Abstract
The chemical and biological diversity of the marine environment is immeasurable and therefore is an extraordinary resource for the discovery of new anticancer drugs. Marine algae are rich sources of new, biologically active compounds. Seaweeds have traditionally been used as food, but have also been used as folk medicine, particularly by coastal peoples. Recently, much attention has been paid to the antitumor activity of seaweeds. Thus, the extracts of some Egyptian marine algae were for their anticancer activity against Ehrlich Ascites Carcinoma (EAC) cell line. This paper highlight the anticancer activity of petroleum ether, chloroform and methanol extracts of the marine algae Ulva rigida, Enteromorpha clathrata, Jania adherans, Corallina elongate in vitro against Ehrlich Ascites Carcinoma (EAC) cell line. The results indicate that chloroform and methanol extracts of Ulva rigida has more activity than other extracts, of other algae in vitro. So methanol and chloroform extracts of Ulva rigida were tested in vivo and the results denote that maximal reductions of tumor volume (84.2 and 77.8) were observed when solid tumor-bearing mice were treated with methanol extracts 60 and 80 µg/ml, respectively. The maximal inhibitory action on the level of lipid peroxidation (64.8 and 69.6 at methanol 80,100 µg/ml, respectively). Treatment with Ulva rigida extracts leads to remarkable increases in of superoxide dismutase and catalase activities that associated with reduction in tumor volume revealing their antitumor activity, (65.0 and 69.0, respectively) and catalase levels (8.1 and 8.3, respectively) at the same concentrations.

Key words: Anticancer, marine algae, Ulva rigida, Enteromorpha clathrata, Jania adherans, Corallina elongate