4.10. A Mouse Model of LPS-Induced Systemic Inflammation

BALB/c mice were obtained from Clea Japan and housed in an animal room under a 12 h light/dark cycle at 24 ± 1 °C. Animals received a pelleted basal diet and water ad libitum. Systemic inflammation was induced according to our previous study [42] with modifications. After acclimatization to their housing environment for 1 week, 8-week-old female BALB/c mice were randomly assigned to 3 groups (7 mice per group): control and LPS groups received water by gavage (7.5 mL/kg) for 7 consecutive days (day 1 to day 7); LPS + CLE group received CLE by gavage (300 mg/kg) for 7 consecutive days. Animals were weighed daily. LPS and LPS + CLE groups were intraperitoneally injected with LPS (5 mg/kg) 2 h after the last oral administration on day 7, whereas the control group was injected with 200 µL of PBS. Two hours later, all mice were anesthetized, and the blood was collected by cardiac puncture to characterize inflammatory cytokine profiles. The liver and spleen were quickly removed, flash-frozen in liquid nitrogen, and kept at −80 °C until analysis. The study was conducted according to the guidelines of Animal Experiments of Ehime University and approved by the Animal Experiment Committee of Ehime University.