Nitric oxide inhibitory activity and antioxidant evaluations of 2-benzoyl-6-benzylidenecyclohexanone analogs, a novel series of curcuminoid and diarylpentanoid derivatives

Targeted regulated cell death with small molecule compounds in colorectal cancer: Current perspectives of targeted therapy and molecular mechanisms

Colorectal cancer (CRC), a tumor of the digestive system, is characterized by high malignancy and poor prognosis. Currently, targeted therapy of CRC is far away from satisfying. The molecular mechanisms of regulated cell death (RCD) have been clearly elucidated, which can be intervened by drug or genetic modification. Numerous studies have provided substantial evidence linking these mechanisms to the progression and treatment of CRC. The RCD includes apoptosis, autophagy-dependent cell death (ADCD), ferroptosis, necroptosis, and pyroptosis, and immunogenic cell death, etc, which provide potential targets for anti-cancer treatment. For the last several years, small-molecule compounds targeting RCD have been a well concerned therapeutic strategy for CRC. This present review aims to describe the function of small-molecule compounds in the targeted therapy of CRC via targeting apoptosis, ADCD, ferroptosis, necroptosis, immunogenic dell death and pyroptosis, and their mechanisms. In addition, we prospect the application of newly discovered cuproptosis and disulfidptosis in CRC. Our review may provide references for the targeted therapy of CRC using small-molecule compounds targeting RCD, including the potential targets and candidate compounds.

Bioactive Diarylpentanoids: Insights into the Biological Effects beyond Antitumor Activity and Structure–Activity Relationships

Diarylpentanoids, a class of natural products and their synthetic analogs which are structurally related to chalcones, have gained increasing attention due to their wide array of biological activities, including antitumor, anti-infective, antioxidant, anti-inflammatory, antidiabetic, anti-hyperuricemic, and neuroprotective properties. Previously, we reviewed diarylpentanoids with promising antitumor activity. However, in view of the wide range of biological activities described for this class of compounds, the purpose of this review is to provide a more detailed overview of the synthetic bioactive diarylpentanoids that have been described over the last two decades, beyond simply their antitumor effects. A total of 745 compounds were found, highlighting the main synthetic methodologies used in their synthesis as well as the structure–activity relationship studies and structural features for all activities reported. Collectively, this review highlights the diarylpentanoid scaffold as a promising starting point for the development of new therapeutic agents.

Antinociceptive activities of a novel diarylpentanoid analogue, 2-benzoyl-6-(3-bromo-4-hydroxybenzylidene)cyclohexen-1-ol, and its possible mechanisms of action in mice

A novel synthetic compound from the 2-benzoyl-6-benzylidenecyclohexanone analogue, namely 2-benzoyl-6-(3-bromo-4-hydroxybenzylidene)cyclohexen-1-ol (BBHC), showed pronounced nitric oxide inhibition in IFN-γ/LPS-induced RAW 264.7 cells. Based on this previous finding, our present study aimed to investigate the antinociceptive effects of BBHC via chemical and thermal stimuli in vivo. The investigation of the antinociceptive activity of BBHC (0.1, 0.3, 1.0 and 3.0 mg/kg, i.p.) was initiated with 3 preliminary screening tests, then BBHC was subjected to investigate its possible involvement with excitatory neurotransmitters and opioid receptors. The potential acute toxicity of BBHC administration was also studied. Administration of BBHC significantly inhibited acetic acid-induced abdominal constrictions, formalin-induced paw licking activity and developed notable increment in the latency time. BBHC’s ability to suppress capsaicin- and glutamate-induced paw licking activities, as well as to antagonise the effect of naloxone, had indicated the possible involvement of its antinociception with TRPV1, glutamate and opioid receptors, respectively. The antinociceptive activities of BBHC was not related to any sedative action and no evidence of acute toxic effect was detected. The present study showed that BBHC possessed significant peripheral and central antinociceptive activities via chemical- and thermal-induced nociceptive murine models without any locomotor alteration and acute toxicity.

