The most noticeable and bothersome symptoms of urinary tract infections are pain, urge and frequency, which are a consequence of the ensuing inflammation, the body’s innate response to infection that is triggered by release of cytokines and eicosanoids as well as recruitment of immune cells.
Here we investigated the effects of BNO2103, the active pharmaceutical ingredient in Canephron® N, on recruitment of immune cells using various in vitro and in vivo assays. To assess effects on chemotaxis, polymorphonuclear leukocytes (PMNs) were stimulated with the bacterial peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) and migration into a 150 μm membrane was measured. Adhesion of PMNs to a monolayer of hTNF (human tumor necrosis factor)- or LPS (lipopolysaccharide)-stimulated umbilical vein endothelial cells (EAhy926) and transmigration of PMNs through a layer of hTNF- or LPS-stimulated EAhy926 or kidney epithelial cells (HK-2) in Boyden chambers were also measured. Finally, effects of BNO2103 on recruitment of immune cells were investigated in a mouse model of zymosan-induced peritonitis by counting immune cells in the peritoneal exudate 4 h after injection of zymosan.
While pretreatment with BNO2103 had little effect on chemotaxis and transmigration of PMNs through endothelial cells, it reduced adhesion of PMNs to endothelial cells (max. inhibition approx. 60% at 300 μg/ml) as well as transmigration of PMNs through epithelial cells (max. inhibition approx. 100% at 300 μg/ml). In the in vivo peritonitis model, oral application of BNO2103 reduced the number of immune cells in the exudate (2.95 ± 0.716 x 106 cells with BNO2103 (twice the human dose) vs. 5.5 ± 0.872 x 106 cells in control).
These data indicate that BNO2103 displays anti-inflammatory actions by interfering with the recruitment of immune cells. If pain, urge and frequency are a consequence of inflammation, then BNO2103 should also have a beneficial effect on these typical symptoms of urinary tract infection.