Influence of capsaicin on fluctuation of digoxin pharmacokinetics in lipopolysaccharide-treated rats

Abstract

1. In the present study, we investigated the influence of Cap on digoxin pharmacokinetics in lipopolysaccharide (LPS)-treated rats.

2. After the oral administration of digoxin (0.1 mg/kg), the area under the plasma concentration-time curve (AUC) of digoxin increased significantly until day 3 after LPS treatment. In the LPS + Cap group, the recovery period of AUC was shortened to 3 days. On days 5 and 7, the maximum plasma concentrations decreased significantly as compared to the control group. The bioavailability of digoxin in LPS group was higher than that in the LPS + Cap group.

3. The hepatic cytochrome P450 (CYP) 3A2 content decreased significantly until day 5 after LPS administration, but it returned to the control level until 5 days in the LPS + Cap group. Hepatic CYP3A2 mRNA expression of LPS group decreased significantly until day 3, but it returned to the control level on day 3 and increased significantly until day 7 in the LPS + Cap group.

4. The DNA-binding activity of pregnane X receptor (PXR) was increased on days 3–7 in the Cap and LPS + Cap group.

5. Cap decreased the absorption of digoxin by inducing CYP3A2 mRNA expression via indirect activation of PXR in LPS-treated rats.

Keywords::

• Lipopolysaccharide
• capsaicin
• CYP3A2
• PXR

Acknowledgements

The authors thank Maruishi Pharmaceutical Co., Ltd. for the gift of Cap.

Declaration of interest

The authors report no conflicts of interest.