Synthesis and evaluation of mutual prodrugs of ibuprofen with menthol, thymol and eugenol

Enhanced transdermal delivery of flurbiprofen via eutectic mixtures and novel terpene ester derivatives of L-amino acids

The present study aimed to evaluate the influence of chemical modifications on the properties of flurbiprofen derivatives, focusing particularly on their skin permeation and accumulation. Comprehensive characterization of all synthesized compounds was conducted using NMR, FTIR, and HRMS for structural analysis. Crystallinity was assessed via XRD, while thermal stability and properties were evaluated using TG and DSC, respectively. In addition, solubility in water, organic solvents, and PBS, as well as lipophilicity, were examined to better understand their physicochemical behavior. Biological properties were investigated through antioxidant and anti-inflammatory activity assessments, along with cytotoxicity evaluations. The study specifically tested a flurbiprofen salt, which combined the flurbiprofenate anion with the menthyl ester of the L-alanine cation. Comparisons were made with unmodified flurbiprofen to evaluate differences in skin permeability and accumulation. Several mixtures of individual substrates (L-alanine, menthol, and L-alanine menthyl ester hydrochloride) with flurbiprofen were also prepared, with some forming eutectic mixtures. Results indicated that both the eutectic mixtures and the flurbiprofen derivative, L-alaninium menthyl ester flurbiprofenate, exhibited significantly enhanced skin permeation and accumulation, reaching levels 1.5-2.5 times higher than unmodified flurbiprofen. These findings underscore the effectiveness of chemical modifications in improving flurbiprofen's transdermal delivery potential, especially via eutectic mixtures, which appear to play a critical role in enhancing skin permeability. Consequently, this study supports the potential of tailored chemical modifications in developing more effective and controlled transdermal therapies.

Phytophenols as Promoieties for Prodrug Design

One lucrative method for overcoming challenges in drug discovery or for enhancing undesirable properties of already-approved medications is prodrug design. The goal of this review is to present researchers with a profile of naturally occurring Phytophenols as carriers that would be used for prodrug synthesis as well as their advantages. Phytophenols offer several advantages when used as promoieties as they also possess antioxidant and analgesic properties, they are obtained naturally and their safety profile is well established. Several phytophenols like menthol, thymol, eugenol, guaiacol, sesamol, vanillin, and umbelliferone are some of the phytophenols having several beneficial properties and are extensively employed in the field of food processing and medicine. In the current review, we have listed all types of promoieties that are used for prodrug synthesis and phytophenols are reviewed, which may help researchers to select phytophenols based on their need and suitability for drug candidates.

Assessing Therapeutic Value and Side Effects of Key Botanical Compounds for Optimized Medical Treatments

Due to the significance of variable chemical groups across a wide spectrum of modern medicine, it is imperative to determine what is the most widely used group in medical applications with the fewest side effects. Ten compounds from ten chemical groups that are most commonly known for their medical uses were compared in terms of their therapeutic potential and side effects. The comparison among the selected compounds indicated the superiority of the flavonoids over other groups in the multitude of their utilizations and the lower side effects. Kaempferol and quercetin showed higher medical utilization with lower side effects. Whereas alkaloid compounds showed the lowest levels of medical use and the highest levels of side effects. Based on the comparison conducted, it is concluded to give priority to flavonoid compounds being used in medical applications because they exhibit the highest medical uses with the lowest side effects. Within flavonoids, kaempferol and quercetin are the two compounds that are highly recommended to be used in the widest range of medical applications. Serious caution should be considered before applying alkaloids to any medical service. Understanding the characteristics of these compounds can aid in developing safer and more effective treatments for medicinal plants.

2-Trifluoromethyl-2H-chromene ethers: The dual triumph of anti-inflammation and analgesia with minimal ulcer threat

In this report, we disclose the design and synthesis of a series of 2-trifluoromethyl-2H- chromene ethers as novel COX-2 inhibitors with low ulcerogenicity. Among them, 6-fluoro-3-(4-methoxyphenyl)-2-(2-(thiophen-3-yl)ethoxy)-2-(trifluoromethyl)-2H-chromene (E25) significantly suppressed LPS-induced release of NO and PGE2, expression of COX-2 and iNOS, and activation of NF-κB pathway. The inhibitory effect of E25 on human recombinant COX-2 (IC50 = 70.7 ± 4.7 nM) and molecular docking studies suggest that E25 functions as a COX-2 inhibitor. Moreover, the results of the cellular thermal shift assay also substantiate the interaction between E25 and COX-2. E25 manifests potent anti-inflammatory and analgesic efficacy on a par with or even superior to indomethacin in rodent models including carrageenan-induced paw edema, cotton pellet-induced granuloma, acetic acid-induced writhes, and adjuvant-induced arthritis. The possible mechanism of action of E25 might be to bind to COX-2 and suppress the NF-κB pathway as well as the expression of related proteins, thereby exerting anti-inflammatory and analgesic effects. Encouragingly, compared with indomethacin, E25 induces smaller areas and fewer ulcers, a lower level of inflammatory infiltration, a lower expression of MMP-9 and apoptosis of mucosal epithelial cells in rat gastric tissues. Overall, E25 and other analogues are promising candidates worthy of further investigation for the treatment of inflammation and pain, as well as other symptoms in which COX-2 and PGE2 play a role in their etiology.

Comprehensive evaluation of ibuprofenate amino acid isopropyl esters: insights into antioxidant activity, cytocompatibility, and cyclooxygenase inhibitory potential

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for pain relief and inflammation management, but there are challenges related to poor solubility and bioavailability. We explored modifications of ibuprofen (IBU) by forming ionic pairs using amino acid alkyl esters to enhance solubility without compromising the ability to inhibit cyclooxygenase (COX)-1 and COX-2). We comprehensively evaluated the pharmacological properties of the IBU derivatives, focusing on antioxidant activity (based on the ability to scavenge DPPH and ABTS), biocompatibility (using human dermal fibroblasts), and COX inhibitory potential. The antioxidant activity assays significantly enhanced DPPH scavenging activity for several IBU derivatives, particularly [L-SerOiPr][IBU], suggesting potential therapeutic benefits. There was enhanced cell viability with select derivatives, indicating possible stimulatory effects on cellular proliferation. Finally, predominant COX-1 inhibition across derivatives was consistent with IBU's profile. This study provides insights into the pharmacological properties of IBU amino acid derivatives, highlighting their potential as therapeutic agents. Further exploration into structure-activity relationships and in vivo efficacy warranted to advance these derivatives toward clinical applications, offering prospects for novel NSAIDs with enhanced efficacy and reduced side effects.

