TOXICITY OF LIPOPHILIC FRACTIONS EXTRACTED FROM SUMMER OYSTERS, CRASSOSTREA-GIGAS

The toxicities on mice and Escherichia coli were examined on the lipid extracts from oyster digestive glands treated with 4% acetic acid or PBS at 37 degrees C for 3 h and their lipid fractions (Frs. 1-4) obtained by TLC after the acid treatment. Almost all mice that had been administered intraperitoneally the lipid extracts were alive for 24 h after the injection. The mice which had been given Fr.2 mainly consisting of free fatty acids, the oxides and monoglycerides were killed within 5 h after the injection. Histopathological observation were injury of villi and hemorrhage in the upper intestine, as well as hemorrhage in the kidneys. Fraction 2 markedly inhibited the growth of E. coli. Among the standard fatty acids, polyunsaturated fatty acids (linolic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)) and oxidized EPA or DHA also inhibited the growth at the concentrations of 4.4-5.5 X 10(-3) mM.