Compared with vehicle-treated ALI model group, 30 and 60 mg/kg of DYY-4 reduced the levels of C3, C3c and C5a (p < 0.01, Figure 5); while 60 mg/kg of that significantly lowered the levels of C5b-9 and C5aR1 (p < 0.05, Table 2). Here, C3 is linked to acute respiratory distress syndrome.