Novel 1,3,4-Oxadiazole Derivatives of Pyrrolo[3,4-d]Pyridazinone Exert Anti-Inflammatory Activity without Acute Gastrotoxicity in the Carrageenan-Induced Rat Paw Edema Test

1,3,4-Oxadiazole Derivatives of Pyrrolo[3,4-d]pyridazinone Alleviate TNBS-Induced Colitis and Exhibit No Significant Testicular Toxicity

Background/Objectives: Inflammatory bowel disease significantly impairs the patient's quality of life. In young individuals, both the disease and the drugs used for the treatment may impact fertility. Our study aimed to assess the action of new 1,3,4-oxadiazole derivatives of pyrrolo[3,4-d]pyridazinone on the rat testes in a model of TNBS-induced colitis in rats. Methods: In the current study, testes from eight randomly chosen rats were taken from each of the following groups: the control group (K), the colitis group (C), and the groups receiving compounds 7b, 10b, and 13b in higher doses (20 mg/kg). Results: Colitis did not affect the testicular index (expressed as a percentage of the body weight), but in group 13b, this parameter was significantly higher than in group K. No significant differences between groups were noticed in malondialdehyde, superoxide dismutase, interleukin-1, or metalloproteinase 9 levels. In the colitis group, lactate dehydrogenase activity in the testes was not increased; however, the administration of compound 10b significantly increased this parameter when compared to both groups K and C. Histological evaluation also did not reveal abnormalities, and the morphology of the testicular tissues was comparable in all groups. Conclusions: The results may suggest that the new 1,3,4-oxadiazole derivatives of pyrrolo[3,4-d]pyridazinone did not exert significant testicular toxicity.

Hepatoprotective, anti-inflammatory, and wound healing effects of spirulina in rats

Objective

This study aims to investigate the hepatoprotective, anti-inflammatory, and wound-healing potentials of spirulina utilizing a rat model.

Materials and Methods

Carbon tetrachloride (CCl4) was used to induce hepatotoxicity, while carrageenan was employed to induce hind paw inflammation. The wound healing capability was assessed by making a 6 mm round wound with a biopsy punch on the dorsal interscapular area of each rat. The animals were fed a diet mixed with spirulina at dosages of 250 and 500 mg.kg-1bwt. Paw thickness measurements were taken at 1, 3, and 6 h after carrageenan injection.

Results

Intraperitoneal injection of CCl4 leads to hepatotoxicity, as evidenced by significantly elevated serum levels of alanine aminotransferase and aspartate aminotransferase. Treatment with spirulina markedly reduced these biochemical markers. CCl4-induced hepatic cellular necrosis, central vein congestion, and steatosis were notably improved following spirulina administration. Additionally, spirulina treatment diminished paw edema and shortened wound closure time in a dose-dependent manner. Histopathological analysis of the inflamed paw revealed massive infiltration of inflammatory cells and thickening of the epidermis, both of which showed significant improvement with spirulina treatment. The anti-inflammatory and wound-healing effects of spirulina were comparable to those of indomethacin, an established anti-inflammatory drug.

Conclusion

Our findings demonstrate that Spirulina platensis possesses beneficial properties in counteracting hepatotoxicity and inflammation. Additionally, it exhibited significant wound-healing effects in rat models. These results reinforce the potential health advantages of spirulina as an effective functional food.

Substrate-based synthetic strategies and biological activities of 1,3,4-oxadiazole: A review

The five-membered 1,3,4-oxadiazole heterocyclic ring has received considerable attention because of its unique bio-isosteric properties and an unusually wide spectrum of biological activities. After a century since 1,3,4-oxadiazole was discovered, its uncommon potential attracted medicinal chemist's attention, leading to the discovery of a few presently accessible drugs containing 1,3,4-oxadiazole units, and a large number of patents have been granted on research related to 1,3,4-oxadiazole. It is worth noting that interest in 1,3,4-oxadiazoles' biological applications has doubled in the last few years. Herein, this review presents a comprehensive overview of the recent achievements in the synthesis of 1,3,4-oxadiazole-based compounds and highlights the major advances in their biological applications in the last 10 years, as well as brief remarks on prospects for further development. We hope that researchers across the scientific streams will benefit from the presented review articles for designing their work related to 1,3,4-oxadiazoles.

