Herbal medicine Catuama induces endothelium-dependent and -independent vasorelaxant action on isolated vessels from rats, guinea-pigs and rabbits
✍ Scribed by João B. Calixto; Daniela A. Cabrini
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 147 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0951-418X
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✦ Synopsis
The present study was designed to examine the vasorelaxant action of the herbal medicine Catuama and the hydroalcoholic extracts (HE) of each plant present in this product and to compare their effects with that caused by acetylcholine (ACh) in intact ( + E) or in endothelium-rubbed ( Ϫ E) rings of rat thoracic aorta (RA), guinea-pig pulmonary artery (GPPA), guinea-pig mesenteric artery (GPMA), rabbit pulmonary artery (RPA) and rabbit mesenteric artery (RMA) precontracted with noradrenaline (NA) or phenylephrine (PE). The extract of Catuama (1-3000 g/mL) produced graded relaxation of RA, + E or Ϫ E, with mean EC 50 of 430 g/mL and Х 3000 g/mL and E max of 81% ± 15% and 47% ± 4%, respectively. The nitric oxide (NO) synthase inhibitor, N -nitro-L-arginine (L-NOARG, 100 M), inhibited its vasorelaxant action (p < 0.05) in RA ( + E), while indomethacin (3 M), propranolol (1 M), glibenclamide (1 M), methylene blue (10 M) and apamin (0.1 M) had no significant effect. ACh (1-1000 M) caused graded relaxation in RA with + E, these effects being markedly antagonized by L-NOARG (100 M), by methylene blue (10 M) and partially by apamin (0.1 M), but not by indomethacin (3 M), glibenclamide (1 M) or propranolol (1 M). The Catuama extract (1-3000 g/mL) produces partial relaxations in rings of RMA (mean EC 50 of 1073 g/mL and E max 56% ± 13%), an effect which was antagonized by L-NOARG (100 M). In RPA ( + E) the extract produces partial relaxation followed by contraction (E max 28% ± 6%), an effect which was abolished by L-NOARG (100 M) or methylene blue (10 M). The extract caused graded relaxation in rings of GPPA and GPMA with mean EC 50 values of 60 g/mL and 1148 g/mL and E max 96% ± 2% and 88% ± 12%, respectively. L-NOARG (100 M) blocked the Catuama extract vasorelaxation in GPPA and only partially in GPMA, but markedly antagonized the vasorelaxations caused by ACh in both GPPA and RMA. The HE Paullinea cupana, Zinziber officinalis and Trichilia catigua (1-3000 g/mL) caused a graded vasorelaxant effect + E of RA with a mean EC 50 of 22, 55 and 1793 g/mL and E max 100%, 86% ± 7%, 70% ± 2%, respectively. In addition, the HE of P. cupana also caused graded relaxation in Ϫ E of RA with EC 50 and E max of 233 g/mL and 100%, respectively, while T. catigua and Z. officinalis produced partial relaxation in RA + E. In contrast the HE of Ptychopetalum olacoides caused little contraction (46% ± 14%). These results demonstrate that the medicinal herb Catuama produces significant vasorelaxation responses in vessels from different animal species, and show that its effects are in great part dependent on the release of NO or NO-derived substances. Our results also demonstrate that the vasorelaxant action of the product Catuama seems to be due to the action of the active principles present mainly in P. capuna; T. catigua and, to a lesser extent, in Z. officinalis. Such results may contribute to the explanation of its beneficial effect of Catuama herbal medicine in the management of cardiovascular disturbances.