Antiplatelet and antithrombotic activities of non-steroidal anti-inflammatory drugs containing an N-acyl hydrazone subunit

The Multifaceted Effects of Non-Steroidal and Non-Opioid Anti-Inflammatory and Analgesic Drugs on Platelets: Current Knowledge, Limitations, and Future Perspectives

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely utilized pharmaceuticals worldwide. Besides their recognized anti-inflammatory effects, these drugs exhibit various other pleiotropic effects in several cells, including platelets. Within this article, the multifaceted properties of NSAIDs on platelet functions, activation and viability, as well as their interaction(s) with established antiplatelet medications, by hindering several platelet agonists' pathways and receptors, are thoroughly reviewed. The efficacy and safety of NSAIDs as adjunctive therapies for conditions involving inflammation and platelet activation are also discussed. Emphasis is given to the antiplatelet potential of commonly administered NSAIDs medications, such as ibuprofen, diclofenac, naproxen and ketoprofen, alongside non-opioid analgesic and antipyretic medications like paracetamol. This article delves into their mechanisms of action against different pathways of platelet activation, aggregation and overall platelet functions, highlighting additional health-promoting properties of these anti-inflammatory and analgesic agents, without neglecting the induced by these drugs' side-effects on platelets' functionality and thrombocytopenia. Environmental issues emerging from the ever-increased subscription of these drugs are also discussed, along with the need for novel water treatment methodologies for their appropriate elimination from water and wastewater samples. Despite being efficiently eliminated during wastewater treatment processes on occasion, NSAIDs remain prevalent and are found at significant concentrations in water bodies that receive effluents from wastewater treatment plants (WWTPs), since there is no one-size-fits-all solution for removing all contaminants from wastewater, depending on the specific characteristics of the wastewater. Several novel methods have been studied, with adsorption being proposed as a cost-effective and environmentally friendly method for wastewater purification from such drugs. This article also presents limitations and future prospects regarding the observed antiplatelet effects of NSAIDs, as well as the potential of novel derivatives of these compounds, with benefits in other important platelet functions.

α-amylase inhibition and in silico studies of novel naphtho[2,3-d]imidazole-4,9-dione linked N-acyl hydrazones

Aim: To enrich the pool of α-amylase inhibitors to manage Type 2 diabetes. Methods: Synthesis, conformational study, α-amylase inhibitory action and various in silico studies of novel N'-(arylbenzylidene)-2-(4,9-dioxo-4,9-dihydro-1H-naphtho[2,3-d]imidazol-1-yl)acetohydrazides carried out. Results: Compound H6 demonstrated the highest activity (IC50 = 0.0437 μmol mL-1) among the tested compounds. Structure-activity relationship study suggested that variable substitution at the aryl ring has a pivotal role in determining the inhibitory action of tested compounds. Docking simulations of the most active compound (H6) confirmed its interaction potential with active site residues of A. oryzae α-amylase. The root-mean-square deviation fluctuations substantiated the stability of protein-ligand complex. Absorption, distribution, metabolism and excretion prediction revealed optimal values for absorption, distribution, metabolism and excretion parameters. Conclusion: The developed molecules could be beneficial for the development of novel α-amylase inhibitors to treat Type 2 diabetes.

Synthesis, Biological, Spectroscopic and Computational Investigations of Novel N-Acylhydrazone Derivatives of Pyrrolo[3,4-d]pyridazinone as Dual COX/LOX Inhibitors

Secure and efficient treatment of diverse pain and inflammatory disorders is continually challenging. Although NSAIDs and other painkillers are well-known and commonly available, they are sometimes insufficient and can cause dangerous adverse effects. As yet reported, derivatives of pyrrolo[3,4-d]pyridazinone are potent COX-2 inhibitors with a COX-2/COX-1 selectivity index better than meloxicam. Considering that N-acylhydrazone (NAH) moiety is a privileged structure occurring in many promising drug candidates, we decided to introduce this pharmacophore into new series of pyrrolo[3,4-d]pyridazinone derivatives. The current paper presents the synthesis and in vitro, spectroscopic, and in silico studies evaluating the biological and physicochemical properties of NAH derivatives of pyrrolo[3,4-d]pyridazinone. Novel compounds 5a-c-7a-c were received with high purity and good yields and did not show cytotoxicity in the MTT assay. Their COX-1, COX-2, and 15-LOX inhibitory activities were estimated using enzymatic tests and molecular docking studies. The title N-acylhydrazones appeared to be promising dual COX/LOX inhibitors. Moreover, spectroscopic and computational methods revealed that new compounds form stable complexes with the most abundant plasma proteins-AAG and HSA, but do not destabilize their secondary structure. Additionally, predicted pharmacokinetic and drug-likeness properties of investigated molecules suggest their potentially good membrane permeability and satisfactory bioavailability.