Anti-inflammatory, analgesic, antitussive and antipyretic activities of polyphenol-enriched fraction from Nymphaea candida

ETHNOPHARMACOLOGICAL RELEVANCE

"Snow-white waterlily" (Nymphaea candida) dried flower possesses various efficacy in Uighur medicine such as reducing fever and nourishing the liver, anti-inflammatory and cough relieving, moistening the throat and quenching thirst.

AIM OF THE STUDY

Polyphenols are characteristic component of N. candida as well as its quality markers, and the purpose of this study was to conduct investigations into anti-inflammatory, antitussive, antipyretic, and analgesic activities of the polyphenol-enriched fraction from N. candida (NCTP) in order to validate the traditional efficacy of this plant.

MATERIALS AND METHODS

The polyphenols in NCTP were analyzed by HPLC, and an acute oral toxicity study was conducted for NCTP. The anti-inflammatory activities of NCTP were evaluated using xylene induced ear edema, capillary permeability, cotton pellet granuloma, and carrageenan-induced rat paw edema, of which multiple biochemical indices were measured in carrageenan-induced rat paw edema such as prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2),5-lipoxygenase (5-LOX), interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) activities; the analgesic activities were investigated using acetic acid writhing, hot plate test, and formalin test; the anti-tussive and antipyretic effects were tested by ammonia induced cough in mice and yeast-induced fever respectively.

RESULTS

NCTP with LD50 of 5222 mg/kg was low toxicity and safety. NCTP (200 mg/kg) could significantly reduce ear swelling and capillary permeability by 30.63% and 31.37%, respectively. NCTP revealed 15.76% inhibiting activities in cotton pellet granuloma in mice at a dosage of 200 mg/kg. Furthermore, NCTP (50, 100, and 200 mg/kg) substantially decreased carrageenin-induced paw edema in rats between 1 and 5 h, and NCTP could decrease PGE2, 5-LOX, COX-2 levels as well as IL-6, IL-1β, TNF-α activities compared with the control group; NCTP could decrease MDA contents in carrageenin-induced rise, and increase SOD and GSH activities. Furthermore, the dose-dependent inhibition effect of NCTP on pain was revealed in the hot plate experiment. In addition to reducing the amount of writhes brought on by acetic acid, NCTP (50, 100, and 200 mg/kg) significantly inhibited pain latency against both stages of the formalin test. Moreover, NCTP (50, 100, 200 mg/kg) showed the better antitussive activities in mice in a dose-dependent manner. In the yeast-induced pyrexia test, dosages of 50, 100, and 200 mg/kg resulted in a statistically significant drop in rectal temperature.

CONCLUSION

The experimental results proved the analgesic, anti-inflammatory, anti-tussive and antipyretic activities of the polyphenol-enriched fraction from N. candida, and supported the traditional use of this plant as well.

Anti-Inflammatory and Antioxidant Pyrrolo[3,4-d]pyridazinone Derivatives Interact with DNA and Bind to Plasma Proteins-Spectroscopic and In Silico Studies

From the point of view of the search for new pharmaceuticals, pyridazinone derivatives are a very promising group of compounds. In our previous works, we have proved that newly synthesized ligands from this group have desirable biological and pharmacokinetic properties. Therefore, we decided to continue the research evaluating the activity of pyrrolo[3,4-dpyridazinone derivatives. In this work, we focused on the interactions of five pyridazinone derivatives with the following biomolecules: DNA and two plasma proteins: orosomucoid and gamma globulin. Using several of spectroscopic methods, such as UV-Vis, CD, and fluorescence spectroscopy, we proved that the tested compounds form stable complexes with all biomacromolecules selected for analysis. These findings were also confirmed by the results obtained by molecular modeling. All tested pyridazinone derivatives bind to the ctDNA molecule via groove binding mechanisms. All these molecules can also be bound and transported by the tested plasma proteins; however, the stability of the complexes formed is lower than those formed with serum albumin.

