Effects of aqueous extract of Baphia nitida on isolated cardiac tissues

The pharmacological action of cold aqueous extract of fresh leaves of Baphia nitida was studied on cardiac preparations. The extract (5.0 × 10 −3 g mL) reduced the rate and force of contraction of the isolated rabbit heart. The rate and force of contraction of the spontaneously beating rat atria was dose‐dependently reduced by 5.0 × 10 −4 to 2.5 × 10 −2 g/mL of the extract and this effect was not antagonized by 3.45 × 10 −7 M atropine. The extract (5.0 × 10 −2 g mL) completely blocked the positive chronotropic and inotropic effects of 10 mM CaCI 2 but only reduced that of 1.61 × 10 −7 M isoprenaline. The effect of the extract on CaCI 2 ‐induced responses of the rat atria was not affected by 3 × 10 −7 M propranolol. The use of this extract for treating palpitation locally may be related to its negative chronotropic and inotropic effects.