Effects of andrographolide on the expression of procoagulant and fibrinolytic inhibition factors in rat type II alveolar epithelial cells stimulated by lipopolysaccharide

OBJECTIVE To determine the effect of andrographolide (AD) on the expression of procoagulant and fibrinolytic inhibitory factors in rat type II alveolar epithelial cells (AEC II) stimulated by lipopolysaccharide (LPS). METHODS The AEC II cells RLE-6TN in the logarithmic growth phase were divided into 5 groups: the normal control (NC) group, the LPS group, and the 6.25, 12.5, and 25 mg/L AD groups (AD 6.25 group, AD 12.5 group, AD 25 group). The NC group was cultured with RPMI 1640 conventional medium. In the LPS group, 5 mg/L LPS was added to the RPMI 1640 conventional medium for stimulation. Cells in the AD groups were treated with 6.25, 12.5, and 25 mg/L AD in advance for 1 hour and then given LPS to stimulate the culture. The cells and cell culture supernatant were collected 24 hours after LPS stimulation. The protein and mRNA expressions of tissue factor (TF), tissue factor pathway inhibitor (TFPI), and plasminogen activator inhibition-1 (PAI-1) in cells were detected by Western blotting and real-time fluorescent quantitative polymerase chain reaction (RT-qPCR). The levels of procollagen III peptide (PIIIP), thrombin-antithrombin complex (TAT), antithrombin III (AT-III) and activated protein C (APC) in the cell supernatant were detected by enzyme linked immunosorbent assay (ELISA). RESULTS Compared with the NC group, the protein and mRNA expressions of TF and PAI-1 in the LPS group were significantly increased, and the protein and mRNA expressions of TFPI were significantly reduced. At the same time, the levels of PIIIP and TAT in the cell supernatant were significantly increased, the levels of AT-III, APC were significantly reduced. Compared with the LPS group, the protein and mRNA expressions of TF and PAI-1 in AD 6.25 group, AD 12.5 group, AD 25 group were significantly reduced [TF/GAPDH: 0.86±0.08, 0.45±0.04, 0.44±0.04 vs. 1.32±0.10, TF mRNA (2-ΔΔCt): 2.59±0.25, 2.27±0.05, 1.95±0.04 vs. 4.60±0.26, PAI-1/GAPDH: 2.11±0.07, 1.45±0.04, 0.86±0.09 vs. 2.56±0.09, PAI-1 mRNA (2-ΔΔCt): 3.50±0.22, 2.23±0.29, 1.84±0.09 vs. 6.60±0.27, all P < 0.05], while the protein and mRNA expressions of TFPI were significantly increased [TFPI/GAPDH: 0.78±0.05, 0.81±0.03, 0.84±0.07 vs. 0.36±0.02, TFPI mRNA (2-ΔΔCt): 0.46±0.09, 0.69±0.07, 0.91±0.08 vs. 0.44±0.06, all P < 0.05]. Also the levels of PIIIP and TAT in the cell supernatant were significantly reduced, and the levels of AT-III and APC were significantly increased [PIIIP (μg/L): 13.59±0.23, 12.66±0.23, 10.59±0.30 vs. 15.82±0.29, TAT (ng/L): 211.57±6.41, 205.69±4.04, 200.56±9.85 vs. 288.67±9.84, AT-III (μg/L): 102.95±3.86, 123.92±2.63, 128.67±1.67 vs. 92.93±3.36, APC (μg/L): 1 188.95±14.99, 1 366.12±39.93, 1 451.15±29.69 vs. 1 145.55±21.07, all P < 0.05]. With the increase of the dose of AD, the above-mentioned promotion and inhibition effects became more obvious. In the AD 25 group, TF, PAI-1 protein and mRNA expressions decreased, TFPI mRNA expression increased, PIIIP level in the supernatant decreased and AT-III, APC levels increased compared with AD 6.25 group, the difference was statistically significant, and the decrease of PAI-1 protein expression and PIIIP level in the supernatant were also statistically significant compared with AD 12.5 group. CONCLUSIONS Andrographolide in the dose range of 6.25-25 mg/L can dose-dependently inhibit the expression and secretion of procoagulant and fibrinolytic inhibitor-related factors in AEC II cells RLE-6TN stimulated by LPS, and promote the secretion of anticoagulant factors. 25 mg/L has the most obvious effect.