3-(2-Trifluoromethyl-3-aryl-4H-chromen-4-yl)-1H-indoles: Mastering anti-inflammation and analgesia while mitigating gastrointestinal side effects

A series of 3-(2-trifluoromethyl-3-aryl-4H-chromen-4-yl)-1H-indoles (5-1 to 5-29) were developed and characterized. Most of compounds were found to be potent for inhibiting the production of NO in LPS-induced RAW264.7 cells, of which 3-(3-(4-chlorophenyl)-6-methoxy-2-(trifluoromethyl)-4H-chromen-4-yl)-1H-indole (5-25) was the most optimal (IC50 = 4.82 ± 0.34 μΜ) and was capable of significantly suppressing the release of PGE2. The inhibitory effect of 5-25 on human recombinant COX-2 (IC50 = 51.7 ± 1.3 nM) was measured and molecular docking was performed, determining 5-25 as a COX-2 inhibitor. Additionally, the interaction between 5-25 and COX-2 was determined by the CETSA technique. Then, 5-25 inhibited the degradation of IκB, the phosphorylation and nuclear translocation of NF-κB p65, and the expression of COX-2 and iNOS. Moreover, it was verified that 5-25 exhibited efficacy in rodent models of inflammation and pain, encompassing the paw edema, cotton pellet-induced granuloma, acid-induced writhing, and adjuvant-induced arthritis models. Therefore, the mechanism of 5-25 may be to bind to COX-2 and exert anti-inflammatory and analgesic effects in vitro and in vivo by suppressing the NF-κB pathway. Encouragingly, in comparison with indomethacin, 5-25 exhibited a lower ulcerative potential in rats, as manifested by generating smaller areas and fewer ulcers, less inflammatory infiltration, a lower expression of MMP-9, and less apoptosis. In conclusion, 5-25 is a candidate drug with high activity and low ulcerogenic potential, and it deserves further research for the treatment of inflammation, pain, and other symptoms in which COX-2 plays a role in their pathogenesis.

Customizable Self-Microemulsifying Rectal Suppositories by Semisolid Extrusion 3D Printing

Objectives: This study aims to create an innovative self-microemulsifying drug delivery system (SMEDDS) suppository for ibuprofen (IBU) using semisolid extrusion (SSE) three-dimensional (3D) printing technology. Methods: Based on solubility studies and the ability to form a transparent microemulsion upon dilution, a selected oil, surfactant, and co-surfactant were utilized to prepare SMEDDS-3DPS containing IBU. The optimal formulation consisted of 10% Triacetin, 80% Gelucire 48/16, and 10% Tetraethylene glycol. SSE 3D printing was employed to create three different-sized suppositories with varying drug contents. These suppositories were assessed for their physicochemical properties, content uniformity, and dissolution profiles. Results: The prepared mixture exhibited suitable physical properties for printing, with nano-sized emulsion droplets providing a large surface area for improved drug absorption in the rectum. Characterization techniques such as differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy indicated that IBU was present in the formulation in an amorphous state. Additionally, in vitro dissolution tests demonstrated that SMEDDS-3DPS had a significantly higher initial dissolution rate compared with IBU powder. Conclusions: This research suggests that SMEDDS-3DPS, as a rectal IBU dosage form, can enhance the rectal bioavailability of IBU. It demonstrates the versatility of 3D printing as a novel manufacturing method for lipid-based suppositories and highlights the simplicity and adaptability of SSE 3D printing technology in producing customized suppositories tailored to individual patient needs, surpassing traditional methods.

Discovery of novel NSAID hybrids as cPLA2/COX-2 dual inhibitors alleviating rheumatoid arthritis via inhibiting p38 MAPK pathway

A series of NSAIDs hybrid molecules were synthesized and characterized, and their ability to inhibit NO release in LPS-induced RAW264.7 macrophages was evaluated. Most of the compounds showed significant anti-inflammatory activity in vitro, of which (2E,6Z,9Z,12Z,15Z)-1,1,1-trifluorohenicosa-2,6,9,12,15-pentaen-2-yl 2-(4-benzoylphenyl) propanoate (VI-60) was the most optimal (IC50 = 3.85 ± 0.25 μΜ) and had no cytotoxicity. In addition, VI-60 notably reduced the production of PGE2 in LPS-stimulated RAW264.7 cells compared to ketoprofen. Futhur more, VI-60 significantly inhibited the expression of iNOS, cPLA2, and COX-2 and the phosphorylation of p38 MAPK in LPS-stimulated RAW264.7 cells. The binding of VI-60 to cPLA2 and COX-2 was directly verified by the CETSA technique. In vivo studies illustrated that VI-60 exerted an excellent therapeutic effect on adjuvant-induced arthritis in rats by regulating the balance between Th17 and Treg through inhibiting the p38 MAPK/cPLA2/COX-2/PGE2 pathway. Encouragingly, VI-60 showed a lower ulcerative potential in rats at a dose of 50 mg/kg compared to ketoprofen. In conclusion, the hybrid molecules of NSAIDs and trifluoromethyl enols are promising candidates worthy of further investigation for the treatment of inflammation, pain, and other symptoms in which cPLA2 and COX-2 play a role in their etiology.

Insights into Prospects of Novel NSAID Prodrugs in the Management of Gastrointestinal Toxicity: A Perspective Review

Non-steroidal anti-inflammatory drugs (NSAIDs) have a long history in the healthcare system due to their therapeutic potential. These NSAIDs cause ulcerogenicity, stomach pains, gastrointestinal hemorrhage, mucosa bleeding, and pancreatitis when used moderately and consistently. With researchers, managing the aforementioned adverse effects therapeutically is getting increasingly difficult. One method for creating NSAID moieties with low penetration as well as ulcerogenic properties is the prodrug technique. During the oral consumption of NSAID-prodrugs, ulcerations, intestinal hemorrhage, and mucosa hemorrhage have significantly decreased. Considering this background, this review focussed on NSAID prodrugs as well as their justifications, the pathogenesis of NSAIDs inducing gastrointestinal toxicity, and the role of different antioxidants and spacer groups. Prodrug moieties have more advantages over parent medicines concerning both solubility and lipophilicity. In general, NSAID-class prodrugs can successfully treat both acute and long-term inflammation and aches without causing ulcerotoxicity and related gastrointestinal side effects, which reduces their burden from the pharmacoeconomic perspective.

