To investigate the effects of different doses of curcumin on the levels of immune factors CD11b and CD19 in peripheral blood of heat stroke rats in a simulation dry-heat environment.
METHODS
160 SPF healthy male Sprague-Dawley (SD) rats were selected and divided into different groups according to random number table method: normal saline (NS) control group (given NS), solvent control group [given sodium carboxymethylcellulose (CMCNa)], and curcumin low, medium and high dose pretreatment group (given 0.05, 0.10, 0.20 mg/g of curcumin+0.5% CMCNa solution). There were 32 rats in each group, and were challenged only by 10 mL×kg
-1×d
-1 lavage, and continuous dosing for 7 days. On the 8th day, rats were challenged at ambient temperature (41.0±0.5) centigrade, relative humidity (10±1)% of the northwest in the special environment of artificial lab, placed in 0 (normal temperature), 50, 100 and 150 minutes respectively. The levels of CD19 and CD11b in peripheral blood of each rat were detected by flow cytometry instrument.
With the extension of time in the simulated dry and heat environment, the level of CD11b in peripheral blood was gradually increased in each group, and the peak value was reached at 150 minutes, the NS control group, solvent control group and curcumin low, medium and high dose pretreatment groups were 0.346±0.013, 0.342±0.013, 0.342±0.012, 0.325±0.012, and 0.281±0.012, respectively. In each group, the level of CD19 was first increased and then decreased, reaching its peak value at 100 minutes, and the level of the NS control group, solvent control group and curcumin low, medium and high dose pretreatment groups were 0.586±0.010, 0.601±0.014, 0.684±0.009, 0.613±0.012 and 0.604±0.006, respectively. The level of CD11b in the curcumin medium and high dose pretreatment groups were significantly lower than those in the NS control group and solvent control group (50 minutes: 0.237±0.011, 0.188±0.006 vs. 0.283±0.009, 0.289±0.012; 100 minutes: 0.260±0.010, 0.248±0.008 vs. 0.293±0.008, 0.290±0.007, all P < 0.05), and after placement for 150 minutes, the level of CD11b in the curcumin high dose pretreatment group was significantly lower than that in the NS control group, solvent control group and curcumin low dose pretreatment group (0.281±0.012 vs. 0.346±0.013, 0.342±0.013, 0.342±0.012, all P < 0.05). The level of CD19 in the curcumin low, medium and high dose pretreatment groups were significantly higher than those in the NS control group and solvent control group at 50 minutes in the dry and hot environment (0.394±0.001, 0.436±0.009, 0.553±0.011 vs. 0.205±0.005, 0.197±0.003, all P < 0.05), at 100 minutes, the level of CD19 in the curcumin low dose pretreatment group was significantly higher than that in the NS control group and solvent control group (0.684±0.009 vs. 0.586±0.010, 0.601±0.014, both P < 0.05), there was no significant difference in CD19 level between the other dose pretreatment groups and NS control group; at 150 minutes, there was no significant difference in CD19 level between the curcumin pretreatment groups, the NS control group, and the solvent control group. The peripheral blood immune factors CD11b and CD19 levels in the NS control group and solvent control group were not significantly changed, and there was no significant difference between two groups.Curcumin pretreatment can reduce the level of CD11b and increase the level of CD19 in peripheral blood of rats with dry heat stroke in the early and middle stages, which may enhance the heat resistance and prevent the occurrence of multiple organ dysfunction by increasing the body immunity, and this effect has nothing to do with the dose of curcumin.
