Acetaminophen (Paracetamol) was used as 1893 to treat pain and fever. The aim of this study was to evaluate the effect of Spirulina algae on the catalase activity of male mice treated with acetaminophen. In this study, 42 adult male mice were divided into seven groups of six. The first group, the control group that received only the standard diet and water. The second group (sham group) which received saline. The third group was treated with acetaminophen (600 mg/kg b.w). The fourth group was treated with Spirulina (600 mg/kg b.w). The fifth group was treated with spirulina (300 mg/kg b.w). The sixth groups of micewere treated with Spirulina 600 mg/kg b.w plus acetaminophen. The seventh groups of micewere treated with Spirulina 300 mg/kg b.w plus acetaminophen. In all groups, the drug was administered through the oral route. All animals were allowed free access to food and water throughout the experiment which lasted for 14 days. Twenty four hours after the last dose was administered (had free access to water), the animals were anesthetized with chloroform vapor, sacrificed and then the catalase activity was measured in liver tissue. In the present study catalase levels in the group treated with acetaminophen showed a significant difference compared with the control group. The sharp decline significantly in the group treated with high doses of acetaminophen plus Spirulina, respectively. The results showed that Spirulina at a dose of 300 mg/kg b.w, shows better protection against damage caused by acetaminophen. The results showed too that the use of Spirulina in combination with acetaminophen modified catalase activity and antioxidant defense system, which showed increased resistance to oxidative stress from drug toxicity.