Diclofenac and eugenol hybrid with enhanced anti-inflammatory activity through activating HO-1 and inhibiting NF-κB pathway in vitro and in vivo

A series of diclofenac hybrid molecules were synthesized and evaluated for their NO-inhibitory ability in LPS-induced RAW 264.7 macrophage cells. Among them, compound 1 showed the highest NO-inhibitory ability (approximately 66%) and no significant cytotoxicity. Compound 1 exhibited superior NF-κB-inhibitory ability compared to diclofenac through the activation of Nrf2/HO-1 signaling pathway in RAW 264.7. 20 mg/kg compound 1 resulted in remarkable colitis improvement in dextran sulfate sodium (DSS)-induced mice model by up-regulating HO-1 and down-regulating phosphorylation level of NF-κB p65. Moreover, 50 mg/kg dose of compound 1 showed a lower ulcerogenic potential compared to diclofenac in rats. The diclofenac-eugenol hybrid (compound 1) may serve as a novel anti-inflammatory agent based on its role in inhibiting the NF-κB signaling pathway and activating HO-1 expression with no toxicity in vitro and in vivo.

A New Avenue for Enhanced Treatment of Hyperuricemia and Oxidative Stress: Design, Synthesis and Biological Evaluation of Some Novel Mutual Prodrugs Involving Febuxostat Conjugated with Different Antioxidants

Febuxostat (FEB) is the first non-purine xanthine oxidase inhibitor (XOI) used for the treatment of hyperuricemia and gout. The oxidative stress induced by reactive oxygen species (ROS) which accompany purine metabolism by XO, could contribute to cellular damage and several pathological conditions. In this view, the present work addresses the evaluation of combining the hypouricemic effect of FEB and the free radical scavenging potential of various natural antioxidants in a single chemical entity by implementing the "mutual prodrug" strategy. Accordingly, a series of five ester prodrugs containing FEB together with different naturally occurring antioxidants namely, thioctic acid (4), thymol (5), menthol (6), vanillin (7), and guaiacol (8) was synthesized. Prominently, all the chemically conjugated prodrugs (4 - 8) revealed an obvious increase in the hypouricemic and antioxidant potentials when compared with their corresponding promoieties and physical mixtures. Moreover, they showed a potential protective effect against CCl4-induced hepatotoxicity and oxidative stress, together with no cytotoxicity on normal breast cells (MCF10A). Furthermore, the in vitro chemical and enzymatic stability studies of the prodrugs (4 - 8) using a developed HPLC method, verified their stability in different pHs, and rapid hydrolysis in rabbit plasma and liver homogenate to their parent metabolites. Moreover, the prodrugs (4 - 8) showed higher lipophilicity and lower aqueous solubility when compared to the parent drugs. Finally, the obtained merits from the implementation of the mutual prodrug strategy would encourage further application in the development of promising candidates with high therapeutic efficacy and improved safety profiles.

Nano crystalline cellulose based drug delivery system for some non-steroidal anti-inflammatory drugs: Synthesis, characterization and in-vitro simulation studies

Nano crystalline cellulose (NCC) created a breakthrough in biomedical field because of its important characteristics like large surface area, good mechanical strength, biocompatibility, renewability and feasibility of incorporation to both hydrophilic and hydrophobic substances. In the present study NCC based drug delivery systems (DDSs) of some non-steroidal anti-inflammatory drugs (NSAIDs) were obtained by covalent bonding between hydroxyl groups of NCC with carboxyl group of NSAIDs. Developed DDSs were characterized by means of FT-IR, XRD, SEM and thermal analysis. In-vitro release study and fluorescence study showed that these systems are stable up to 18 h in upper gastrointestinal (GI) tract at pH 1.2 and released NSAIDs in sustained manner over the period of 3 h in intestine at pH 6.8-7.4. Present study performed with the aim to reuse bio-waste even in the form of DDSs is of greater therapeutic efficacy with reduced dosing frequency that overcome physiological adversities involved with NSAIDs.

Towards the Development of Dual Hypouricemic and Anti-inflammatory Candidates: Design, Synthesis, Stability Studies and Biological Evaluation of Some Mutual Ester Prodrugs of Febuxostat-NSAIDs

Treatment of gout involves two basic approaches: reducing the serum uric acid mainly by xanthine oxidase inhibitors (XOIs) and alleviating the intensity of the accompanying acute arthritic inflammation using non-steroidal anti-inflammatory drugs (NSAIDs). Febuxostat (FEB) is the first non-purine XOI approved for the treatment of hyperuricemia and gout. The present study aims at combining the hypouricemic effect of FEB and the anti-inflammatory (AI) properties of NSAIDs in a single entity by adopting the "mutual prodrug" approach. Accordingly, a series of seven ester prodrugs comprising basically FEB together with different NSAIDs namely, diclofenac (4), ibuprofen (5), ketoprofen (6), indomethacin (7), naproxen (8), ketorolac (9) and etodolac (10) was synthesized. All the investigated seven prodrugs (4-10) were equipotent or even superior to their corresponding parent drugs in the hypouricemic and AI activities, together with a gastrointestinal (GI) safety profile. Among this series, the prodrug FEB-DIC (4) showed excellent dual in vivo hypouricemic and anti-inflammatory activity (43.60 % and 15.96 %, respectively) when compared to the parent drugs FEB and diclofenac (36.82 % and 12.10 %, respectively) and its physical mixture (37.28 % and 12.41 %, respectively). Investigation of the in vitro chemical stability and hydrolysis of the prodrug (4) in aqueous and biological samples using a developed HPLC method confirmed its stability in various pHs, whereas rapid hydrolysis to the parent drugs in liver homogenate and human plasma was proven. Finally, it is concluded that the mutual prodrug approach could be successfully used in drug design and development for overcoming undesirable difficulties without losing the desired activities of the parent drugs.

Enzymatic Synthesis of Thymol Octanoate, a Promising Hybrid Molecule

Interest in the synthesis and application of thymol esters has increased in recent years due to the numerous applications associated with its biological activities. The enzymatic synthesis of thymol octanoate by esterification of thymol and octanoic acid was explored using soluble lipases and immobilized lipase biocatalysts in solvent-free systems. Candida antarctica lipase B in its soluble form was the most active biocatalyst for this reaction. Different thymol and lipase feeding strategies were evaluated to maximize thymol octanoate production. The results suggest that there could be lipase inhibition by the ester product of the reaction. In this way, the optimal reaction condition was given using a thymol/acid molar ratio of 1:4 mol/mol. Under these conditions the conversion of thymol was close to 94% and the lipase maintained more than 90% of its initial activity after the reaction, showing the potential of the enzyme to be used in successive reaction cycles.