The Involvement of l-Arginine-Nitric Oxide-cGMP-ATP-Sensitive K+ Channel Pathway in Antinociception of BBHC, a Novel Diarylpentanoid Analogue, in Mice Model

The present study focuses on the possible involvement of l-arginine-nitric oxide-cGMP-ATP-sensitive K⁺ channel pathway in the antinociceptive activity of a novel diarylpentanoid analogue, 2-benzoyl-6-(3-bromo-4-hydroxybenzylidene)cyclohexen-1-ol (BBHC) via a chemical nociceptive model in mice. The antinociceptive action of BBHC (1 mg/kg, i.p.) was attenuated by the intraperitoneal pre-treatment of l-arginine (a nitric oxide synthase precursor) and glibenclamide (an ATP-sensitive K⁺ channel blocker) in acetic acid-induced abdominal constriction tests. Interestingly, BBHC’s antinociception was significantly enhanced by the i.p. pre-treatment of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a selective inhibitor of soluble guanylyl cyclase (p < 0.05). Altogether, these findings suggest that the systemic administration of BBHC is able to establish a significant antinociceptive effect in a mice model of chemically induced pain. BBHC’s antinociception is shown to be mediated by the involvement of l-arginine-nitric oxide-cGMP-ATP-sensitive K⁺ channel pathway, without any potential sedative or muscle relaxant concerns.

Synthesis of small molecules targeting paclitaxel-induced MyD88 expression in triple-negative breast cancer cell lines

Acquired paclitaxel (PTX) chemoresistance in triple-negative breast cancer (TNBC) can be inferred from the overexpression of toll-like receptor 4 (TLR4) and myeloid differentiation primary response 88 (MyD88) proteins and the activation of the TLR4/MyD88 cascading signalling pathway. Finding a new inhibitor that can attenuate the activation of this pathway is a novel strategy for reducing PTX chemoresistance. In this study, a series of small molecule compounds were synthesised and tested in combination with PTX against TNBC cells. The trimethoxy-substituted compound significantly decreased MyD88 overexpression and improved PTX activity in MDA-MB-231^TLR4+ cells but not in HCC^TLR4- cells. On the contrary, the trifluoromethyl-substituted compound with PTX synergistically improved the growth inhibition in both TNBC subtypes. The fluorescence titrations indicated that both compounds could bind with MD2 with good and comparable binding affinities. This was further supported by docking analysis, in which both compounds fit perfectly well and form some critical binding interactions with MD2, an essential lipid-binding accessory to TLR4 involved in activating the TLR-4/MyD88-dependent pathway.

Novel α-Mangostin Derivatives from Mangosteen (Garcinia mangostana L.) Peel Extract with Antioxidant and Anticancer Potential

The mangosteen peels contain biologically active compounds, with antioxidant and anticancer properties. Among these isolated phytochemicals, α-mangostin is one of the most powerful natural antioxidants and anticancer compounds. This study focused on synthesizing novel α-mangostin (α-MG) derivatives at positions of C-3 and C-6 from extracted α-MG of mangosteen peels and investigating antioxidant and anticancer activities. The structures of the synthesized compounds were determined by using MS, 1H-NMR, 13C-NMR, and HPLC. The analysis of the interaction between structure and bioactivity showed that phenol groups on C-3 and C-6 positions play a crucial role in antiproliferative activity to boost both anticancer efficacy and drug-like properties. The antioxidant activity of α-MG and its derivatives were investigated by the DPPH method. Among α-MG derivatives, 1-hydroxy-7-methoxy-2,8-bis(3-methylbut-2-en-1-yl)-9-oxo-9H-xanthene-3,6-diyl bis(2-bromobenzoate) (compound 4) exhibited significant antioxidant property. The in vitro cytotoxicity against various cancer cell lines (HeLa, MCF-7, NCI–H460, and HepG2) was evaluated by the standard sulforhodamine B assay. The anticancer activities (HeLa, MCF-7, NCI–H460, and HepG2) of compound 4 are five to six times higher than those of α-MG and other derivatives. The acetylation at C-3 and C-6 of α-MG by halogen of benzoyl greatly improved cancer cell toxicity. Our results provide new opportunities for further explorations of α-MG derivatives for antioxidant property and promise as drugs in cancer therapy.

