Comparison of the tissue distribution and metabolism of AN1284, a potent anti-inflammatory agent, after subcutaneous and oral administration in mice

Abstract

Purpose. To establish a liquid chromatography/mass spectrometry method to compare the tissue distribution and metabolism of AN1284 after subcutaneous and oral administration at doses causing maximal reductions in IL-6 in plasma and tissues of mice.Methods. Lipopolysaccharide activated RAW 264.7 macrophages were used to detect the antiin ammatory activity of AN1284 and its metabolites. Mice were given AN1284 by injection or gavage, 15 min before lipopolysaccharide. The reduction of IL-6 measured after 4h.Results. AN1284 is metabolized to the indole (AN1422), a 7-OH derivative and its glucuronide. AN1422 had weaker anti-in ammatory activity than AN1284 in LPS-activated macrophages and in mice. Maximal reductions in IL-6 in plasma, brain and liver were seen after subcutaneous injection of (0.5 mg/kg). This dose was also most effective in reducing IL-6 in the liver after oral drug administration but 2.5 mg/kg was needed for the same reductions in plasma and brain. Peak concentrations after oral administration of AN1284 (2.5 mg/kg) were 5.5-fold higher in the liver but 7-, 11 and 19-fold lower in plasma, brain and kidneys than after injection of 0.5 mg/kg. Similar concentrations in the liver were achieved by AN1284 (1 mg/kg/day) administered in the drinking uid, and 2.5 mg/kg/day, via subcutaneously-implanted minipumps. Although drug levels were only 12% of the peak seen after acute injection of 0.5 mg/kg, they signi cantly decreased hepatocellular damage, liver triglycerides and cholesterol in diabetic mice.Conclusion. AN1284 can be given orally to treat chronic liver disease and its preferential concentration in the liver should limit potential adverse effects.

AN1284 attenuates steatosis, lipogenesis, and fibrosis in mice with pre-existing non-alcoholic steatohepatitis and directly affects aryl hydrocarbon receptor in a hepatic cell line

“…Neither did they produce significant differences in hepatic concentrations, but those of the indole metabolite were higher after 5 mg/kg/day. Although not measured in the current study, the hepatic concentrations of AN1284 after administration of 1 mg/kg/day in the drinking water that significantly reduced fibrosis in the CCl 4 model were similar to those achieved by administration of 2.5 mg/kg/day by mps ( 25 ).…”

“…While the current study was in progress, we completed an examination of the pharmacokinetics and metabolism of AN1284 in mice. Peak drug concentrations were similar in plasma and liver after s.c. injection, but nearly 50-fold higher in the liver when the compound was given orally ( 25 ). This suggested that oral administration should enable AN1284 to reduce hepatic damage.…”

“…AN1284 and its oxidized metabolite, AN1422, were extracted and measured as described in Weitman et al. ( 25 ).…”

“…Twenty microliters of internal standard (rivastigmine 750 ng/ml) and 20 µl of ultra-pure water were added. AN1284 and its oxidized metabolite, AN1422, were extracted and measured as described in Weitman et al (25).…”