Berberine administrated with different routes attenuates inhaled LPS-induced acute respiratory distress syndrome through TLR4/NF-κB and JAK2/STAT3 inhibition

Abstract

Accumulating evidence showed that berberine possessed the anti-inflammatory action in various diseases caused by inflammation. However, it was still unclear whether both inhalation and injection with berberine produced pulmonary protective role in acute respiratory distress syndrome (ARDS). This study was aimed to evaluate the effects of both administration routes including inhalation and injection with berberine in ARDS induced by lipopolysaccharide (LPS) inhalation. Histopathological examination and weight of lung were evaluated. Phosphorylation of NF-κB, JAK2 and STAT3 were measured to assess the activity of inflammation related signaling pathways. Proinflammatory cytokines including interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the bronchoalveolar lavage fluid (BALF) and serum were also detected. The results showed that LPS caused the lung injury, while both administration routes with berberine attenuated the injury and improved the pulmonary morphology. In addition, the primary TLR4/NF-κB and secondary JAK2/STAT3 signaling pathways which were activated by LPS in lung were totally inhibited by berberine administration. Moreover, proinflammatory cytokines in both BALF and serum were decreased by berberine. Considering that molecular docking simulation indicated that berberine could bind with TLR4, the present suggested that the inhibition of the inflammation related TLR4/NF-κB and JAK2/STAT3 signaling pathways might be involved in the pulmonary protective effect of berberine in LPS-induced ARDS.

Keywords: Acute respiratory distress syndrome (ARDS); Berberine; JAK2; Molecular docking; STAT3; TLR4.

Graphical abstract

Fig. 1

Chemical structure of berberine.

Fig. 2

The weight and leakage of lung was decreased by berberine in LPS induced ARDS mice. (A) Organ coefficients of lung of mice in each group; (B) Wet/dry lung weight ratio of mice in each group. NC, Normal control mice; MC, LPS mice; PC, Positive control mice (injection with dexamethasone, 2 mg/kg), BL, injection with berberine at low dose (1 mg/kg) of berberine; BH, injection with berberine at high dose (2 mg/kg); PIC, inhalation with dexamethasone liquid (0.2 mg/ml); BIL, inhalation with berberine at low concentration (0.1 mg/ml); BIH, inhalation with berberine at high concentration (0.2 mg/ml). All data are expressed as mean ± S.E.M. (n = 8). **P < 0.01 vs NC; ^#P < 0.05 and ^##P < 0.01 vs MC.

Fig. 3

The histopathological injury of lung was ameliorated by berberine in ARDS mice induced by LPS inhalation. After three consecutive days of pretreatment with berberine or dexamethasone, C57BL/6 J mice were intratracheally administered LPS. Lungs from each experimental group were processed for histological evaluation at 12 h after the LPS inhalation. Representative photomicrographs of pulmonary histology (H&E staining, × 40, scale bar 500 μm) are shown as low power full image, the upper-right corner of each picture (H&E staining, × 400, scale bar 50 μm) is high magnification image of the area within the yellow rectangle. NC, Normal control mice; MC, LPS mice; PC, Positive control mice (injection with dexamethasone, 2 mg/kg), BL, injection with berberine at low dose (1 mg/kg) of berberine; BH, injection with berberine at high dose (2 mg/kg); PIC, inhalation with dexamethasone liquid (0.2 mg/ml); BIL, inhalation with berberine at low concentration (0.1 mg/ml); BIH, inhalation with berberine at high concentration (0.2 mg/ml).

Fig. 4

The inflammatory cells count of BALF. (A) Total cells count in BALF; (B) Neutrophils count in BALF. NC, Normal control mice; MC, LPS mice; PC, Positive control mice (injection with dexamethasone, 2 mg/kg), BL, injection with berberine at low dose (1 mg/kg) of berberine; BH, injection with berberine at high dose (2 mg/kg); PIC, inhalation with dexamethasone liquid (0.2 mg/ml); BIL, inhalation with berberine at low concentration (0.1 mg/ml); BIH, inhalation with berberine at high concentration (0.2 mg/ml). All data are expressed as mean ± S.E.M. (n = 8). **P < 0.01 vs NC; ^##P < 0.01 vs MC.

Fig. 5

The molecular docking indicating the complex between TLR4-MD2 and berberine. (A) Whole view of TLR4-MD2 showing the surface of binding pocket with berberine. (B) Enlarged view showing the surface of the binding pocket with berberine. (C) Berberine is depicted in the TLR4-MD2 without protein surface. Enlarged view showing the binding between docking pocket and berberine without protein surface.

Fig. 6

The TLR4/NF-κB signaling was inhibited by administration with berberine in LPS induced ARDS mice. NC, Normal control mice; MC, LPS mice; PC, Positive control mice (injection with dexamethasone, 2 mg/kg), BL, injection with berberine at low dose (1 mg/kg) of berberine; BH, injection with berberine at high dose (2 mg/kg); PIC, inhalation with dexamethasone liquid (0.2 mg/ml); BIL, inhalation with berberine at low concentration (0.1 mg/ml); BIH, inhalation with berberine at high concentration (0.2 mg/ml). All data are expressed as mean ± S.E.M. (n = 8). **P < 0.01 vs NC; ^##P < 0.01 vs MC.

Fig. 7

The levels of inflammatory cytokines (TNF-α, IL-1β) in the serum and BALF were decreased by berberine administration in LPS induced ARDS mice. NC, Normal control mice; MC, LPS mice; PC, Positive control mice (injection with dexamethasone, 2 mg/kg), BL, injection with berberine at low dose (1 mg/kg) of berberine; BH, injection with berberine at high dose (2 mg/kg); PIC, inhalation with dexamethasone liquid (0.2 mg/ml); BIL, inhalation with berberine at low concentration (0.1 mg/ml); BIH, inhalation with berberine at high concentration (0.2 mg/ml). All data are expressed as mean ± S.E.M. (n = 8). **P < 0.01 vs NC; ^##P < 0.01 vs MC.

Fig. 8

The JAK2/STAT3 signaling was inhibited by administration with berberine in LPS induced ARDS mice. NC, Normal control mice; MC, LPS mice; PC, Positive control mice (injection with dexamethasone, 2 mg/kg), BL, injection with berberine at low dose (1 mg/kg) of berberine; BH, injection with berberine at high dose (2 mg/kg); PIC, inhalation with dexamethasone liquid (0.2 mg/ml); BIL, inhalation with berberine at low concentration (0.1 mg/ml); BIH, inhalation with berberine at high concentration (0.2 mg/ml). All data are expressed as mean ± S.E.M. (n = 8). **P < 0.01 vs NC; ^#P < 0.05 and ^##P < 0.01 vs MC.