EVALUATION OF THE TOXICOLOGICAL RISK TO HUMANS OF CAULERPENYNE USING HUMAN HEMATOPOIETIC PROGENITORS, MELANOCYTES, AND KERATINOCYTES IN CULTURE

The extensive growth of Caulerpa taxifolia in the Mediterranean sea pr oduces important quantities oi bioactive secondary metabolites unable to enter the food chain. The cytotoxic effects oi caulerpenyne, the ma jor secondary metabolite from C. taxifolia, was studied in different i n vitro models: skin cells, primary cultures oi melanocytes and kerati nocytes, immortalized keratinocytes (HaCaT and HESV), and bone marrow cells (hematopoietic progenitors CFU-CM). Typical dose-response curves from neutral red uptake and MTT assays were recorded in all models wi th IC50 ranging from 6 to 24 mu M. Hematopoietic progenitors were more sensitive to caulerpenyne than melanocyte and keratinocyte cell lines , which could be due to their higher proliferative rate. The distribut ion oi aggregates in colonies, macroclusters, and microclusters of hem atopoietic progenitors was also altered in the presence of caulerpenyn e. From our evaluation of the caulerpenyne concentrations required to result in cellular toxicity, the risks of cutaneous and/or food intoxi cation to humans may De considered minimal.