Brown L, Heyneke O, Brown D, van Wyk J P H, Hamman J H
Department of Pharmacy, University of Limpopo (Medunsa Campus), P.O. Box 218, Ga-Rankuwa 0204, South Africa.
J Ethnopharmacol. 2008 Oct 28;119(3):588-92. doi: 10.1016/j.jep.2008.06.028. Epub 2008 Jul 2.
[corrected] Traditional herbal medicines are often used for the treatment of different diseases in developing countries, especially in the rural areas where a lack of an efficient primary health care system is usually experienced. Many patients infected with the human immunodeficiency virus are taking traditional herbal medicines in conjunction with their modern antiretroviral medication and drug-herb interactions can occur in these cases.
To investigate the effect of water extracts of two traditional medicinal plants, Hypoxis hemerocallidea and Sutherlandia frutescens as well as l-canavanine (a constituent of Sutherlandia frutescens) on the transport of nevirapine across human intestinal epithelial cells.
Nevirapine transport in the apical to basolateral and basolateral to apical directions across Caco-2 cell monolayers was determined alone (normal control) and in the presence of verapamil (positive control), water extracts of Hypoxis hemerocallidea and Sutherlandia frutescens and an aqueous solution of l-canavanine. The cumulative transport and apparent permeability coefficient (P(app)) values were calculated and compared.
Nevirapine alone was substantially effluxed in the basolateral to apical direction across the intestinal epithelial cell monolayers, which was statistically significantly (p < or = 0.05) decreased by addition of verapamil, Hypoxis hemerocallidea extract and the l-canavinine solution. The effect of Sutherlandia frutescens on nevirapine transport was not statistically significantly different from the control.
Hypoxis hemerocallidea and l-canavanine interact with the efflux of nevirapine across intestinal epithelial cells and therefore can potentially increase the bioavailability of this antiretroviral drug when taken concomitantly.
[已修正]在发展中国家，传统草药常被用于治疗各种疾病，尤其是在缺乏高效初级卫生保健系统的农村地区。许多感染人类免疫缺陷病毒的患者在服用现代抗逆转录病毒药物的同时也在服用传统草药，在这些情况下可能会发生药物与草药的相互作用。
研究两种传统药用植物——南非仙茅和灌木南非山柑的水提取物以及L-刀豆氨酸（灌木南非山柑的一种成分）对奈韦拉平在人肠道上皮细胞中转运的影响。
分别测定奈韦拉平在单独存在（正常对照）以及存在维拉帕米（阳性对照）、南非仙茅水提取物、灌木南非山柑水提取物和L-刀豆氨酸水溶液的情况下，在Caco-2细胞单层模型中从顶端到基底外侧以及从基底外侧到顶端方向的转运情况。计算并比较累积转运量和表观渗透系数（P(app)）值。
单独的奈韦拉平在肠道上皮细胞单层模型中从基底外侧到顶端方向有大量外排，加入维拉帕米、南非仙茅提取物和L-刀豆氨酸溶液后，这种外排情况在统计学上显著降低（p≤0.05）。灌木南非山柑对奈韦拉平转运的影响与对照组相比无统计学显著差异。
南非仙茅和L-刀豆氨酸与奈韦拉平在肠道上皮细胞中的外排相互作用，因此在同时服用时可能会提高这种抗逆转录病毒药物的生物利用度。
