Uterine relaxant effects of Ageratum conyzoides essential oil: influence of hormonal status and calcium modulation.

OBJECTIVE

We aim to evaluate the influence of A. conyzoides essential oil on uterine contractility, considering hormonal status and potential mechanisms of action.

METHODS

Uterine strips from mice at different estrous stages or after ovariectomy were mounted in an organ bath, and contractile responses were evoked by potassium chloride (KCl, 80 mM) following pre-incubation with increasing concentrations of the essential oil, in the presence or absence of nifedipine, a calcium channel blocker.

KEY FINDINGS: The oil significantly reduced both phasic and tonic components of KCl-induced contractions (P < .01), demonstrating marked relaxant activity. These effects were consistent across estrous cycle stages but were more pronounced in ovariectomized mice. Nifedipine failed to block the oil's inhibitory action, although a potentiation was observed in the tonic phase during estrus (pIC50; -4671 vs -5734; P < .01).

CONCLUSION

A. conyzoides essential oil modulates uterine contractility partly through calcium-independent pathways. This mechanism potentially involves broader smooth muscle signaling mechanisms. The study showcases the therapeutic potential of A. conyzoides in managing uterine hyperactivity and related reproductive disorders.