Abstract
A crosslinked sodium alginate (SA)/carboxymethyl xanthan gum (CMXG) hydrogel was prepared by blending an equivalent weight ratio of SA and CMXG, followed by crosslinking using CaCl2. Moreover, two nanocomposites were prepared by in situ dispersion of two different concentrations of silver nanoparticles (AgNPs) into the matrix of the prepared hydrogel. The analysis displayed that the order of COX-2 inhibition by the tested samples was SA < CMXG < crosslinked SA/CMXG hydrogel < SA/CMXG/AgNPs1% < SA/CMXG/AgNPs3% < Celecoxib. AgNP composites exhibited a potent inhibition tendency, and their activity increased with increasing the AgNPs content. The recorded MIC values revealed that the MIC values that cause 50% inhibition (IC50) of COX-2 enzyme activity were 14.2 and 3.6 mu g/mL for SA/CMXG/AgNPs1% and SA/CMXG/AgNPs3%, respectively, corresponding to 0.28 mu g/mL for the standard drug Celecoxib. Moreover, SA/CMXG/AgNPs composites showed a greater inhibition efficiency of H. pylori than their parent SA/CMXG hydrogel. Their inhibitory efficiency increased with increasing their AgNPs content; SA/CMXG/AgNPs1% and SA/CMXG/AgNPs3% exhibited 100% inhibition against H. pylori growth at MIC of 3.9 and 1.95 mu g/mL, respectively. The anti-H. pylori activity of SA/CMXG/AgNPs 3% was higher than that of the standard drug Clarithromycin, especially at the low concentrations ranging from 0.24 to 0.98 mu g/mL. These results make SA/CMXG/AgNPs3% a promising anti-H. pylori agent.