Structure-Activity Relationship Analysis of Rhosin, a RhoA GTPase Inhibitor, Reveals a New Class of Antiplatelet Agents

Current antiplatelet therapies have several clinical complications and are mostly irreversible in terms of suppressing platelet activity; hence, there is a need to develop improved therapeutic agents. Previous studies have implicated RhoA in platelet activation. Here, we further characterized the lead RhoA inhibitor, Rhosin/G04, in platelet function and present structure-activity relationship (SAR) analysis. A screening for Rhosin/G04 analogs in our chemical library by similarity and substructure searches revealed compounds that showed enhanced antiplatelet activity and suppressed RhoA activity and signaling. A screening for Rhosin/G04 analogs in our chemical library using similarity and substructure searches revealed compounds that showed enhanced antiplatelet activity and suppressed RhoA activity and signaling. SAR analysis revealed that the active compounds have a quinoline group optimally attached to the hydrazine at the 4-position and halogen substituents at the 7- or 8-position. Having indole, methylphenyl, or dichloro-phenyl substituents led to better potency. Rhosin/G04 contains a pair of enantiomers, and S-G04 is significantly more potent than R-G04 in inhibiting RhoA activation and platelet aggregation. Furthermore, the inhibitory effect is reversible, and S-G04 is capable of inhibiting diverse-agonist-stimulated platelet activation. This study identified a new generation of small-molecule RhoA inhibitors, including an enantiomer capable of broadly and reversibly modulating platelet activity.

Novel N-substituted indole hydrazones as potential antiplatelet agents: synthesis, biological evaluations, and molecular docking studies

Background and purpose:

Antiplatelet agents can diminish the chance of coronary heart diseases due to the prevention of unusual clotting in the arteries by inhibiting platelet aggregation and avoiding the formation of a blood clot. This mechanism can help to prevent ischemic stroke likewise. To improve the activity of these drugs and reduce their side effects, further studies are required.

Experimental approach:

Based on the previous studies representing the promising antiplatelet activity of indole hydrazones, a series of their homologs containing twenty-one compounds were prepared in two steps. First, alkylation reaction on the nitrogen of the indole ring, and second, chiff base formation by condensation of a primary amine and N-substituted indole-3 carbaldehyde. Consequently, their platelet anti-aggregation activity was evaluated based on the Born turbidimetric method.

Findings/Results:

Most of the compounds exhibited noticeable activity against platelet aggregation induced by arachidonic acid. Amongst them, two compounds 2e and 2f showed higher activity with IC₅₀ values that made comparable to indomethacin and acetylsalicylic acid as standard drugs and had no toxicity on platelets.

Conclusion and implications:

The synthesized compounds exhibited promising activity against arachidonic acid-induced aggregation; however, none of them showed noticeable antiplatelet activity induced by adenosine di-phosphate. Chemical structure comparison of the prepared derivatives indicated the existence of a lipophilic medium-sized group on the phenyl ring increased their activity. In addition, the docking studies confirmed this hydrophobic interaction in the lipophilic pocket of cyclooxygenase-1 enzyme suggesting that hydrophobicity of this region plays a pivotal role in the anti-platelet activity of these compounds. To prove this finding, the enzymatic evaluation with the target enzyme is required.

