Anti-Inflammatory and Immunomodulatory Effects of 2-(3-Acetyl-5-(4-Chlorophenyl)-2-Methyl-1H-Pyrrol-1-yl)-3-Phenylpropanoic Acid

Background: The pursuit of novel anti-inflammatory agents with enhanced efficacy and safety is crucial. Pyrrole-containing compounds, integral to many NSAIDs, exhibit promising anti-inflammatory properties. Compound 3f (2-(3-acetyl-5-(4-chlorophenyl)-2-methyl-1H-pyrrol-1-yl)-3-phenylpropanoic acid), a pyrrole derivative structurally inspired by the COX-2 selective inhibitor celecoxib, was evaluated for its anti-inflammatory and immunomodulatory effects. Methods: Anti-inflammatory activity was assessed in a carrageenan-induced paw edema model in Wistar rats. Compound 3f was administered intraperitoneally at 10, 20, and 40 mg/kg, either as a single dose or daily for 14 days. Diclofenac (25 mg/kg) served as the reference. Edema volume was measured by plethysmometry. Systemic inflammation was induced by lipopolysaccharide (LPS), and serum levels of the pro-inflammatory cytokine TNF-α and anti-inflammatory cytokines IL-10 and TGF-β1 were quantified by ELISA following single and repeated administration of compound 3f. Results: Single-dose administration of compound 3f at 20 mg/kg significantly reduced paw edema at 2 h (p = 0.001). After 14 days, all tested doses significantly inhibited paw edema at all time points (p < 0.001). In the LPS-induced systemic inflammation model, repeated treatment with 40 mg/kg of compound 3f significantly decreased serum TNF-α (p = 0.032). TGF-β1 levels increased significantly after both single and repeated doses (p = 0.002 and p = 0.045, respectively), while IL-10 levels remained unaffected. Conclusions: Compound 3f exhibits potent anti-inflammatory activity, particularly after repeated dosing, reflected by reduced local edema and systemic TNF-α suppression. The marked elevation of TGF-β1 indicates a potential immunomodulatory mechanism, selectively modulating cytokine profiles without altering IL-10. These findings support compound 3f as a promising candidate for targeted anti-inflammatory therapy involving cytokine regulation.