Morales M A, Tortoriello J, Meckes M, Paz D, Lozoya X
Departamento de Farmacología, Facultad de Medicina, Universidad de Chile, Santiago.
Arch Med Res. 1994 Spring;25(1):17-21.
The antidiarrheal properties of water and methanolic extracts of Psidium guajava leaves have been demonstrated with anteriority and their spasmolytic effect was attributed to quercetin, a flavonoid contained in this plant. The present paper reports the intestinal smooth muscle relaxation produced by quercetin on isolated guinea pig ileum previously contracted by a depolarizing KCl solution. Quercetin also inhibited intestinal contraction induced by different concentrations of calcium, shifting the contraction curve to the right showing a clear calcium-antagonistic effect. Quercetin effect on ileal and aortic smooth muscles are compared, the ileum being more sensitive to this flavonoid. The calcium-antagonist property of quercetin is discussed and also its contribution to explain the spasmolytic effect of this popular herbal remedy.