Thymus algeriensis and Artemisia herba-alba Essential Oils: Chemical Analysis, Antioxidant Potential and In Vivo Anti-Inflammatory, Analgesic Activities, and Acute Toxicity

The study of bioactive molecules of natural origin is a focus of current research. Thymus algeriensis and Artemisia herba-alba are two medicinal plants widely used by the Moroccan population in the traditional treatment of several pathologies linked to inflammation. This study aimed to evaluate the single and combined antioxidant, anti-inflammatory and analgesic effects of the essential oils extracted from these two medicinal plants, and also their potential toxicity. Essential oils were extracted using hydro-distillation in a Clevenger-type apparatus. The antioxidant activity was evaluated by two methods: the scavenging of the free radical DPPH, and the reduction in iron. Anti-inflammatory activity was evaluated by evaluating the edema development induced by carrageenan injecting, while the analgesic power was evaluated according to the number of abdominal contortions induced by the intraperitoneal injection of acetic acid (0.7%). The acute oral toxicity was performed to assess the potential toxicity of the studied EOs, followed by an analysis of the blood biochemical parameters. The results of the two antioxidant tests indicated that our extract mixture exhibits good iron reduction capacity and very interesting DPPH free radical scavenging power, with an IC₅₀ of around 4.38 ± 0.98 μg/mL higher than that of the benchmark antioxidant, BHT. The anti-inflammatory test demonstrated that the mixture administered orally at a dose of 150 mg/kg has a better activity, exceeding that of 1% Diclofenac, with a percentage of maximum inhibition of the edema of 89.99 ± 4.08. The number of cramps in the mice treated with the mixture at a dose of 150 mg/kg is significantly lower (29.80 ± 1.92) than those of the group treated with Tramadol (42.00 ± 2.70), respectively. The toxicity results show no signs of toxicity with an LD₅₀ greater than 150 mg/Kg. These interesting results show that the two plants’ EOs had an important anti-inflammatory, analgesic, and antioxidant activity, and also a powerful synergistic effect, which encourages further in-depth investigations on their pharmacological proprieties.

Synthesis and Antiplatelet Activity Evaluation of a Group of Novel Ethyl Acetoacetate Phenylhydrazone Derivatives

A group of Novel phenylhydrazone derivatives of ethyl acetoacetate was synthesized and evaluated for their antiplatelet activities. Fourteen ethyl acetoacetate phenylhydrazone derivatives were synthesized using the diazonium salt of various aromatic primary amines with good yields and purity. The structure of the final compounds was confirmed and approved by spectroscopic techniques such as ¹HNMR, FTIR, and ESI-Mass. We examined the antiplatelet activity of the derivatives against Arachidonic Acid (AA) and Adenosine Diphosphate (ADP) as platelet aggregation inducers. The final results indicated the acceptable potency for different derivatives. In this regard, the para-hydroxyphenylhydrazine derivative of ethyl acetoacetate has the best activity among all derivatives, both on AA and ADP pathways. It seems that the derivatives with electron-releasing substituents (hydroxyl, methoxy, and methyl group) have better inhibition activities against the aggregation induced by AA. In contrast, those with an electron-withdrawing group showed a significant decrease in their potency. Based on the results of this study, we would proceed with further assessments both in-vitro and in-vivo to get success in introducing some new antiplatelet agents to the clinic.

Synthesis of Novel Diclofenac Hydrazones: Molecular Docking, Anti-Inflammatory, Analgesic, and Ulcerogenic Activity

This study was aimed to design novel diclofenac hydrazones having anti-inflammatory and analgesic activity with gastric sparing effect. A new series of 2-[2-(2,6-dichloroanilino)phenyl]-N’-[(substituted phenyl) methylidene] acetohydrazide derivatives (1−14) were synthesized and evaluated for their anti-inflammatory, analgesic, and ulcerogenic activity. The compounds were identified and confirmed by elemental analysis and spectral data. During anti-inflammatory activity by carrageenan-induced paw edema method, compounds (2, 3, 7, 8, 11, and 13) were found to be most promising. Compounds 3, 8, and 13 have been found to have significant analgesic activity compared to the reference drug diclofenac in analgesic activity by both the hot plate method and acetic acid-induced writhing method. The compounds which presented highly significant anti-inflammatory and analgesic activity were further tested for their ulcerogenic activity. Compounds 3 and 8 showed maximum ulcerogenic reduction activities. Compound 8 was found to have LD50 of 168 mg/kg. Compound 8 with 3,5-dimethoxy-4-hydroxyphenyl substitution was found to be the most promising anti-inflammatory and analgesic agent with gastric sparing activity. Molecular docking of compounds was performed for COX−1/COX−2 binding site. Lead compound 8 showed better binding affinities of −9.4 kJ/mol with both COX-1 and COX-2 as compared to the standard drug, diclofenac with binding affinities of −6.6 kJ/mol and −8.1 kJ/mol for COX−1 and COX−2, respectively.

