(-)-Carvone Inhibits Oxytocin-induced Writhing Via Uterine Relaxation in Rodents

(-)-Carvone, a ketone monoterpene, is the main component of essential oils from several medicinal plants and has been reported to have anti-arthriric, anticonvulsive, antidiabetic, anti-inflammatory, anticancer, and immunomodulatory effects. Therefore, this study aimed to investigate the spasmolytic activity of (-)-carvone in rodent models. The isolated virgin rat uterus was mounted in an organ bath apparatus, and the relaxing effect of ( -)-carvone and its mechanism of action were evaluated in tonic contractions induced by carbachol, KCl, PGF_2α, or oxytocin. The animal model of primary dysmenorrhea was replicated with the injection of estradiol benzoate in female mice for three consecutive days, followed by intraperitoneal administration of oxytocin. Non-clinical acute toxicity evaluation was also performed. (-)-Carvone potency and effectiveness were larger in carbachol (pEC₅₀ = 5.41 ± 0.14 and E_max = 92.63 ± 1.90% at 10^-3 M) or oxytocin (pEC₅₀ = 4.29 ± 0.17 and E_max = 86.69 ± 1.56% at 10^-3 M) contractions. The effect of ( -)-carvone was altered in the presence of 4-aminopyridine, glibenclamide, L-NAME, or methylene blue. Mice pre-treated with (-)-carvone at a dose of 100 mg/kg showed a significant reduction in the number of writhing after oxytocin administration. No toxicity was observed after oral administration of 1 g/kg ( -)-carvone. Taken together, we showed that (-)-carvone reduced writhing by a spasmolytic effect, probably through the participation of K_V and K_ATP channels and the nitric oxide pathway.