Quercetin intraperitoneal administration ameliorates lipopolysaccharide-induced systemic inflammation in mice.

Aims: The purpose of this study was to unravel pharmacological effects of quercetin (Q) on systemic inflammation in septic mice, and compare it to quercetin-3-glucuronide (Q3G), a major metabolite of Q.

Main Methods: A suitable sepsis mouse model was first established using lipopolysaccharide (LPS) injected intraperitoneally (i.p.). Q or Q3G was administered i.p. to septic mice in a prophylactic or therapeutic manner. Pro-inflammatory (TNF-α, IL-1β and IL-6) and anti-inflammatory (IL-10) cytokine secretion profiles by peritoneal macrophages of the mice were measured using ELISA.

Key Findings: Mice which received 8mg/kg BW LPS i.p. for 12h resulted in intermediate systemic inflammation, suggesting a useful mild septic mouse model. At non-toxic doses, Q or Q3G (0.06 or 0.15μmol/mouse) i.p. injected in a prophylactic manner significantly (P<0.05) increased anti-inflammatory IL-10 secretions by peritoneal macrophages of the LPS-induced septic mice. Q, but not Q3G, i.p. injected in a therapeutic manner significantly (P<0.05) increased IL-10 secretions by peritoneal macrophages of the septic mice.

Significance: Our data suggest that Q, but not Q3G, has pharmacological effects to ameliorate systemic inflammation. These results are the first to show that Q has potent potential against sepsis in both prophylactic and therapeutic manners in vivo.