Identification of curcumin analogues with anti-seizure potential in vivo using chemical and genetic zebrafish larva seizure models

Seizures are the outward manifestation of abnormally excessive or synchronous brain activity. While seizures can be somewhat symptomatically managed with anti-epileptic drugs (AEDs), many patients are still refractory to the currently available AEDs. As a result, there is a need to identify new molecules with anti-seizure properties. Curcumin is the principle curcuminoid of Curcuma longa, or colloquially turmeric, and has been experimentally proven to have anti-convulsive properties, but its poor bioavailability has dampened further therapeutic interest. Hence, this study aimed to ask if structural analogues of curcumin with an adequate bioavailability could have an anti-seizure effect in vivo. To do so, we tested these analogues following a multipronged approach combining the use of several zebrafish seizure models (chemically-induced and genetic) and complementary assays (behavioural and brain activity). Overall, from the 68 analogues tested, we found 15 different derivatives that were able to significantly decrease the behavioural hyperactivity induced by pentylenetetrazol. Of those, only a few showed an effect on the hyperactivity phenotype of two genetic models of brain seizures that are the gabra1 and gabrg2 knockouts. Two analogues, CA 80(1) and CA 74(1), were able to significantly alleviate brain seizures of gabrg2-mutant larvae. As a result, these analogues are good candidates as novel anti-seizure agents.

A Review on Biological Properties and Synthetic Methodologies of Diarylpentadienones

Medicinal chemists have continuously shown interest in new curcuminoid derivatives, diarylpentadienones, owing to their enhanced stability feature and easy preparation using a one-pot synthesis. Thus far, methods such as Claisen-Schmidt condensation and Julia- Kocienski olefination have been utilised for the synthesis of these compounds. Diarylpentadienones possess a high potential as a chemical source for designing and developing new and effective drugs for the treatment of diseases, including inflammation, cancer, and malaria. In brief, this review article focuses on the broad pharmacological applications and the summary of the structure-activity relationship of molecules, which can be employed to further explore the structure of diarylpentadienone. The current methodological developments towards the synthesis of diarylpentadienones are also discussed.

A Diarylpentanoid with Potential Activation of the p53 Pathway: Combination of in silico Screening Studies, Synthesis, and Biological Activity Evaluation

In silico studies of a library of diarylpentanoids led us to the identification of potential new MDM2/X ligands. The diarylpentanoids with the best docking scores obeying the druglikeness and ADMET prediction properties were subsequently synthesized and evaluated for their antiproliferative activity on colon cancer HCT116 and fibroblasts HFF-1 cells. The effect on p53-MDM2/X interactions was evaluated through yeast-based assays for compounds showing potent antiproliferative activity in HCT116 cells and low toxicity in normal cells, resulting in the identification of a potential dual inhibitor. Moreover, its antiproliferative effect was significantly reduced in the absence of p53 and in MDA-MB-231 cells expressing a mutant p53 form. The antiproliferative effect of this compound was associated with induction of cell cycle arrest, apoptosis, PARP cleavage and increased p53 and its transcriptional targets, p21 and PUMA, in HCT116 cells. Docking poses and residues involved in the inhibition of p53-MDM2/X interactions were predicted by docking studies.

In-Vitro and In-Silico Evaluations of Heterocyclic-Containing Diarylpentanoids as Bcl-2 Inhibitors Against LoVo Colorectal Cancer Cells

In the present study, we investigated the in-vitro anti-cancer potential of six diarylpentanoids against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, SW620, LoVo, HT29, NCI-H508, RKO, and LS411N cells. Structure-activity relationship study suggested that the insertions of tetrahydro-4H-thiopyran-4-one and brominated phenyl moieties are essential for better cytotoxicity. Among the evaluated analogs, 2e has been identified as the lead compound due to its low IC50 values of approximately 1 µM across all cancer cell lines and high chemotherapeutic index of 7.1. Anti-proliferative studies on LoVo cells showed that 2e could inhibit cell proliferation and colony formations by inducing G2/M cell cycle arrest. Subsequent cell apoptosis assay confirmed that 2e is a Bcl-2 inhibitor that could induce intrinsic cell apoptosis by creating a cellular redox imbalance through its direct inhibition on the Bcl-2 protein. Further molecular docking studies revealed that the bromophenyl moieties of 2e could interact with the Bcl-2 surface pocket through hydrophobic interaction, while the tetrahydro-4H-thiopyran-4-one fragment could form additional Pi-sulfur and Pi-alkyl interactions in the same binding site. In all, the present results suggest that 2e could be a potent lead that deserves further modification and investigation in the development of a new Bcl-2 inhibitor.

