Design, synthesis, and biological evaluation of a novel dual peroxisome proliferator-activated receptor alpha/delta agonist for the treatment of diabetic kidney disease through anti-inflammatory mechanisms

Novel Cinnamic Acid Derivatives Containing Naproxen as NLRP3 Inhibitors: Synthesis and Evaluation of Their Biological Activity

Long-term use of naproxen can lead to serious side effects. Inspired by the biological activity of cinnamic acid, a series of cinnamic acid derivatives containing naproxen were designed and synthesized, and their anti-inflammatory activities and mechanisms were explored in vitro. Our results indicated that all of naproxen derivatives showed more significant inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) production and had a lower degree of cytotoxicity than that of naproxen. The present studies revealed that compound 23 (IC50 = 5.66 ± 1.66 µM) markedly inhibited the LPS-induced NO production and the over-expression of pro-inflammatory cytokines, including interleukin (IL)-1β, inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2). Furthermore, it blocked the activation of NF-κB signaling pathway and pyrin domain-containing protein 3 (NLRP-3) inflammasome in a concentration-dependent manner. Additionally, docking studies confirmed that compound 23 exhibited a well-fitting into the NLRP3 active site. Considering these results, compound 23 might be a novel NLRP3 inhibitor to treat inflammatory diseases.

Identification of Novel Organo-Se BTSA-Based Derivatives as Potent, Reversible, and Selective PPARγ Covalent Modulators for Antidiabetic Drug Discovery

Recent studies have identified selective peroxisome proliferator-activated receptor γ (PPARγ) modulators, which synergistically engage in the inhibition mechanism of PPARγ-Ser273 phosphorylation, as a promising approach for developing safer and more effective antidiabetic drugs. Herein, we present the design, synthesis, and evaluation of a new class of organo-Se compounds, namely, benzothiaselenazole-1-oxides (BTSAs), acting as potent, reversible, and selective PPARγ covalent modulators. Notably, 2n, especially (R)-2n, displayed a high binding affinity and superior antidiabetic effects with diminished side effects. This is mainly because it can reversibly form a unique covalent bond with the Cys285 residue in PPARγ-LBD. Further mechanistic investigations revealed that it manifested such desired pharmacological profiles primarily by effectively suppressing PPARγ-Ser273 phosphorylation, enhancing glucose metabolism, and selectively upregulating the expression of insulin-sensitive genes. Collectively, our results suggest that (R)-2n holds promise as a lead compound for treating T2DM and also provides an innovative reversible covalent warhead reference for future covalent drug design.

Elafibranor: A promising treatment for alcohol-associated liver disease?

We comment on an article by Koizumi et al. Elafibranor (EFN) is a dual pero-xisome proliferator-activated receptor α/δ agonist. The experimental results from Koizumi et al demonstrated that EFN significantly increases intestinal barrier function and ameliorates liver fibrosis. These positive outcomes suggest that EFN could be a promising therapeutic option for alcohol-associated liver disease (ALD). However, this study has limitations that necessitate further research to evaluate the efficacy of EFN. Future studies should consider the use of more appropriate animal models and cell types, optimize the administration routes and dosages of the drug, and conduct an in-depth investigation into the underlying mechanisms of action to determine the therapeutic effects of EFN in humans. With sustained and in-depth research, EFN has the potential to emerge as a novel therapeutic agent for the treatment of ALD.

Design, synthesis, and biological evaluation of piperazine derivatives as pan-PPARs agonists for the treatment of liver fibrosis

Liver fibrosis is commonly occurred in chronic liver diseases, but there is no approved drug for clinical use. The nuclear receptor peroxisome proliferator-activated receptors (PPARs) could not only regulate metabolic homeostasis but also possess anti-inflammatory and antifibrotic effects, and pan-PPARs agonist was considered as a potential anti-liver fibrosis agent. In this study, a series of novel piperazine pan-PPARs agonists were developed, and the preferred compound 12 displayed potent and well-balanced pan-PPARs agonistic activity. Moreover, compound 12 could dose-dependently stimulate the PPARs target genes expression and showed high selectivity over other related nuclear receptors. Importantly, compound 12 exhibited excellent pharmacokinetic profiles and good anti-liver fibrosis effects in vivo. Collectively, compound 12 holds promise for developing an anti-liver fibrosis agent.

