Cytoprotective effects of glycyrrhetinic acid liposome against cyclophosphamide-induced cystitis through inhibiting inflammatory stress

This study was designed to investigate the pharmacological efficacy of glycyrrhetinic acid liposome (GAL) against female mice with nonbacterial cystitis induced by cyclophosphamide (CPS). Mice in different groups were subjected to tests for lactate dehydrogenase (LD), cytokine contents (IL-6, TNF-α) in serum, and histological changes in bladder tissue and to immunoassays. As a result, cyclophosphamide-induced cystitis in mice showed an increased LD level in serum, and the contents of cytokines (IL-6, TNF-α) were elevated. Interestingly, GAL-treated mice showed decreased LD and inflammatory cytokines of IL-6 and TNF-α in blood. Inflammatory infiltration and cell death in bladder tissue were reduced by GAL treatments. In addition, intravesical mRNAs of NF-κB and TNF-α were lowered dose-dependently in GAL-treated mice. As shown in cytohistological staining, the number of intravesical caspase-3, PARP-positive cells decreased in GAL-treated mice. Furthermore, a GAL-treated bladder showed down-regulated NF-κB and TNF-α expressions in a dose-dependent manner. In conclusion, our current findings may be the first to provide scientific evidence demonstrating that glycyrrhetinic acid liposomes provide benefits against cyclophosphamide-induced cystitis, which possibly occurs through underlying mechanisms that inhibit cell death and inflammatory stress.