Hepatotoxicity Evaluation Of Traditional Chinese Herb Components Based On The Liver-on-a-chip

In recent years,China has paid more and more attention to Chinese herbal medicines,encouraging the research and development of Chinese medicines and related preparations,but at the same time it has caused many problems.Chinese herbal medicines are considered to be safer than western medicines,but the composition of Chinese herbal medicines is mixed,and active substances,drug mechanisms,and safety properties are difficult to explore.This has led to fewer studies on the toxicity of Chinese herbal medicines and its research subjects.In addition,drug-induced liver injury is an important reason why drugs are difficult to pass preclinical tests and clinical phase I,II and III tests.Once they fail to pass,it will be a waste of time and money,and Chinese herbal medicine is the second largest reason of the drug-induced liver injury.So studying the hepatotoxicity of Chinese herbal medicine is very necessary.At present,the research on hepatotoxicity of Chinese herbal medicines at home and abroad mainly through orifice plate models and animal models has certain limitations.Among them,the orifice plate models has a single structure and a large difference from the real conditions in the body.The animal model has a long cycle,high cost,and individual differences.Therefore,in this experiment,U937 cells(human tissue lymphoma cell line),HUVEC cells(human umbilical vein endothelial cell line),LX-2 cells(human liver stellate cell line)and HepG-2 cells(human hepatoma cell line)are cultured in a certain spatial order in the platform to construct an organ chip model for mimicking the structure of the hepatic sinusoids,and detect the hepatotoxicity of the Chinese herbal medicine component through a microfluidic chip platform.The organ chip model used in the experiment mainly consisted of two layers of acrylic sheets,three layers of PDMS(polydimethylsiloxane)and two polycarbonate porous membranes with a diameter of 8 mm.A layer of polycarbonate porous membrane is sandwiched between the upper PDMS substrate and the intermediate layer PDMS substrate,HUVEC cells are inoculated on the upper surface of the porous membrane,and LX-2 cells are inoculated on the lower surface to simulate the sinus gap;the intermediate layer PDMS and the lower PDMS substrate are separated by a polycarbonate porous membrane having a pore size of 8 mm,and HepG-2 cells embedded in Matrigel are cultured in the intermediate layer culture chamber for three-dimensional culture,thereby simulating normal growth pattern of hepatocytes,and normal function is characterized by MRP2(Multidrug Resistance-associated Protein2)expression and albumin secretion;then cell suspension containing differentiated U937 cells is injected into the upper PDMS culture chamber to simulate the growth of Kupffer cells.Then,the culture solution is pushed from the upper chip inlet at a speed of 1 r/min under the push of a peristaltic pump to construct an organ chip model for hepatotoxicity screening of Chinese herbal ingredients.The experimental results show that the in vitro model of liver microchip can maintain the secretion of albumin and the expression of MRP2 in 72 h,and can detect the content of AST(aspartate aminotransferase)and ALT(alanine aminotransferase)in the chip culture medium.The hepatotoxicity of oxymatrine,evodiamine,oleic acid and nitidine chloride is reflected in the concentration and time.The same concentration of oxymatrine,evodiamine,oleic acid and nitidine chloride show different degrees of hepatocyte inhibition in the chip model and the traditional plate model,and the hepatotoxicity of the Chinese herbal ingredients in the chip is weaker.