The present investigation aimed to study the biological effects of barely βglucan or barley extracts on arsenic trioxide-induced immunosuppression. Fiftyfour male albino rats (weighing 100±25 g) were divided into eight groups, each 
group including six rats. Group 1: PBS was injected intraperitoneally into the rats, 
while saline was given orally (negative control). Groups 2–8 received daily 
intraperitoneal injections of As2O3 (5 mg/kg) for 4 weeks. Group 2 serves as a 
positive control. The rats in groups 3, 4, and 5 were received daily doses of βglucan extracts of 40, 80, and 160 mg/kg bw/day, respectively, with ATO (arsenic 
trioxide). Groups 6, 7, and 8 were given barley extract at doses of 0.7, 1.4, and 2.8 
g/kg bw/day, respectively, with ATO. At the end of the experiment, all of the rats 
were slaughtered for biochemical, hematological, and histopathological analysis. 
The obtained results revealed that barley β-glucan and barley extracts increased 
CAT and GPx activity while lowering MDA levels in the spleen tissue of rats.