Antihypertensive activity of Salvia elegans Vahl. (Lamiaceae): ACE inhibition and angiotensin II antagonism.
BACKGROUND
Salvia elegans Vahl. (Lamiaceae), recognized with the popular name of "mirto" is widely used in Mexico for healing purposes, and also them as antihypertensive treatment.


OBJECTIVE
The high prevalence of this illness and the side effects of antihypertensive drugs conducted us to the evaluation of the Salvia elegans extract on angiotensin II action.


METHODS
The acute response of blood pressure to angiotensin II administration was measured in mice. We also tested in vitro the inhibitory effect on angiotensin convertase enzyme. Additionally, characterization of the pharmacological effect of the extract fraction was obtained.


RESULTS
We obtained dose-response curve for the administration of complete extract and extract fractions. Due to the hydroalcoholic extract (SeHA) treatment blood pressure decreased significantly from systolic dose of 0.75 mg kg(-1) (p<0.05) and even had an antihypertensive effect that was greater than that treatment with losartan. SeHA extract decreased the E(max) of the AG II hypertensive effect by about 20% in both systolic and diastolic pressures, treatment with losartan also decreased the same parameter between 6% and 8% for systolic and diastolic pressures, respectively. Fractions SeF8 and SeF8-8 showed similar levels of AG II ED(50) for both pressures compared with losartan, these fractions showed major compounds with maximum absorbance peaks at 221, 289 and 330 nm typical of flavonoids. In the inhibition assay the activity of angiotensin converting enzyme (ACE), the extract SeHA showed percentage inhibition (%IACE) of 50.27+/-5.09% (n=5). SeBuOH fraction is found to have greater inhibitory capacity of achieving a IACE 78.40+/-2.24% (n=5), which was similar to the values obtained in the presence of the SeF8-22 fraction (82.61+/-1.74%) and lisinopril (87.18+/-1.16%). The changes in the value of K(M) suggest that components of the extracts and fractions were recognized by the enzyme's active site. The main compounds of the fractions SeBuOH, SeF8-22 were by flavonoid and phenyl propanoid types, according to UV absorption spectra of the fractions.


CONCLUSIONS
The experimental results demonstrated the antihypertensive effect of Salvia elegans and it was due to the AG II antagonism and inhibition of angiotensin converting enzyme.
Jiménez-Ferrer
Enrique
E
Centro de Investigación Biomédica del Sur, Instituto Mexicano del Seguro Social (IMSS), Xochitepec, Morelos, Mexico.
Badillo
Fidel Hernández
FH
González-Cortazar
Manases
M
Tortoriello
Jaime
J
Herrera-Ruiz
Maribel
M
D000804:Angiotensin II / Q000008:administration & dosage / Q000037:antagonists & inhibitors*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D002855:Chromatography, Thin Layer; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D007275:Injections, Intravenous; D007700:Kinetics; D017706:Lisinopril / Q000494:pharmacology; D019808:Losartan / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D027544:Salvia; D013056:Spectrophotometry, Ultraviolet
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D010936:Plant Extracts; D000804:Angiotensin II; D017706:Lisinopril; D007703:Peptidyl-Dipeptidase A; D019808:Losartan