Effect of panaxydol on ventilator-induced lung injury in mice: relationship with Keap1/Nrf2 signaling pathway / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of panaxydol on ventilator-induced lung injury(VILI) in mice, and the relationship with Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor E2-related factor 2 (Nrf2) signaling pathway.Methods:Fifty healthy clean-grade male C57BL/6 mice, aged 6-8 weeks, weighing 20-25 g, were divided into 5 groups ( n=10 each) using a random number table method: control group (group C), VILI group, low-dose panaxydol group (L-PX group, 5 mg/kg), medium-dose panaxydol group (M-PX group, 10 mg/kg) and high-dose panaxydol group (H-PX group, 20 mg/kg). The corresponding doses of panaxydol were intraperitoneally injected for 7 consecutive days once a day in L-PX group, M-PX group and H-PX group. The equal volume of normal saline was given instead in C group and VILI group. Only tracheotomy was performed and animals kept spontaneous breathing for 4 h in group C, and the animals were mechanically ventilated (tidal volume 30 ml/kg, respiratory rate 70 breaths/min, inspiratory/expiratory ratio 1∶2, fraction of inspired oxygen 21%) for 4 h in VILI, L-PX, M-PX and H-PX groups. Blood samples from the femoral artery were collected for arterial blood gas analysis at 4 h of ventilation, and PaO 2 was recorded. The mice were then sacrificed under deep anesthesia, and bronchoalveolar lavage fluid (BALF), lung tissues and serum samples were collected. The concentrations of TNF-α and IL-1β in BALF and serum were measured by enzyme-linked immunosorbent assay. The wet/dry lung weight (W/D) ratio was measured, the protein concentrations in BALF were measured by bicinchoninic acid assay, the pathological changes of lung tissues were examined by HE staining, lung injury was scored, and the level of ROS in lung tissues was detected by DCFH-DA fluorescence probe.The expression of Keap1 and Nrf2 in lung tissues was detected by Western blot. Results:Compared with group C, the PaO 2 was significantly decreased, the lung injury score, W/D ratio, protein concentrations in BALF and concentrations of TNF-α and IL-1β in BALF and serum were increased, the expression of Keap1 and Nrf2 was up-regulated, and the fluorescence of ROS was enhanced in the other four groups ( P<0.05). Compared with group VILI, PaO 2 was significantly increased, the lung injury score was decreased, lung W/D ratio, protein concentrations in BALF, and concentrations of TNF-α and IL-1 β in BALF and serum were decreased, and the fluorescence of ROS was weakened in L-PX, M-PX, and H-PX groups, and the expression of Keap1 was down-regulated, the fluorescence of ROS was weakened, and the expression of Nrf2 was up-regulated in M-PX and H-PX groups ( P<0.05). Compared with group L-PX, PaO 2 was significantly increased, the lung injury score, W/D ratio, protein concentrations in BALF and concentrations of TNF-α and IL-1β in BALF were decreased, the expression of Keap1 was down-regulated, and the expression of Nrf2 was up-regulated and the fluorescence of ROS was weakened in M-PX and H-PX groups ( P<0.05). Compared with group M-PX, PaO 2 was significantly increased, the lung injury score, W/D ratio, protein concentrations in BALF and concentrations of TNF-α and IL-1β in BALF were decreased, the expression of Keap1 was down-regulated, the expression of Nrf2 was up-regulated, and the fluorescence of ROS was weakened in H-PX group( P<0.05). Conclusions:Panaxydol can reduce VILI in mice, and the mechanism may be related to activation of the Keap1/Nrf2 signaling pathway and inhibition of oxidative stress.