Nitric oxide releasing derivatives of tolfenamic acid with anti-inflammatory activity and safe gastrointestinal profile

Inducing Immunogenic Cancer Cell Death through Oxygen-Economized Photodynamic Therapy with Nitric Oxide-Releasing Photosensitizers

Photodynamic therapy (PDT) utilizes reactive oxygen species (ROS) for eradication of cancer cells. Its effectiveness is governed by the oxygen content, which is scarce in the hypoxic tumor microenvironment. We report herein two zinc(II) phthalocyanines substituted with two or four nitric oxide (NO)-releasing moieties, namely ZnPc-2NO and ZnPc-4NO, which can suppress the mitochondrial respiration, thereby sparing more intracellular oxygen for PDT. Using HT29 human colorectal adenocarcinoma cells and A549 human lung carcinoma cells, we have demonstrated that both conjugates release NO upon interaction with the intracellular glutathione, which can reduce the cellular oxygen consumption rate and adenosine triphosphate generation and alter the mitochondrial membrane potential. They can also relieve the hypoxic status of cancer cells and decrease the expression of hypoxia-inducible factor protein HIF-1α. Upon light irradiation, both conjugates can generate ROS and induce cytotoxicity even under a hypoxic condition, overcoming the oxygen-dependent nature of PDT. Interestingly, the photodynamic action of ZnPc-2NO elicits the release of damage-associated molecular patterns, inducing the maturation of dendritic cells and triggering an antitumor immune response. The immunogenic cell death caused by this oxygen-economized PDT has been demonstrated through a series of in vitro and in vivo experiments.

Fenamates: Forgotten treasure for cancer treatment and prevention: Mechanisms of action, structural modification, and bright future

Fenamates as classical nonsteroidal anti-inflammatory agents are widely used for relieving pain. Preclinical studies and epidemiological data highlight their chemo-preventive and chemotherapeutic potential for cancer. However, comprehensive reviews of fenamates in cancer are limited. To accelerate the repurposing of fenamates, this review summarizes the results of fenamates alone or in combination with existing chemotherapeutic agents. This paper also explores targets of fenamates in cancer therapy, including COX, AKR family, AR, gap junction, FTO, TEAD, DHODH, TAS2R14, ion channels, and DNA. Besides, this paper discusses other mechanisms, such as regulating Wnt/β-catenin, TGF-β, p38 MAPK, and NF-κB pathway, and the regulation of the expressions of Sp, EGR-1, NAG-1, ATF-3, ErbB2, AR, as well as the modulation of the tumor immune microenvironment. Furthermore, this paper outlined the structural modifications of fenamates, highlighting their potential as promising leads for anticancer drugs.

Organohalide Precursors for the Continuous Production of Photocatalytic Bismuth Oxyhalide Nanoplates

Metal heteroanionic materials, such as oxyhalides, are promising photocatalysts in which band positions can be engineered for visible-light absorption by changing the halide identity. Advancing the synthesis of these materials, bismuth oxyhalides of the form BiOX (X = Cl, Br) have been prepared using rapid and scalable ultrasonic spray synthesis (USS). Central to this advance was the identification of small organohalide molecules as halide sources. When these precursors are spatially and temporally confined in the aerosol phase with molten salt fluxes, powders composed of single-crystalline BiOX nanoplates can be produced continuously. A mechanism highlighting the in situ generation of halide ions is proposed. These materials can be used as photocatalysts and provide proof-of-concept toward USS as a route to more complex bismuth oxyhalide materials.

