School of Chinese Medicine
Magnolol inhibits colonic motility through down-regulation of voltage-sensitive L-type Ca2+ channels of colonic smooth muscle cells in rats
This study aimed to investigate the effect of magnolol (5,5′-diallyl- 2,2′-biphenyldiol) on contraction in distal colonic segments of rats and the underlying mechanisms. Colonic segments were mounted in organ baths for isometric force measurement. Whole-cell voltage-sensitive L-type Ca2+ currents were recorded on isolated single colonic smooth muscle cells using patch-clamp technique. The spontaneous contractions and acetylcholine (ACh)- and Bay K 8644-induced contractions were inhibited by magnolol (3-100 μM). In the presence of Bay K8644 (100 nM), magnolol (10-100 μM) inhibited the contraction induced by 10 μM ACh. By contrast, tetrodotoxin (100 nM) and Nώ-nitro-l-arginine methyl ester (l-NAME 100 μM) did not change the inhibitory effect of magnolol (10 μM). In addition, magnolol (3-100 μM) inhibited the L-type Ca2+ currents. The present results suggest that magnolol inhibits colonic smooth muscle contraction through downregulating L-type Ca2+ channel activity. © 2013 Elsevier GmbH.
Colonic motility, L-type Ca2+ channels, Magnolia officinalis, Magnolol, Smooth muscle cells
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Zhang, M., Zang, K., Luo, J., Leung, F., Huang, Y., Lin, C., Yang, Z., Lu, A., Tang, X., Xu, H., Sung, J., & Bian, Z. (2013). Magnolol inhibits colonic motility through down-regulation of voltage-sensitive L-type Ca2+ channels of colonic smooth muscle cells in rats. Phytomedicine, 20 (4), 1272-1279. https://doi.org/10.1016/j.phymed.2013.07.008