Asiaticoside attenuates hyperoxia-induced lung injury in vitro and in vivo.

Asiaticoside (AS) displays anti-inflammation, and anti-apoptosis effect, but the role of AS in hyperoxia-induced lung injury (HILI) treatment is undefined. Therefore, the aim of this study was to investigate the effects of AS on HILI on premature rats and alveolar type II (AEC II) cells.

Sprague-Dawley premature rats (n=25/group) were exposed to 80% O₂ with or without AS. Then, we detected 80% O₂-induced lung injury and survival rate of premature rat. We tested the concentration of malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidant capacity (TAOC), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β) in premature rats' blood. Then, the AEC II cell apoptosis was observed by Hoechst 33258 staining and flow cytometry. Simultaneously, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathway was measured by Western blot.

Our results found that AS-treated group rats had significantly higher survival rates than 80% O₂ group at day 14 (P<0.05). AS protected HILI, decreased the MPO and MDA concentration, and reversed TAOC level (P<0.05). AS also downregulated the levels of TNF-α, IL-1β, and IL-6 in the premature rat's blood (P<0.01). Moreover, AS markedly attenuated AEC II cell apoptosis and increased Nrf2 and Heme oxygenase 1 (HO-1) expression in the nucleus (P<0.05).

AS showed protective effects on premature rats of HILI in vitro and in vivo. AS can potentially be developed as a novel agent for the treatment of HILI diseases.