Recent advances in regulating lipid metabolism to prevent coronary heart disease

The pathogenesis of coronary heart disease is a highly complex process, with lipid metabolism disorders being closely linked to its development. Therefore, this paper analyzes the various factors that influence lipid metabolism, including obesity, genes, intestinal microflora, and ferroptosis, through a comprehensive review of basic and clinical studies. Additionally, this paper delves deeply into the pathways and patterns of coronary heart disease. Based on these findings, it proposes various intervention pathways and therapeutic methods, such as the regulation of lipoprotein enzymes, lipid metabolites, and lipoprotein regulatory factors, as well as the modulation of intestinal microflora and the inhibition of ferroptosis. Ultimately, this paper aims to offer new ideas for the prevention and treatment of coronary heart disease.

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.

Impact of Eucalyptus maculata Hook resin exudate constituents on reducing COX-2 gene expression: In-vivo anti-inflammatory, molecular docking and dynamics studies

ETHNOPHARMACOLOGICAL RELEVANCE

Eucalyptus maculata Hook from the Myrtaceae family is a native Australian plant that is frequently cultivated in Egypt. Many Eucalyptus species, including E. maculata, were widely used by the Dharawal, the indigenous Australian people, for their anti-inflammatory properties.

AIM OF THE STUDY

The purpose of this study was to determine the anti-inflammatory activity of the ethanol extract of E. maculata resin exudate, its methylene chloride and n-butanol fractions, as well as the isolated compounds.

MATERIALS AND METHODS

the ethanol extract was partitioned by methylene chloride, and n-butanol saturated with water. The fractions were chromatographed to isolate pure compounds. In-vivo anti-inflammatory activity of the ethanol extract, the fractions at a dose of 200 mg/Kg, and the isolated compounds (20 mg/Kg) was estimated using carrageenan-induced rat paws edema method against indomethacin (20 mg/Kg). The activity was supported by histopathological and biochemical parameters.

RESULTS

Three isolated compounds were identified as aromadendrin (C1), 7-O-methyl aromadendrin (C2), and naringenin (C3). Our findings demonstrated that the tested fractions significantly reduced the paw edema starting from the 3rd to the 5th hour as compared to the positive control, compounds C2 and C3 showed the greatest significant reduction in paw edema. The ethanol extract, fractions, C2, and C3 demonstrated an anti-inflammatory potential through reducing the levels of TNF-α, IL-6, and PGE2, as well as COX-2 protein expression compared to the negative control. These results were supported by molecular docking, which revealed that the isolated compounds had high affinity to target COX-1 and COX-2 active sites with docking scores ranging from -7.3 to -9.6 kcal mol^-1 when compared to ibubrofen (-7.8 and -7.4 kcal mol^-1, respectively). Molecular dynamics simulations were also performed and confirmed the docking results.

CONCLUSION

The results supported the traditional anti-inflammatory potency of E. maculata Hook, and the biochemical mechanisms underlying this activity were highlighted, opening up new paths for the development of potent herbal anti-inflammatory medicine. Finally, our findings revealed that E. maculata resin constituents could be considered as promising anti-inflammatory drug candidates.

Cornus mas L. Extract Targets the Specific Molecules of the Th17/Treg Developmental Pathway in TNBS-Induced Experimental Colitis in Rats

Given that one of the crucial events in the pathogenesis of inflammatory bowel disease is the loss of homeostasis between Th17 and Treg cells, targeting the specific molecules of the Th17/Treg axis developmental pathway is a promising strategy for inflammatory bowel disease prevention and treatment. The current study aimed to assess the impact of cornelian cherry (Cornus mas L.) extract, rich in iridoids and polyphenols known for their potential anti-inflammatory activity, at two doses (20 or 100 mg/kg) on the crucial factors for Th17/Treg cell differentiation in the course of experimental colitis and compare this action with that of sulfasalazine. This study was conducted on the biobank colon tissue samples collected during the previous original experiment, in which colitis in rats was induced by trinitrobenzenesulfonic acid (TNBS). The levels of IL-6, RORγt, total STAT3, p-STAT3, and Foxp3 were determined by ELISA. The expression of PIAS3 mRNA was quantified by qPCR. Cornelian cherry extract at a dose of 100 mg/kg counteracted the TNBS-induced elevation of IL-6, RORγt, and p-STAT3 levels and a decrease in Foxp3 level and PIAS3 mRNA expression, while given concomitantly with sulfasalazine was more effective than sulfasalazine alone in reversing the TNBS-induced changes in IL-6, RORγt, total STAT3, p-STAT3, Foxp3 levels, and PIAS3 mRNA expression. The beneficial effect of cornelian cherry extract on experimental colitis may be due to its immunomodulatory activity reflected by the influence on factors regulating the Th17/Treg axis.

