In vitro and In vivo Effect of Quercetin on Hepatocyte Transmembrane N+, K+- ATPase Activity in Rats

Aims: This study investigated In vitro and In vivo effect of quercetin on transmembrane hepatocyte Na+, K+- ATPase activity in normal Wistar rats.

Study Design: One factor experimental design.

Place and Duration of Study: Department of Biochemistry, Federal University of Technology, Akure, Ondo State, Nigeria, between April and September 2010.

Methodology: In vitro effect of quercetin on transmembrane hepatocyte Na+, K+-ATPase activity was investigated through enzyme assay by measuring the released inorganic phosphate (Pi) through the method of Fiske and Subbarow, while in In vivo experiment, three (3) main groups of male Wistar rats weighing 200-250 g (n=5) were randomly selected. Group 1 (IP; Intraperitoneal), group 2 (IV; Intravenous) and 3 (OR; Oral) group. All three groups were administered with quercetin 50 mg/kg body weight (once/day) for 5 days through respective routes. The control for each group received equal volume of vehicle through respective routes of administration. Hepatocyte Na+, K+-ATPase activity for each group was assayed after days of quercetin administration.

Results: In vitro results indicated that quercetin, with IC50 of 5.75 µm showed high inhibitory activity on Na+, K+-ATPase, while in vivo result showed inhibitory activity on hepatic Na+ K+-ATPase irrespective of the routes of administration. Quercetin through the oral route showed significant (F5, 12= 265.8; P=0.05) inhibitory effect on hepatic Na+ K+-ATPase compared to control. Administration of quercetin though the parenteral routes (intraperitoneal and intravenous) showed significant (F5, 12= 265.8; P<0.001) inhibitory effect compared to respective control. The parenteral routes of administration of quercetin have significant (F5, 12= 265.8; P<0.001) inhibitory effect on hepatic Na+ K+-ATPase compared to the oral route

Conclusion: Quercetin showed high inhibitory effect In vitro on hepatocyte Na+, K+- ATPase activity in normal rats. In vivo administration of quercetin showed significant inhibitory effect on hepatocyte Na+, K+- ATPase activity in normal rats, with the parenteral routes of administration exerting significant inhibitory effect compared to the oral route.