Isopropyl Amino Acid Esters Ionic Liquids as Vehicles for Non-Steroidal Anti-Inflammatory Drugs in Potential Topical Drug Delivery Systems with Antimicrobial Activity

New derivatives of non-steroidal anti-inflammatory drugs were synthesized via conjugation with L-amino acid isopropyl esters. The characteristics of the physicochemical properties of the obtained pharmaceutically active ionic liquids were determined. It has been shown how the incorporation of various L-amino acid esters as an ion pair affects the properties of the parent drug. Moreover, the antimicrobial activity of the obtained compounds was evaluated. The proposed structural modifications of commonly used drugs indicate great potential for use in topical and transdermal preparations.

Exploring ibuprofen derivatives as α-glucosidase and lipoxygenase inhibitors: Cytotoxicity and in silico studies

This study reports the synthesis of a series of ibuprofen derivatives, including thiosemicarbazides 4a-f, 1,3,4-oxadiazoles 5a-f, 1,3,4-thiadiazoles 6a-f, 1,2,4-triazoles 7a-f, and their S-alkylated derivatives 8a-d. All of the newly synthesized derivatives were analyzed using ¹ H NMR, ¹³ C NMR spectroscopy, and high-resolution mass spectra (electron ionization) spectrometry. These synthetic molecules were examined for their in vitro baking yeast α-glucosidase and soybean 15-lipoxygenase (15-LOX) inhibition and cell viability studies. The results revealed that the compounds N-(3,4-dichlorophenyl)-5-[1-(4-isobutylphenyl)ethyl]-1,3,4-oxadiazol-2-amine 5f (IC₅₀ 3.05 ± 1.23 µM) and N-(3-fluorophenyl)-5-[1-(4-isobutylphenyl)ethyl]-1,3,4-oxadiazol-2-amine 5b (IC₅₀ 3.12 ± 1.21 µM) were the most potent with respect to the α-glucosidase enzyme while in case of 15-LOX, the compound 4-(2,4-dichlorophenyl)-1-[2-(4-isobutylphenyl)propanoyl]thiosemicarbazide 4e showed potent inhibition with an IC₅₀ value of 55.41 ± 0.41 µM. All these compounds were found least toxic by displaying a blood mononuclear cell viability value of 69.2%-97.8% by the MTT assay compared to the standards when assayed at 0.25 mM concentration. Molecular docking analyses were conducted to evaluate the inhibition profiles of these derivatives against the said enzymes and the data supported the in vitro profiles.

Influence of the Type of Amino Acid on the Permeability and Properties of Ibuprofenates of Isopropyl Amino Acid Esters

Modifications of (RS)-2-[4-(2-methylpropyl)phenyl] propanoic acid with amino acid isopropyl esters were synthesised using different methods via a common intermediate. The main reaction was the esterification of the carboxyl group of amino acids with isopropanol and chlorination of the amino group of the amino acid, followed by an exchange or neutralisation reaction and protonation. All of the proposed methods were very efficient, and the compounds obtained have great potential to be more effective drugs with increased skin permeability compared with ibuprofen. In addition, it was shown how the introduction of a modification in the form of an ion pair affects the properties of the obtained compound.

Design and synthesis of ibuprofen-quinoline conjugates as potential anti-inflammatory and analgesic drug candidates

A new set of ibuprofen-quinoline conjugates comprising quinolinyl heterocycle and ibuprofen moieties linked by an alkyl chain were synthesized in good yields utilizing an optimized reaction procedure in a molecular hybridization approach to overcome the drawbacks of the current non-steroidal anti-inflammatory drugs. The synthesized conjugates were screened for their anti-inflammatory, and ulcerogenic properties. Several conjugates were found to have significant anti-inflammatory properties in the carrageenan-induced rat paw edema test without showing any ulcerogenic liability. In addition, most conjugates showed promising peripheral analgesic activity in the acetic acid-induced writhing test as well as central analgesic properties in the in vivo hot plate test. The most promising conjugates were the unsubstituted and 6-substituted fluoro- and chloro-derivatives of 2-(trifluoromethyl)quinoline linked to ibuprofen by a propyl chain. Their anti-inflammatory activity was evaluated against LPS-stimulated inflammatory reactions in RAW264.7 mouse macrophages. In this regard, it was found that most of the conjugates were able to significantly reduce the release and production of nitric oxide in the LPS-stimulated macrophages. The secretion and expression of the pro-inflammatory cytokines IL-6, TNF-α, and inducible nitric oxide synthase (iNOS) were also significantly suppressed.

Tailored Functionalization of Natural Phenols to Improve Biological Activity

Phenols are widespread in nature, being the major components of several plants and essential oils. Natural phenols' anti-microbial, anti-bacterial, anti-oxidant, pharmacological and nutritional properties are, nowadays, well established. Hence, given their peculiar biological role, numerous studies are currently ongoing to overcome their limitations, as well as to enhance their activity. In this review, the functionalization of selected natural phenols is critically examined, mainly highlighting their improved bioactivity after the proper chemical transformations. In particular, functionalization of the most abundant naturally occurring monophenols, diphenols, lipidic phenols, phenolic acids, polyphenols and curcumin derivatives is explored.

Design, synthesis, biological assessment and in silico ADME prediction of new 2-(4-(methylsulfonyl) phenyl) benzimidazoles as selective cyclooxygenase-2 inhibitors

A novel series of benzimidazole derivatives wherein 4-(methylsulfonyl) phenyl pharmacophore attached via its C-2 position was designed and synthesized. These compounds were evaluated in vitro as cyclooxygenase-1(COX-1)/cyclooxygenese-2(COX-2) inhibitors. Furthermore, the synthesized compounds were also in vivo evaluated for their anti-inflammatory activity and ulcerogenic liability. Examination of histopathological lesions was also performed to evaluate the cariogenic effect of most active compounds. In silico prediction of physicochemical properties, ADME, and drug-likeness profiles were also studied. Several compounds as 11b, 11k, 12b, and 12d showed selective inhibition to (COX-2) isozyme. Compound 11b showed the most potent (COX-2) inhibitory activity with (IC₅₀ = 0.10 μM) and selectivity index (SI = 134); the tested compounds also have shown good anti-inflammatory activity. Regarding the ulcerogenic liability, compound 11b was also safest one (Ulcer Index) (UI = 0.83). The results of the molecular docking studies is closely related to the results of the in vitro COX-2 inhibitory activities.

A novel series of benzimidazole derivatives wherein 4-(methylsulfonyl) phenyl pharmacophore attached via its C-2 position was designed and synthesized.