Interactions of N-Mannich Bases of Pyrrolo[3,4-c]pyrrole with Artificial Models of Cell Membranes and Plasma Proteins, Evaluation of Anti-Inflammatory and Antioxidant Activity

Despite the widespread and easy access to NSAIDs, effective and safe treatment of various inflammatory disorders is still a serious challenge because of the severe adverse effects distinctive to these drugs. The Mannich base derivatives of pyrrolo[3,4-c]pyrrole are potent, preferential COX-2 inhibitors with a COX-2/COX-1 inhibitory ratio better than meloxicam. Therefore, we chose the six most promising molecules and subjected them to further in-depth research. The current study presents the extensive biological, spectroscopic and in silico evaluation of the activity and physicochemical properties of pyrrolo[3,4-c]pyrrole derivatives. Aware of the advantages of dual COX-LOX inhibition, we investigated the 15-LOX inhibitory activity of these molecules. We also examined their antioxidant effect in several in vitro experiments in a protection and regeneration model. Furthermore, we defined how studied compounds interact with artificial models of cell membranes, which is extremely important for drugs administered orally with an intracellular target. The interactions and binding mode of the derivatives with the most abundant plasma proteins-human serum albumin and alpha-1-acid glycoprotein-are also described. Finally, we used computational techniques to evaluate their pharmacokinetic properties. According to the obtained results, we can state that pyrrolo[3,4-c]pyrrole derivatives are promising anti-inflammatory and antioxidant agents with potentially good membrane permeability.

Synthesis, carbonic anhydrase inhibition, anticancer activity, and molecular docking studies of 1,3,4-oxadiazole derivatives

In this work, we have synthesized various organic compounds possessing 1,3,4-oxadiazole as a core structure and the structure of the newly synthesized target compounds has been revealed using different analytical approaches such as FT-IR, LCMS, and NMR (proton and carbon), respectively. The in vitro carbonic anhydrase potentials of these synthesized 17 different analogues were investigated. The result suggests that compound 7g, a 3-pyridine substituted analogue with an IC₅₀ of 0.1 µM, was found to have the most potent carbonic inhibitory activity (11-fold more active) than the positive control (acetazolamide) with an IC₅₀ of 1.1 ± 0.1 µM. Besides, among the series 7(a-q) approved in the identification of four potent carbonic anhydrase inhibitors with the IC₅₀ standards varies from 0.1 to 1.0 ± 0.1 µM. Additionally, the non-competitive behaviour for potent compound 7g was analysed using the Lineweaver-Burk plot from the kinetic study. Furthermore, the anticancer activity of all the synthesized compounds screened against B16F10 melanoma cells using the MTT assay method. Additionally, the molecular docking studies revealed that 7g inhibitor shows good binding energy as well as good binding interaction pattern along with enzyme.

Targeting Lineage-Specific Transcription Factors and Cytokines of the Th17/Treg Axis by Novel 1,3,4-Oxadiazole Derivatives of Pyrrolo[3,4-d]pyridazinone Attenuates TNBS-Induced Experimental Colitis

The pharmacotherapy of inflammatory bowel disease (IBD) is still not fully effective and safe. Attempts to search for new IBD drugs remain an incessant research aim. One of the novel approaches is targeting the developmental pathway molecules and effector cytokines of Th17/Treg axis. This study aimed to elucidate the impact of new pyrrolo[3,4-d]pyridazinone derivatives, compounds 7b, 10b, or 13b, on the course of experimental colitis in rats and to assess whether these new compounds may influence Th17/Treg axis. Rats were pretreated with studied compounds intragastrically before intrarectal administration of 2,4,6-trinitrobenzenesulfonic acid used for colitis induction. Body weight loss, disease activity index, colon index, and colon tissue damage were analyzed to evaluate the severity of colitis. The colonic levels of RORγt, STAT3, CCR6, Foxp3, IL-6, IL-10, IL-17, TNF-α, IL-23, and PGE₂ were assessed. Pretreatment with compounds 7b and 13b alleviated the severity of colitis and concomitantly counteracted the increased levels of RORγt, STAT3, CCR6, IL-6, IL-17, IL-23, TNF-α, and PGE₂. The beneficial effect of compounds 7b and 13b may be due to the decrease in the levels of Th17-specific transcription factors and cytokines. The studied compounds might therefore constitute a promising therapeutic strategy in Th17/Treg imbalance-driven inflammatory conditions such as IBD.

