Results and discussionAntioxidant activityReactive oxygen species (ROS) attack and damage mol- ecules in biological systems, leading to various disorders and diseases. Thus, oxidative stress plays a role in many diseases, including hypertension, diabetes mellitus, ath- erosclerosis, ischemic disease, and malignancy. The lipid peroxides (LPOs) malondialdehyde (MDA) and 4-hydrox- ynonenal are important markers of oxidative stress (Yoshi- kawa and Naito 2002). Recently, much attention has been paid to the antioxidant potential of Spirulina species. Many in vitro and in vivo studies show that treatment with Spir- ulina significantly reduces oxidative stress. These antioxi- dant and protective effects are mediated by phycocyanins, β-carotene, and other vitamins and minerals contained within Spirulina (Abdel-Daim et al. 2013; Upasani and Balaraman 2003).