Dexamethasone and Fumaric Acid Ester Conjugate Synergistically Inhibits Inflammation and NF-κB in Macrophages

Macrophage-mediated inflammation drives autoimmune and chronic inflammatory diseases. Treatment with anti-inflammatory agents can be an effective strategy to reduce this inflammation; however, high concentrations of these agents can have immune-dampening and other serious side effects. Synergistic combination of anti-inflammatory agents can mitigate dosing by requiring less drug. Multiple anti-inflammatory agents were evaluated in combination for synergistic inhibition of macrophage inflammation. The most potent synergy was observed between dexamethasone (DXM) and fumaric acid esters (e.g., monomethyl fumarate (MMF)). Furthermore, this combination was found to synergistically inhibit inflammatory nuclear factor κB (NF-κB) transcription factor activity. The optimal ratio for synergy was determined to be 1:1, and DXM and MMF were conjugated by esterification at this molar ratio. The DXM-MMF conjugate displayed improved inhibition of inflammation over the unconjugated combination in both murine and human macrophages. In the treatment of human donor monocyte-derived macrophages, the combination of DXM and MMF significantly inhibited inflammatory gene expression downstream of NF-κB and overall performed better than either agent alone. Further, the DXM-MMF conjugate significantly inhibited expression of NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome-associated genes. The potent anti-inflammatory activity of the DXM-MMF conjugate in human macrophages indicates that it may have benefits in the treatment of autoimmune and inflammatory diseases.

Synthesis of Novel Esters of Mefenamic Acid with Pronounced Anti-nociceptive Effects and a Proposed Activity on GABA, Opioid and Glutamate Receptors

BACKGROUND

Mefenamic acid (MFA), a commonly prescribed non-steroidal anti-inflammatory drug (NSAID), possesses a greater risk of dose-related central nervous system (CNS) toxicity than other NSAIDs. In this study, α-tocopherol and α-tocopherol acetate were selected as prodrug moieties for MFA in an attempt to reduce the CNS toxicity and enhance the therapeutic efficacy.

METHOD

α-tocopherol monoester of MFA (TMMA) and α-tocopherol di-ester of MFA (TDMA) were synthesized by esterification reaction and were subjected to various in vivo characterizations.

RESULTS

Masking of the carboxylate group of MFA with the proposed pro-moieties significantly (p<0.05) delayed the onset of tonic-clonic seizure in mice. Besides, the intraperitoneal administration of TMMA and TDMA in mice produced significantly (p<0.05) stronger anti-inflammatory effects in the carrageenan-induced paw edema test and greater anti-nociceptive effect in the acetic acid-induced writhing test than MFA at an equimolar dose of 20 mg/kg. Treatment with TMMA and TDMA caused a significant (p<0.05) inhibition of pain at 1st and 2nd phases of formalin-induced licking test in mice, whereas treatment with MFA inhibited the 2nd phase only. Pretreatment with naloxone and flumazenil significantly (p<0.05) reversed the anti-nociceptive effect of MFA, TMMA and TDMA in the acetic acid-induced writhing test. In addition, treatment with TMMA and TDMA caused significantly (p<0.05) a higher inhibition of pain in the glutamate-induced licking response in mice than MFA.

CONCLUSION

Masking the carboxylate moiety of MFA by α-tocopherol and α-tocopherol acetate has a great potential for reducing CNS toxicity, enhancing the therapeutic efficacy and altering the mode of anti-nociceptive action.

Synthesis of Paeonol-Ozagrel Conjugate: Structure Characterization and In Vivo Anti-Ischemic Stroke potential

Ischemic stroke is a common neurological disease that can lead to mortality and disability. The current curative effect remains unsatisfactory because drug accumulation in the diseased areas is insufficient as a result of the unique blood–brain barrier. Therefore, much attention has been paid to develop a novel therapeutic compound, paeonol-ozagrel conjugate (POC), for ischemic stroke. Then, POC was successfully synthesized by conjugating of paeonol and ozagrel as mutual prodrug. A series of in vitro characterizations and evaluations, including high - resolution mass spectroscopy, nuclear magnetic resonance spectroscopy, partition coefficient, and assessment of cytotoxicity against PC12 cells, were performed. Pharmacokinetic study demonstrated POC is eliminated quickly (t_1/2 = 53.46 ± 19.64 min), which supported a short dosing interval. The neurological score, infarct volume, histopathological changes, oxidative stress, inflammatory cytokines levels, and TXA₂ levels also were evaluated in vivo in middle cerebral artery occlusion (MCAO) rats. All results showed that POC had a significant curative and therapeutic effect on ischemic stroke, as evaluated by the middle cerebral artery occlusion. Overall, POC can be expected to become a new drug candidate for the treatment of ischemic stroke.

Butyl methyl imidazolium silica sulfate (BMIm)SS: A novel hybrid nano-catalyst for highly efficient synthesis of new 1,2-diol monoesters of ibuprofen as the novel prodrugs of ibuprofen having potent analgesic property

The fabrication, characterization of butyl methyl imidazolium silica sulfate [BMIm]SS as a novel nano hybrid catalyst and its application in synthesis of new ibuprofen (IBP) 1,2-diol mono esters were described. [BMIm]SS catalyzed the reaction of IBP with epoxides to afford the new IBP 1,2-diol mono esters in good to excellent yields. The products were tested in vivo for the analgesic properties on female mice using formalin test. The test results revealed that most compounds, in particular compounds 1h, 1k and 1o displayed potent analgesic activity compare to IBP as a reference drug. No mortality was observed due to the toxicity of the synthesized compounds. The docking analysis was conducted that confirmed the strong binding affinity of active compounds to active site of murine cyclooxygenase-2 (COX-2) enzyme compare to IBP. The in silico pharmacokinetic profile, drug likeness and toxicity predictions were carried out for all compounds which determined that 1h can be suggested as an appropriate future drug candidate.

Synergistic interaction between 4-allyl-1-hydroxy-2-methoxybenzene (eugenol) and diclofenac: An isobolograpic analysis in Wistar rats

Clinical and preclinical research that contributes pain palliation has suggested that drugs favor the expected effects and minimize the adverse effects. Among the most widely used strategies is the combination of analgesic drugs among those in the same group, with those in another group of analgesics or with co-adjuvants (nonanalgesic drugs or elements of traditional medicine). This work aims to evaluate the interaction between eugenol (EUG) and diclofenac (DFC) on nociception in the presence of a noxious stimulus through the formalin test and isobolographic analysis. The results indicate that EUG, DFC, or the combination of both produce an antinociceptive effect in rodents (p ≤ 0.05). Local co-administration of EUG and DFC gave a theoretical effective dose (Zadd ) 2,936.27 ± 155.33 μg/kg (p ≤ 0.05) significantly higher as compared to the effective experimental doses (Zmix ) of 866.89 ± 0.02 μg/kg in phase 1 and 292.88 ± 0.05 μg/kg in phase 2, with an interaction index of 0.29 and 0.09, respectively. These data allow concluding that the interaction derived from the joint administration of EUG and DFC, in the rodent at a local level, is synergistic.

