Amin Mokhtari-Zaer - Neurogenic Inflammation Research Centre and Dept. of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Mohammad Reza Khazdair - Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
Mohammad Hossein Boskabady - Neurogenic Inflammation Research Centre and Dept. of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

Saffron, Crocus sativus L. (C. sativus) is rich in carotenoids and used in traditional medicine for treatment of various conditions such as coughs, stomach disorders, amenorrhea, asthma and cardiovascular disorders. These therapeutic effects of the plant are suggested to be due to its relaxant effect on smooth muscles. The effect of C. sativus and its constituents on different smooth muscles and the underlying mechanisms have been studied. Several studies have shown the relaxant effects of C. sativus and its constituents including safranal, crocin, crocetin and kaempferol on blood vessels. In addition, it was reported that saffron stigma lowers systolic blood pressure. The present review highlights the relaxant effects of C. sativus and its constituents on various smooth muscles. The possible mechanisms of this relaxing effect including activation of ß2-adrenoceptors, inhibition of histamine H1 and muscarinic receptors and calcium channels and modulation of nitric oxide (NO) are also reviewed.

Crocus sativus, Saffron, Crocin, Smooth muscle, Relaxant effect, Possible mechanisms