Fig. 1.

Metformin alleviates PM_2.5-induced systemic and pulmonary inflammation. WT and AMPKα2^−/− mice were administered PBS or 10 mg/kg PM_2.5 every other day via intratracheal instillation for 4 weeks. During the entire experimental period, some of the PM_2.5-exposed mice were treated with metformin in the drinking water (300 mg/kg/day). After PM_2.5 exposure, serum IL-6 and TNFα levels (A–B), and mRNA levels of inflammatory and fibrotic genes in the lungs of WT and AMPKα2^−/− mice were measured (C–D). N = 5; data are presented as the mean ± SEM; * indicates p < 0.05, ** indicates p < 0.01.