Carvacrol-Loaded Nanoemulsion Promotes Tocolytic and Anti-Dysmenorrhea Effects in Rodents

Abstract

<b><i>Introduction:</i></b> Carvacrol is a phenolic constituent of essential oils that has antinociceptive, anti-inflammatory, and antioxidant activities. <b><i>Method:</i></b> This study aimed to evaluate the in vitro spasmolytic and in vivo anti-dysmenorrhea potential of a nanoemulsion-containing carvacrol (nanoCARV). <b><i>Results:</i></b> In isolated rat uterus, nanoCARV reduced spontaneous contractions (pEC₅₀ = 3.91 ± 0.25) and relaxed preparations pre-contracted with oxytocin (pEC₅₀ = 3.78 ± 0.2), carbachol (pEC₅₀ = 4.15 ± 0.4), prostaglandin F_2α (pEC₅₀ = 3.00 ± 0.36), and KCl (pEC₅₀ = 3.98 ± 0.32). The investigation of the mechanism of action revealed significant differences (<i>p</i> &lt; 0.05) between the pEC₅₀ values of nanoCARV in the absence or presence of aminophylline or tetraethylammonium. In a primary dysmenorrhea model, treatment with nanoCARV reduced the number of oxytocin-induced abdominal writhes. <b><i>Conclusions:</i></b> These data indicate that the anti-dysmenorrhea effect of nanoCARV may be related to the relaxation of uterine smooth muscle, with participation of the cAMP signaling pathway and potassium channels.