Baş A L, Simşek A, Erganiş O, Corlu M
Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Selçuk, Konya, Turkey.
Dtsch Tierarztl Wochenschr. 2005 Jun;112(6):219-23.
The aim of this study was to evaluate the intracellular activity of two types of liposome-encapsulated enrofloxacin (LE) compared with free enrofloxacin and non-treated control against Staphylococcus aureus, phagocytosed by monocytes in healthy Anatolian Shepherd dogs. Enrofloxacin was encapsulated with two different types of liposome in multilamellar large vesicles (MLV). Type A MLV were composed of 15 mg phosphatidylcholine and 35 mg cholesterol, Type B MLV were composed of phosphatidylcholine, cholesterol and enrofloxacin in a molar ratio of 1:1:1. Intracellular activity was estimated by comparing the numbers of bacteria surviving intracellularly in monocytes exposed to free enrofloxacin and LE for 4 h at the doses of 0.25, 0.5 and 1 microg/ml, with those surviving intracellularly in untreated control monocytes. All three forms of enrofloxacin (free, Type A and B liposomes) increased the intracellular killing of S. aureus in a concentration dependent manner. Comparison of 1 microg/ml Type B LE revealed that killing activity was significantly higher than those of other concentrations. The results showed that LE was superior in reducing the number of intracellularly located bacteria compared to the free drug and control. The beneficial effect of liposomal encapsulation is presumably due to the fact that both liposomes and bacteria are localized at the same spot in phagocytic cells.
本研究旨在评估两种脂质体包封恩诺沙星（LE）与游离恩诺沙星及未处理对照组相比，对健康安纳托利亚牧羊犬单核细胞吞噬的金黄色葡萄球菌的细胞内活性。恩诺沙星用两种不同类型的脂质体包封在多层层状大囊泡（MLV）中。A型MLV由15毫克磷脂酰胆碱和35毫克胆固醇组成，B型MLV由磷脂酰胆碱、胆固醇和恩诺沙星按1:1:1的摩尔比组成。通过比较在0.25、0.5和1微克/毫升剂量下，暴露于游离恩诺沙星和LE 4小时的单核细胞内存活细菌数量与未处理对照单核细胞内存活细菌数量，来估计细胞内活性。三种形式的恩诺沙星（游离、A型和B型脂质体）均以浓度依赖性方式增加了金黄色葡萄球菌的细胞内杀伤作用。比较1微克/毫升的B型LE发现，其杀伤活性显著高于其他浓度。结果表明，与游离药物和对照组相比，LE在减少细胞内细菌数量方面更具优势。脂质体包封的有益作用可能是由于脂质体和细菌都定位在吞噬细胞的同一部位。
