potential peroxisome proliferation-activated receptor-α (PPARα) agonists and characterized using elemental analysis, FTIR, ¹H-NMR, ¹³C-NMR and mass spectroscopy and then tested for their hypolipidemic activity in Triton WR-1339-induced acute hyperlipidemic rat model in comparison with bezafibrate. The compounds showed significant hypolipidemic activity. Induced fit docking showed that the compounds are potential activators of PPARα with binding scores - 8.00 Kcal/mol for 2,5-bis(4-hydroxybenzylidenamino)-1,3,4-thiadiazole. PCR array analysis showed an increase in the expression of several genes involved in lipid metabolism through mitochondrial fatty acid β oxidation and are part of PPARα signaling pathway including Acsm3, Fabp4 and Hmgcs1. Gene expression of Lrp12 and Lrp1b involved in LDL uptake by liver cells and Cyp7a1 involved in cholesterol catabolism were also found to be upregulated.