| Aims1. Based on the hepatobiliary membrane transporters to investigate the mechanisms of rifampicin (RIF) and/or isoniazid (INH) induced liver injury in rats.2. Based on the hepatobiliary membrane transporters to investigate the protective effects of monoammonium glycyrrhizinate (MAG) on RIF and/or INH induced hepatotoxicity and the underlying mechanisms in rats.Methods1. Male Wistar rats were randomly divided into three groups:control, RIF and MAG group. Rats in RIF group were orally administered with RIF (60mg·kg-1·d-1), rats in control group were orally administered with saline; while rats in MAG group were orally administrated with MAG (45mg·kg-1·d-1)3h before RIF (60mg·kg-1·d-1). Drugs were given to rats once a day for successive21days. At7,14, and21days after drugs administration,5rats in each group were randomly selected and fasted for6h. Blood were collected by abdominal aortic puncture, and the serum was obtained for ALT, AST, TBIL, DBIL, IBIL and TBA analysis. Liver were removed, one part for histological analysis; the other part for Western blotting analysis to detect the expression of transporter Mrp2and Ntcp.2. Male Wistar rats were randomly divided into three groups:control, INH and MAG group. Rats in INH group were orally administered with INH (60mg·kg-1·d-1), rats in control group were orally administered with saline; while rats in MAG group were orally administrated with MAG (45mg·kg-1·d-1)3h before INH (60mg·kg-1·d-1). Drugs were given to rats once a day for successive21days. At7,14, and21days after drugs administration,5rats in each group were randomly selected and fasted for6h. Blood were collected by abdominal aortic puncture, and the serum was obtained for ALT, AST, TBIL, DBIL, IBIL and TBA analysis. Liver were removed, one part for histological analysis; the other part for Western blotting analysis to detect the expression of transporter Mrp2and Ntcp.3. Male Wistar rats were randomly divided into four groups:control, RIF+INH group, low dose MAG (MAG-L) group and high dose MAG (MAG-H) group. Rats in RIF+INH group were orally administered with RIF (60mg·kg-1·d-1) plus INH (60mg·kg-1·d-1), rats in control group were orally administered with saline; rats in MAG-L group were orally administrated with MAG (45mg·kg-1·d-1), rats in MAG-H group were administrated with MAG (90mg·kg-1’·d-1), respectively at3h before RIF (60mg·kg-1·d-1) and INH (60mg·kg-1·d-1). Drugs were given to rats once a day for successive21days. At7,14, and21days after drugs administration,5rats in each group were randomly selected and fasted for6h. Blood were collected by abdominal aortic puncture, and the serum was obtained for ALT, AST, TBIL, DBIL, IBIL and TBA analysis. Liver were removed, one part for histological evaluation and immunohistochemical analysis of Oatp1a4expression; one for GSH and MDA level detection, and one for Western blotting analysis to detect the expression of transporter Mrp2and Ntcp.Results1. Compared to the control group, the levels of serum biochemical indicators were significantly elevated at7,14, and21days after RIF administration, and HAI scores were also markedly increased (P<0.05), suggesting the hepatotoxicity induced by RIF. Compared to the RIF group, MAG treatment significantly and dose-dependently reduced the AST, ALT, TBIL and TBA level as well as the HAI scores at7,14and21days after drug administration, respectively. Compared to the control group, the expression of Mrp2was significantly increased (P<0.05) in RIF-treated group; while MAG treatment significantly reduced the expression of Mrp2in RIF-treated rats (P<0.05). Concerning the expression of Ntcp, no difference was found among control group, RIF group and MAG group (P>0.05).2. Compared to the control group, the serum level of biochemical indicators and the HAI scores were markedly elevated in INH-treated rats at14and21day time points (P<0.05), while MAG treatment markedly decreased the biochemical parameters as well as HAI scores (P<0.05), suggesting the hepatoprotective effect of MAG. Compared to the control group, the expression of Mrp2in INH-treated rats were significantly decreased at7day time point, but significantly increased at21day time point (P<0.05), while MAG treatment significantly elevated Mrp2expression at7and14day time points and reduced Mrp2expression at21day time point. The expression of Ntcp was significantly increased in INH-treated rats at7and21day time points when compared to that of the control; while MAG treatment markedly reduced the expression of Ntcp at21day time point, indicating that the hepatoprotective effect of MAG may have correlation with its effect on regulating Mrp2and Ntcp expression.3. RIF and INH treatment significantly increased biochemical parameter, HAI score and hepatic MDA level, but decreased GSH level when compared to that of the control, suggesting the hepatotoxicity induced by RIF and INH. MAG treatment significantly and dose-dependently reduced the biochemical parameter, HAI score as well as MDA level, and gradually elevated the hepatic GSH level in RIF and INH treat rats, indicating the hepatoprotective effect of MAG. Concerning the transporter expression, RIF and INH treatment significantly increased Mrp2expression, but reduced Oatpla4expression at7,14and21day time points when compared to that of the control, while MAG treatment markedly and dose-dependently reversed the alterations induced by RIF and INH. Compared to the control group, Ntcp expression in RIF and INH treated rats was markedly reduced at7day, but increased at14and21day time points; while MAG treatment significantly and dose-dependently elevated Ntcp expression at7,14and21day time points (P<0.05).Conclusions1. The mechanisms of RIF and INH induced liver injury in rats have close correlation with the alterations in hepatobiliary transporters:RIF-induced liver injury up-regulated the expression of Mrp2; INH-induced liver injury up-regulated the expression of Ntcp; while RIF and INH induced liver injury down-regulated the expression of Oatpla4.2. MAG presents hepatoprotective effect in RIF and INH induced liver injury in a dose-dependent manner, the underlying mechanism is related to the down-regulation of Mrp2expression as well as the up-regulation of Oatpla4expression. |
PDF Full Text Request