Effect of total flavones from stem and leaf of Scutellaria baicalensis on the blood pressure of normal and renal arterial stenosis rat models

Wenjie YI; Limin ZHANG; Jiming TONG

ABSTRACT

BACKGROUND:

The effective fraction of stem and leaf of Scutellaria baicalensis, total flavones from stem and leaf of Scutellaria baicalensis (SSTF) can improve blood flow of coronary artery and cerebral blood flow,prolong the time of cruor and prothrombin and decrease blood lipid.

OBJECTIVE:

To observe the effect of SSTF on blood pressure of normal rats and rat models of renal artery stenosis.

DESIGN:

A completely randomized and controlled experiment.

SETTING:

Institute of Traditional Chinese Medicine, Chengde Medical College (Key Laboratory of Research and Exploiture of Traditional Chinese Medicine in Hebei Province) MATERIALS Totally 70 Wistar rats, aged 2 months old , of clean degree, with body mass of (250±50) g, male and female in half, with permission number of 01-3003 , were provided by the Experimental Animal Research Institute, Chinese Academy of Medical Sciences. SSTF was provided by the phytochemical laboratory of Institute of Traditional Chinese Medicine, Chengde Medical College; Niuhuangjiangya pian was produced by Shiyitang Pharmaceutical Factory, Hayao Company (batch number9802304).

METHODS:

The experiment was conducted in Institute of Traditional Chinese Medicine, Chengde Medical College from January to October 1999. The rats were raised in the environment of (22±1) ℃, with relative humidity of 50%-55%, of daylight and darkness for 12 hours for each. ①In the experiment 1, we studied the effect of SSTF on the blood pressure of normal rats. Totally 30 Wistar rats were randomly divided into SSTF group of 100 mg/kg (n=10, 100 mg/kg SSTF), SSTF group of 50 mg/kg (n=10, 50 mg/kg SSTF), and normal saline control group (n=10, 0.5 mL /100 g normal saline). Before being administrated, rats were anaesthetized by intraperitoneal injection of pentobarbital sodium. Blood pressure was recorded by MecLab/4e four-channel physiologic instrument. Then intragastric administration of SSTF and normal saline were performed on the rats in SSTF groups and normal saline control group respectively. Thirty minutes later, the changes of blood pressure of rats in each group were observed successively. ②In the experiment 2, we studied the effect of SSTF on the blood pressure of model rats with hypertension induced by renal artery stenosis. The rest 40 Wistar rats were randomly divided into SSTF group of high dosage, SSTF group of low dosage, normal saline control group, Niuhuangjiangya pian group, with 10 rats in each group. Rats in each group were created into rat models with hypertension induced by renal artery stenosis according to methods from the literatures. Two weeks after operation, intragastric administration of 100 mg/kg SSTF, 50 mg/kg SSTF, 0.5 mL/100 g normal saline and 1 200 mg/kg Niuhuangjiangya pian were daily performed on the rats in four groups respectively for one month successively. Carotid blood pressure of rats in all groups was measured.MAIN OUTCOME

MEASURES:

① The effect of SSTF on the blood pressure of normal rats. ②The effect of SSTF on the blood pressure of model rats with hypertension induced by arteria renalis stenosis.

RESULTS:

① Effect of SSTF on the blood pressure of normal rats Blood pressure of SSTF group of 50 mg/kg and SSTF group of 100 mg/kg presented a little decrease compared with before administration. There was no significant difference when compared with normal saline control group (P ＞ 0.05). ②Effeet of SSTF on the blood pressure of model rats with hypertension induced by arteria renalis stenosis Blood pressure of rats with hypertension in normal saline control group was significantly increased after modeling; Blood pressure of rats with hypertension in SSTF group of 50 mg/kg , SSTF group of 100 mg/kg and Niuhuangjiangya pian group was significantly lower than that in the normal saline control group, especially significantly in SSTF group of 100 mg/kg [(126.3±14.5),(120.2±15.9),(127.8 ±23.4 ) ,(139.6±15.8) mm Hg; P ＜ 0.05-0.01].

CONCLUSION:

SSTF has the significant hypotensive effect on model rats with hypertension; it does not have obvious effect on normal rats.