Study On Targetability Of Lactosaminated Matrine Liposomes To Liver In Vivo And Inhibition To HepG2 Cells In Vitro

Matrine(M) is a alkaloid of quinolizidine group, extracted from a traditional Chinese medicine, Ku-dou-zi or the aired root of Sophora flavescens ait..The studies of pharmacological have shown that M has wide pharmacological effects including anti-arrhythmic, anti-inflammatory, anti-tumor, immunol-ogical enhancement. At present, M is widely used for the treatment of chronic type B hepatitis, but M injection used clinically has some disadvantages including short half-life, low drug concentration in tissues.Liposomes are well recognized as drug delivery vehicles that have target effents, delayed drug release and degraded drug toxicity. Thus, in this study we intend to prepare the lactosaminated matrine liposome(LML) to improve its pharmacokinetics characters such as half-life and target effect and enhance therapeutic efficacy.We had applied an evaporation-ultrasonic technique to prepare LML. Through orthogonal experimental design, one optimum recipes of LML was founded that showed M/PC 1:10, PC/Ch 3:1, pH 6.8, incubation tempreture 60℃. Under the optimal formulation, M was encapsulated 48.1%.A method was developed for the determination of M concentration in liposomes and entrapment efficiency and biological samples by HPLC, it was proved that this method was accurate, sensitive, specific and good enough to be used in pharmacokinetic study of M. The small unilamellar vesicle liposomes were observed by scanning electron microscope. The mean particle diameter is about 80～150nm. The stability of LML was valuated with the entrapment efficiency and preoxidation value in 4, 25℃for 1 month. The results showed that the LML stored in 4℃would keep stability.The tissues distribution of M-sol or ML or LML were studied after intravenous administration M-sol or ML or LML to mice, respectively. The experimental results showed that Compared with matrine solution, ML and LML exhibited long circulation time. Tissue distribution results proved that the area under curve of liver was significantly difference among modified matrine liposomes, regular matrine liposomes and matrine solutions(P<0.05). The accumulation of LML in the mice liver was 2.7 times as in the spleen, 3 times as in the lung, 6.6times as in the kidney, and 8.5 times as in the heart(P<0.01). The result of tissues distribution showed that LML had better tissues targeting and slow-release effect than M-sol and ML.The cytotoxic effect of LML on human hepatoma cell line HepG2 in vitro was detected by thiazolyl blue(MTT)assay. The inhibitory rate of LML,ML and M-sol on HepG2 ceells were 51.97%,31.89% and 28.34% at the concentrations of 0.5mg/ml, respectively. And there were markd difference between the former and the latter two(p<0.05).