Protective action of 2,2-bis(parachlorophenyl). 1,1,1-trichloroethane against intoxication of cells by staphylococcal enterotoxin B

Chlorinated hydrocarbon 2,2-bis(parachlorophenyl)-1,1,1-trichloroethane (DDT) and its derivative 2,2-bis(parachlorophenyl)-1,1-dichloroethane (o,p'-DDD) protected the cells of human embryonic intestine, Henle strain, against the cytotoxic effects induced by staphylococcal enterotoxin B (SEB). The hydrocarbons were incorporated in the culture medium, and the cytotoxicity of SEB was measured by cell destruction and by inhibition of cell growth during incubation for 48 hr. When DDT at nontoxic levels (4 to 25 mug/ml) was added to cultures, 24 or 4 hr prior to or 7 hr after the administration of toxin (100 mug/ml), the cells did not show the characteristic cytotoxicity. A therapeutic effect was also observed with o,p'-DDD added to cultures 9 hr after SEB. Because the cells treated with DDT for a period of 24 hr remained resistant to the toxin when DDT was removed from the cultures, it appears that DDT acts upon the cells rather then upon enterotoxin B. The protective effect of DDT was also observed against the toxin-induced skin erythemas and necrosis in guinea pigs treated with DDT.