PPARα/δ dual agonist H11 alleviates diabetic kidney injury by improving the metabolic disorders of tubular epithelial cells

Diabetic kidney disease (DKD) is responsible for nearly half of all end-stage kidney disease and kidney failure is a major driver of mortality among patients with diabetes. To date, few safe and effective drugs are available to reverse the decline of kidney function. Kidney tubules producing energy by fatty acid metabolism are pivotal in development and deterioration of DKD. Peroxisome proliferator-activated receptors (PPARs), comprising PPARα, PPARδ and PPARγ play a senior role in the pathogenesis of DKD for their functions in glycemic control and lipid metabolism; whereas systemic activation of PPARγ causes serious side-effects in clinical settings. Compound H11 was a potent PPARα and PPARδ (PPARα/δ) dual agonist with potent and well-balanced PPARα/δ agonistic activity and a high selectivity over PPARγ. In this study, the potential therapeutic effects of compound H11 were determined in a db/db mouse model of diabetes. Expressions of PPARα and PPARδ in nuclei of tubules were markedly reduced in diabetes. Transcriptional changes of tubular cells showed that H11 was an effective PPARα/δ dual agonist taking effects both in vivo and in vitro. Systemic administration of H11 showed glucose tolerance and lipid metabolic benefits in db/db mice. Moreover, H11 treatment exerted protective effects on diabetic kidney injury. In addition to fatty acid metabolism, H11 also regulated diabetes-induced metabolic alternations of branch chain amino acid degradation and glycolysis. The present study demonstrated a crucial role of H11 in regulation of energy homeostasis and metabolism in glucose-treated tubular cells. Overall, compound H11 holds therapeutic promise for DKD.

Essential oil from Fructus Alpiniae zerumbet ameliorates vascular endothelial cell senescence in diabetes by regulating PPAR-γ signalling: A 4D label-free quantitative proteomics and network pharmacology study

ETHNOPHARMACOLOGICAL RELEVANCE

Vascular endothelial cell senescence is associated with cardiovascular complications in diabetes. Essential oil from Fructus Alpiniae zerumbet (Pers.) B.L.Burtt & R.M.Sm. (EOFAZ) has potentially beneficial and promising diabetes-related vascular endothelial cell senescence-mitigating effects; however, the underlying molecular mechanisms remain unclear.

AIM OF THE STUDY

To investigate the molecular effects of EOFAZ on vascular endothelial cell senescence in diabetes.

MATERIALS AND METHODS

A diabetes mouse model was developed using a high-fat and high-glucose diet (HFD) combined with intraperitoneal injection of low-dose streptozotocin (STZ, 30 mg/kg) and oral treatment with EOFAZ. 4D label-free quantitative proteomics, network pharmacology, and molecular docking techniques were employed to explore the molecular mechanisms via which EOFAZ alleviates diabetes-related vascular endothelial cell senescence. A human aortic endothelial cells (HAECs) senescence model was developed using high palmitic acid and high glucose (PA/HG) concentrations in vitro. Western blotting, immunofluorescence, SA-β-galactosidase staining, cell cycle, reactive oxygen species (ROS), cell migration, and enzyme linked immunosorbent assays were performed to determine the protective role of EOFAZ against vascular endothelial cell senescence in diabetes. Moreover, the PPAR-γ agonist rosiglitazone, inhibitor GW9662, and siRNA were used to verify the underlying mechanism by which EOFAZ combats vascular endothelial cell senescence in diabetes.

RESULTS

EOFAZ treatment ameliorated abnormal lipid metabolism, vascular histopathological damage, and vascular endothelial aging in diabetic mice. Proteomics and network pharmacology analysis revealed that the differentially expressed proteins (DEPs) and drug-disease targets were associated with the peroxisome proliferator-activated receptor gamma (PPAR-γ) signalling pathway, a key player in vascular endothelial cell senescence. Molecular docking indicated that the small-molecule compounds in EOFAZ had a high affinity for the PPAR-γ protein. Western blotting and immunofluorescence analyses confirmed the significance of DEPs and the involvement of the PPAR-γ signalling pathway. In vitro, EOFAZ and rosiglitazone treatment reversed the effects of PA/HG on the number of senescent endothelial cells, expression of senescence-related proteins, the proportion of cells in the G0/G1 phase, ROS levels, cell migration rate, and expression of pro-inflammatory factors. The protective effects of EOFAZ against vascular endothelial cell senescence in diabetes were aborted following treatment with GW9662 or PPAR-γ siRNA.

CONCLUSIONS

EOFAZ ameliorates vascular endothelial cell senescence in diabetes by activating PPAR-γ signalling. The results of the present study highlight the potential beneficial and promising therapeutic effects of EOFAZ and provide a basis for its clinical application in diabetes-related vascular endothelial cell senescence.

Organophosphorus-Catalyzed Direct Dehydroxylative Thioetherification of Alcohols with Hypervalent Organosulfur Compounds

A metal-free and thiol-free organophosphorus-catalyzed method for forming thioethers was disclosed, driven by PIII/PV═O redox cycling. In this work, one-step dehydroxylative thioetherification of alcohols was fulfilled with various hypervalent organosulfur compounds. This established strategy features an excellent functional group tolerance and broad substrate scope, especially inactivated alcohols. The scale-up reaction and further transformation of the product were also successful. Additionally, this method offers a protecting-group-free and step-efficient approach for synthesizing peroxisome proliferator-activated receptor agonists which exhibited promising potential for treating osteoporosis in mammals.

