More effects of chlorinated cake flour

Bleaching and maturing agents- Miscellaneous direct additives no significant increase in GOT or in hepatic lesions detectable by light microscopy, and a detailed investigation by electron microscopy was therefore undertaken. EQ given by gavage or in the drinking-water increased liver weight by 38 and 23”/,. repectively. while levels of the antioxidant in the liver and plasma were about 6.5 and 85 times greater after intubation than after drinking-water treatment. Ultrastructural changes were obvious only in the livers of intubated rats. and consisted of a proliferation of the smooth endoplasmic reticulum. dilatation of the perinuclear space. disorganization of mitochondrial membranes and desquamation and fragmentation of living cells. In rats treated orally. a slight proliferation of the endoplasmic reticulum was the only finding. Endoplasmic reticular proliferation is generally regarded as a sign of microsomal-enzyme induction. which in this case was associated with a decrease rather than an increase in cytochrome P-450 and pro-

BLEACHING More

effects

of chlorinated

cake

AND

flour

Cunningham. H. M. & Lawrence. G. A. (1978). ERect of chlorinated lipid and protein fractions of cake flour on growth rate and organ weight of rats. Bnll. enr. cfv~rum. & Touicol. (U.S.) 19, 73. Chlorinated cake flour lipids. produced during the bleaching of flour with chlorine gas. have been shown to remain in the adipose tissue of rats for about the same period as normal lipids (Cunningham & Lawrence, Fd Cosrnur. Toxicol. 1977. 15. 105). Chlorination of cake flour. flour lipids and wheat gluten yields products that have been found to produce toxic effects when fed to rats for 2 wk (Cifrd in F.C.T. 1978. 16. 191). The work cited above extended the studies in rats and investigated the effects of baking on the toxicity of the chlorinated cake flour lipids. Groups of ten male rats were fed for IO wk on 87,4”,, cake flour containing 7.93”,, protein and 0.2 or I.@‘,, chlorine. The animals given the I”,,-chlorinated flour had reduced weight gains. and the relative weights of liver, kidney, heart and brain were increased. The only effects of 0.2”,,-chlorinated flour were to reduce weight gain and increase relative kidney weight. Lipid and lipid-free fractions of the flour were separately chlorinated with 2,Og chlorine/kg of original flour and fed to rats for 2 wk. The chlorinated

MISCELLANEOUS The

teratogenicity

of crude

papain

Singh, S. & Devi. S. (1978). Teratogenic and embryotoxic effect of papain in rat. ftulitrrl J. nwd. Res. 67, 499.

307

tein synthesis. EQ is apparently not unique in this respect (Meldolesi. Biockrrn. Phurnw. 1967. 16, 125). and. as NDMA can have similar effects. it is suggested that the additive effects of the two compounds may have been responsible ror the observed enhancement or NDMA hepatotoxiciiy. [However, the reductions in liver proteins and cytochrome P-450 concentrations induced by ethoxyquin plus nitrosodimethylamine were not significantly greater than those induced by either compound alone. and a more plausible explanation for the antioxidant’s effects may lie in the BIBRA finding that nitrosodimethylamine metabolism is not mediated entirely by a microsomal mixed-function oxidase system dependent on cytochrome P-450 (Phillips et 01. Fd Cosmet. Toxicol. 1975, 13, 611; Lake er ul. To.uico/ogJ 1976, 5, 297). It seems likely that, in the above study. ethoxyquin induced a different enzyme system, which led to a greater evolution of hepatotoxic metabolites from the nitrosamine.]

MATURING

AGENTS

lipid fraction significantly reduced growth rate and increased the relative weights of liver. kidney and heart. while chlorine in the lipid-Bee fraction produced only an increase in relative kidney weight, Wheat gluten, heed from lipids and chlorinated at 2 or 5”,,, was fed at a level of IO”,, in the rat diet ror IO wk. At 2”,, chlorinated it significantly increased relative kidney weight and at 5”,, it also decreased growth rate. There was again an increase in relative brain weight, but this is normally expected when growth is markedly restricted. Lipids extracted from sponge cakes baked using 0.2”,,-chlorinated cake flour were incorporated into ground rat chow at a level of about 6”/1,. The chow was fed ud lib. to ten rats for 2 wk. controls being pair-fed. The treated rats showed reduced growth rate and increased absolute liver weight compared with controls; brain weight unadjusted for body weight was significantly lower in the exposed rats, providing additional evidence for a reduction in growth. Liver lipids were not altered in any ol these experiments. It appears. therefore, that both the lipid and nonlipid fractions of chlorinated wheat flour have a harmful effect when fed to rats for extended periods. the lipid fractions having the more deleterious effect for the same amount of chlorine. Baking did not counteract these effects.

DIRECT

ADDITIVES

Papain. a proteolytic enzyme obtained from unripe papaya fruit. was found to deplete the cartilage matrix when given intravenously to young rabbits. and its direct injection into the’tibial medulla produced epiphyseal arrest (Cited in F.C.T. 1964. 2. 95). However. the only known effect of its industrial handling is the occasional induction of allergy. particularly asthma