Analysis of Folium Epimedium toxicity in combination with Radix Morindae Officinalis based on zebrafish toxicity/metabolism synchronization / 药学学报

ABSTRACT

Metabolic transformation in vivo is a critical approach in the study of toxicity, but real-time dynamic observation of the transformation is difficult. We proposed that zebrafish toxicity/metabolism synchronization may be used in the analysis of toxicity of Folium Epimedium (Yinyanghuo for Chinese, YYH) and the toxicity may be reduced by Radix Morindae Officinalis (Bajitian for Chinese, BJT). Healthy zebrafish embryos 1 day post fertilization (1 dpf) were exposed to different concentrations of YYH, total flavonoids of YYH (YTF), representative flavonoids (epimedin C and icariin) and their respective in combination with BJT. Death numbers of the embryos or larvals were counted during 1-5 days after dosing (2-6 dpf); embryonic micro-morphology of zebrafish (3 dpf) was observed and pictures were taken. The blank vehicle (0.4% DMSO) was used in the control group, and LC50 value of 2 to 6 dpf was calculated by SPSS16.0. A relative safe concentration was sampled every day to analyze the dynamic metabolites changes of major flavonoids of YYH. The results showed that epimedin A/B/C (EA/EB/EC) and icariin, the major flavonoids of YYH, were dynamically transformed into major metabolites of sagittatoside C (SC) and baohuoside I (BI) by zebrafish. BI was mainly derived from EA, EB and icariin. Neither original form nor their metabolite BI can cause zebrafish poisoning. SC was mainly derived from EC, and its accumulation was closely related to the toxicity of YYH, YTF and EC. After combination with BJT, the metabolism of EC was slowed down and the toxicity was alleviated. Zebrafish toxicity/metabolism synchronization revealed that the toxicity of EC of YYH was increased after metabolism into SC, which maybe the key potential poisonous factor of YYH, and BJT can reduce the toxicity by slowing down the metabolism rate of EC. The data provides new ideas and methods in the study of toxic substances in Chinese medicine and mechanism of detoxicity by combination.