Biocompatibility and mechanical properties evaluation of chitosan films containing an N-acylhydrazonic derivative

The N-acylhydrazone subunit is considered a privileged structure in medicinal chemistry for its importance in pharmaceutical research. Also, alternative methods to deliver these molecules have a great pharmaceutical interest. Therefore, the objective of this work was to encapsulate JR19, an N-acyl hydrazone subunit, into chitosan films and evaluate several properties relevant for transdermal delivery, including biocompatibility using in vitro tests. CHI + JR19 film demonstrates greater strength, flexibility, water absorption capacity, low contact angle and higher surface roughness when compared to CHI. Agar diffusion and 3-(4,5-dimethyl)-2,5-diphenyl tetrazolium bromide (MTT) assay show the absence of cytotoxicity and the higher cell viability for CHI + JR19 films. Therefore, the addition of JR19 in the system positively influenced mechanical properties and granted better compatibility with biological environments, showing the potential to treat skin inflammation.

(E)-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide protecting rat heart tissues from isoproterenol toxicity: Evidence from in vitro and in vivo tests

The current study was aimed to assess the protective effect of a new molecule (E)-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide, denoted 1c, against cardiac remodeling process in isoproterenol (Isop) induced myocardial infarction (MI) in rats. Male Wistar rats were randomly divided into four groups, control, Isop (85 mg/kg body weight was injected subcutaneously into rats at an interval of 24 h for 2 days (6^th and 7^th day) to induce MI and pretreated animals with acenocoumarol (Ace) (150 μg/kg bw) and 1c (150 μg/kg bw) by oral administration during 7 days and injected with isoproterenol (Isop + Ace) and (Isop + 1c) groups. Results in vitro showed that 1c is endowed with potent inhibition of angiotensin-converting enzyme (ACE) with an IC₅₀ 39.12 μg/ml. The in vivo exploration evidenced alteration in the ECG pattern, notable cardiac hypertrophy and increase in plasma level of fibrinogen, troponin-T, CK-MB and LDH, AST and ALT by 171%, 300%, 50%, 64% and 75% respectively with histological myocardium necrosis and cells inflammatory infiltration. However, pre-treatment with 1c improved the ECG pattern reduced significantly the cardiac dysfunction markers and ameliorated the thrombolytic process by decreasing fibrinogen level as compared to untreated infracted rats. Overall, (E)-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide 1c could be used as anticoagulant agent to prevent thrombosis in acute myocardial infarction.

The Use of Hydrazones for Biomedical Applications

The use of hydrazones presents an opportunity for enhancing drug delivery through site-specific drug release, including areas such as tumor tissue or thrombosis. Many researchers are experimenting on how to more efficiently form these hydrazones, specifically using heat and chemical catalysts. Hydrazones respond on the pH environment or are synthesized with particular functional groups of the hydrazone and are two of the many unique features that allow for their programmed drug release. Their flexibility allows them to be relevant in a diverse range of applications, from anti-inflammatory to anticancer to acting as a chelating agent. This review paper discusses efficient ways to optimize the properties of hydrazones and their utilization in various clinical applications, including anticancer, anti-inflammatory, the prevention of platelet aggregation, and roles as chelating agents.

Synthesis, characterization, molecular docking evaluation, antiplatelet and anticoagulant actions of 1,2,4 triazole hydrazone and sulphonamide novel derivatives

