Microalgae have the ability to grow rapidly, synthesize and accumulate large amounts (approximately 20-50% of dry weight) of lipids. A successful and economically viable algae based oil industry will depend on the selection of appropriate microalgal strains and the selection of the most suitable lipid extraction method. In this paper, five extraction methods were evaluated regarding the extraction of lipids from Chlorella vulgaris: Bligh and Dyer, Chen, Folch, Hara and Radin, and Soxhlet. Furthermore, the addition of silica powder was studied to evaluate the introduction of more shear stress to the system as to increase the disruption of cell walls. Among the studied methods, the Bligh and Dyer method assisted by ultrasound resulted in the highest extraction of oil from C. vulgaris (52.5% w/w). Addition of powder silica did not improve the extraction of oil.

We have characterized the structure of a sulfated Dgalactan from the red algae Botryocladia occidentalis. Possibly, the addition of two sulfate esters to a single ␣-galactose residue has an "amplifying effect" on the anticoagulant action, which cannot be totally ascribed to the increased charge density of the polymer. These results indicate that the wide diversity of polysaccharides from marine alga and invertebrates is a useful tool to elucidate structure/anticoagulant activity relationships.

In recent years, much attention has been focused on polysaccharides isolated from natural sources. The aim of this study was to investigate the in vitro and in vivo antitumor properties of a sulfated polysaccharide isolated from the seaweed C. feldmannii (Cf-PLS). Hematological, biochemical and histopathological analyses were performed in order to evaluate the toxicological aspects related to Cf-PLS treatment. Its effects on the immunological system were also investigated. The Cf-PLS did not show any significant in vitro cytotoxicity at the experimental exposure levels that were used, but showed in vivo antitumor effect. The inhibition rates of sarcoma 180 tumor development were 48.62 and 48.16% at the doses of 10 and 25 mg kg(-1), respectively. In addition, Cf-PLS was also able to increase the response elicited by 5-fluorouracil (5-FU) from 48.66 to 68.32%. The histopathological analysis of liver and kidney showed that both organs were moderately affected by Cf-PLS-treatment. Neither enzymatic activity of alanine aminotransferase nor urea or creatinine levels were significantly altered. In hematological analysis, leucopeny was observed after 5-FU treatment, but this effect was prevented when the treatment was associated with the Cf-PLS. It was also demonstrated that Cf-PLS acts as an immunomodulatory agent, raising the production of specific antibodies, and increasing the production of OVA-specific antibodies. It also induced a discreet hyperplasia of lymphoid folicules of the white pulp in the spleen of treated mice. In conclusion, Cf-PLS has some interesting anticancer activity that could be associated with its immunostimulating properties.