Moringa oleifera Lam leaves extract and its compounds effect on the intracellular calcium release in human aortic smooth muscle cells

Abstract The calcium influx and release blocking effects of Moringa oleifera Lam leaf extract and its compounds on the human aortic smooth muscle cells (HAoSMCs) were studied. The cell viability assay was carried out to determine the concentrations of M. oleifera Lam leaf extract and its compounds for the assay. The test compounds in HAoSMCs were incubated with Quin-2-AM in the presence and absence of extracellular calcium (Ca2+) and with the addition of caffeine and potassium (K+). Following treatments with amlodipine, chlorogenic acid, gallic acid, kaempferol, M. oleifera leaf extract, quercetin and vicenin-2, the influx of extracellular Ca2+ into the cytosol of HAoSMCs was significantly inhibited (p <0.001). The test compounds significantly (p <0.001) decreased the concentration of cytosolic Ca2+ induced by K+ depolarisation. The test compounds also significantly (p <0.001) affected the intracellular Ca2+ metabolism, regulated by the caffeine-sensitive storage site in HAoSMCs. No synergistic effect on the decreasing cytosolic Ca2+ level was observed when the test compounds were used in combination with amlodipine. M. oleifera Lam leaf extract and its compounds may act as Ca2+ channel blockers (CCBs) and also possibility of interactions between the test compounds and amlodipine.