Calcium channel blockade and anti-free-radical actions of panaxatriol saponins in cultured myocardiocytes
Abstract
AIM: To identify the calcium channel blockade and anti-free-radical actions of panaxatriol saponins Re, Rf, Rg1, Rg2, Rh1, and oleanolic acid saponin Ro.
METHODS: On ventricular myocytes of Wistar rats, single channel activities of B, L, and T type calcium channels were recorded with the cell-attached configuration of patch-clamp technic, and free radical contents were measured with electron spin resenance method.
RESULTS: Re, Rg1, Rg2, and Rh1 shortened the open times, prolonged the close times, and reduced the open-state probabilities of B, L, and T type calcium channels; Rf shortened the open time, prolonged the close time and reduced the open-state probability of L type calcium channel; Ro did not influence the activity of calcium channels (60 mumol.L-1). Re, Rg1, Rg2, and Rh1 antagonized the increase of free radical content induced by xanthine 0.42 mmol.L-1-xanthine oxidase 5.3 nmol.L-1; Ro and Rf had no effect (30 mumol.L-1).
CONCLUSION: Re, Rg1, Rg2, and Rh1 had both the calcium channel blockade and antifree-radical actions. Rf had blockade action on L type calcium channel.
Keywords:
METHODS: On ventricular myocytes of Wistar rats, single channel activities of B, L, and T type calcium channels were recorded with the cell-attached configuration of patch-clamp technic, and free radical contents were measured with electron spin resenance method.
RESULTS: Re, Rg1, Rg2, and Rh1 shortened the open times, prolonged the close times, and reduced the open-state probabilities of B, L, and T type calcium channels; Rf shortened the open time, prolonged the close time and reduced the open-state probability of L type calcium channel; Ro did not influence the activity of calcium channels (60 mumol.L-1). Re, Rg1, Rg2, and Rh1 antagonized the increase of free radical content induced by xanthine 0.42 mmol.L-1-xanthine oxidase 5.3 nmol.L-1; Ro and Rf had no effect (30 mumol.L-1).
CONCLUSION: Re, Rg1, Rg2, and Rh1 had both the calcium channel blockade and antifree-radical actions. Rf had blockade action on L type calcium channel.