Ethnopharmacological evaluation of the anticonvulsant, sedative and antispasmodic activities of Lavandula stoechas L

Lavandula stochas L. (Lamiaceae) has been used for a long time in tradition al medicine as an anticonvulsant and antispasmodic. The aqueous-methanolic extract of L. stoechas flowers (LS) was studied for its possible anticonvul sant and antispasmodic activities. When tested in mice, LS (600 mg/kg) sign ificantly reduced the severity and increased the latency of convulsions ind uced by pentylene tetrazole (PTZ). LS likewise reduced PTZ's lethality. LS up to a dose of 600 mg/kg was found devoid of any hypnotic effect in mice, however, animals were found to be dull, calm and relaxed. The sedative effe ct of the plant extract was confirmed, as it prolonged the pentobarbital sl eeping time in mice similar to that of diazepam. In isolated rabbit jejunum preparations, LS caused a dose-dependent (0.1-1.0 mg/ml) relaxation of spo ntaneous contractions. LS also inhibited K+-induced contractions in a simil ar dose range, thereby suggesting calcium channel blockade. This effect was confirmed when pretreatment of the jejunum preparation with LS produced a dose-dependent shift of the Ca2+ dose-response curve to the right, similar to the effect of verapamil. a standard calcium channel blocker. These data indicate that the plant extract exhibits anticonvulsant and antispasmodic a ctivities. Its calcium channel blocking property may be mechanistically rel ated to these activities. Its usefulness in folk medicine appears thus to b e based on a sound mechanistic background. (C) 2000 Elsevier Science Irelan d Ltd. All rights reserved.