Studies on Characterization of Active Constituents in Prunella vulgaris L. and Mechanism of their Antihypertensive Effect

Abstract

Prunella vulgaris L. is widely distributed around China, which is used for facial paralysis, muscle and bone pain, soothing liver qi and dispersing liver stagnation. Scholars have done extensive researches on the chemical composition, pharmacological efficacy and quality control of Prunella vulgaris L. and have isolated and purified many compounds from it, which can be divided into triterpenoids and their saponins, steroids, flavonoids, coumarins, etc. The object of the study is to isolate, purify and characterize the active constituents in Prunella vulgaris L. and to study their antihypertensive effect. Reflux extraction was used to extract active constituents, column chromatography and preparative TLC were used to purify compounds and spectroscopy was used to analyze the structures of the compounds. The antihypertensive effect of Prunella vulgaris L. in SHR rats was observed by intragastric administration. As results five compounds were isolated, namely 2a,3a-24-trihydmxyursa-12-en-28-oic acid-28-O-b-D- glucopyranosly ester, chrysophanol, rotundic acid 28-O-a-D-glueopyranosyl(1 ® 6)-b-D-g1ueopyranoside, A-spinasterol and b-sitosterol. Three weeks after administration at the test dose, compared with the blank control group, each Prunella vulgaris L. ethanol extract group could significantly reduce the systolic and diastolic blood pressures in SHR rats, the differences were statistically significant and showed certain dose-effect relationship. In conclusion Prunella vulgaris L. has certain antihypertensive effect.