Quercetin partially improves lung function in elastase-LPS exposed mice. Mice were anesthetized and pressure-volume relationships, compliance and elastance were measured using flexivent system. Chord length was determined by morphometry. Seven days after the last exposure to elastase/LPS, untreated mice showed a leftward and upward shift in the pressure-volume (PV)-loop (A) compared to PBS-exposed vehicle treated mice, indicative of a loss of elastic recoil. Seventeen days after the last exposure to elastase/LPS, this curve shifted further, indicating progression in the loss of elastic recoil. Quercetin treatment for 10 days prevented progression in loss of elastic recoil in elastase/LPS-exposed mice but had no effect on PBS-exposed mice (B). Each of these mice was examined 17 days after the last elastase/LPS treatment. Elastase/LPS-exposed mice treated with quercetin also showed increased elastance (C), decreased compliance (D) and decreased alveolar chord length (E) compared to vehicle treated mice. Representative PV curves from 5 to 6 mice from each group are shown in A and B. Data in C, D and E represent mean and SD calculated from 6 animals per group (*different from PBS group, p≤0.05 one-way ANOVA; † different from vehicle treated mice, p≤0.05 Mann-Whitney test).