Effects of kaempferol on airway inflammation in rats with chronic obstructive pulmonary disease
Objective To explore the mechanism of kaempferol in improving airway inflammation in chronic obstructive pulmonary disease(COPD)rats.Methods Twenty-for male SD rats were randomly divided into control group,model group(exposed to second-hand smoke for 36 weeks)and experimental group(intragastric administration of 20 mg·kg-1 kaempferol from the 7th day of exposure to secondhand smoke).Pulmonary function was measured by small animal pulmonary function test system,lung index was calculated by body weight and lung weight,inflammatory infiltration and fibrosis changes in lung tissue were observed histologically,the expression of interleukin-1(IL-1),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in bronchoalveolar lavage fluid was detected by enzyme linked immunosorbent assay(ELISA);the expression of superoxide dismutase(SOD)and malondialdehyde(MDA)was detected by the detection kit;and the protein expression of Toll-like receptor 4(TLR4)and nuclear factor-κB(NF-κB)p65 in lung tissue was detected by Western blotting.Results The peak expiratory flow in the control group,model group and experimental group were(19.48±1.61),(15.86±1.00)and(18.07±0.83)mL·s-1;valsalva maneuver were(231.22±10.26),(244.94±9.32)and(225.71±3.80)mL·min-1;lung compliance were(0.53±0.08),(0.29±0.02)and(0.48±0.03)mL·cm-1 H2O;total airway resistance were(0.19±0.12),(0.21±0.01)and(0.20±0.01)cmH2O·mL-1;running economy were(0.19±0.01),(0.26±0.03)and(0.21±0.01)mL·s-1;lung weight were(2.76±0.10),(2.94±0.18)and(2.29±0.26)g;body weight were(375.13±23.55),(243.00±26.75)and(325.38±23.80)g;lung index were 0.74±0.02,1.22±0.09 and 0.70±0.05;the expression levels of cytokines IL-1 in bronchoalveolar lavage fluid(BALF)were(32.39±3.37),(161.88±9.02)and(66.44±6.81)pg·mL-1;IL-6 were(75.07±8.87),(129.58±13.29)and(99.94±9.92)pg·mL-1;TNF-α were(441.76±9.92),(814.47±122.02)and(656.70±70.06)pg·mL-1;MDA expression were(135.73±6.20),(179.05±15.18)and(149.40±13.83)nmol·mL-1;SOD expression were(4 258.55±384.12),(1 232.24±237.08)and(2 134.33±197.99)U·mL-1;TLR4 protein expression level in lung tissue were 0.98±0.02,1.55±0.04,1.34±0.02;NF-κB p65 protein expression level were 0.98±0.02,1.61±0.03,1.09±0.03;the above indicators,control group compared with model group,experimental compared with and model group,the differences were all statistically significant(all P<0.05).Conclusion Kaempferol ameliorates lung injury induced by airway inflammation in COPD rats by inhibiting TLR4/NF-κB signaling pathway.
kaempferolchronic obstructive pulmonary diseaseinflammationToll-like receptor 4/nuclear factor κB signal pathway