Synergistic protection of matrine and lycopene against lipopolysaccharide-induced acute lung injury in mice

Acute lung injury (ALI) is a major cause of morbidity and mortality globally, and is characterized by widespread inflammation in the lungs. Increased production of reactive oxygen species is hypothesized to be associated with ALI. Matrine and lycopene are active products present in traditional Chinese medicine. Matrine is an effective inhibitor of inflammation, whereas lycopene decreases lipid peroxidation. Therefore, it was hypothesized that combinatorial treatment with matrine and lycopene may provide synergistic protection against ALI. In the present study, mice were treated with dexamethasone (DEX; 5 mg/kg), matrine (25 mg/kg), lycopene (100 mg/kg), and matrine (25 mg/kg) + lycopene (100 mg/kg) for 7 days prior to injury induction using lipopolysaccharide (LPS; 5 mg/kg) for 6 h. Lung tissues were collected following the sacrifice of the mice and hematoxylin and eosin staining was used for histological analysis. Malondialdehyde (MDA), glutathione (GSH) and myeloperoxidas (MPO) levels were examined by respective kits. The expressions of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA. The expressions of IκBα and NF-κB p65 were examined by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry. The results indicated that the combined treatment exhibited a similar effect to DEX, both of which attenuated lung structural injuries, downregulated the expressions of IL-6, TNF-α, MPO and MDA, and upregulated that of GSH. Furthermore, the combined treatment and DEX inhibited NF-κB p65 activation. The present study revealed that combined treatment with matrine and lycopene exhibited protective effects on an LPS-induced mouse model of ALI, suggesting that they may serve as a potential alternative to glucocorticoid therapy for ALI.