Anti-cancer effect
Fucoxanthin is a widely recognized anticancer carotenoid. It has been reported that fucoxanthin could cause growth inhibition of human neuroblastoma GOTO cells (Nishino et al. 1992) and human leukemia cells (Hosokawa et al. 1999), and significantly reduce viability of human prostate and colon cancer cells (KotakeNara et al. 2001, Hosokawa et al. 2004). The metabolic fate of dietary fucoxanthin in mammals has also been investigated. It has been reported that fucoxanthin is hydrolyzed to fucoxanthinol during absorption by Caco-2 human intestinal cells (Sugawara et al. 2002). In another work, fucoxanthinol and amarouciaxanthin were determined to be the primary metabolites of fucoxanthin in rats. Moreover, other metabolites, which were further deacetylated, hydrolyzed, and/or demethylated, were also detected with an LC-MS system. Based on the results, possible metabolic pathways for fucoxanthin in rats were proposed (Sangeetha et al. 2010). These works may help to explain the biological functions of fucoxanthin. The specific objectives will be carried out as follows: a) first, determine the optimum perimeters of extraction of fucoxanthin, including
ratio of extractant to raw material, extraction time, and temperature, then separate, purify, and identify fucoxanthin from algae; and b) use this product to determine the effect of the extracted fucoxanthin, administered daily, on the energy balance of rats fed a high-fat diet.
Fucoxanthin extraction The following steps are involved in extracting fucoxanthin from algae:
and temperature are probably the three most important factors affecting extraction efficiency. Optimized combination of the three parameters is a key to a successful extraction process. In this project, we’ll try to establish a procedure to search for the optimized parameter combination under different conditions (different raw materials, different extractant, etc.)
2. Selection of extractant. Many kinds of low boiling point organic solvents can be used to extract fucoxanthin from the raw material. In some previous works, a high toxic and expensive solvent such as chloroform was employed (Maeda et al. 2005). In order to establish a safe and feasible extraction process, low-toxic and low-cost solvents (e.g. methanol, ethanol, and acetone) and combinations of these will be investigated in this project. Their extraction efficiencies and economic feasibilities will be compared to determine the best option.
Response surface methodology (RSM) is a powerful mathematical and statistical technique for designing experiments, building models, and evaluating effects of independent variables (Box and Draper 1987, Montgomery 1997). It can help researchers get results in interested 229 parameter ranges with fewer experiments. Moreover, different from traditional experiment design, RSM considers not only the effect of a single factor but also the interactions between the factors. The interactions, if any, can be easily observed based on the resulting regression equation. In this project, RSM will be employed to find the optimized parameter combinations of extractant/raw material ratio and extraction time and temperature under different conditions.
3. Optimization of extraction condition. The ratio of extractant to raw material, extraction time,
Radio frequency (RF) heating is a promising dielectric heating technology. The heating
1. Selection of raw material. Thalassiosira weissflogii, a kind of microalgae, rich in fucoxanthin, will be selected as the raw material for the extraction.