Synthesis and Biological Evaluation of Amino Acid Based Mutual Amide Prodrugs of Phenytoin as Anticonvulsant Agents

BACKGROUND

Phenytoin (5,5-diphenyl hydantoin) has poor water solubility, which results in incomplete oral availability. Other problems associated with the oral and intramuscular administration of phenytoin are gastric irritation and inflammation at the site of injection.

OBJECTIVE

The purpose of this study was to synthesize mutual amide prodrugs of phenytoin by using amino acids like glycine, L-tryptophan, L-lysine and taurine.

METHODS

These prodrugs were synthesized and characterized by Fourier Transform Infrared (FTIR), Proton nuclear magnetic resonance (1H NMR) and Mass Spectra. Physical and spectral characterization was performed by determination of solubility, maximum wavelength, partition coefficient (log P), ionization constant (pKa), specific (α) and molar rotation (μ), refractive index (n), specific refraction (RS) and molar refraction (RM).

RESULTS

The results obtained from solubility and log P values determination indicated that phenytoin prodrugs can be administered by oral as well as a parenteral route by minimizing the limitations associated with phenytoin. Anticonvulsant activity of prodrugs (4a-4d) was evaluated by using maximal electroshock (MES) and strychnine induced seizure test on albino mice of either sex weighing 25-30 g in which 4b and 4d were found to have significant anticonvulsant activity for MES and strychnine induced seizure test. In vitro enzymatic hydrolysis study of 4b and 4d was performed on liver, intestinal mucosa and plasma sample of male Sprague Dawley rats weighing 280-300 g in which phenytoin was eluted at 10.13 to 10.68 minutes at 220 nm.

CONCLUSION

The results obtained from the present work showed that amino acid-based mutual prodrug strategy can be a promising method to increase the solubility and anticonvulsant activity of phenytoin for the development of anticonvulsant agents.

Systematic Analysis of Monoterpenes: Advances and Challenges in the Treatment of Peptic Ulcer Diseases

Peptic ulcer disease (PUD) is a multifactorial and complex disease caused by an imbalance of protective and aggressive factors (endogenous and exogenous). Despite advances in recent years, it is still responsible for substantial mortality and triggering clinical problems. Over the last decades, the understanding of PUD has changed a lot with the discovery of Helicobacter pylori infection. However, this disease continues to be a challenge due to side-effects, incidence of relapse from use of various anti-ulcer medicines, and the rapid appearance of antimicrobial resistance with current H. pylori therapies. Consequently, there is the need to identify more effective and safe anti-ulcer agents. The search for new therapies with natural products is a viable alternative and has been encouraged. The literature reports the importance of monoterpenes based on the extensive pharmacological action of this class, including wound healing and anti-ulcerogenic agents. In the present study, 20 monoterpenes with anti-ulcerogenic properties were evaluated by assessing recent in vitro and in vivo studies. Here, we review the anti-ulcer effects of monoterpenes against ulcerogenic factors such as ethanol, nonsteroidal anti-inflammatory drugs (NSAIDs), and Helicobacter pylori, highlighting challenges in the field.

Novel aryl carboximidamide and 3-aryl-1,2,4-oxadiazole analogues of naproxen as dual selective COX-2/15-LOX inhibitors: Design, synthesis and docking studies

A series of novel naproxen analogues containing 3-aryl-1,2,4-oxadiazoles moiety (4b-g) and their reaction intermediates aryl carboximidamides moiety (3b-g) was synthesized and evaluated in vitro as dual COXs/15-LOX inhibitors. Compounds 3b-g exhibited superior inhibitory activity than celecoxib as COX-2 inhibitors. Compounds 3b-d and 3g were the most potent COX-2 inhibitors with IC50 range of 6.4 - 8.13 nM and higher selectivity indexes (3b, SI = 26.19; 3c, SI = 13.73; 3d, SI = 29.27; 3g, SI = 18.00) comparing to celecoxib (IC50 = 42.60 nM, SI = 8.05). Regarding 15-LOX inhibitory activity, compounds belonging to aryl carboximidamide backbone 3b-e and 3g were the most potent with IC50 range of 1.77-4.91 nM comparing to meclofenamate sodium (IC50 = 5.64 µM). Data revealed that The levels of NO released by aryl carboximidamides 3b-g were more higher than 3-aryl-1,2,4-oxadiazole derivatives 4b-g, which correlated well with their COX-2 inhibitory activities.

Preparation and biological evaluation of metronidazole derivatives with monoterpenes and eugenol

Two series of metronidazole derivatives (ester derivatives and ether derivatives) were prepared reacting metronidazole and its acetic acid oxidized form with menthol, thymol, carvacrol, and eugenol. Both series of compounds were tested in vitro against two strains of Helicobacter pylori (the ATCC 26695 and P12), and one strain of Clostridium (Clostridium perfringens). Most of the prepared compounds showed biological activity against the targeted bacteria. Compound 11 was highly active against all tested bacterial strains, especially against P12 with IC₅₀ 0.0011 μM/ml. Compound 6 was highly active against C. perfringens with MIC 0.0094 nM/ml. Viability test was conducted for compound 11 to test its selectivity for normal human fetal lung fibroblasts (MRC5), and it was found to be non-toxic with IC₅₀ more than 50 μM/ml.

Molecular Consortia-Various Structural and Synthetic Concepts for More Effective Therapeutics Synthesis

The design and discovery of novel drug candidates are the initial and most probably the crucial steps in the drug development process. One of the tasks of medicinal chemistry is to produce new molecules that have a desired biological effect. However, even today the search for new pharmaceuticals is a very complicated process that is hard to rationalize. Literature provides many scientific reports on future prospects of design of potentially useful drugs. Many trends have been proposed for the design of new drugs containing different structures (dimers, heterodimers, heteromers, adducts, associates, complexes, biooligomers, dendrimers, dual-, bivalent-, multifunction drugs and codrugs, identical or non-identical twin drugs, mixed or combo drugs, supramolecular particles and various nanoindividuals. Recently much attention has been paid to different strategies of molecular hybridization. In this paper, various molecular combinations were described e.g., drug–drug or drug-non-drug combinations which are expressed in a schematic multi-factor form called a molecular matrix, consisting of four factors: association mode, connection method, and the number of elements and linkers. One of the most popular trends is to create small–small molecule combinations such as different hybrids, codrugs, drug–drug conjugates (DDCs) and small-large molecule combinations such as antibody-drug conjugates (ADCs), polymer-drug conjugates (PDCs) or different prodrugs and macromolecular therapeutics. A review of the structural possibilities of active framework combinations indicates that a wide range of potentially effective novel-type compounds can be formed. What is particularly important is that new therapeutics can be obtained in fast, efficient, and selective methods using current trends in chemical synthesis and the design of drugs such as the “Lego” concept or rational green approach.

