Extrinsic Pathway of Apoptosis Caused by Formalin-Containing Fish: Normalization of Caspase-8 Overactivation by Chlorophyllin

Abstract

Our previous studies proved that mice exposed to formalin-containing foods had an increase in the number of liver cells that activated caspase-8. Overactivation occurs even after two days of exposure. Caspase-8 is one of the enzyme responsible for apoptosis through extrinsic death receptor pathways. This study aims to test the ability of chlorophyllin (chlorophyll derivative) in reducing the number of liver cells that activate caspase-8. This study uses a 4 x 4 factorial design, with type and time of exposure as independent variables. The factors of exposure type consisted of: negative control (NC), formalin-containing fish (FF), formalin-containing fish plus chlorophyllin (FFChln), and chlorophyllin (Chln), while the factors of exposure time consisted of: 0, 2, 14, and 62 day. Caspase-8 activation in liver cells of mice was determined by immunohistochemistry (avidin-biotin sandwich assay), and analyzed by two-way ANOVA followed by Duncan's Multiple Range Test (DMRT, α = 0.01). The results of the data analysis of the type of exposure factors showed that the number of liver cells that activated caspase-8 from the FF group was significantly higher compared to the NC, FFChln, and Chln groups. Furthermore, the results of the data analysis of the time of exposure factors showed that the number of liver cells that activated caspase-8 from the 0-day group was significantly lower compared to groups 2, 14, and 62 days.

Keywords: caspase-8, formalin-containing fish, chlorophyllin, apoptosis, mice liver cell.