Fragment merging approach for the design of thiazole/thiazolidine clubbed pyrazoline derivatives as anti-inflammatory agents: Synthesis, biopharmacological evaluation and molecular modeling studies.

Fragment merging approach was applied for the design of thiazole/thiazolidinone clubbed pyrazoline derivatives 5a-e, 6a-c, 7 and 10a-d as dual COX-2 and 5-LOX inhibitors. Compounds 5a, 6a, and 6b were the most potent and COX-2 selective inhibitors (IC50= 0.03-0.06 µM, SI = 282.7-472.9) with high activity against 5-LOX (IC50 = 4.36-4.86 µM), while compounds 5b and 10a were active and selective 5-LOX inhibitors with IC50 = 2.43 and 1.58 µM, respectively. In vivo assay and histopathological examination for most active candidate 6a revealed significant decrease in inflammation with higher safety profile in comparison to standard drugs. Compound 6a exhibited the same orientation and binding interactions as the reference COX-2 and 5-LOX inhibitors (celecoxib and quercetin, respectively). Consequently, compound 6a has been identified as a potential lead for further optimization and the development of safe and effective anti-inflammatory drugs.

Probenecid ameliorates testosterone-induced benign prostatic hyperplasia: Implications of PGE-2 on ADAM-17/EGFR/ERK1/2 signaling cascade.

Benign prostatic hyperplasia (BPH) is one of the most prevalent clinical disorders in the elderly. Probenecid (Prob) is a well-known FDA-approved therapy for gout owing to its uricosuric effect. The present study evaluated the use of Prob for BPH as a COX-2 inhibitor. Prob (100 and 200 mg/kg) was intraperitoneally injected into male Wistar rats daily for 3 weeks. In the second week, testosterone (3 mg/kg) was subcutaneously injected to induce BPH. Compared with BPH-induced rats, Prob treatment reduced prostate weight and index and improved histopathological architecture. The protease activity of ADAM-17/TACE and its ligands (TGF-α and TNF-α) were regulated by prob, which in turn abolished EGFR phosphorylation, and several inflammatory mediators (COX-2, PGE2, NF-κB (p65), and IL-6) were suppressed. By reducing the nuclear import of extracellular regulated kinase protein 1/2 (ERK1/2), Prob helped re-establish the usual equilibrium between antiapoptotic proteins like Bcl-2 and cyclin D1 and proapoptotic proteins like Bax. All of these data point to Prob as a promising treatment for BPH because of its ability to inhibit COX-2-syntheiszed PGE2 and control the ADAM-17/TGF-α-induced EGFR/ERK1/2 signaling cascade. These findings might help to repurpose Prob for the treatment of BPH.

Cyclooxygenase-2 activates EGFR-ERK1/2 pathway via PGE2-mediated ADAM-17 signaling in testosterone-induced benign prostatic hyperplasia.

OBJECTIVE AND DESIGN: Prostatic inflammation is the driving force in benign prostatic hyperplasia (BPH). This work investigated the potential modulatory effect of COX-2 inhibition on ADAM-17/EGFR/ERK1/2 axis. MATERIALS OR SUBJECTS: Adult male Wistar rats were used. TREATMENT: Celecoxib (10 and 20 mg/kg; i.p.) was injected i.p. daily for three weeks. Testosterone (TST) (3 mg/kg; s.c.) was used to induce BPH. METHODS: Prostatic inflammation and hyperplasia were assessed by organ weight and histopathology. Inflammatory mediators were measured using ELISA technique. Protein analysis was performed using western blotting and immunohistochemistry. Gene expression analysis was performed using qRT-PCR. Statistical analyses included one-way ANOVA and Tukey's multiple comparison test. RESULTS: Testosterone-treated rats had a marked increase in COX-2, prostate weight, and index. Moreover, TST-induced COX-2 was inferred from cytoskeletal changes and was attributable to the overexpression of PGE2, NF-κB (p65), and IL-6. COX-2-derived PGE2 increased the activity of ADAM-17, TGF-α, and TNF-α. Consequently, EGFR-ERK1/2 pathway was over-activated, disrupting anti-apoptotic Bcl-2, cyclin D1, and pro-apoptotic Bax. Celecoxib reversed these effects. CONCLUSION: COX-2 stimulates the ERK1/2 pathway via PGE2-ADAM-17-catalyzed shedding of TGF-α in testosterone-induced BPH. The results indicate a functional correlation between inflammation and hyperplasia in BPH.

Cyclosporin A activates human hepatocellular carcinoma (HepG2 cells) proliferation: implication of EGFR-mediated ERK1/2 signaling pathway.

One of the most common causes of cancer mortality worldwide is hepatocellular carcinoma (HCC). Extracellular signal-regulated kinase (ERK1/2) pathway has been shown to play an important role in the development and progression of HCC. Here, we demonstrate that the immunosuppressive agent cyclosporin A (CsA) has the ability to increase the cellular growth in HCC (HepG2 cells) via activation of ERK1/2 signaling cascade. It was found that ERK1/2 phosphorylation induced by CsA was highly reduced in the presence of the reactive oxygen species (ROS) scavenger polyethylene glycol-superoxide dismutase (PEG-SOD). Furthermore, it was observed that inhibition of metalloproteinase activity using TAPI-2 prevents ERK1/2 activation by CsA. Moreover, a disintegrin and metalloproteinase domain 17 (ADAM-17) activity was found to be critical for ERK phosphorylation by CsA. In addition, CsA-induced ERK phosphorylation was highly reduced in the presence of either neutralizing anti-heparin-binding-epidermal growth factor (HB-EGF) antibody or UO126 (MEK inhibitor). By using the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor AG1478, it was found that EGFR is critical for ERK phosphorylation induced by CsA. Furthermore, CsA-induced cell proliferation was strongly reduced in the presence of either PEG-SOD or TAPI-2 or neutralizing anti-ADAM17 antibody or neutralizing anti-HB-EGF antibody or AG1478 or UO126. Collectively, these data demonstrate that CsA has the ability to activate ERK1/2 signaling cascade that could be translated into an increase in HepG2 cell proliferation. Furthermore, these data support the role of ROS, ADAM-17, and EGFR in ERK1/2 signaling activation and subsequent cell proliferation induced by CsA in HepG2 cells.