Résumé:
Algae are a potentially rich source of metabolites including proteins, lipids, anti-oxidants such as poly-phenols.
The present work is moving to wards an evaluation way that is very exploited in Algeria. Its main objective is the study of the characterization of some bio-chemical elements as well as the metallic contamination by three trace metals namely Zinc, Copper and Lead, at the level of the brown alga Cystoseira stricta sp of the west coast Algerian.
The result sindicate a high yield of crude extract (8.8%). In addition, the brown alga Cystoseira stricta sp is characterized by a high level of total poly-phenols ( 5.43 mg EAG / g DM).
The study of the antioxidant power by two methods, the trapping of the radical DPPH, and the quantification of the total antioxidant capacity, reveals the presence of antioxidant properties for the studied extract.
The evaluation of the sample shows that the brown alga studied is low in lipids whose content is evaluated at (4%).
On the basis of the chemical analysis, the algae have the advantage of being rich in proteins and rawash whose contents are of the order of (21%) and (19.4%) respectively.
Regarding the metal contamination, our alga has higher levels of zinc followed by copper and lead, however these rates remain relatively questionable given the short period of our sampling.
All these results obtained in vitro are only a first step in the search for biologically active natural substances from marine algae. So for futur long-term studies should be considered to confirm the bioactivity of marine algae and their bioaccumulation potential
