Design, synthesis, and evaluation of anti-inflammatory, analgesic, ulcerogenicity, and nitric oxide releasing studies of novel indomethacin analogs as non-ulcerogenic derivatives

Fenamates and ibuprofen as foundational components in the synthesis of innovative, targeted COX-2 anti-inflammatory drugs, undergoing thorough biopharmacological assessments and in-silico computational studies

Cyclooxygenase-2 plays a vital role in inflammation by catalyzing arachidonic acid conversion toward prostaglandins, making it a prime therapeutic objective. Selective COX-2 inhibitors represent significant progress in anti-inflammatory therapy, offering improved efficacy and fewer side effects. This study describes the synthesis of novel anti-inflammatory compounds from established pharmaceutically marketed agents like fenamates III-V and ibuprofen VI. Through rigorous in vitro testing, compounds 7b-c, and 12a-b demonstrated substantial in vitro selective inhibition, with IC50 values of 0.07 to 0.09 μM, indicating potent pharmacological activity. In vivo assessment, particularly focusing on compound 7c, revealed significant anti-inflammatory effects. Markedly, it demonstrated the highest inhibition of paw thickness (58.62 %) at the 5-hr mark compared to the carrageenan group, indicating its potency in mitigating inflammation. Furthermore, it exhibited a rapid onset of action, with a 54.88 % inhibition observed at the 1-hr mark. Subsequent comprehensive evaluations encompassing analgesic efficacy, histological characteristics, and toxicological properties indicated that compound 7c did not induce gastric ulcers, in contrast to the ulcerogenic tendency associated with mefenamic acid. Moreover, compound 7c underwent additional investigations through in silico methodologies such as molecular modelling, field alignment, and density functional theory. These analyses underscored the therapeutic potential and safety profile of this novel compound, warranting further exploration and development in the realm of pharmaceutical research.

Synthesis and anti-inflammatory activity evaluation of NO-releasing furoxan/1,2,4-triazole hybrid derivatives

An efficient synthesis method was developed for furoxan/1,2,4-triazole hybrids 5a-k from methyl 5-(halomethyl)-1-aryl-1H-1,2,4-triazole-3-carboxylates 1 through two-steps reaction including hydrolyzation and esterification. All of the furoxan/1,2,4-triazole hybrid derivatives were characterized by spectroscopy. On the other hand, the influence of newly synthesized multi-substituted 1,2,4-triazoles on the exogenous NO release ability, in vitro and in vivo anti-inflammatory activity, and in silico predictions were experimentally evaluated. Based on the exogenous NO release ability study and SAR studies of in vitro anti-inflammatory activity, all of compounds 5a-k exhibited slightly NO release ability and potential anti-inflammatory activity on LPS-induced RAW264.7 cells (IC₅₀ = 5.74-15.3 μM) compared to Celecoxib (IC₅₀ = 16.5 μM) and Indomethacin (IC₅₀ = 56.8 μM). Furthermore, compounds 5a-k were also subjected to in vitro COX-1/COX-2 inhibition assays. Particularly, compound 5f exhibited extraordinary COX-2 inhibition (IC₅₀ = 0.0455 μM) and selectivity (SI = 209). In addition, compound 5f was also examined in vivo pro-inflammatory cytokine productions and gastric safety and possessed the better inhibition of cytokine and safety compared with Indomethacin at the same concentration. Through the molecular modeling and in silico physicochemical and pharmacokinetic properties prediction, compound 5f was stabilized in COX-2 active binding site and possessed the fundamental strong H-bond interaction with Arg499 to form the significant physicochemical and pharmacological properties as a candidate drug. Following the in vitro, in vivo, and in silico study results, compound 5f demonstrated to be a potential anti-inflammatory agent and had comparable effects with Celecoxib.

Design, synthesis, modeling studies and biological evaluation of pyrazole derivatives linked to oxime and nitrate moieties as nitric oxide donor selective COX-2 and aromatase inhibitors with dual anti-inflammatory and anti-neoplastic activities

Two new series of pyrazole derivatives 10a-f and 11a-f with selective COX-2 inhibition pharmacophore and oxime/nitrate moieties as NO donor moiety were designed, synthesized and tested for anti-inflammatory, cytotoxic activities and NO release. Compounds 10c, 11a, 11e were more selective for COX-2 isozyme (S.I. = 25.95, 22.52 and 21.54 respectively) in comparison to celecoxib (S.I. = 21.41). Regarding anti-cancer activity, all synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines representing the following cancer types: leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers. Compounds 10c, 11a, 11e were found to be the most potent inhibitors on breast, ovarian and melanoma cell lines (MCF-7, IGROV1 and SK-MEL-5), compound 11a causing 79 % inhibition in case of MCF-7, 78.80 % inhibition in case of SK-MEL-5 and unexpected cell growth -26.22 % inhibition in case of IGROV1 (IC₅₀ = 3.12, 4.28, 4.13 μM respectively). On the other hand, compounds 10c and 11e showed lower inhibition on the same cell lines with IC₅₀ = 3.58, 4.58, 4.28 μM respectively for 10c, IC₅₀ = 3.43, 4.73, 4.43 μM respectively for 11e. Furthermore, DNA-flow cytometric analysis showed that compound 11a induces cell cycle arrest at G2/M phase leading to cell proliferation inhibition and apoptosis. Additionally, these derivatives examined against F180 fibroblasts to investigate their selectivity indexes. The pyrazole derivative with internal oxime 11a was the most potent compound against most used cell lines especially MCF-7, IGROV1 and SK-MEL-5 (IC₅₀ = 3.12, 4.28, 4.13 μM respectively) with 4.82-fold selectivity towards MCF-7 than F180 fibroblasts. Moreover, oxime derivative 11a showed potent aromatase inhibitory activity (IC₅₀ 16.50 μM) when compared with reference compound letrozole (IC₅₀ 15.60 μM). All compounds 10a-f and 11a-f released NO in a slow rate (0.73-3.88 %) and the six derivatives 10c, 10e, 11a, 11b, 11c and 11e were the highest NO releasers (3.88, 2.15, 3.27, 2.27, 2.55 and 3.74 % respectively). Herein structure based and ligand based studies were implemented to under stand and evaluate the compounds activity for further in vivo and preclinical studies. Docking mode of final designed compounds with celecoxib (ID: 3LN1) represented that their triazole ring adopted as the core aryl in Y shaped structure. Regarding aromatase enzyme inhibition, docking was carried out with ID: 1 M17. The internal oxime series was more active as anticancer because of their ability to form extra HBs with receptor cleft.

