Airways and vascular smooth muscles relaxant activities of Gaultheria trichophylla

ABSTRACT

The aim of this experimental work was to explore the potential pharmacological activities of Gaultheria trichophylla Royle in hyperactive respiratory and vascular conditions. Gaultheria trichophylla was extracted with solvents, phytochemical detection tests were performed, and rabbit trachea and aorta strips were used to evaluate its effects on airways and vascular smooth muscles. Qualitative phytochemical tests showed the presence of flavonoids, alkaloids, anthraquinones, saponins, terpenoids, and condensed tannins. The methanol extract caused inhibition [EC[50] values of 3.12 mg/mL] of carbachol [1 micro M] and partial relaxation of K[+][80 mM] caused contractions in tracheal strips. The chloroform extract was comparatively more potent against carbachol than K[+] induced contraction with EC[50] values of 0.64 and 2.26 mg/mL, respectively. However, the n-hexane extract showed more potency against K[+] than cabachol induced contractions, as in case with verapamil, with EC[5]0 values of 0.61 and 6.58 mg/mL, respectively. In isolated prepared trachea, the extracts displaced the carbachol concentration response curves and maximum response was suppressed. In rabbit aorta preparations, methanol and n-hexane extracts partially relaxed phenylephrine [1 micro M] and K[+] induced vasoconstrictions. However, the chloroform extract inhibited phenylephrine induced contractions and exhibited a vasoconstrictor effect at lower concentrations and a relaxant effect at higher concentrations against K[+] precontractions. The data indicates that, in addition to others, the extracts of G .trichophylla possess verapamil like Ca[++] channel blocking components which explain the possible role of this plant in respiratory and vascular conditions