Effect of isoorientin isolated from Arum palaestinum on uterine smooth muscle of rats and guinea pigs.

The phytochemical investigation of Arum palaestinum resulted in the isolation of two flavone C-glucosides, namely isoorientin (luteolin 6-C-glucoside) and vitexin (apigenin 8-C glucoside). The effects of isoorientin on rat isolated aorta, ileum, trachea and uterus and on guinea-pig uterus were studied. Isoorientin (10(-7)M-6 x 10(-4)M) caused concentration-dependent inhibition of the amplitude and the frequency of the phasic contractions of the rat and guinea-pig uterus but did not affect the isolated aorta, ileum or trachea. The results were discussed in relation to the effects of its aglycone luteolin reported in the literature.