en پژوهشي Research Article The whole plant of Biophytum petersianum was extracted with a mixture of water – alcohol (1:1) to evaluate its relaxant effect on aorta rings. In isolated Wistar rat tissue, the hydro-ethanolic extract (0.1; 0.25 and 0.5 mg/ml) non-competitively antagonized calcium chloride and high-K + - induced aorta contractions in a concentration-dependent manner. Moreover, the inhibition of noradrenaline–induced contractions in the presence of extract (1 mg/ml) suggests that the extract has an effect on mobilization of intracellular calcium. These results indicate that hypotensive effect of Biophytum petersianum may result from inhibition of calcium influx via both voltage-and receptor-operated calcium channels. 185 0 http://ijpt.iums.ac.ir/browse.php?a_code=A-10-100-142&slc_lang=en&sid=1 Siménou Titrikou 1003194753284600458 1003194753284600458 No Kwashie Eklu - Gadegbeku 1003194753284600459 1003194753284600459 No Aklesso Mouzou 1003194753284600460 1003194753284600460 No Kodjo Aklikokou 1003194753284600461 1003194753284600461 No Messanvi Gbeassor 1003194753284600462 1003194753284600462 No