Protective effect of pristimerin against LPS-induced acute lung injury in mice

Pristimerin (Pris) is a triterpenoid derivative obtained from Celastraceae and Hippocrateaceae families. This compound has been extensively tested for its potent anti-cancer activity against different types of tumors. However, its effects against acute lung injury (ALI) remain to be investigated. This study explored the efficacy of Pris to protect against lipopolysaccharide (LPS)-induced ALI and its possible pathways. Results have shown that Pris possesses potent protective activity against LPS-induced acute lung damage. It significantly decreased pulmonary edema as presented by significant decrease in lung W/D ratio and in protein content. Pris attenuated LPS-induced inflammatory cell infiltration into the lung tissue and suppressed the activity of myeloperoxidase in lung. LPS-induced histopathological lesions were significantly improved via Pris pretreatment. Pris exhibited not only inhibition of LPS-induced oxidative stress, but also enhancement of the suppressed antioxidant capacity of the lung tissue. The anti-inflammatory activity of Pris against LPS-induced ALI was clearly evident via attenuation of the levels of pro-inflammatory cytokines namely, tumor necrosis factor-alpha and interleukin-6. Similarly, Pris inhibited LPS-induced elevation of pro-apoptotic protein, Bax, and caspase-3. Pris also increased the diminished level of Bcl2 induced by LPS. Collectively, Pris exerted protective activity against LPS-induced ALI via anti-oxidant, anti-inflammatory and anti-apoptotic pathways.