Design of a multi-target focused library for antidiabetic targets using a comprehensive set of chemical transformation rules

Virtual small molecule libraries are valuable resources for identifying bioactive compounds in virtual screening campaigns and improving the quality of libraries in terms of physicochemical properties, complexity, and structural diversity. In this context, the computational-aided design of libraries focused against antidiabetic targets can provide novel alternatives for treating type II diabetes mellitus (T2DM). In this work, we integrated the information generated to date on compounds with antidiabetic activity, advances in computational methods, and knowledge of chemical transformations available in the literature to design multi-target compound libraries focused on T2DM. We evaluated the novelty and diversity of the newly generated library by comparing it with antidiabetic compounds approved for clinical use, natural products, and multi-target compounds tested in vivo in experimental antidiabetic models. The designed libraries are freely available and are a valuable starting point for drug design, chemical synthesis, and biological evaluation or further computational filtering. Also, the compendium of 280 transformation rules identified in a medicinal chemistry context is made available in the linear notation SMIRKS for use in other chemical library enumeration or hit optimization approaches.

Organophosphorus-Catalyzed "Dual-Substrate Deoxygenation" Strategy for C-S Bond Formation from Sulfonyl Chlorides and Alcohols/Acids

A green method to construct C-S bonds using sulfonyl chlorides and alcohols/acids via a P^III/P^V═O catalytic system is reported. The organophosphorus-catalyzed umpolung reaction promotes us to propose the "dual-substrate deoxygenation" strategy. Herein, we adopt the "dual-substrate deoxygenation" strategy, which achieves the deoxygenation of sulfonyl chlorides and alcohols/acids to synthesize thioethers/thioesters driven by P^III/P^V═O redox cycling. The catalytic method represents an operationally simple approach using stable phosphine oxide as a precatalyst and shows broad functional group tolerance. The potential application of this protocol is demonstrated by the late-stage diversification of drug analogues.

Integration of network pharmacology, transcriptomics and molecular docking reveals two novel hypoglycemic components in snow chrysanthemum

Our previous studies uncovered the glucose-lowering properties of snow chrysanthemum tea, however, the active ingredients and underlying mechanisms were yet to be uncovered. Flavonoids are the most active and abundant components in snow chrysanthemum tea. In this study, we treated leptin-deficient diabetic ob/ob or high-fat diet (HFD)-induced C57BL/6 J obese mice with or without total flavonoids of snow chrysanthemum (TFSC) for 14 weeks. Results indicated that TFSC ameliorated dyslipidemia and fatty liver, thereby reducing hyperlipidemia. Further mechanism experiments, including RNA-seq and experimental validation, revealed TFSC improved glycolipid metabolism primarily by activating the AMPK/Sirt1/PPARγ pathway. Additionally, by integrating UPLC, network pharmacology, transcriptomics, and experimental validation, we identified two novel hypoglycemic compounds, sulfuretin and leptosidin, in TFSC. Treatment with 12.5 μmol/L sulfuretin obviously stimulated cellular glucose consumption, and sulfuretin (3.125, 6.25 and 12.5 μmol/L) significantly mitigated glucose uptake damage and reliably facilitated glucose consumption in insulin-resistant HepG2 cells. Remarkably, sulfuretin interacted with the ligand-binding pocket of PPARγ via three hydrogen bond interactions with the residues LYS-367, GLN-286 and TYR-477. Furthermore, a concentration of 12.5 μmol/L sulfuretin effectively upregulated the expression of PPARγ, exhibiting a comparable potency to a renowned PPARγ agonist at 20 μmol/L. Taken together, our findings have identified two new hypoglycemic compounds and revealed their mechanisms, which significantly expands people's understanding of the active components in snow chrysanthemum that have hypoglycemic effects.

Novel O-benzylcinnamic acid derivative L26 treats acute lung injury in mice by MD-2

Acute lung injury (ALI) is an inflammation-mediated respiratory disease that is associated with a high mortality rate. In this study, a series of novel O-benzylcinnamic acid derivatives were designed and synthesized using cinnamic acid as the lead compound. We tested the preliminary anti-inflammatory activity of the compounds by evaluating their effect on inhibiting the activity of alkaline phosphatase (ALP) in Hek-Blue-TLR4 cells, in which compound L26 showed the best activity and 7-fold more active than CIN. ELISA, immunoprecipitation, and molecular docking indicated that L26 targeted MD-2 protein and competed with LPS to bind to MD-2, which resulted in the inhibition of inflammation. In the LPS-induced mouse model of ALI, L26 was found to decrease ALP activity and inflammatory cytokine TNF-α release to reduce lung injury by inhibiting the NF-κB signaling pathway. Acute toxicity experiments showed that high doses of L26 did not cause adverse reactions in mice, and it was safe in vivo. Also, the preliminary pharmacokinetic parameters of L26 were investigated in SD rats (T_1/2 = 4.246 h). In summary, L26 exhibited optimal pharmacodynamic and pharmacokinetic characteristics, which suggested that L26 could serve as a potential agent for the development of ALI treatment.

