2011年1月
Inhibitory effect of Iboga-type indole alkaloids on capsaicin-induced contraction in isolated mouse rectum
JOURNAL OF NATURAL MEDICINES
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- 巻
- 65
- 号
- 1
- 開始ページ
- 157
- 終了ページ
- 165
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1007/s11418-010-0478-6
- 出版者・発行元
- SPRINGER TOKYO
Voacanga africana (Apocynaceae) is used as an anti-diarrheal medicine in West Africa. In the present study, we investigated the effect of an extract of V. africana and its constituents on smooth muscle contraction induced by capsaicin in mouse rectum, where transient receptor potential vanilloid type 1 (TRPV1)-immunoreactive fibers are abundant. Methanol and alkaloid extracts of the root bark of V. africana were found to inhibit capsaicin-induced contraction in a dose-dependent manner (30-300 mu g/ml). Major constituents isolated from the alkaloid extract were then studied for their effects on the capsaicin-induced contraction. The main active constituents were found to be Iboga-type alkaloids, including voacangine (1), 3-oxovoacangine (2), voacristine (3), and (7 alpha)-voacangine hydroxyindolenine (4). The voacangine concentration dependently (3-100 mu M) inhibited the capsaicin-induced contraction. The capsaicin-induced contraction was almost completely inhibited by the TRPV1 antagonist, N-(4-tertiarybutylphenyl)-4-(3-chloropyridin-2-yl)tetrahydropyrazine-1(2H)-carbox-amide (BCTC). On the other hand, the Iboga-type alkaloids did not inhibit the contractions induced by 3 mu M acetylcholine and 300 mu M nicotine. These results suggest that Iboga-type alkaloids isolated from V. africana inhibit capsaicin-induced contraction in the mouse rectum, possibly via the inhibition of a TRPV1-mediated pathway. This inhibition may be involved in the anti-diarrheal effect of V. africana.
- リンク情報
- ID情報
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- DOI : 10.1007/s11418-010-0478-6
- ISSN : 1340-3443
- Web of Science ID : WOS:000285156800023