The species Lippia alba (Mill.) N. E. Brown belongs to the Verbenaceae family. It is abundant and grows spontaneously throughout the Brazilian territory. Popularly known as “erva-cidreira”, it is widely used because of its sedative, carminative and analgesic properties. The objective of this study was to investigate the mechanism of action of the L. alba essential oil (EOLa) and its major constituents citral and limonene, on isolated rat uterus muscle. To evaluate the EOLa, citral and limonene effect, cumulative concentrations curves for EOLa and citral (1–600 μg/mL) and for limonene (1–1200 μg/mL) were constructed from contractions of rat uterine strips under a 1 g tension. EOLa, citral and limonene dose-dependently relaxed myometrial preparations pre-contracted with 60 mM KCl, 10-2 IU/mL oxytocin, serotonin (10 μM), or ACh (10 μM). The results demonstrate that the EOLa, citral and limonene cause relaxation of the uterine smooth muscle. These results suggest that the relaxation induced by EOLa, citral and limonene is caused by inhibition of L-type VOCC, inhibiting the Ca²⁺ current through these channels, although other mechanisms of action are likely to contributing to relaxant activity. There was no involvement of K⁺ channels (BKca, K_ATP, K_V) or cyclooxygenase on the relaxation promoted by EOLa. Then studies of the tocolytic effects of EOLa, citral and limonene may yield new insights into their therapeutic use.

该物种马鞭草阿尔巴（穆勒）NE布朗属于马鞭草家庭。它丰富，并在整个巴西领土上自发生长。因其具有镇静，镇静和镇痛作用而被广泛使用，被广泛称为“ erva-cidreira”。这项研究的目的是调查白僵菌的作用机理精油（EOLa）及其主要成分柠檬醛和柠檬烯，位于离体大鼠子宫肌肉上。为了评估EOLa，柠檬醛和柠檬烯的作用，从大鼠子宫条在1 g张力下的收缩量绘制了EOLa和柠檬醛（1–600μg/ mL）和柠檬烯（1–1200μg/ mL）的累积浓度曲线。EOLa，柠檬醛和柠檬烯剂量依赖性地放松了与60 mM KCl，10-2 IU / mL催产素，5-羟色胺（10μM）或ACh（10μM）签订的子宫肌层制剂。结果表明，EOLa，柠檬醛和柠檬烯会引起子宫平滑肌松弛。这些结果表明，EOLa，柠檬醛和柠檬烯引起的弛豫是由抑制L型VOCC，抑制Ca ^{2+引起的。}尽管其他作用机制可能会促进放松活动，但目前仍通过这些渠道获得电流。EOLa促进的弛豫不涉及K ⁺通道（BKca，K _ATP，K _V）或环氧合酶。然后对EOLa，柠檬醛和柠檬烯的溶菌作用的研究可能会为它们的治疗用途提供新的见解。