In the present study, a series of new hydrazone and sulfonamide derivatives of 1,2,4-triazole were synthesized. Initially three 4-substituted-5-(2-pyridyl)-1,2,4-triazole-3-thiones ZE-1(a–c) were treated with ethyl chloroacetate to get the corresponding thioesters ZE-2(a–c), which were reacted with hydrazine hydrate to the respective hydrazides ZE-3(a–c). The synthesized hydrazides were condensed with different aldehydes and p-toluene sulfonylchloride to furnish the target hydrazone derivatives ZE-4(a–c) and sulfonamide derivatives ZE-5(a–c) respectively. All the synthesized compounds were characterized by FTIR, ¹HNMR, ¹³CNMR and elemental analysis data. Furthermore, the new hydrazone and sulfonamide derivatives ZE-4(b–c) and ZE-5(a–b) were evaluated for their antiplatelet and anticoagulant activities. ZE-4b, ZE-4c, ZE-5a and ZE-5b inhibited arachidonic acid, adenosine diphosphate and collagen-induced platelets aggregation with IC₅₀ values of 40.1, 785 and 10.01 (ZE-4b), 55.3, 850.4 and 10 (ZE-4c), 121.6, 956.8 and 30.1 (ZE-5a), 99.9, 519 and 29.97 (ZE-5b) respectively. Test compounds increased plasma recalcification time (PRT) and bleeding time (BT) with ZE-4c being found most effective, which at 30, 100, 300 and 1000 µM increased PRT to 84.2 ± 1.88, 142 ± 3.51, 205.6 ± 5.37 and 300.2 ± 3.48 s and prolonged BT to 90.5 ± 3.12, 112.25 ± 2.66, 145.75 ± 1.60 s (P < 0.001 vs. saline group) respectively. In silico docking approach was also applied to screen these compounds for their efficacy against selected drug targets of platelet aggregation and blood coagulation. Thus in silico, in vitro and in vivo investigations of ZE-4b, ZE-4c, ZE-5a and ZE-5b prove their antiplatelet and anticoagulant potential and can be used as lead molecules for further development.

Design, synthesis and pharmacological evaluation of N-benzyl-piperidinyl-aryl-acylhydrazone derivatives as donepezil hybrids: Discovery of novel multi-target anti-alzheimer prototype drug candidates

A new series of sixteen multifunctional N-benzyl-piperidine-aryl-acylhydrazones hybrid derivatives was synthesized and evaluated for multi-target activities related to Alzheimer's disease (AD). The molecular hybridization approach was based on the combination, in a single molecule, of the pharmacophoric N-benzyl-piperidine subunit of donepezil, the substituted hydroxy-piperidine fragment of the AChE inhibitor LASSBio-767, and an acylhydrazone linker, a privileged structure present in a number of synthetic aryl- and aryl-acylhydrazone derivatives with significant AChE and anti-inflammatory activities. Among them, compounds 4c, 4d, 4g and 4j presented the best AChE inhibitory activities, but only compounds 4c and 4g exhibited concurrent anti-inflammatory activity in vitro and in vivo, against amyloid beta oligomer (AβO) induced neuroinflammation. Compound 4c also showed the best in vitro and in vivo neuroprotective effects against AβO-induced neurodegeneration. In addition, compound 4c showed a similar binding mode to donepezil in both acetylated and free forms of AChE enzyme in molecular docking studies and did not show relevant toxic effects on in vitro and in vivo assays, with good predicted ADME parameters in silico. Overall, all these results highlighted compound 4c as a promising and innovative multi-target drug prototype candidate for AD treatment.

Rational Design and Synthesis of 1-(Arylideneamino)-4-aryl-1H-imidazole-2-amine Derivatives as Antiplatelet Agents

Based on previous studies indicating the pharmacophoric role of a hydrazone group and azole rings for antiplatelet aggregation activity, a few series of compounds with both hydrazone and an azole (imidazole) ring in their structures were synthesized, and their platelet aggregation inhibitory effects were evaluated. Two of these 1-(arylideneamino)-4-aryl-1H-imidazole-2-amine derivatives, compounds 4 a [(E)-1-(benzylideneamino)-4-phenyl-1H-imidazol-2-amine] and 4 p [(E)-4-phenyl-1-((thiophen-2-ylmethylene)amino)-1H-imidazol-2-amine], exhibited IC₅₀ values similar to that of acetylsalicylic acid against collagen as a platelet aggregation inducer. Structural comparison of the synthesized compounds revealed that those with a para-substituted phenyl ring on the imidazole were among the most active compounds against platelet aggregation induced by arachidonic acid (AA), and the presence of a thiophene ring in these compounds maximized their antiplatelet activity.

New approaches in tail-bleeding assay in mice: improving an important method for designing new anti-thrombotic agents

This report describes a modified, simple, low-cost and more sensitive method to determine bleeding patterns and haemoglobin concentration in a tail-bleeding assay using BALB/c mice and tail tip amputation. The cut tail was immersed in Drabkin's reagent to promote erythrocyte lysis and haemoglobin release, which was monitored over 30 min. The operator was blinded to individual conditions of the mice, which were treated with either saline (NaCl 0.15m), DMSO (0.5%) or clinical anti-thrombotic drugs. Our experimental protocols showed good reproducibility and repeatability of results when using Drabkin's reagent than water. Thus, the use of Drabkin's reagent offered a simple and low-cost method to observe and quantify the bleeding and rebleeding episodes. We also observed the bleeding pattern and total haemoglobin loss using untreated animals or those under anti-coagulant therapy in order to validate the new Drabkin method and thus confirm that it is a useful protocol to quantify haemoglobin concentrations in tail-bleeding assay. This modified method provided a more accurate results for bleeding patterns in mice and for identifying new anti-thrombotic drugs.