Design, Synthesis and Study of Nitrogen Monoxide Donors as Potent Hypolipidaemic and Anti-Inflammatory Agents

Inflammation and oxidative stress are involved in cardiovascular diseases. Nitrogen monoxide participates in the regulation of endothelial processes. Thus, derivatives of classic nonsteroidal anti-inflammatory drugs (NSAIDs), trolox or cinnamic acids esterified with 2-(nitrooxy)ethanol were designed and studied. It was found that the nitrogen monoxide (NO) releasing activity was comparable to that of S-nitroso-N-acetylpenicillamine. The nitrooxy derivatives decreased potently lipid indices in the plasma of hyperlipidaemic rats (30–85%). All compounds presented increased anti-inflammatory activity in vivo, inhibiting carrageenan-induced rat paw oedema as high as 76%, up to six times higher than that of the parent acids. Lipoxygenase inhibitory activity was significant for most of them, although the parent molecules exerted a minor effect (IC₅₀ > 0.2 mM). Those compounds incorporating an antioxidant structure inhibited rat microsomal membrane lipid peroxidation strongly and possessed radical scavenging activity. These results indicated that the described compounds could act at different targets in multifactorial diseases, further limiting the possible adverse effects of drug combinations.

Design, synthesis and biological evaluation of novel ferrocene-pyrazole derivatives containing nitric oxide donors as COX-2 inhibitors for cancer therapy

A series of novel ferrocene-pyrazole derivatives containing nitric oxide donors as COX-2 inhibitors for cancer therapy were designed, synthesized and biologically evaluated. Among them, compound 7l displayed the most potent inhibitory against COX-2 (IC₅₀ = 0.82 μM) and antiproliferative activities against Hela cells (IC₅₀ = 0.34 μM) compared with Celecoxib (IC₅₀ = 0.38 and 7.91 μM). The further mechanistic studies revealed that 7l could induce apoptosis of Hela cells by mitochondrial depolarization and the antiproliferative activities of 7l were positively correlated with the levels of intracellular NO release in Hela cells. Most notably, 7l could dramatically suppress tumor growth in Hela cells xenografted mouse model. In summary, compound 7l may be promising candidates for cancer therapy.

Docking assisted design of novel 4-adamantanyl-2-thiazolylimino-5-arylidene-4-thiazolidinones as potent NSAIDs

Docking analysis was used to predict the effectiveness of adamantanyl insertion in improving cycloxygenase/lipoxygenase (COX/LOX) inhibitory action of previously tested 2-thiazolylimino-5-arylidene-4-thiazolidinones. The crystal structure data of human 5-LOX (3O8Y), ovine COX-1 (1EQH) and mouse COX-2 (3ln1) were used for docking analysis. All docking calculations were carried out using AutoDock 4.2 software. Following prediction results, 11 adamantanyl derivatives were synthesized and evaluated for biological action. Prediction evaluations correlated well with experimental biological results. Comparison of the novel adamantanyl derivatives with the 2-thiazolylimino-5-arylidene-4-thiazolidinones previously tested showed that insertion of the adamantanyl group led to the production of more potent COX-1 inhibitors, as well as LOX inhibitors (increased activity from 200% to 560%). Five compounds out of the 11 exhibited better activity than naproxen; while nine out of 11 showed better activity than NDGA and seven compounds possessed better anti-inflammatory activity than indomethacin.

Nonsteroidal Anti-Inflammatory Therapy: A Journey Toward Safety

The efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) against inflammation, pain, and fever has been supporting their worldwide use in the treatment of painful conditions and chronic inflammatory diseases until today. However, the long-term therapy with NSAIDs was soon associated with high incidences of adverse events in the gastrointestinal tract. Therefore, the search for novel drugs with improved safety has begun with COX-2 selective inhibitors (coxibs) being straightaway developed and commercialized. Nevertheless, the excitement has fast turned to disappointment when diverse coxibs were withdrawn from the market due to cardiovascular toxicity. Such events have once again triggered the emergence of different strategies to overcome NSAIDs toxicity. Here, an integrative review is provided to address the breakthroughs of two main approaches: (i) the association of NSAIDs with protective mediators and (ii) the design of novel compounds to target downstream and/or multiple enzymes of the arachidonic acid cascade. To date, just one phosphatidylcholine-associated NSAID has already been approved for commercialization. Nevertheless, the preclinical and clinical data obtained so far indicate that both strategies may improve the safety of nonsteroidal anti-inflammatory therapy.