Synthesis and in-vitro anti-cancer evaluations of multi-methoxylated asymmetrical diarylpentanoids as intrinsic apoptosis inducer against colorectal cancer

In the present study, a series of nine stable 3,4,5-methoxylphenyl-containing asymmetrical diarylpentanoids, derivatives of curcuminoids, have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, LoVo and SW620, HT29, RKO and NCI-H508, respectively. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-hydroxyl and adjacent dimethoxyl groups are crucial for enhanced cytotoxicity of diarylpentanoids. Among the evaluated analogs, 8 has been identified as the lead compound due to its highest chemotherapeutic index of 9.9 and nano molar scale cytotoxicity against SW620 and RKO. Colonies formation and cell cycle analyses on 8-treated RKO cells showed that 8 exhibits strong anti-proliferative activity by inducing G2/M-phase cell arrest. Subsequent flow cytometry based annexin-V and DCFHDA studies suggested that 8 could induce apoptosis through intracellular ROS-dependent pathway. Further Western blot studies confirmed that 8 has induced intrinsic apoptosis in RKO cells through the up-regulations of Bad and Bax pro-apoptotic proteins and down-regulations of Bcl-2 and Bcl-xL pro-survival proteins. In all, the present results suggest that 8 could be a potent lead which deserves further modification and investigation in the development of small molecule-based anti-colorectal cancer agents.

Inhibition of nitric oxide and prostaglandin E2 production by pyrrolylated-chalcones: Synthesis, biological activity, crystal structure analysis, and molecular docking studies

In search of potent anti-inflammatory agents, twenty-four chalcone derivatives including seven new compounds (13 - 17, 21 and 23) containing pyrrole moiety were designed, synthesized, and assessed for their nitric oxide (NO) and prostaglandin E₂ (PGE₂) suppression ability on IFN-γ/LPS-induced RAW 264.7 macrophage cells. Results showed that none of the synthesized compounds were PAINS-associated molecules, with 3-(2,5-dimethoxyphenyl)-1-(1H-pyrrol-2-yl)-prop-2-en-1-one (compound 16) exhibiting remarkable inhibition activity towards PGE₂ and NO production with IC₅₀ values of 0.5 ± 1.5 µM and 12.1 ± 1.5 µM, respectively. Physicochemical and ADMET studies showed that majority of the compounds obey to Lipinski's rule of five (RO5) having high blood brain barrier (BBB) penetration, human intestinal absorption (HIA), P- glycoprotein (PgP) inhibition and plasma binding protein (PPB) inhibition. The obtained atomic coordinates for the single-crystal XRD of 16 were then applied in a molecular docking simulation, and compound 16 was found to participate in a number of important binding interactions in the binding sites of ERK and mPGES-1. Based on these results, we have observed the potential of compound 16 as a new hit anti-inflammatory agent, and these findings could serve as a basis for further studies on its mechanism of action.

Curcumin-Synthetic Analogs Library Screening by Docking and Quantitative Structure-Activity Relationship Studies for AXL Tyrosine Kinase Inhibition in Cancers

AXL is an important drug target for cancers. Two-dimensional quantitative structure-activity relationship (2D-QSAR) tests were performed to elucidate a relationship between molecular structures and the activity of a series of 400 curcumin derivatives subjected to AXL kinase by ATP competition in the catalytic site. The partial least square regression method implanted in molecular operating environment software was applied to develop QSAR models, which were further validated for statistical significance by internal and external validation. The best model has proven to be statistically robust with a good predictive correlation of R ²  = 0.996 and a significant cross-validation correlation coefficient of q ²  = 0.707. Docking analysis reveled that three curcumin derivatives have the best affinity for AXL and formed a hydrogen bond with the important amino acid residues in the binding pocket. As treated in this article, the docking studies and 2D-QSAR approach will pave the way for the development of new drugs while highlighting curcumin and its derivatives.

Insights on the synthesis of asymmetric curcumin derivatives and their biological activities

Curcumin is a small organic molecule with pleiotropic biological activities. However, its multiple structural-pharmacokinetic challenges prevent its development into a clinical drug. Various structural modifications have been made to improve its drug profile. In this review, we focus on the methods adopted in the synthesis of asymmetric curcumin derivatives and their biological activities and forecast the future of this exciting class of compounds in the field of medicine.

