Chen Weiyang, Lu Zhilei, Viljoen Alvaro, Hamman Josias
Department of Pharmaceutical Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
Planta Med. 2009 May;75(6):587-95. doi: 10.1055/s-0029-1185341. Epub 2009 Feb 12.
The effect of Aloe vera (L.) Burm. f. (Aloe barbadensis Miller) gel and whole leaf extract on the permeability of Caco-2 cell monolayers was determined. Solutions of gel and the whole leaf extract were applied to the cell monolayers, and the transepithelial electrical resistance was monitored for 2 hours, which was then continued for another 2 hours after removal of the test solutions to measure reversibility of the effect. The transport of insulin in the presence and absence of the A. vera gel and whole leaf extract solutions was also investigated. Both the A. vera gel and whole leaf extract were able to significantly reduce the transepithelial electrical resistance of the Caco-2 cell monolayers at concentrations above 0.5 % w/v and thereby showed the ability to open tight junctions between adjacent cells. This effect was fully reversible, as the electrical resistance of the cell monolayers returned to the original value upon removal of the test solutions. The A. vera gel and whole leaf extract solutions significantly enhanced the transport of insulin across the Caco-2 cell monolayers compared with the control. The results suggest that these plant products have a high potential to be used as absorption enhancers in novel dosage forms for drugs with poor bioavailabilities when administered orally. On the other hand, an uncontrolled increase in the bioavailability of drugs that are taken simultaneously with A. vera gel and whole leaf extract products may result in adverse effects, and the potential exists that toxic blood plasma levels may be reached.
测定了库拉索芦荟（Aloe vera (L.) Burm. f.，即巴巴多斯芦荟（Aloe barbadensis Miller））凝胶和全叶提取物对Caco - 2细胞单层通透性的影响。将凝胶溶液和全叶提取物溶液施加于细胞单层，监测跨上皮电阻2小时，在去除测试溶液后再持续监测2小时以测量该效应的可逆性。还研究了在有和没有库拉索芦荟凝胶及全叶提取物溶液存在的情况下胰岛素的转运情况。库拉索芦荟凝胶和全叶提取物在浓度高于0.5% w/v时均能显著降低Caco - 2细胞单层的跨上皮电阻，从而显示出打开相邻细胞间紧密连接的能力。这种效应是完全可逆的，因为在去除测试溶液后细胞单层的电阻恢复到原始值。与对照组相比，库拉索芦荟凝胶和全叶提取物溶液显著增强了胰岛素跨Caco - 2细胞单层的转运。结果表明，这些植物产品在口服给药时，作为生物利用度差的药物新型剂型中的吸收促进剂具有很高的潜力。另一方面，与库拉索芦荟凝胶和全叶提取物产品同时服用的药物生物利用度不受控制地增加可能会导致不良反应，并且存在达到有毒血浆水平的可能性。