Esters of some non-steroidal anti-inflammatory drugs with cinnamyl alcohol are potent lipoxygenase inhibitors with enhanced anti-inflammatory activity

Novel esters of non steroidal anti-inflammatory drugs, α-lipoic acid and indol-3-acetic acid with cinnamyl alcohol were synthesised by a straightforward method and at high yields (60-98%). They reduced acute inflammation more than the parent acids and are potent inhibitors of soybean lipoxygenase. Selected structures decreased plasma lipidemic indices in Triton-induced hyperlipidemia to rats. Therefore, the synthesised compounds may add to the current knowledge about agents acting against various inflammatory disorders.

Synthesis and evaluation of antiinflammatory, analgesic and ulcerogenic potential of NSAIDs bearing 1,3,4-oxadiazole scaffold

Synthesis of 1,3,4-oxadiazole derivatives of diclofenac and mefenamic acid are described. The target compounds 5-[2-(2,6-dichloroanilino)benzyl]-2-aryl-1,3,4-oxadiazole (3a-3e) and 5-[2-(2,3-dimethylanilino)phenyl]-2-(aryl)-1,3,4-oxadiazole (6a-6e) were obtained by treating 2 and 5 with various aromatic acids using POCl₃ as dehydrating agent. They were purified and characterized by IR, ¹H-NMR and elemental analysis. These compounds were further subjected to antiinflammatory, analgesic and acute ulcerogenic activity. Compound 3c and 6d exhibited good antiinflammatory activity and compounds 3c, 3e, 6c, 6d, 6e were found to be non ulcerogenic.

Design and synthesis of neuroprotective methylthiazoles and modification as NO-chimeras for neurodegenerative therapy

Learning and memory deficits in Alzheimer's disease (AD) result from synaptic failure and neuronal loss, the latter caused in part by excitotoxicity and oxidative stress. A therapeutic approach is described that uses NO-chimeras directed at restoration of both synaptic function and neuroprotection. 4-Methylthiazole (MZ) derivatives were synthesized, based upon a lead neuroprotective pharmacophore acting in part by GABA(A) receptor potentiation. MZ derivatives were assayed for protection of primary neurons against oxygen-glucose deprivation and excitotoxicity. Selected neuroprotective derivatives were incorporated into NO-chimera prodrugs, coined nomethiazoles. To provide proof of concept for the nomethiazole drug class, selected examples were assayed for restoration of synaptic function in hippocampal slices from AD-transgenic mice, reversal of cognitive deficits, and brain bioavailability of the prodrug and its neuroprotective MZ metabolite. Taken together, the assay data suggest that these chimeric nomethiazoles may be of use in treatment of multiple components of neurodegenerative disorders, such as AD.

Cyclooxygenase (COX)-1 and -2 inhibitory labdane diterpenes from Crassocephalum mannii

Two new labdane diterpenes, 8alpha,19-dihydroxylabd-13 E-en-15-oic acid (1) and 13,14,15,16-tetranorlabdane-8alpha,12,14-triol (2), as well as an acetylated derivative, 8alpha-O-beta-D-glucopyranosyllabd-13 E-ene-15,19-diol-8alpha-2',3',4',6'-hexaacetate (3a), were isolated from the aerial parts of Crassocephalum mannii. The structures of 1, 2, and 3a were elucidated by spectroscopic data analysis. Selective inhibitory activity for 1 and 2 and their acetate derivatives, 1a and 2a, against cyclooxygenases (COX-1 and COX-2) was detected.

Design and study of some novel ibuprofen derivatives with potential nootropic and neuroprotective properties

Six novel ibuprofen derivatives and related structures, incorporating a proline moiety and designed for neurodegenerative disorders, are studied. They possess anti-inflammatory properties and three of them inhibited lipoxygenase. One compound was found to inhibit cyclooxygenase (COX)-2 production in spleenocytes from arthritic rats. The HS-containing compounds are potent antioxidants and one of them protected against glutathione loss after cerebral ischemia/reperfusion. They demonstrated lipid-lowering ability and seem to acquire low gastrointestinal toxicity. Acetylcholinesterase inhibitory activity, found in two of these compounds, may be an asset to their actions.