Effects of melatonin on the expression of hepatic antioxidant enzymes.

<p>Mice were treated as Materials and Methods. Liver samples were collected at 4 h after APAP. The expression of hepatic antioxidant enzymes were detected using real-time RT-PCR. (A) SOD1; (B) Catalase; (C) GSHRd; (D) GSHPx1. All data were expressed as means ± SEM (n = 6). *<i>P</i><0.05, **<i>P</i><0.01 as compared with the control. ‡ <i>P</i><0.05, ‡‡ <i>P</i><0.01 as compared with APAP group.</p

Melatonin protects against APAP-induced hepatocyte death.

<p>Mice were treated as Materials and Methods. Liver samples were collected at 4 h after APAP administration. Hepatocyte death was determined using TUNEL assay. Representative photomicrographs of liver section from mice treated with saline (A as control), APAP alone (B), melatonin alone (C), and combination of APAP and melatonin (D) are shown. (E) TUNEL+ cells were analyzed. All data were expressed as means ± SEM (n = 6). **<i>P</i><0.01 as compared with the control. ‡‡ <i>P</i><0.01 as compared with APAP group.</p

Melatonin attenuates APAP-induced acute liver injury.

<p>Mice were treated as Materials and Methods. Liver samples were collected at 4 h after APAP administration. Representative photomicrographs of liver histology from mice treated with saline (A as control), APAP alone (B), melatonin alone (C), and combination of APAP and melatonin (D) are shown (H & E, magnification: 100×). (E) Sera were collected at 4 h after APAP administration. Serum ALT was measured. All data were expressed as means ± SEM (n = 6). **<i>P</i><0.01 as compared with the control. ‡‡ <i>P</i><0.01 as compared with APAP group.</p

Melatonin attenuates APAP-induced hepatic RIP1 activation and JNK phosphorylation.

<p>Mice were treated as Materials and Methods. Liver samples were collected at 1 h after APAP administration. (A) Hepatic RIP1 was detected by immunoblots. (B) All mice except controls were i.p. injected with APAP (300 mg/kg). In melatonin+APAP group, mice were i.p. injected with different doses of melatonin (1.25, 5, 20 mg/kg) 30 min before APAP (300 mg/kg, i.p.). Liver samples were collected at 4 h after APAP administration. Hepatic phosphorylated JNK was detected by immunoblots. All experiments were repeated for four times. Quantitative analyses of scanning densitometry on four different samples were performed. All data were expressed as means±SEM (n = 4). **<i>P</i><0.01 as compared with the control. ‡‡ <i>P</i><0.01 as compared with APAP group.</p

Effects of melatonin on APAP-induced release of cytochromec and AIF translocation.

<p>Mice were treated as Materials and Methods. Liver samples were collected at 4 h after APAP administration. Nuclear translocation of AIF was analyzed using immunohistochemistry. Representative photomicrographs of liver histology from mice treated with saline (A as control), melatonin alone (B), APAP alone (C) and melatonin+APAP (D) are shown. Original magnification: 200×.(E) Cyt c in cytosol was detected by immunoblots. All experiments were repeated for four times. All data were expressed as means ± SEM (n = 4). **<i>P</i><0.01 as compared with the control. ‡‡ <i>P</i><0.01 as compared with APAP group.</p

Primers for real-time RT-PCR.

<p>Primers for real-time RT-PCR.</p

Effects of melatonin on APAP-induced hepatic GSH depletion.

<p>Mice were treated as Materials and Methods. Liver samples were collected at 4 h after APAP. Hepatic GSH and GSSG contents were detected. (A) GSH; (B) GSSG; (C) GSSG/GSH. All data were expressed as means ± SEM (n = 6). **<i>P</i><0.01 as compared with the control.</p