Synthesis, Characterization and Evaluation of Gemfibrozil-Stilbene Hybrid as Antioxidant Agent

The Small Molecule PPARγ Agonist GL516 Induces Feeding-Stimulatory Effects in Hypothalamus Cells Hypo-E22 and Isolated Hypothalami

PPARγ agonists are implicated in the regulation of diabetes and metabolic syndrome and have therapeutic potential in brain disorders. PPARγ modulates appetite through its central effects, especially on the hypothalamic arcuate nucleus (ARC). Previous studies demonstrated that the small molecule GL516 is a PPARγ agonist able to reduce oxidative stress and apoptosis with a potential neuroprotective role. Herein, we investigated the effects of GL516, in vitro and ex vivo, on the levels of hypothalamic dopamine (DA) and serotonin (5-HT). The gene expressions of neuropeptide Y, CART, AgRP, and POMC, which play master roles in the neuroendocrine regulation of feeding behavior and energy balance, were also evaluated. HypoE22 cells were treated with H₂O₂ (300 μM) for 2 h e 30’ and with different concentrations of GL516 (1 nM-100 µM). The cell viability was evaluated after 24 and 48 h of culturing using the MTT test. DA and 5-HT levels in the HypoE22 cell supernatants were analyzed through HPLC; an ex vivo study on isolated hypothalamic specimens challenged with scalar concentrations of GL516 (1–100 µM) and with pioglitazone (10 µM) was carried out. The gene expressions of CART, NPY, AgRP, and POMC were also determined by a quantitative real-time PCR. The results obtained showed that GL516 was able to reduce DA and 5-HT turnover; moreover, it was effective in stimulating NPY and AgRP gene expressions with a concomitant reduction in CART and POMC gene expressions. These results highlight the capability of GL516 to modulate neuropeptide pathways deeply involved in appetite control suggesting an orexigenic effect. These findings emphasize the potential use of GL516 as a promising candidate for therapeutical applications in neurodegenerative diseases associated with the reduction in food intake and stimulation of catabolic pathways.

Design, Synthesis and Biological Evaluation of Aromatase Inhibitors Based on Sulfonates and Sulfonamides of Resveratrol

A library of sulfonate and sulfonamide derivatives of Resveratrol was synthesized and tested for its aromatase inhibitory potential. Interestingly, sulfonate derivatives were found to be more active than sulfonamide bioisosteres with IC₅₀ values in the low micromolar range. The sulfonate analogues 1b–c and 1j exhibited good in vitro antiproliferative activity on the MCF7 cell line, evidenced by MTT and LDH release assays. Structure–activity relationships suggested that electronic and lipophilic properties could have a different role in promoting the biological response for sulfonates and sulfonamides, respectively. Docking studies disclosed the main interactions at a molecular level of detail behind the observed inhibition of the more active compounds whose chemical stability has been evaluated with nano-liquid chromatography. Finally, 1b–c and 1j were highlighted as sulfonates to be further developed as novel and original aromatase inhibitors.

In Vitro Anticancer Effects of Stilbene Derivatives: Mechanistic Studies on HeLa and MCF-7 Cells

BACKGROUND AND OBJECTIVE

The growing prevalence of cancer and the resulting chemoresistance exert a huge burden on healthcare systems and impose a great challenge to public health around the world. In efforts to develop new chemotherapeutic agents for cancer treatment, a class of heterocyclic compounds i.e. triazine-based molecules were investigated as anticancer agents.

MATERIALS AND METHODS

New triazine hybrids of stilbene were synthesized and evaluated as anticancer agents for cervical (HeLa) and breast (MCF-7) carcinoma cells. The compound (7e), sodium (E)-6,6'-(ethene-1,2- diyl)bis(3-((4-chloro-6-((3-luorophenyl)amino)-1,3,5-triazin-2-yl)amino)benzenesulfonate) was found to be most potent among synthesized derivatives and was explored further for detailed mechanistic studies.

RESULTS

In a set comprised of twelve derivatives, compound 7e, sodium (E)-6,6'-(ethene-1,2-diyl)bis(3-((4- chloro-6-((3-luorophenyl)amino)-1,3,5-triazin-2-yl)amino)benzenesulfonate) was found most potent inhibitor for HeLa and MCF-7 cells.

DISCUSSION

The present study has revealed that compound 7e may activate mitochondrial pathway of apoptosis in HeLa and MCF-7 cells which was assessed by DNA binding studies, estimation of the release of Lactate Dehydrogenase (LDH), fluorescence imaging, production of Reactive Oxygen Species (ROS) in cancer cells, analysis of cell cycle by flow cytometry, change in Mitochondrial Membrane Potential (MMP) and activation of caspase-9 and caspase-3.

