Paquinimod reduces the loss of lung function in aged mice. 18-mo-old C57BL/6J mice were administered paquinimod or vehicle orally each day for 2 mo. A: pressure-volume loops with the area under the curve, forced expiratory volume (FEV) in the first 0.05 s of forced vital capacity (FVC), and compliance analysis were determined in each animal. B: mean linear intercept (MLI) was measured in the lungs of the mice to assess airspace size, and comparative histology images of the four mouse groups are presented here (scale bars = 500 µm). C: bronchoalveolar lavage fluid (BALF) concentrations for IL-6, keratinocyte-derived chemokine (KC), and matrix metalloproteinase-3 (MMP-3) were quantified using Luminex bead assays. Graphs are represented as means ± SE, where n = 6 animals per group. P values shown when comparing both treatments connected by a line were determined by Student t tests.