Codonopsis lanceolata extract prevents hypertension in rats

Background Codonopsis lanceolata, a plant with antioxidant, anti-cancer, anti-inflammatory and blood lipid improving effects, has been widely used as a therapeutic agent in traditional medicine. Purpose The present study investigated the ability of an ethanol extract of Codonopsis lanceolata (ECL) to prevent hypertension in hypertensive rats. Methods Rats were orally administered daily doses of 0 mg/kg, 200 mg/kg and 400 mg/kg ECL for 3 weeks. As a positive control, rats were orally administered 10 mg/kg/day nifedipine. Hypertension was induced by immobilization stress for 2 h/day and by administration of 0.8 mg/kg/day nicotine for 3 weeks, followed by injection of 3 mg/kg nicotine on the day of sacrifice. Blood pressure and heart rate were measured using a volume pressure recording system. Vasoconstriction and vasodilation of aortic cross sections were measured with a physiological recorder. Neutrophil counts in bronchoalveolar lavage fluid were estimated with an automated cell counter. Results Treatment with both dosages of ECL significantly reduced systolic blood pressure (SBP) in hypertensive rats. Both doses of ECL tended to increase ACh- and SNP-induced vascular relaxation in hypertensive rats. Treatment with 200 mg/kg ECL significantly reduced neutrophil in hypertensive rats. Conclusions These results suggest that ECL is effective in reducing SBP and inflammation in hypertensive conditions.