Salvianolic acid B protects against acute lung injury by decreasing TRPM6 and TRPM7 expressions in a rat model of sepsis

This study aimed to investigate the protective effects of salvianolic acid B (SA-B) on acute lung injury (ALI) through decreasing the expressions of channel kinase’s TRPM6 and TRPM7. Wistar Septic rat models were established by lipopolysaccharide (LPS), which were separated into the control, lipopolysaccharide (LPS), SA-B, SA-B + si-TRPM6, SA-B + si-TRPM7, si-TRPM6, and si-TRPM7 groups. Arterial blood gas, protein content, total white blood cell (WBC) count and the percentage of polymorphonuclear neutrophils (PMN%) were measured. Levels of TNF-α and IL-6 levels in bronchoalveolar lavage fluid (BALF) were monitored. Lung coefficient, myeloperoxidase (MPO) and superoxide dismutase (SOD) activity were conducted by MPO and SOD kit. The mRNA expressions of TRPM6 and TRPM7 were detected by qRT-PCR. Compared with the control group, the PaO₂ and PaO₂ /FiO₂ values exhibited decreases in other group, while the PaCO₂ value_, protein content, total WBC, PMN%, TNF-α, IL-6 levels and lung coefficient values all increased. MPO activity in lung tissue increased, while SOD activity decreased. TRPM6 and TRPM7 expressions increased significantly. Compared with the LPS group, the SA-B, SA-B + si-TRPM6, SA-B + si-TRPM7, si-TRPM6, and si-TRPM7 groups had increased PaO₂ and the PaO₂ /FiO₂ , while decreased PaCO_2, protein content, total WBC, PMN%, TNF-α, IL-6 levels, and lung coefficient. MPO activity in lung tissue decreased while SOD activity increased. Decreased mRNA expressions of TRPM6 and TRPM7 in the SA-B, SA-B + si-TRPM6, and SA-B + si-TRPM6 groups were observed. Through decreasing the expressions of the channel kinase TRPM6 and TRPM7, SA-B protects against ALI in septic rats.