Effect of different concentrations of curcumin on inflammatory factors and endotoxin changes in lung tissues of rats with heatstroke in dry-heat environment / 医学研究生学报

ABSTRACT

Objective Thermal injury causes pulmonary edema, which may lead to acute respiratory distress syndrome, sepsis, multiorgan failure and even death. The article aimed to study the mechanism of curcumin pretreatment on inflammatory factors in lung tissues and serum endotoxin of rats with dry-heat environment.Methods A total of 50 SD rats were randomly divided into 5 groups (n=10) normal control group, dry heat control group, low concentraion group (50mg/kg curcumin pretreatment group), middle concentraion group (100mg/kg curcumin pretreatment group), and high concentration group (200mg/kg curcumin pretreatment group). Rats in normal control group and dry heat control group were given normal saline by gavage, while rats in 3 curcumin pretreatment groups were given curcumin of different concentrations (50 mg/kg, 100 mg/kg, 200 mg/kg) by gavage once a day for 7 consecutive days. At 8d, all the other 4 groups except normal control group were transferred to the climate cabin (The Simulated Climate Cabin for Special Environment of Northwest of China) with the condition of (41±0.5)℃, (10±1)% relative humidity.The rats were put in the dry-heat environment for 150min, then they were anaesthetized and sacrificed at 150min to collect the blood, lung tissues for further analysis. Observation was made on the pathological changes of lung tissues of rats in each group and the changes of inflammatory factors such as IL-1β, IL-6, TNF-α and LPS.Results Compared with dry heat control group, the concentrations of IL-1β, IL-6, TNF-α and LPS in normal control group, curcumin pretreatment groups with low concentration, middle concentration and high concentration were significantly higher(P<0.01). The concentrations of IL-1β, IL-6, TNF-α and LPS in curcumin pretreatment group with low concentration were significantly lower than those curcumin pretreatment groups with middle concentration and high concentration(P<0.05). Compared with curcumin pretreatment group with middle concentration, LPS concentration of curcumin pretreatment group with high concentration decreased significantly (P<0.01). Pearson correlation analysis showed that there was a positive correlation between the plasma of LPS and inflammatory cytokines of IL-1β, IL-6, and TNF-α in lung tissues (correlation coefficient r=0.866, r=0.900, r=0.885, P=0.000).Conclusion Curcumin inhibits bacterial endotoxin in blood, reduces the expression of inflammatory factors, and plays an important role in alleviating secondary multiple organ damage, which means curcumin pretreatment can relieve lung damage caused by heatstroke and reduce the mortality of heatstroke.