portulaca oleracea seeds extract does not prevent dexamethasone-induced hypertension in rats

Introduction: portulaca oleracea is used as a nutritional and medicinal plant. the aim of this study was to assess the effect of hydroalcoholic extract of p. oleracea seeds in dexamethasone -induced hypertension in rats. methods: for induction of hypertension, dexamethasone (30 μg/kg/d, subcutaneously) was administered for 14 days. animals received p. oleracea extract as a pretreatment at various doses of 100, 200 and 400 mg/kg/d orally from 4 days before dexamethasone administration and during the test period. systolic blood pressure (sbp) and heart rate were measured using tail-cuff method. the weight of thymus gland was estimated as a marker of glucocorticoid activity. results: dexamethasone injection significantly increased sbp (p < 0.001) while decreased the body and thymus weights (p < 0.05 and p < 0.001, respectively). oral administration of p. oleracea could not prevent rising in sbp and decreasing in thymus weight. it also increased heart rate in hypertensive rats at the dose of 400 mg/kg/d (p < 0.05). conclusion: the results of this study revealed that hydroalcoholic extract of p. oleracea seeds aggregates hypertension in dexamethasone-induced hypertensive rats. hence, it should be used with caution in hypertensive patients receiving glucocorticoids.