Fig. 4. Anti-inflammatory HS 18-mer HP protects against liver damage caused by acetaminophen overdose. Panel A shows the mechanism of action of 18-mer HP. Left panel shows that acetaminophen (APAP) is converted to a reactive metabolite, N-acetyl-p-benzoquinone imine (NAPQI) by P450 enzyme in the liver. Middle panel shows that NAPQI causes hepatocyte necrosis leading to DAMP release. DAMPs, i.e. HMGB1, recruit neutrophils to the injury site. This dysregulated response causes continued hepatocyte necrosis and inflammation. 18-mer-HP binds to HMGB1 and neutralizes its pro-inflammatory activity. The right panel shows that neutralization of HMGB1 by 18-mer-HP attenuates neutrophil infiltration, reducing the injury damage caused by dysregulated inflammatory response. Panel B shows the chemical structure of 18-mer-HP.