Thesis (BS Biology) -- University of the Philippines Mindanao, 2002

Cytotoxicity assay was employed using a 96-microwell plate in order to determine the cytotoxic activity of the leaf extracts of Jatropha curcas, Diospyros blancoi, Areca catechu, Ehretia microphylla and Quisqualis indica. In the cytotoxicity test, wells containg nauolii were mixed with different concentrations (10ppm, 100ppm and 1000 ppm) of leaf extracts of the five test plants. Mortality rates were observed after 24 hours. Results showed that the average median lethal concentration of the leaf extracts of J. curcas and A. catechu was 60.34 ppm and 464.05 ppm respectively. LC50 was undetermined for the other three plants since they were not able to cause 50% mortality rate of the brine shrimp nauplii. On the other hand, phenol test was also done in the different leaf extracts on order to detect the probable presence of phenol. Among the five plants, only leaf extract of J. curcas tested positive for the presence of phenol. Thus, it can be concluded that J. curcas leaf extract may contain phenolic compounds that can cause mortality of the brine shrimps nauplii. Substances other than phenols may also cause mortality although at a lower rate