Abstract: In the present study blue-green alga Spirulina platensis and Spirulina maxima were grown in batch culture at different nitrogen and NaCl concentrations, respectively. Both species were found to respond to nitrogen deficiency and high NaCl level by accumulation of large amounts of commercially important chemicals such as carotenoids and tocopherols. The higher carotenoids and α-tocopherol contents was obtained when Spirulina sp grown at low nitrogen level (51 ppm N), with values ranged from 19.82 to 24.1 mg g-1 and from 533.2 to 978.5 μg Kg-1 (dry weight, d.w.), respectively. Whilst, these values in cells grown in free nitrogen medium were ranged from 30.15 to 31.13 mg g-1 and from 960.4 to 1325.7 μg Kg-1 (d. w), respectively. The high performance liquid chromatography (HPLC) elution patter of total caroteniods extracted from S. platensis and S maxima culture contained β-carotene (49.6 to 319.5 μg g-1), lutein (0.06 to17.21 μg g-1), astaxanthin (6.61 to 160.27 μg g-1), zeaxanthin (1.25 to 18.55 μg g-1) and cryptoxanthin (1.41 to 20.13 μg g-1). S. maxima accumulated a large amount of cryptoxanthin and zeaxanthin than that found in S. platensis. The effect of Spirulina species extracts containing various carotenoid compounds and tocopherols on the viability of Ehrlich ascites carcinoma cells (EACC) were evaluated. All algae extracts at different concentration of 200 and 400 ppm significant reduced the cell viability ranged from 89.11 to 5.25%. These extracts did not induce any significant changes in DNA fragmentation of treated EACC compared with untreated cells. But lactate dehydrogenase (LDH) and glutathione-S- transferase (GST) enzyme activities and glutathione level in treated EACC were significantly higher than that in untreated cells. These finding suggest that algae extracts may be reduce cell viability by other mechanism such as membrane lyases instead of apoptosis. Thus, Spirulina extract rich in carotenoids and tocopherols could be used as chemopreventive agents since they are relative non-toxic