A study of pharmacokinetic interactions among co-existing ingredients in Viscum coloratum after intravenous administration of three different preparations to rats

BACKGROUND: Viscum coloratum (Komar) Nakai, known as Hujisheng in china, has been widely used as a herb medicine to treat a variety of diseases, including cardiovascular diseases, cancer, hypertension, hepatitis and hemorrhage. OBJECTIVE: The aim was to investigate pharmacokinetic interactions among co-existing ingredients in V. coloratum after intravenous administration of three different preparations (four monomer solutions, the mixture of them and Viscum coloratum extracts) to rats. MATERIALS AND METHODS: After protein precipitation pretreatment with plasma samples, high performance liquid chromatographic methods were developed and applied to quantitatively determinate the four components [syringin (Syri), homoeriodictyol-7-O-β-D-glycoside (Hedt-III), homoeriodictyol-7-O-β-D-apiose (1 → 2)-β-D-glycoside (Hedt-II) and homoeriodictyol-7-O-β-D-apiosiyl-(1 → 5)-β-D-apiosyl-(1 → 2)-β-D-glycoside (Hedt-I)]. The pharmacokinetic parameters (Area under the curve [AUC((0-t))], AUC((0-∞)), t(1/2)) were calculated using DAS 2.1 software (Chinese Pharmacological Society, Shanghai, China) and compared statistically by One-way analysis of variance using SPSS software (18.0, Chicago, IL, USA) with P < 0.05 considered statistically significant. RESULTS: Good linearities were achieved in the measured concentration range with R(2) it0.9920. Precision, accuracy and extraction recovery were all within the acceptable range. For Syri, there was a significant difference only on t(1/2) among three treatment groups. For Hedt-I, Hedt II and Hedt-III, three flavonoid glycosides, the change of AUC((0-t)), AUC((0-∞)) and t(1/2) were markedly distinctive and even converse. CONCLUSION: Complex, extensive pharmacokinetic interactions were observed among these components in V. coloratum. They were mutually influenced by the in vivo absorption, distribution, metabolism and elimination. The result suggested traditional Chinese medicine was a complicated system, and we should take a scientific and dialectic view in the research and development processes.