Synthesis and Preliminary Evaluation of N-Oxide Derivatives for the Prevention of Atherothrombotic Events

Thrombosis is the main outcome of many cardiovascular diseases. Current treatments to prevent thrombotic events involve the long-term use of antiplatelet drugs. However, this therapy has several limitations, thereby justifying the development of new drugs. A series of N-oxide derivatives (furoxan and benzofuroxan) were synthesized and characterized as potential antiplatelet/antithrombotic compounds. All compounds (3a,b, 4a,b, 8a,b, 9a,b, 13a,b and 14a,b) inhibited platelet aggregation induced by adenosine-5-diphosphate, collagen, and arachidonic acid. All compounds protected mice from pulmonary thromboembolism induced by a mixture of collagen and epinephrine; however, benzofuroxan derivatives (13a,b and 14a,b) were the most active compounds, reducing thromboembolic events by up to 80%. N-oxide derivative 14a did not induce genotoxicity in vivo. In conclusion, 14a has emerged as a new antiplatelet/antithrombotic prototype useful for the prevention of atherothrombotic events.

Azine or hydrazone? The dilemma in amidinohydrazones

Amidinohydrazone, an important class of biologically active molecules, is generally represented as a hydrazone. This moiety prefers to exist in its azine tautomeric state and hence, influences the physical, chemical and receptor binding properties.

Leishmanicidal activities of novel synthetic furoxan and benzofuroxan derivatives

A novel series of furoxan (1,2,5-oxadiazole 2-oxide) (compounds 3, 4a and -b, 13a and -b, and 14a to -f) and benzofuroxan (benzo[c][1,2,5]oxadiazole 1-oxide) (compounds 7 and 8a to -c) derivatives were synthesized, characterized, and evaluated for in vitro activity against promastigote and intracellular amastigote forms of Leishmania amazonensis. The furoxan derivatives exhibited the ability to generate nitric oxide at different levels (7.8% to 27.4%). The benzofuroxan derivative 8a was able to increase nitrite production in medium supernatant from murine macrophages infected with L. amazonensis at 0.75 mM after 48 h. Furoxan and benzofuroxan derivatives showed remarkable leishmanicidal activity against both promastigote and intracellular amastigote forms. Compounds 8a, 14a and -b, and 14d exerted selective leishmanicidal activities superior to those of amphotericin B and pentamidine. In vitro studies at pH 5.4 reveal that compound 8a is stable until 8 h and that compound 14a behaves as a prodrug, releasing the active aldehyde 13a. These compounds have emerged as promising novel drug candidates for the treatment of leishmaniasis.

Pharmacological evaluation and preparation of nonsteroidal anti-inflammatory drugs containing an N-acyl hydrazone subunit

A series of anti-inflammatory derivatives containing an N-acyl hydrazone subunit (4a-e) were synthesized and characterized. Docking studies were performed that suggest that compounds 4a-e bind to cyclooxygenase (COX)-1 and COX-2 isoforms, but with higher affinity for COX-2. The compounds display similar anti-inflammatory activities in vivo, although compound 4c is the most effective compound for inhibiting rat paw edema, with a reduction in the extent of inflammation of 35.9% and 52.8% at 2 and 4 h, respectively. The anti-inflammatory activity of N-acyl hydrazone derivatives was inferior to their respective parent drugs, except for compound 4c after 5 h. Ulcerogenic studies revealed that compounds 4a-e are less gastrotoxic than the respective parent drug. Compounds 4b-e demonstrated mucosal damage comparable to celecoxib. The in vivo analgesic activities of the compounds are higher than the respective parent drug for compounds 4a-b and 4d-e. Compound 4a was more active than dipyrone in reducing acetic-acid-induced abdominal constrictions. Our results indicate that compounds 4a-e are anti-inflammatory and analgesic compounds with reduced gastrotoxicity compared to their respective parent non-steroidal anti-inflammatory drugs.