Liver gene expressions. Downregulation of iNOS and NF-κB in different treatment groups of paracetamol induced liver damage in mice. Relative expression of iNOS and NF-κB genes by different treatment groups were normalized to the expression of the paracetamol control group. Group 1: normal mice; group 2: paracetamol control (250 mg/kg PCM + PBS); group 3: positive control (250 mg/kg PCM + 50 mg/kg silybin); group 4: acetic acid control (250 mg/kg PCM + 2 mL/kg synthetic vinegar; group 5: acetic acid control (250 mg/kg PCM + 0.08 mL/kg synthetic vinegar; group 6: 250 mg/kg PCM + pineapple vinegar (2 mL/kg); group 7: 250 mg/kg PCM + pineapple vinegar (0.08 mL/kg). Values were significant difference compared with paracetamol control group, P < 0.05. Values are expressed as mean ± SD where * indicates that the values are significantly difference from paracetamol control group, P < 0.05.