Fig 1.
Changes in nitric oxide (NO) concentration in the blood serum and cytochrome P450 (CYP) 2A5, CYP1A, and CYP2B activities in the liver with time elapsed after lipopolysaccharide (LPS) injection.
Nitrite concentration (μM), coumarin 7-hydroxylase (COH, CYP2A5), benzyloxy-resorufin-O-debenzylase (BROD, CYP2B), and ethoxy-resorufin-O-deethylase (EROD, CYP1A) activities (pmol/[min·mg protein]) in the hepatic microsomal fraction of liver samples from female DBA-2 mice injected intraperitoneally (i.p.) with phosphate-buffered saline (control) or LPS (2, 5 or 20 mg/kg) were determined 6, 12 or 24 h after treatment. N = 7 for all groups, except for the control (0 h; N = 20) and LPS (5 mg/kg) groups at 6 h (N = 15). Data represent means ± standard error of the mean (SEM). An asterisk (*) indicates that the mean value differs (analysis of variance [ANOVA] and Dunnett’s multiple comparison test, P < 0.05) from that of the control group.
Fig 2.
Non-monotonic dose response of CYP2A5 activity in mouse livers after treatment with LPS.
NO concentration (μM) and COH activity (pmol/[min·mg protein]) in the hepatic microsomal fraction of liver samples from female DBA-2 mice 24 h after treatment. Mice per LPS dose (mg/kg i.p.) group numbered as follows: 0 (PBS), N = 26; 0.025, N = 3; 0.05, N = 8; 0.1, N = 6; 0.2, N = 6; 0.5, N = 8; 1, N = 6; 2, N = 7; 5, N = 7; 10, N = 10; and 20, N = 7. Data represent means ± SEM. An asterisk (*) indicates that the mean value differs (ANOVA and Dunnett’s multiple comparison test, P < 0.05) from that of the control group.
Fig 3.
Levels of pro-inflammatory cytokines in the blood serum of mice treated with pentoxifylline (PTX) and LPS.
Concentrations of tumour necrosis factor alpha (TNF-α), interferon gamma (IFN- γ), interleukin (IL)-6, and IL-17A were measured in the serum of female DBA-2 mice 24 h after treatment. Animals were treated with LPS (0, 0.05, 0.1, 0.5, 1, 5, 10 or 20 mg/kg i.p., N = 8 per dose group (except the 0 and 20 mg/kg LPS groups, N = 10) alone (●) or PTX plus LPS (2 × 100 mg/kg i.p., 60 min apart, N = 8 per dose group) (▲). Data represent means ± SEM: a indicates that the mean differs from the control value in the LPS-treated group; b indicates that the mean differs from the control value in the PTX+LPS-treated group; and the asterisk (*) indicates that the mean value in the PTX+LPS-treated group differs from that in the LPS-treated group for the same dose (Kruskal-Wallis and Mann-Whitney tests, P < 0.05).
Fig 4.
Concentrations of IL-2, IL-4, and IL-10 in the blood serum of mice treated with PTX and LPS.
Concentrations of cytokines were measured in the serum of female DBA-2 mice 24 h after treatment. Animals were treated with LPS (0, 0.05, 0.1, 0.5, 1, 5, 10 or 20 mg/kg i.p., N = 8 per dose group [except the 0 and 20 mg/kg LPS groups, N = 10]) alone (●) or with PTX plus LPS (2 × 100 mg/kg i.p., 60 min apart, N = 8 per LPS dose group) (▲). Data are shown as means ± SEM: a indicates that the mean differs from control value in the LPS-treated group; b indicates that the mean differs from control value in the PTX+LPS-treated group; and the asterisk (*) indicates that the mean value in the PTX+LPS-treated group differs from the mean value in the LPS-treated group for the same dose (Kruskal-Wallis and Mann-Whitney tests, P < 0.05).
Fig 5.
Activities (pmol/[min·mg protein]) of CYP2A5 (COH) and CYP1A and CYP2B (EROD and BROD, respectively) in the liver of mice treated with PTX and LPS.
Monooxygenase activities were measured in the liver of female DBA-2 mice 24 h after treatment. Animals were treated with LPS (0, 0.05, 0.1, 0.5, 1, 5, 10 or 20 mg/kg, i.p., N = 10 per dose group) alone (●) or with PTX plus LPS (2 × 100 mg/kg i.p., 60 min apart, N = 8 per LPS dose group) (▲). Data are shown as means ± SEM: a indicates that the mean differs from control value in the LPS-treated group; b indicates that the mean differs from control value in the PTX+LPS-treated group; and the asterisk (*) indicates that the mean value in the PTX+LPS-treated group differs from the mean value in the LPS-treated group for the same dose (ANOVA and Dunnett’s multiple comparison test followed by the Student’s t-test, P < 0.05).
Fig 6.
Effect of inducible NO synthase (iNOS) inhibition with aminoguanidine (AG) on LPS-induced changes in CYP2A5 (COH) and CYP1A and CYP2B (EROD and BROD, respectively) activities (pmol/[min·mg protein]) in the mouse liver.
NO levels were determined in the blood serum and monooxygenase was measured in liver microsomes from female DBA-2 mice 24 h after treatment. Animals were treated with LPS (0 or 10 mg/kg i.p.) alone or LPS (0 or 10 mg/kg i.p.) plus AG (0, 50 or 100 mg/kg i.p.). The mice per group numbered as follows: 0 (PBS alone), N = 7; LPS alone, N = 9; a50 (AG, 50 mg/kg plus PBS), N = 6; a100 (AG, 100 mg/kg plus PBS), N = 6; a50L (AG, 50 mg/kg plus LPS), N = 6; and a100L (AG, 100 mg/kg plus LPS), N = 6. Data are shown as means ± SEM. a and b above the bars indicate that the mean values differ (ANOVA and Bonferroni’s multiple comparison test, P < 0.05) from that of the group treated with PBS alone (a), LPS alone (b), or both.