The expression of COX-1, COX-2, LOX-12, and CYP450 mRNA in the spleen, bursa of Fabricius, and thymus tissues of chickens. LPS—birds at 32 days of age, for the subsequent 3 days, were intraperitoneally injected at a dose of 250 μg/kg of body weight with E. coli LPS, acetylsalicylic acid (ASA) at a dose of 1 g/kg of diet, and a basal level of vitamin E (vE) at a dose of 80 mg/kg of diet; the vE dose was gradually increased to 160/240 mg/kg of diet during the periods of 8–21 days and 22–35 days, respectively. a,b,c,d The different letters represent significant differences (P < 0.05). The same letters indicate that the differences between the test group and the placebo group were not significant (P > 0.05). Error bars represent the mean values of standard errors for 9 birds in each dietary treatment.