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Antitumor and antifungal activities from red algae Bostrychia radicans and B. tenella (Rhodophyta)
Marine algae have been a rich source of active metabolites with antineoplastic, antimicrobial and antiviral effects . Considering the potential of red algae, the antitumor and antifungal activities were evaluated in Bostrychia radicans (Mont.) Mont. (BRC–shore, BRM–mangrove) and Bostrychia tenella (J.V. Lamour.) J. Agardh (BTC–shore). Investigations were performed using the dichloromethane-methanol (2:1) extracts. These extracts were partitioned yielding hexane, dichloromethane, methanol and aqueous fractions. The antitumor assays were performed using the cell lines HCT-8 (colon); HL-60 (leukemia) and SF-295 (CNS) . The most active fraction, BRC-H (hexane, 100µg/mL), showed inhibition tumor growing of 104.5±0.15% and 36.1±5.0% in HL-60 and HCT-8, respectively, while the hexane fraction obtained from mangrove species did not exhibit any antitumor potential. By means of spectroscopic methods and by comparison with literature data, the major components of BRC-H were determined as: heptadecane, hexadecanoic acid, oleanoic acid, cholesterol, trans-phytol, and others that are being investigated. Also, in a preliminary TLC bioautographic assay with Cladosporium cladosporioides and C. sphaerospermum only the hexane and dichloromethane fractions (200µg) from BRM displayed antifungal activities. However, B. tenella demonstrated interesting antifungal potential from hexane fraction. Also, from BTC initial extract were isolated two phenolic compounds, 1-methoxyphenethyl alcohol and a novel compound, potassium 4-(hydroxymethyl)-benzenosulfonate, but neither showed antifungal property. Thus, these results suggest that red algae are an interesting source of bioactive compounds. Further studies are in progress to determine the IC50 of bioactive fractions and compounds.
Acknowledgements: BIOPROSPECTA-FAPESP, CNPq, CAPES.
References: 1. Xu, N. et al. (2004)J Applied Phycol 16: 451–456 2. Mosmann, T. (1983)J Immunol Meth 16: 55–63.