Lactate dehydrogenase release assay
Lactate dehydrogenase (LDH) test kit (Beyotime Biotechnology, Nanjing, China) was used to assess the cytotoxicity of Ziyu II. Cells were cultured in 96-well plates (6x103 cells/well). After treatment with various concentrations of Ziyu II for 24h, cell culture supernatant was transferred to the new 96-well plate for LDH analysis.