Novel 2-Benzoyl-6-(2,3-Dimethoxybenzylidene)-Cyclohexenol Confers Selectivity toward Human MLH1 Defective Cancer Cells through Synthetic Lethality

DNA mismatch repair (MMR) deficiency has been associated with a higher risk of developing colorectal, endometrial, and ovarian cancer, and confers resistance in conventional chemotherapy. In addition to the lack of treatment options that work efficaciously on these MMR-deficient cancer patients, there is a great need to discover new drug leads for this purpose. In this study, we screened through a library of commercial and semisynthetic natural compounds to identify potential synthetic lethal drugs that may selectively target MLH1 mutants using MLH1 isogenic colorectal cancer cell lines and various cancer cell lines with known MLH1 status. We identified a novel diarylpentanoid analogue, 2-benzoyl-6-(2,3-dimethoxybenzylidene)-cyclohexenol, coded as AS13, that demonstrated selective toxicity toward MLH1-deficient cancer cells. Subsequent analysis suggested AS13 induced elevated levels of oxidative stress, resulting in DNA damage where only the proficient MLH1 cells were able to be repaired and hence escaping cellular death. While AS13 is modest in potency and selectivity, this discovery has the potential to lead to further drug development that may offer better treatment options for cancer patients with MLH1 deficiency.

Preparation, Characterization and Antioxidant Evaluation of Poorly Soluble Polyphenol-Loaded Nanoparticles for Cataract Treatment

Cataract, one of the leading causes of blindness worldwide, is a condition in which complete or partial opacity develops in the lens of the eyes, thereby impairing vision. This study aimed to examine the potential therapeutic and protective effects of poorly soluble polyphenols like curcumin, resveratrol, and dibenzoylmethane, known to possess significant antioxidant activity. The polyphenols were loaded into novel lipid-cyclodextrin-based nanoparticles and characterized by particle size, polydispersity index, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy (SEM), entrapment efficiency, and release studies. Ferric-reducing ability of plasma and 2,2-diphenyl-1-picrylhydrazyl chemical assays were used to evaluate their antioxidant properties based on their free radical quenching ability. Biochemical in vitro assays were used to examine these polyphenols on hydrogen peroxide-induced formation of cataracts in bovine lenses by estimating total glutathione content and superoxide dismutase activity. Nanoparticles were thermostable and amorphous. Particle size of curcumin, resveratrol, and dibenzoylmethane nanoparticles were 331.0 ± 17.9 nm, 329.9 ± 1.9 nm, and 163.8 ± 3.2 nm, respectively. SEM confirmed porous morphology and XRD confirmed physical stability. Entrapment efficiency for curcumin-, resveratrol-, and dibenzoylmethane-loaded nanoparticles was calculated to be 84.4 ± 2.4%, 72.2 ± 1.5%, and 86.4 ± 0.6%, respectively. In vitro release studies showed an initial burst release followed by a continuous release of polyphenols from nanoparticles. Chemical assays confirmed the polyphenols' antioxidant activity. Superoxide dismutase and glutathione levels were found to be significantly increased (p < 0.05) after treatment with polyphenol-loaded nanoparticles than pure polyphenols; thus, an improved antioxidant activity translational into potential anticataract activity of the polyphenols when loaded into nanoparticles was observed as compared to pure polyphenols.

Asymmetrical meta-methoxylated diarylpentanoids: Rational design, synthesis and anti-cancer evaluation in-vitro

In the present study, a series of forty-five asymmetrical meta-methoxylated diarylpentanoids have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential. Among the forty-five analogs, three compounds (20, 33 and 42) have been identified as lead compounds due to their excellent inhibition against five human cancer cell lines including SW620, A549, EJ28, HT1080 and MCF-7. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-oxygenated phenyl ring played a critical role in enhancing their cytotoxic effects. Compounds 33 and 42 in particular, exhibited strongest cytotoxicity against tested cell lines with the IC₅₀ values ranging from 1.1 to 4.3 μM. Subsequent colony formation assay on SW620 cell line showed that both compounds 33 and 42 possessed strong anti-proliferative activity. In addition, flow cytometry based experiments revealed that these compounds could trigger intracellular ROS production thus inducing G2/M-phase cell arrest and apoptosis. All these results suggested that poly meta-oxygenated diarylpentnoid is a promising scaffold which deserved further modification and investigation in the development of natural product-based anti-cancer drug.

An overview of structure-activity relationship studies of curcumin analogs as antioxidant and anti-inflammatory agents

Curcumin, extracted mainly from Curcuma longa rhizomes, has been reported to possess potent anti-inflammatory and anti-oxidant activities. Although safe at higher doses and exhibiting multiple biological activities, curcumin still has the problem of poor bioavailability which has been an attractive area of research over the last few years. A number of efforts have been made by modifying structural features of curcumin. This review highlights the structurally modified and more stable newly synthesized curcumin analogs that have been screened against antioxidant and anti-inflammatory activities. Also the structure-activity relationship to gain insight into future guidelines for scheming new compounds has been discussed, and further these analogs being more stable may serve as promising agents for use in different pathological conditions.

