Abstract: To investigate the effect of volatile oil and its representative components on the vessels under tension stimulated with potassium chloride (KCl) from Perilla leaves.The pharmacodynamic effects of volatile oil were evaluated by rat aortic rings,which were collected and recorded by the tissue perfusion model and the PowerLab data analysis system.The components of the essential oil obtained by hydrodistillation were investigated by GCMS.And the representative compound was further studied in order to explain the pharmacodynamic basis of vasodilatation of perilla oil.The volatile oil exhibited significant activities on KCl-indued vascular rings,with EC₅₀ values of 8.6 μg/mL.Thus,according to the GC/MS analysis,the vasodilatory activity of perilla oil was relevant to the monoterpenoids.And perilla aldehyde was found to exhibit certain vasodilatory activity.The perilla oil was found to showed vasodilatory activity for the first time.And further study showed that perilla aldehyde was an active constituent,which provided a new basis for the research and development of the perilla leaves.

Key words: leaves of Perilla frutescens, volatile oil, vasodilatory activity, perilla aldehyde