Abstract: Objective To investigate the differences in hepatotoxicity between diverse prepared samples of Paris polyphylla in a zebrafish system and confirm the role of PolyphyllinⅠ(PPⅠ) in the overall hepatotoxicity of the herb so as to provide data for elucidating the toxic material basis of PPⅠ and its safe applications. Methods Methanol was used to extract Paris polyphylla medicinal materials while crude total saponins were obtained via n-Butanol extraction. More separation by column chromatography yielded the Paris extract without PolyphyllinⅠ(PE-PPⅠ). On this basis, a zebrafish model was used to evaluate the toxicity of different samples, involving the determination of lethal concentration 10% (LC₁₀), observation of histopathological sections of livers, Nile Red staining, acridine orange staining, and fluorescence morphological analysis of livers. Meanwhile, the serum levels of triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) were detected. Real-time quantitative PCR (RT-qPCR) was used to measure the mRNA expression levels of such genes as apoa2, cyp7a1, cyp27a1, hmgcs1, fabp4 and cd36. Results At specific mass concentrations, the methanol extract (ME), n-Butanol extract (NBE), and PE-PPⅠ of Paris polyphylla all induced liver injury in zebrafish, but there were significant differences in toxicity and pathology. In the high- and low-dose NBE groups, toxicity was relatively strong, characterized by extensive liver tissue damage that was accompanied by obvious hepatocyte apoptosis, compensatory enlargement of the liver size, and significant lipid metabolism disorders. In the ME group, focal hepatocyte damage with moderate lipid accumulation was observed. In the PE-PPⅠ group, only mild liver lesions occurred. RT-qPCR results indicated that the expression levels of core genes related to lipoprotein metabolism were significantly upregulated, the rate-limiting enzyme genes for bile acid synthesis were inhibited, the regulatory genes for cholesterol synthesis were upregulated, and that the key factors for fat transport trended upward. Conclusion PolyphyllinⅠ is one of the key active components responsible for the hepatotoxicity of Paris polyphylla, which may interfere with lipid metabolism pathways, leading to liver lipid accumulation, hepatocyte apoptosis, and structural damage to liver tissues.

Key words: PolyphyllinⅠ, Hepatotoxicity, Zebrafish, Methanol Extract, Safety Evaluation