OBJECTIVETo prepare the lyophilized powder of naringenin liposome and investigate its pharmacodynamics in rat models of acute lung injury (ALI).

METHODSNaringenin liposome was prepared by ethanol injection method and then its quality was evaluated. Also, the related characteristics was evaluated by adding mannitol (5%,W/V) as lyoprotectant to be freeze-dried. The rat ALI models were established by inhaling lipopolysaccharide (LPS) (5 mg/kg). Totally 48 female Sprague-Dawley rats were randomly divided into six groups:control group(A), LPS group(B), LPS+naringenin group(C), LPS+lyophilized liposome group(D), LPS+dexamethasone group(E), and LPS+blank liposome group(F), with 8 rats in each group. Lung wet/dry weight ratio was calculated, and the histopathological morphologies were observed under the light microscope.

RESULTSThe encapsulation efficiency of the prepared liposome was (82.44 ± 0.98)%, the average particle size was (133 ± 11)nm, and the Zeta potential was (-35.9 ± 5)mV. The angle of repose of lyophilized powder was 36℃ and the bulk density was 0.3 g/ml. Compared with the group A, the lung tissues from groups B to F showed different remarkable histopathological changes under a light microscope, including infiltration of inflammatory cells, capillary congestion, hemorrhage, and marked thickening of the alveolar wall,among which group B and F changed the most significant, followed by group C, whereas groups D and E were the lightest. The wet/dry weight ratios increased in groups B to F compared with group A in some degree, and the increase of the lung wet/dry weight ratio in group D and E was significantly lower than in group B(P=0.0012, P=0.0018).

CONCLUSIONThe technology of preparing naringenin liposome by ethanol injection is simple and feasible, and lyophilized powder has an obvious therapeutic effect on ALI.