Vasodilator activity of methanol extract obtained from Crataegus rosei leaves and the chemical characterization of its main constituents.

Persistent arterial hypertension (AHT) plays a very important role in the development of cardiovascular diseases (CVD). The present study assessed the vasodilator activities of the methanol extract (ME) and its fractions obtained from leaves of a Mexican Crataegus rosei plant. The fat- and tannin-free ME fraction (FTFME) produced the most potent vasodilator effect [EC50 8.253 (4.672 to 14.58 μg/mL)], that was 6.7-fold higher than that of the ME [EC50 = 55.49 (29.78 to 68.69) μg/mL], which was similar to that of ACh used as a positive control. This effect was dependent on the nitric oxide/cGMP pathway. Six triterpene acids (ursolic, oleanolic, euscaphic, maslinic, corosolic, and alphitolic) were identified as the main constituents of this fraction. In contrast to the commercially available Crataegus extracts, these compounds must be the most suitable chemical and pharmacological markers for this methanol extract in research into obtaining a standardised antihypertensive extract.