TY - JOUR
T1 - Endothelium-independent vasodilatory effect of Sailuotong (SLT) on rat isolated tail artery.
AU - Yeon, S. Y.
AU - Seto, S. W.
AU - Chan, G. H. H.
AU - Low, M.
AU - Kiat, H.
AU - Wang, N.
AU - Liu, J.
AU - Chang, D.
N1 - Copyright the Author(s) 2020. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.
PY - 2020
Y1 - 2020
N2 - Background. Sailuotong (SLT) is a standardized three-herb formulation consisting of extracts of Panax ginseng, Ginkgo biloba, and Crocus sativus for the treatment of vascular dementia (VaD). Although SLT has been shown to increase cerebral blood flow, the direct effects of SLT on vascular reactivity have not been explored. This study aims to examine the vasodilatory effects of SLT and the underlying mechanisms in rat isolated tail artery. Methods. Male (250–300 g) Wistar Kyoto (WKY) rat tail artery was isolated for isometric tension measurement. The effects of SLT on the influx of calcium through the cell membrane calcium channels were determined in Ca2+-free solution experiments. Results. SLT (0.1–5,000 μg/ml) caused a concentration-dependent relaxation in rat isolated tail artery precontracted by phenylephrine. In the contraction experiments, SLT (500, 1,000, and 5,000 μg/mL) significantly inhibited phenylephrine (0.001 to 10 μM)- and KCl (10–80 mM)-induced contraction, in a concentration-dependent manner. In Ca2+-free solution, SLT (500, 1,000, and 5,000 μg/mL) markedly suppressed Ca2+-induced (0.001–3 mM) vasoconstriction in a concentration-dependent manner in both phenylephrine (10 μM) or KCl (80 mM) stimulated tail arteries. L-type calcium channel blocker nifedipine (10 μM) inhibited PE-induced contraction. Furthermore, SLT significantly reduced phenylephrine-induced transient vasoconstriction in the rat isolated tail artery. Conclusion. SLT induces relaxation of rat isolated tail artery through endothelium-independent mechanisms. The SLT-induced vasodilatation appeared to be jointly meditated by blockages of extracellular Ca2+ influx via receptor-gated and voltage-gated Ca2+ channels and inhibition of the release of Ca2+ from the sarcoplasmic reticulum.
AB - Background. Sailuotong (SLT) is a standardized three-herb formulation consisting of extracts of Panax ginseng, Ginkgo biloba, and Crocus sativus for the treatment of vascular dementia (VaD). Although SLT has been shown to increase cerebral blood flow, the direct effects of SLT on vascular reactivity have not been explored. This study aims to examine the vasodilatory effects of SLT and the underlying mechanisms in rat isolated tail artery. Methods. Male (250–300 g) Wistar Kyoto (WKY) rat tail artery was isolated for isometric tension measurement. The effects of SLT on the influx of calcium through the cell membrane calcium channels were determined in Ca2+-free solution experiments. Results. SLT (0.1–5,000 μg/ml) caused a concentration-dependent relaxation in rat isolated tail artery precontracted by phenylephrine. In the contraction experiments, SLT (500, 1,000, and 5,000 μg/mL) significantly inhibited phenylephrine (0.001 to 10 μM)- and KCl (10–80 mM)-induced contraction, in a concentration-dependent manner. In Ca2+-free solution, SLT (500, 1,000, and 5,000 μg/mL) markedly suppressed Ca2+-induced (0.001–3 mM) vasoconstriction in a concentration-dependent manner in both phenylephrine (10 μM) or KCl (80 mM) stimulated tail arteries. L-type calcium channel blocker nifedipine (10 μM) inhibited PE-induced contraction. Furthermore, SLT significantly reduced phenylephrine-induced transient vasoconstriction in the rat isolated tail artery. Conclusion. SLT induces relaxation of rat isolated tail artery through endothelium-independent mechanisms. The SLT-induced vasodilatation appeared to be jointly meditated by blockages of extracellular Ca2+ influx via receptor-gated and voltage-gated Ca2+ channels and inhibition of the release of Ca2+ from the sarcoplasmic reticulum.
UR - http://www.scopus.com/inward/record.url?scp=85092889383&partnerID=8YFLogxK
U2 - 10.1155/2020/8125805
DO - 10.1155/2020/8125805
M3 - Article
C2 - 33029174
SN - 1741-427X
VL - 2020
SP - 1
EP - 10
JO - Evidence-based Complementary and Alternative Medicine
JF - Evidence-based Complementary and Alternative Medicine
M1 - 8125805
ER -