Óleos essenciais obtidos de espécies de Lippia (Verbenaceae) induzem efeitos tocolítico in vitro e antidismenorreico in vivo em roedores

Abstract

Pain relief related to muscle spasms, whether due to gastrointestinal problems or the female reproductive system, is a constant concern. Plants have emerged as important sources for treating conditions such as uterine and intestinal cramps, which are associated with abnormal regulation of smooth muscle contractility. The aim of this study was to investigate the pharmacological potential of the species Lippia insignis Moldenke and Lippia lasiocalycina Cham. in uterine smooth muscle, found in the Caatinga. Chemical analyses of the oils, acute dose toxicological, neurotoxic and sedative tests, as well as pharmacological analyses involving spasmolytic and antidysmenorrheal activity were performed. The results showed the prominent presence of thymol and γ-terpinene in L. insignis (LIO) and E-ocimenone and βmyrcene in L. lasiocalycina (LLO). The essential oils did not present toxicity or damage to the central nervous system of the animals studied. The data indicate that LIO and LLO have spasmolytic activity, significantly reducing muscle contractions. In the in vivo model of dysmenorrhea, oral treatment with LIO (10 mg/kg) associated with nifedipine (0.7 mg/kg) or mefenamic acid (9 mg/kg) significantly reduced the number of abdominal contortions. LLO (10 mg/kg) associated with nifedipine (0.7 mg/kg), scopolamine (0.35 mg/kg) and mefenamic acid (9 mg/kg) promoted a significant reduction in abdominal contortions in the animals. Therefore, this study suggests that the essential oils of the species, when associated with standard medications at a subtherapeutic dose, enhance the therapeutic effect by reducing side effects, being effective in the treatment of primary dysmenorrhea and supporting the popular use of these plants to treat colic.