Design, synthesis and evaluation of phenylfuroxan nitric oxide-donor phenols as potential anti-diabetic agents

Both nitric oxide (NO) dysfunction and oxidative stress have been regarded as the important factors in the development and progression of diabetes and its complications. Multifunctional compounds with hypoglycemic, NO supplementation and anti-oxidation will be the promising agents for treatment of diabetes. In this study, six phenylfuroxan nitric oxide (NO) donor phenols were synthesized, which were designed via a combination approach with phenylfuroxan NO-donor and natural phenols. These novel synthetic compounds were screened in vitro for α-glucosidase inhibition, NO releasing, anti-oxidation, anti-glycation and anti-platelet aggregation activity as well as vasodilatation effects. The results exhibited that compound T5 displayed more excellent activity than other compounds. Moreover, T5 demonstrated significant hypoglycemic activity in diabetic mice and oral glucose tolerance test (OGTT) mice. T5 also showed NO releasing and anti-oxidation in diabetic mice. Based on these results, compound T5 deserves further study as potential new multifunctional anti-diabetic agent with antioxidant, NO releasing, anti-platelet aggregation and vasodilatation properties.

1,2,4-Triazole/oxime hybrids as new strategy for nitric oxide donors: Synthesis, anti-inflammatory, ulceroginicity and antiproliferative activities

A series of novel nitric oxide (NO) donating triazole/oxime hybrids was prepared and evaluated for their anti-inflammatory activity and antiproliferative activity. Most of the tested compounds showed significant anti-inflammatory activity using carrageenan-induced rat paw edema method compared to indomethacin. Calculation of the ulcer indices and histopathological investigation indicated that the prepared NO-donating oximes exhibited less ulcerogenicity compared to their ketone intermediates and indomethacin. The NO-donating oximes 7i and 7k achieved remarkable cell growth inhibition activity against most of the tested cell lines. Compound 7k was found to be with high selectivity against CNS subpanel with selectivity ratio of 11.99 at GI₅₀ level.

The role of cyclooxygenase-derived oxidative stress in surgically induced lymphedema in a mouse tail model

CONTEXT

Oxidative stress may contribute to lymphedema and subsequent tissue damage. However, the causal role of oxidative stress in lymphedema remains unclear.

OBJECTIVE

We attempted to detect and identify the free radicals formed in lymphedema fluid and assessed the protective mechanisms and effects of specific enzyme inhibitors and natural antioxidants.

MATERIALS AND METHODS

To study the level of postsurgical oxidative stress with lymphedema in a mouse tail model, we used an electron spin resonance (ESR) method and an ascorbyl radical's ESR spectrum as an oxidative stress biomarker. The drug-treatment group received an i.p. injection with indomethacin (2 mg/kg), baicalein (15 mg/kg), MK-886 (3 mg/kg), zileuton (6.25 mg/kg), diphenyleneiodonium (DPI; 1 mg/kg), sulforaphane (30 mg/kg), oryzanol (30 mg/kg) or sesamol (30 mg/kg) once daily for 14 d from the day of operation. All animals were sacrificed on day 14.

RESULTS

Administration of indomethacin, sulforaphane, oryzanol and sesamol significantly suppressed both the tail volume (56.9%, 77.8%, 72.2% and 38.1% inhibition, respectively, p < 0.01) and ascorbyl radical signals (31.4%, 54.5%, 79.3% and 57.1% inhibition, respectively, p < 0.01), compared with the control mice. No significant differences were found between any of the baicalein, MK-886, or zileuton groups compared with the control. DPI suppressed the tail volume (25.9% inhibition, p < 0.01) but not the ascorbyl radical signals.

CONCLUSION

This study showed that COX-derived oxidative stress plays a major role in the pathological mechanisms of surgically induced lymphedema. Indomethacin, sulforaphane, oryzanol and sesamol exhibit potent protective properties against surgically induced lymphedema.

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.

Synthetic approaches and pharmacological activity of 1,3,4-oxadiazoles: a review of the literature from 2000-2012

This review provides readers with an overview of the main synthetic methodologies for 1,3,4-oxadiazole derivatives, and of their broad spectrum of pharmacological activities as reported over the past twelve years.

Anti-Inflammatory Drug Design Using a Molecular Hybridization Approach

The design of new drugs with better physiochemical properties, adequate absorption, distribution, metabolism, and excretion, effective pharmacologic potency and lacking toxicity remains is a challenge. Inflammation is the initial trigger of several different diseases, such as Alzheimer's disease, asthma, atherosclerosis, colitis, rheumatoid arthritis, depression, cancer; and disorders such as obesity and sexual dysfunction. Although inflammation is not the direct cause of these disorders, inflammatory processes often increase related pain and suffering. New anti-inflammatory drugs developed using molecular hybridization techniques to obtain multiple-ligand drugs can act at one or multiple targets, allowing for synergic action and minimizing toxicity. This work is a review of new anti-inflammatory drugs developed using the molecular modification approach.