Prodrugs of NSAIDs: A Review

INTORODUCTION

Prodrug approach deals with chemical biotransformation or enzymatic conversion or involves inactive or less active bio-reversible derivatives of active drug molecules. They have to pass through enzymatic or chemical biotransformation before eliciting their pharmacological action.

METHODS & MATERIALS

The two different pharmacophores combine to give synergistic activity or may help in targeting the active drug to its target. Prodrug super seeds the problems of prodrug designing, for example solubility enhancement, bioavailability enhancement, chemical stability improvement, presystemic metabolism, site specific delivery, toxicity masking, improving patient acceptance, or eradicating undesirable adverse effects.

RESULTS

As an outcome the search for a prodrug or mutual prodrug with reduced toxicity has continued during recent years. This present review emphasizes the common help to revamp physiochemical, pharmaceutical and therapeutic effectiveness of drugs.

CONCLUSION

This gives the researcher a common platform where they can find prodrugs of commonly used NSAIDs to overcome the gastrointestinal toxicity (irritation, ulcergenocity and bleeding).

UPLC-Q-TOF/MS-based metabonomic studies on the intervention effects of aspirin eugenol ester in atherosclerosis hamsters

Based on the pro-drug principle, aspirin and eugenol were used to synthesize aspirin eugenol ester (AEE) by esterification reaction. In present study, the anti-atherosclerosis effects of AEE were investigated in hamsters with the utilization of metabonomic approach based on UPLC-Q-TOF/MS. Biochemical parameters and histopathological injures in stomach, liver and aorta were evaluated. In atherosclerotic hamster, oral administration of AEE normalized biochemical profile such as reducing TG, TCH and LDL, and significantly reduced body weight gain, alleviated hepatic steatosis and improved pathological lesions in aorta. Slight damages in stomach mucous were found in AEE group. Plasma and urine samples in control, model and AEE groups were scattered in the partial least squares-discriminate analysis (PLS-DA) score plots. Thirteen endogenous metabolites in plasma such as lysophosphatidylcholine (LysoPC), leucine and valine, and seventeen endogenous metabolites in urine such as citric acid, phenol sulphate and phenylacetylglycine were selected as potential biomarkers associated with atherosclerosis. They were considered to be in response to anti-atherosclerosis effects of AEE, mainly involved in glycerophospholipid metabolism, amino acid metabolism and energy metabolism. This study extended the understanding of endogenous alterations of atherosclerosis and offered insights into the pharmacodynamic activity of AEE.

UPLC-Q-TOF/MS-based urine and plasma metabonomics study on the ameliorative effects of aspirin eugenol ester in hyperlipidemia rats

The main objective of this study was to investigate the ameliorative effects of aspirin eugenol ester (AEE) in hyperlipidemic rat. After five-week oral administration of AEE in high fat diet (HFD)-induced hyperlipidemic rats, the impact of AEE on plasma and urine metabonomics was investigated to explore the underlying mechanism by UPLC-Q-TOF/MS analysis. Blood lipid levels and histopathological changes of liver, stomach and duodenum were also evaluated after AEE treatment. Without obvious gastrointestinal (GI) side effects, AEE significantly relieved fatty degeneration of liver and reduced triglyceride (TG), low density lipoprotein (LDL) and total cholesterol (TCH) (P<0.01). Clear separations of metabolic profiles were observed among control, model and AEE groups by using principal component analysis (PCA) and orthogonal partial least-squares-discriminate analysis (OPLS-DA). 16 endogenous metabolites in plasma and 18 endogenous metabolites in urine involved in glycerophospholipid metabolism, fatty acid metabolism, fatty acid beta-oxidation, amino acid metabolism, TCA cycle, sphingolipid metabolism, gut microflora and pyrimidine metabolism were considered as potential biomarkers of hyperlipidemia and be regulated by AEE administration. It might be concluded that AEE was a promising drug candidate for hyperlipidemia treatment. These findings could contribute to the understanding of action mechanisms of AEE and provide evidence for further studies.

Association of terpinolene and diclofenac presents antinociceptive and anti-inflammatory synergistic effects in a model of chronic inflammation

Pharmacological treatment of inflammatory pain is usually done by administration of non-steroidal anti-inflammatory drugs (NSAIDs). These drugs present high efficacy, although side effects are common, especially gastrointestinal lesions. One of the pharmacological strategies to minimize such effects is the combination of drugs and natural products with synergistic analgesic effect. The monoterpene terpinolene (TPL) is a chemical constituent of essential oils present in many plant species, which have pharmacological activities, such as analgesic and anti-inflammatory. The association of ineffective doses of TPL and diclofenac (DCF) (3.125 and 1.25 mg/kg po, respectively) presented antinociceptive and anti-inflammatory effects in the acute (0, 1, 2, 3, 4, 5 and 6 h, after treatment) and chronic (10 days) inflammatory hyperalgesia induced by Freund's complete adjuvant (CFA) in the right hind paw of female Wistar rats (170-230 g, n=6-8). The mechanical hyperalgesia was assessed by the Randall Selitto paw pressure test, which determines the paw withdrawal thresholds. The development of edema was quantified by measuring the volume of the hind paw by plethismography. The TPL/DCF association reduced neutrophils, macrophages and lymphocytes in the histological analysis of the paw, following a standard staining protocol with hematoxylin and eosin and the counts were performed with the aid of optical microscopy after chronic oral administration of these drugs. Moreover, the TPL/DCF association did not induce macroscopic gastric lesions. A possible mechanism of action of the analgesic effect is the involvement of 5-HT2A serotonin receptors, because ketanserin completely reversed the antinociceptive effect of the TPL/DCF association. These results suggest that the TPL/DCF association had a synergistic anti-inflammatory and analgesic effect without causing apparent gastric injury, and that the serotonergic system may be involved in the antinociceptive effect of this association.

Separation of epimeric aromatic acid (-)-menthol esters by countercurrent chromatography using hydroxypropyl-β-cyclodextrin as an additive

The separation of ten epimeric aromatic acid (-)-menthol esters by countercurrent chromatography with hydroxypropyl-β-cyclodextrin as the mobile phase additive was investigated, and methods for the analysis of all the epimeric esters by reversed-phase high-performance liquid chromatography were established. A biphasic solvent system composed of n-hexane/20-70% methanol containing 50 mmol/L of hydroxypropyl-β-cyclodextrin (1:1, v/v) was selected, which provided high separation factors for five of the epimeric esters, and successful separations by countercurrent chromatography were achieved. The complete separation of five pairs of epimeric ester was obtained with the purity being over 98% for each peak fractions, as determined by high-performance liquid chromatography. The recovery of each analyte from the eluted fractions reached around 80-88%.

