Effects of organic and inorganic compounds isolated of Argemone mexicana on the perfusion pressure of the mesenteric vascular bed

In a previous study, we found that the methanolic extract (ME) from the aerial parts of Argemone mexicana has vasoconstrictor and vasodilator effects in isolated aortic rings of rat [1]. In the present work, these effects were characterized on a perfused mesenteric artery preparation (MAP) of rat and were correlated with the effects on the cardiovascular system of the anesthetized rats. ME from A. mexicana significantly increased the perfusion pressure of MAP. On the other hand, the cumulative concentration-response curve from norepinephrine diminished without affecting the slope in the KCl curve. Two active compounds with antagonic effects were isolated from the ME through biodirected fractionation. The substance that increases the perfusion pressure in the MAP was identified as KNO₃ by IR, atomic-absorption spectroscopy, as well as by analytical reactions to determine K⁺ and NO₃ ^- ions. This effect can be explained since KNO₃ induces a calcium flow toward the intracellular compartment. The substance that diminished the perfusion pressure of the MAP was positive with Dragendorff and Mayer reactions and belongs to the protoberberine alkaloid group, according to its ¹H and ¹³C NMR, MS, and IR data. The action mechanism of this alkaloid does not seem to influence the increment in the calcium flow.

Acknowledgements: UNAM, PAPIIT. CLAVE: IN211508–2

Reference: 1. Páez-Sánchez, E. et al. (2006). Proc. West. Pharmacol. Soc. 49: 63–65