【Animal Modeling】-Effect of geranin on meconium-induced acute lung injury in neonatal rats and its mechanism

  Objective To investigate the effect of geranin on meconium-induced acute lung injury in neonatal rats and its molecular mechanism.

  Methods Forty-eight 1-day-old SPF male SD rats were injected with 1.5 mL kg of meconium through tracheal intubation to establish a meconium lung injury model. Rats were randomly divided into 4 groups: control group, model group, methylprednisolone group and geranilin group. Automatic blood gas analyzer was used to detect the arterial oxygenation index of rats in each group. HE staining was used to detect the degree of pathological damage of rat lung tissue, and the pathological score of lung damage was performed. Twenty-four hours after the establishment of the lung injury model, the lung tissue was excised and its mass was weighed; inflammatory factors such as tumor necrosis factor-α (TNF-α), interleukin-1β (interleukin-1β) were detected by enzyme-linked immunosorbent assay. 1β, Ⅱ-1β) and Ⅱ-6 levels; Western blot detection of NOD-like receptor with pyrin domain 3 (NLRP3) inflammasome, spliced cystein Winter enzyme 1 (cleaved caspase-1, c-caspase-1) and L-1β protein levels.

  Results Compared with the model group, the mean arterial oxygenation index of rats in methylprednisolone group and geranialin group was significantly decreased (both P<0.05), the degree of pathological injury and the pathological score of lung injury were significantly decreased (both P<0.05). The levels of inflammatory factors TNF-α, L-1β and -6 were significantly decreased (all P<0.01), and the protein expressions of NLRP3, c-caspase-1 and I-1β were significantly down-regulated (all P<0.01).

  Conclusion Geranin has a certain therapeutic effect on meconium-induced acute lung injury in neonatal rats by reducing the arterial oxygenation index and the expression levels of inflammatory factors, and down-regulating the protein expressions of NLRP3, c-caspase-1 and L-1β.