Anti-inflammatory activity of pyridazinones: A review

The pyridazinone core has emerged as a leading structure for fighting inflammation, with low ulcerogenic effects. Moreover, easy functionalization of various ring positions of the pyridazinone core structure makes it an attractive synthetic and therapeutic target for the design and synthesis of anti-inflammatory agents. The present review surveys the recent advances of pyridazinone derivatives as potential anti-inflammatory agents to provide insights into the rational design of more effective anti-inflammatory pyridazinones.

Exploring the Antiparasitic Activity of Tris-1,3,4-Thiadiazoles against Toxoplasma gondii-Infected Mice

Nitrogen-containing atoms in their core structures have been exclusive building blocks in drug discovery and development. One of the most significant and well-known heterocycles is the 1,3,4-thidiazole nucleus, which is found in a wide range of natural products and therapeutic agents. In the present work, certain tris-1,3,4-thiadiazole derivatives (6, 7) were synthesized through a multi-step synthesis approach. All synthesized compounds were characterized using different spectroscopic tools. Previously, thiadiazole compounds as anti-Toxoplasma gondii agents have been conducted and reported in vitro. However, this is the first study to test the anti-Toxoplasma gondii activity of manufactured molecular hybrids thiadiazole in an infected mouse model with the acute RH strain of T. gondii. All the observed results demonstrated compound (7)’s powerful activity, with a considerable reduction in the parasite count reaching 82.6% in brain tissues, followed by liver and spleen tissues (65.35 and 64.81%, respectively). Inflammatory and anti-inflammatory cytokines assessments proved that Compound 7 possesses potent antiparasitic effect. Furthermore, docking tests against TgCDPK1 and ROP18 kinase (two major enzymes involved in parasite invasion and egression) demonstrated compound 7’s higher potency compared to compound 6 and megazol. According to the mentioned results, tris-1,3,4-thiadiazole derivatives under test can be employed as potent antiparasitic agents against the acute RH strain of T. gondii.

Sanguinarine-Chelerythrine Fraction of Coptis chinensis Exerts Anti-inflammatory Activity in Carrageenan Paw Oedema Test in Rats and Reveals Reduced Gastrotoxicity

Inflammatory diseases are a common therapeutic problem and nonsteroidal anti-inflammatory drugs are not deprived of side effects, of which ulcerogenic activity is one of the most frequent. The aim of the study was to evaluate the anti-inflammatory activity of the sanguinarine-chelerythrine (SC) fraction of Coptis chinensis and its influence on the integrity of gastric mucosa. The study was conducted on sixty male rats randomly divided into six experimental groups: two control groups (a negative control group CON and a positive control group CAR); three groups receiving an investigational fraction of C. chinensis (1, 5, 10 mg/kg i.g.) named SC1, SC5, and SC10, respectively; and a group receiving indomethacin (IND) (10 mg/kg i.g.) as a reference drug. In all animals, the carrageenan-induced paw oedema was measured; PGE2 release, TNFα production, and MMP-9 concentration in inflamed tissue were determined. Additionally, the macroscopic and microscopic damage of gastric mucosa was evaluated. Administration of SC dose-dependently inhibited the second phase of carrageenan rat paw oedema and PGE2 release, decreased the production of TNFα, and reduced the concentration of MMP-9, and the efficacy of the highest dose was comparable to the effect of IND. Contrary to IND, no gastrotoxic activity of SC was detected. The investigated sanguinarine-chelerythrine fraction of C. chinensis seems to be a promising candidate for further research on new anti-inflammatory and analgesic drugs characterized with a safer gastric profile compared to existing NSAIDs.