New Diaryl-1,2,4-triazolo[3,4-<i>a</i>]pyrimidine Hybrids as Selective COX-2/sEH Dual Inhibitors with Potent Analgesic/Anti-inflammatory and Cardioprotective Properties

Abstract

COX-2-selective drugs were withdrawn from the market just a few years after their development due to cardiovascular side effects. As a result, developing a selective COX-2 inhibitor as an anti-inflammatory agent with cardioprotective characteristics has become a prominent objective in medicinal chemistry. New 15 diaryl-1,2,4-triazolo[3,4-<i>a</i>]pyrimidine hybrids <b>8a</b>-<b>o</b> were synthesized and investigated <i>in vitro</i> as dual COX-2/sEH inhibitors. Compounds <b>8b</b>, <b>8m</b>, and <b>8o</b> have the highest potency and selectivity as COX-2 inhibitors (IC₅₀ = 15.20, 11.60, and 10.50 μM, respectively; selectivity index (COX-1/COX-2) = 13, 20, and 25, respectively), compared to celecoxib (COX-2; IC₅₀ = 42 μM; SI = 8). The 5-LOX inhibitory activity of compounds <b>8b</b>, <b>8m</b>, and <b>8o</b> was further examined <i>in vitro</i>. Compounds <b>8m</b> and <b>8o</b>, the most effective COX-2 selective inhibitors, demonstrated stronger 5-LOX inhibitory action than the reference quercetin, with IC₅₀ values of 2.90 and 3.05 μM, respectively. Additionally, compounds <b>8b</b>, <b>8m</b>, and <b>8o</b> were the most potent dual COX-2/sEH inhibitors, with IC₅₀ values against sEH of 3.20, 2.95, and 2.20 nM, respectively, and were equivalent to AUDA (IC₅₀ = 1.2 nM). <i>In vivo</i> investigations also demonstrated that these compounds were the most efficacious as analgesic/anti-inflammatory derivatives with a high cardioprotective profile against cardiac biomarkers and inflammatory cytokines. The docking data analysis inquiry helped better understand the binding mechanisms of the most active hybrids within the COX-2 active site and supported their COX-2 selectivity. Compounds <b>8b</b>, <b>8m</b>, and <b>8o</b> exhibited a similar orientation to rofecoxib and celecoxib, with a larger proclivity to enter the selectivity side pocket than the reference compounds.