Suppression of Gelatinase Activity in Human Peripheral Blood Mononuclear Cells by Verapamil

OBJECTIVE Gelatinases are a large group of proteolytic enzymes that belong to the matrix metalloproteinases (MMPs). MMPs are a broad family of peptidases, which proteolyse the extracellular matrix and have an important role in inflammation. Verapamil is a calcium channel blocker extensively used in the treatment of numerous cardiovascular diseases such as arrhythmia and hypertension. The anti-tumor and anti-inflammatory effects of verapamil have also been shown. In this study, the effect of verapamil on gelatinase activity in human peripheral blood mononuclear cells (PBMCs) has been assessed in vitro. MATERIALS AND METHODS In this experimental study, PBMCs from healthy adult volunteers were isolated by ficoll-hypaque-gradient centrifugation. The cells were then cultured in complete RPMI-1640 medium and after that incubated with different concentrations of verapamil (0-200 μM) in the presence or absence of phytoheamagglutinin (PHA) (10 μg/ml) for 48 hours. The gelatinase A (MMP-2)/gelatinase B (MMP-9) activity in cell-conditioned media was then evaluated by gelatin zymography. Statistical comparisons between groups were made by analysis of variance (ANOVA). RESULTS Verapamil significantly decreased the MMP-2/MMP-9 activity in human PBMCs after 48 hours incubation time compared with untreated control cells. The association was dose-dependent. CONCLUSION In this study verapamil exhibited a dose-dependent inhibitory effect on gelatinase A and gelatinase B activity in human PBMCs. It seems that the anti-inflammatory properties of verapamil may be in part due to its inhibitory effects on gelatinase activity. Regarding the beneficial effects of MMPs- inhibitors in the treatment of some cardiovascular diseases, the positive effect of verapamil on such diseases may be in part due to its anti-MMP activity. Verapamil with its inhibitory effects on gelatinases activity may be a useful MMP-inhibitor. Given the beneficial effect of MMP-inhibitors in some cancerous, inflammatory and autoimmune disorders, it seems likely that verapamil could also be used to treat these diseases.