CONCLUSION

Compound 7e may serve as a lead in designing new anticancer compounds based on stilbene scaffold.

Druggability profile of stilbene-derived PPAR agonists: determination of physicochemical properties and PAMPA study

PPAR agonists represent a new therapeutic opportunity for the prevention and treatment of neurodegenerative disorders, but their pharmacological success depends on favourable pharmacokinetic properties and capability to cross the BBB. In this study, we assayed some PPAR agonists previously synthesized by us for their physicochemical properties, with particular references to lipophilicity, solubility and permeability profiles, using the PAMPA. Although tested compounds showed high lipophilicity and low aqueous solubility, the results revealed a good overall druggability profile, encouraging further studies in the field of neurodegenerative diseases.

PPAR Ligands Containing Stilbene Scaffold

Peroxisome proliferator-activated receptors (PPARs) are transcriptional factors which belong to the ligand-activated nuclear receptor superfamily. They are ubiquitously expressed throughout the body. So far, three major subtypes have been identified, PPARα, PPARβ/δ and PPARγ. They are crucial for lipid and glucose metabolism and are also involved in the regulation of several types of tumors, inflammation, cardiovascular diseases and infertility. The importance of these transcription factors in physiology and pathophysiology has been largely investigated. Synthetic PPAR ligands are widely used in the treatment of dyslipidemia (e.g. fibrates - PPARα activators) or in diabetes mellitus (e.g. thiazolidinediones - PPARγ agonists) while a new generation of dual agonists reveals hypolipemic, hypotensive, antiatherogenic, anti-inflammatory and anticoagulant action. Many natural ligands, including polyphenolic compounds, influence the expression of these receptors. They have several health-promoting properties, including antioxidant, anti-inflammatory, and antineoplastic activities. Resveratrol, a stilbene polyphenol, is a biological active modulator of several signaling proteins, including PPARs. Given the enormous pharmacological potential of resveratrol, stilbene-based medicinal chemistry had a rapid increase covering various areas of research. The present review discusses ligands of PPARs that contain stilbene scaffold and summarises the different types of compounds on the basis of chemical structure.

Novel Phenyldiazenyl Fibrate Analogues as PPAR α/γ/δ Pan-Agonists for the Amelioration of Metabolic Syndrome

The development of PPARα/γ dual or PPARα/γ/δ pan-agonists could represent an efficacious approach for a simultaneous pharmacological intervention on carbohydrate and lipid metabolism. Two series of new phenyldiazenyl fibrate derivatives of GL479, a previously reported PPARα/γ dual agonist, were synthesized and tested. Compound 12a was identified as a PPAR pan-agonist with moderate and balanced activity on the three PPAR isoforms (α, γ, δ). Moreover, docking experiments showed that 12a adopts a different binding mode in PPARγ compared to PPARα or PPARδ, providing a structural basis for further structure-guided design of PPAR pan-agonists. The beneficial effects of 12a were evaluated both in vitro, on the expression of PPAR target key metabolic genes, and ex vivo in two rat tissue inflammatory models. The obtained results allow considering this compound as an interesting lead for the development of a new class of PPAR pan-agonists endowed with an activation profile exploitable for therapy of metabolic syndrome.

Stilbene derivatives as new perspective in antifungal medicinal chemistry

The high incidence and mortality of invasive fungal infections and serious drug resistance have become a global public health issue. There is an urgent need for alternative antimicrobials to control fungal infections and targeting it by antifungal substances from the natural sources represents a promising new strategy for the development of novel antifungal agents. Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a phytoalexin produced by plant species in response to environmental stress or pathogenic attacks. It has many known and potential therapeutic applications in human general homeostasis; it mediates a great number of biological responses relevant for human health such as anticancer, cardio and neuroprotective, antioxidant, and antimicrobial activities. Resveratrol is a natural antifungal agent, therefore it can be considered as a scaffold for designing structural relatives potentially capable of mediating more intense responses in a more specific way. Also, stilbenes produced by several plants may be useful lead structure for the chemical synthesis of antifungal. Their antifungal potential represents a useful solution to the drug resistance and side effect complications that occur after pharmacological treatment of infectious diseases. The purpose of this review is to present an overview on resveratrol derivatives, both natural and synthetic, with antifungal activity and summarize the chemical structure and the therapeutic versatility of stilbene-containing compounds.