Synthesis and evaluation of novel mutual prodrugs of Piroxicam

Therapeutic efficacy of piroxicam can be improved by retarding gastrointestinal side effects by means of temporarily modification of enolic hydroxyl group chemically. The NSAIDs such as aceclofenac, ibuprofen, mefenamic acid and naproxen were selected as promoities with the aim of getting synergistic effect through these well known pharmaco-counter parts. The targeted prodrugs are synthesized successfully and confirmed by characterization. Synthesis involved chlorination of NSAIDs and coupling of this acid chloride with piroxicam through enolic hydroxyl group to get ester derivatives. Mutual prodrugs were evaluated by hydrolysis study at different pH (acidic, neutral, alkaline) using phosphate buffer. Prodrug derivatives were found to be stable at acidic and neutral pH but prone to hydrolysis at alkaline pH. Thus the objective of the presented study was to overcome the undesirable side effects of NSAIDs. Thus, current studies confirms that the mutual prodrug approach can be applied  effectively in order to  achieve the purpose of raising effectiveness of piroxicam under two lines; firstly, masking of enolic hydroxyl group through acids and converting them to esters and secondly, utilizing the known NSAIDs for achieving the synergistic effect.

One-pot preparation of polylactic acid-ibuprofen conjugates and their performance characterization

Merging esterification modification, carrier preparation, and chemical conjugation into a one-pot reaction as a new strategy for developing the polylactic acid-ibuprofen conjugates is described.

Prodrug approach: An overview of recent cases

In this review we highlight the most modern trends in the prodrug strategy. In drug research and development, the prodrug concept has found a number of useful applications. Selected examples of this approach are provided in this paper and they are classified according to the aim of their design.

Design, Synthesis, and Biological Evaluation of Some Novel Pyrrolizine Derivatives as COX Inhibitors with Anti-Inflammatory/Analgesic Activities and Low Ulcerogenic Liability

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most commonly prescribed anti-inflammatory and pain relief medications. However, their use is associated with many drawbacks, including mainly serious gastric and renal complications. In an attempt to circumvent these risks, a set of N-(4-bromophenyl)-7-cyano-6-substituted-H-pyrrolizine-5-carboxamide derivatives were designed, synthesized and evaluated as dual COX/5-LOX inhibitors. The structural elucidation, in vivo anti-inflammatory and analgesic activities using a carrageenan-induced rat paw edema model and hot plate assay, were performed, respectively. From the results obtained, it was found that the newly synthesized pyrrolizines exhibited IC₅₀ values in the range of 2.45–5.69 µM and 0.85–3.44 µM for COX-1 and COX-2, respectively. Interestingly, compounds 12, 13, 16 and 17 showed higher anti-inflammatory and analgesic activities compared to ibuprofen. Among these derivatives, compounds 16 and 19 displayed better safety profile than ibuprofen in acute ulcerogenicity and histopathological studies. Furthermore, the docking studies revealed that compound 17 fits nicely into COX-1 and COX-2 binding sites with the highest binding affinity, while compound 16 exerted the highest binding affinity for 5-LOX. In light of these findings, these novel pyrrolizine-5-carboxamide derivatives represent a promising scaffold for further development into potential dual COX/5-LOX inhibitors with safer gastric profile.

Proulcerogenic effect of water extract of Boswellia sacra oleo gum resin in rats

CONTEXT

The water extract of Boswellia sacra Flueck. (Burseraceae) is used in the treatment of gastric and hepatic disorders in the Arab countries.

OBJECTIVE

The effect of Boswellia sacra water extract on gastric secretion and experimentally induced gastric ulcers in rats was studied.

MATERIALS AND METHODS

Acetic acid-induced chronic gastric ulcers, pylorus ligation, aspirin-induced, ethanol-induced, and restraint plus cold stress-induced gastric ulcer models were employed. The effect on normal rats was also studied. The water extract of B. sacra was administered orally at doses of 2 and 5 ml/kg once daily ranging from single dose to 30 d treatment depending on the model. The extract was subjected to GC-MS analysis to determine the presence of various phytoconstituents.

RESULTS

Boswellia sacra water extract (5 ml/kg, p.o (per os)) aggravated acetic acid-induced chronic ulcers, wherein an increase in ulcer index (p < 0.01) and ulcer score (p < 0.05) was observed. In pylorus-ligated rats, the extract increased gastric content volume (p < 0.01), free acidity (p < 0.01), total acidity (p < 0.01), ulcer index (p < 0.01), and pepsin activity (p < 0.05). There was no significant effect on the development of ethanol-induced and aspirin-induced ulcers while an increase in the development of stress-induced ulcers was observed (p < 0.01). The extract did not produce any ulcers when administered to normal rats. The dose of 2 ml/kg was less proulcerogenic compared with 5 ml/kg. The GC-MS analysis revealed the presence of several phytoconstituents that included menthol, 3-cyclohexen-1-ol, and octanoic acid.

CONCLUSION

Boswellia sacra water extract has proulcerogenic activity due to its gastric hypersecretory effect.

Anti-Inflammatory and Gastroprotective Evaluation of Prodrugs of Piroxicam

Therapeutically potential prodrugs of piroxicam were synthesized by effective masking of enolic hydroxyl group through generation of ester congeners. The reaction facilitated using N,N′-dicyclohexylcarbodiimide coupled with acetic acid, benzoic acid, p-toluic acid, m-toluic acid, and cinnamic acid. Synthesized prodrugs were characterized for confirmation of the said structures. The modification of piroxicam showed better anti-inflammatory activity as evoked by all prodrugs. Interestingly, compound 3e, cinnamic acid ester prodrug, depicted 75 percent inhibition of rat paw edema as compared to 56 percent for parent piroxicam at 6 h of study. The present work proves the applicability not only with increased anti-inflammatory activity, but also with marked attenuation in ulcerogenicity. Novel prodrug 3e, cinnamic acid derivative, was found to be the least ulcerogenic having ulcer index of 0.67 as compared to parent drug piroxicam with 2.67.

Anti-ulcer activity of essential oil constituents

Essential oils have attracted considerable worldwide attention over the last few decades. These natural products have wide-ranging pharmacological activities and biotechnological applications. Faced with the need to find new anti-ulcer agents and the great effort on the development of drugs for the treatment of ulcers, in this review, the anti-ulcer activities of 21 bioactive compounds found in essential oils are discussed.