Role of calcium and potassium channels in Moringa oleifera flowers extract-induced myometrial contractility in buffalo uterus

The study was conducted todetermine the role of Ca²⁺ and K⁺ channels inMoringa oleifera flowers extract-induced myometrial contractility of buffalo uterus. Myometrial strips were prepared, mounted in an organ bath containing Ringer Locke solution maintained at 37°C and responses recorded using a kymograph. Moringa oleifera flowers extract (MOFE) produced quite conspicuous and concentration-dependent contractile effect on buffalo myometrium and the EC₅₀ value was found to be 31.62 μg/ml. Verapamil (10⁻¹²M) not only completely inhibited normal spontaneous rhythmic contractions of myometrial uterine strips but also inhibited MOFE-induced spontaneous rhythmic contractions. Ethylene glycol tetra acetic acid (EGTA; 0.1–0.2mM) reduced both the frequency and amplitude of spontaneous contractions and also produced around 28% reduction in the amplitude of MOFE-induced contractile effect. Similalrly, pinacidil (10⁻⁶M-10⁻⁵M), glibenclamide (10⁻⁵M) and 4amino pyridine (4-AP; 1mM) pretreatments inhibited spontaneous contractions as well as the contractile effects of MOFE (250μg/ml). Based on the results of present study, it may be inferred that both the extra- and intracellular Ca²⁺ are very vital for the oxytocic effect of MOFE. Functional presence of K⁺_ATP, K⁺_v and/or K⁺_ca channels in buffalo myometrium and their involvement in mediating MOFE-induced contractility can not be ruled out. Moringa oleifera flowers possessed promising oxytocic activity and can be exploited in drug-development programme for evolving natural and effective oxytocic or abortifacient.