Leveraging ToxCast data and protein sequence conservation to complement aquatic life criteria derivation

The USEPA's 1985 guidelines for the derivation of aquatic life criteria (ALC) are robust but data-intensive. For many chemicals, the extensive in vivo data sets required for ALC derivation are not available. Thus, alternative analyses and processes that can provide provisional values to guide states, tribes, and other stakeholders while data accumulate and more rigorous criteria are derived would be beneficial. The overarching purpose of this study was to assess the feasibility of using data from new approach methodologies (NAMs) like ToxCast to derive first-pass, provisional values to guide chemical prioritization and resource management as a complement to traditional ALC derivation. To address this goal, the study objectives were to (1) estimate chemical potency using data from NAMs for nine compounds with available aquatic benchmarks, (2) evaluate the utility of using NAM data to elucidate potential mechanisms of toxicity to guide problem formulation, and (3) determine the species relevance of toxicity pathways for compounds with clearly defined mechanisms of action as a means to evaluate whether minimum data requirements could potentially be waived when deriving a more formal ALC. Points of departure were derived from ToxCast data based on the fifth percentile of the distribution of activity concentration above cutoff values falling below the cytotoxic burst. Mechanistic inferences were made based on active target hits in ToxCast and, where applicable, assessed for taxonomic conservation using SeqAPASS. ToxCast-based point-of-departure aligned relatively closely (six of nine test chemicals within a factor of 10; eight of nine within a factor of 100) with aquatic benchmarks from the USEPA and US Department of Energy (DOE). Moreover, pathways of toxicity gleaned from NAM data were reflective of in vivo-based findings from the literature. These results, while preliminary, and based on a limited number of substances, support the potential application of NAM data to complement traditional ALC derivation approaches and prioritization. Integr Environ Assess Manag 2023;19:224-238. © 2022 Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Development of Heterocyclic PPAR Ligands for Potential Therapeutic Applications

The family of nuclear peroxisome proliferator-activated receptors (PPARα, PPARβ/δ, and PPARγ) is a set of ligand-activated transcription factors that regulate different functions in the body. Whereas activation of PPARα is known to reduce the levels of circulating triglycerides and regulate energy homeostasis, the activation of PPARγ brings about insulin sensitization and increases the metabolism of glucose. On the other hand, PPARβ when activated increases the metabolism of fatty acids. Further, these PPARs have been claimed to be utilized in various metabolic, neurological, and inflammatory diseases, neurodegenerative disorders, fertility or reproduction, pain, and obesity. A series of different heterocyclic scaffolds have been synthesized and evaluated for their ability to act as PPAR agonists. This review is a compilation of efforts on the part of medicinal chemists around the world to find novel compounds that may act as PPAR ligands along with patents in regards to PPAR ligands. The structure-activity relationship, as well as docking studies, have been documented to better understand the mechanistic investigations of various compounds, which will eventually aid in the design and development of new PPAR ligands. From the results of the structural activity relationship through the pharmacological and in silico evaluation the potency of heterocycles as PPAR ligands can be described in terms of their hydrogen bonding, hydrophobic interactions, and other interactions with PPAR.

Design, Synthesis, and Biological Evaluation of Triazolone Derivatives as Potent PPARα/δ Dual Agonists for the Treatment of Nonalcoholic Steatohepatitis

Peroxisome proliferator-activator receptors α/δ (PPARα/δ) are regarded as potential therapeutic targets for nonalcoholic steatohepatitis (NASH). However, PPARα/δ dual agonist GFT-505 exhibited poor anti-NASH effects in a phase III clinical trial, probably due to its weak PPARα/δ agonistic activity and poor metabolic stability. Other reported PPARα/δ dual agonists either exhibited limited potency or had unbalanced PPARα/δ agonistic activity. Herein, we report a series of novel triazolone derivatives as PPARα/δ dual agonists. Among them, compound H11 exhibited potent and well-balanced PPARα/δ agonistic activity (PPARα EC50 = 7.0 nM; PPARδ EC50 = 8.4 nM) and a high selectivity over PPARγ (PPARγ EC50 = 1316.1 nM) in PPAR transactivation assays. The crystal structure of PPARδ in complex with H11 revealed a unique PPARδ-agonist interaction. H11, which had excellent PK properties and a good safety profile, showed potent in vivo anti-NASH effects in preclinical models. Together, H11 holds a great promise for treating NASH or other inflammatory and fibrotic diseases.