Immunosuppressive Effects of Natural α,β-Unsaturated Carbonyl-Based Compounds, and Their Analogs and Derivatives, on Immune Cells: A Review

The immune system is complex and pervasive as it functions to prevent or limit infections in the human body. In a healthy organism, the immune system and the redox balance of immune cells maintain homeostasis within the body. The failure to maintain the balance may lead to impaired immune response and either over activity or abnormally low activity of the immune cells resulting in autoimmune or immune deficiency diseases. Compounds containing α,β-unsaturated carbonyl-based moieties are often reactive. The reactivity of these groups is responsible for their diverse pharmacological activities, and the most important and widely studied include the natural compounds curcumin, chalcone, and zerumbone. Numerous studies have revealed the mainly immunosuppressive and anti-inflammatory activities of the aforesaid compounds. This review highlights the specific immunosuppressive effects of these natural α,β-unsaturated carbonyl-based compounds, and their analogs and derivatives on different types of immune cells of the innate (granulocytes, monocytes, macrophages, and dendritic cells) and adaptive (T cells, B cells, and natural killer cells) immune systems. The inhibitory effects of these compounds have been comprehensively studied on neutrophils, monocytes and macrophages but their effects on T cells, B cells, natural killer cells, and dendritic cells have not been well investigated. It is of paramount importance to continue generating experimental data on the mechanisms of action of α,β-unsaturated carbonyl-based compounds on immune cells to provide useful information for ensuing research to discover new immunomodulating agents.

Antinociceptive Effect of 3-(2,3-Dimethoxyphenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one in Mice Models of Induced Nociception

The antinociceptive effects produced by intraperitoneal administration of a novel synthetic chalcone, 3-(2,3-dimethoxyphenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one (DMFP), were investigated in several mouse models of induced nociception. The administration of DMFP (0.1, 0.5, 1.0 and 5.0 mg/kg) produced significant attenuation on the acetic acid-induced abdominal-writhing test. It also produced a significant increase in response latency time in the hot-plate test and a marked reduction in time spent licking the injected paw in both phases of the formalin-induced paw-licking test. In addition, it was also demonstrated that DMFP exhibited significant inhibition of the neurogenic nociceptive response induced by intraplantar injections of capsaicin and glutamate. Moreover, the antinociceptive effect of DMFP in the acetic acid-induced abdominal-writhing test and the hot-plate test was not antagonized by pretreatment with a non-selective opioid receptor antagonist, naloxone. Finally, DMFP did not show any toxic effects and/or mortality in a study of acute toxicity and did not interfere with motor coordination during the Rota-rod test. Our present results show that DMFP exhibits both peripheral and central antinociceptive effects. It was suggested that its peripheral antinociceptive activity is associated with attenuated production and/or release of NO and various pro-inflammatory mediators, while central antinociceptive activity seems to be unrelated to the opioidergic system, but could involve, at least in part, an interaction with the inhibition of capsaicin-sensitive fibers and the glutamatergic system.

2-Benzoyl-6-benzylidenecyclohexanone analogs as potent dual inhibitors of acetylcholinesterase and butyrylcholinesterase

In the present study, a series of 2-benzoyl-6-benzylidenecyclohexanone analogs have been synthesized and evaluated for their anti-cholinesterase activity. Among the forty-one analogs, four compounds (38, 39, 40 and 41) have been identified as lead compounds due to their highest inhibition on both AChE and BChE activities. Compounds 39 and 40 in particular exhibited highest inhibition on both AChE and BChE with IC50 values of 1.6μM and 0.6μM, respectively. Further structure-activity relationship study suggested that presence of a long-chain heterocyclic in one of the rings played a critical role in the dual enzymes' inhibition. The Lineweaver-Burk plots and docking results suggest that both compounds could simultaneously bind to the PAS and CAS regions of the enzyme. ADMET analysis further confirmed the therapeutic potential of both compounds based upon their high BBB-penetrating. Thus, 2-benzoyl-6-benzylidenecyclohexanone containing long-chain heterocyclic amine analogs represent a new class of cholinesterase inhibitor, which deserve further investigation for their development into therapeutic agents for cognitive diseases such as Alzheimer.