Arthur A. Nelson

Food flavourings and compounds of related structure. II. Subacute and chronic toxicity

Abstract The subacute and/or chronic toxicity of 48 food flavourings was studied in rats. The toxicity of five of these flavourings (coumarin, 6-methylcoumarin, dihydrocoumarin, methyl salicylate and safrole) was also studied in dogs. A summary of the studies is presented. The loss of 21 flavourings from laboratory animal diets during a 7-day period was also determined.

Chronic oral toxicity of aldrin and dieldrin in rats and dogs

Abstract The results of feeding rats and dogs diets containing aldrin and dieldrin for 2 yr are reported. When groups of 24 (12 male and 12 female) rats were placed on diets containing 0 (controls), 0·5, 2, 10, 50, 100 or 150 ppm of aldrin or dieldrin at 3 weeks of age and continued on their respective diets for 2 yr, neither aldrin nor dieldrin affected growth. Survival was markedly decreased among rats on either supplement at 50 ppm or greater, and a dose-response relationship occurred. Liver weight to body weight ratios were significantly increased in rats at all levels of aldrin and dieldrin fed, although not necessarily for both sexes at each level. Both gross and microscopic changes were caused by aldrin and dieldrin at all levels given. In rats on the higher dose levels distended and haemorrhagic urinary bladders, enlargement of the liver, and an increased incidence of nephritis occurred. Rats, fed smaller amounts of either insecticide, showed a general increase in tumour incidence, which was almost doubled. In rats on all dose levels the characteristic microscopic liver lesions, which occur in rodents given any of a number of chlorinated insecticides, were found. Such liver change was minimal in rats on 0·5 ppm of dieldrin, and especially, of aldrin. Among rats on 50 ppm or more this change was generally pronounced. In a total of 26 dogs, fed aldrin or dieldrin at 0·2–10 mg/kg/day for up to 25 months, those on 0·5 mg or more showed gross toxic effects, including loss of weight and convulsions, and they died progressively earlier with increasing dose level. Microscopic effects were limited to fatty degenerative changes in liver and kidney and bone marrow changes (reduced cellularity, particularly in the erythroid line) in those dogs on 1 mg/kg/day or more of either insecticide. Similar effects occurred in dogs on 0·5 mg dieldrin; however, no microscopic change was noted in dogs on 0·5 mg aldrin. No effect, gross or microscopic, was seen in dogs on 0·2 mg of either insecticide.

Mycotoxins: aflatoxin isolated from Penicillium puberulum.

Penicillium puberulum Bainer was found growing on a sample of moldy peanuts. It also grows on shredded wheat, potatoes, and laboratory culture media such as wort, potato dextrose, and Sabouraud agars, and synthesizes aflatoxin on these substrates. Thin-layer chromatograms of the chloroform-soluble toxin produced by the mold when grown on shredded wheat show fluorescent bands with RF values identical with those of the fractions B1, B2, G1, and G2 of the toxin produced by Aspergillus flavus. This extract produces typical bile duct proliferation type of liver damage in 2-to 3-day-old Peking white ducklings.

The pharmacological evaluation of antioxidants.

Publisher Summary This chapter presents a general plan for the pharmacological investigation, which permits a thorough appraisal of the toxicology of an antioxidant. Many compounds have been found to possess antioxidant properties, the more common compounds being gum guaiac, gallic acid, catechol, and hydroquinone. Naturally occurring antioxidants have received considerable attention, the purpose being to develop a nontoxic substance suitable for food use. Lecithin, cephalin, tocopherols, and products obtained from cereals, yeasts, sugars, and other food substances have been proposed. The criteria that are considered necessary for establishing the usefulness of a chemical as an antioxidant have been listed. Of the many chemicals proposed for antioxidant use and under active investigation, available pharmacological data on the compounds have been listed. The chapter tabulates a summary of the acute toxicity of the antioxidants. Chronic studies on propyl gallate have been conducted in animals such as guinea pigs and dogs, and lifetime feeding studies in rats have been carried out. The predominant pathologic lesions produced by the various antioxidants after lifetime feeding to rats have been summarized.

Chronic oral toxicities of four stearic acid emulsifiers

Four emulsifiers were fed in concentrations ranging from 2% to 25% in the diets of rats for two years; two of these were also fed to dogs for 19 to 20 months at 5% of the diet. Deleterious effects, largely limited to the higher levels of feeding, included increased liver weight with all substances at 25% except Myrj 52, plus the following for each substance. Span 60 caused significant increase in mortality of rats at the 10 and 25% levels, growth depression and kidney enlargement at 25%, two instances of enlargement of the common bile duct at the 25% level, and slight fatty changes in some livers. The feeding of 5% had no effect on dogs. Myrj 52 caused growth depression among male rats fed at 25% dietary concentration, diarrhea ranging from marked to slight from the 25% level downward, very slight to moderate enlargement of the cecum at the three higher levels, and very slight focal adenomatoid hyperplasia of the liver at 10% and 25%. Tween 60 produced marked diarrhea at 10% and 25%, enlargement of the cecum which was slight to moderate at the 25% level and less at 10%, and questionable fatty changes of a very slight degree in the livers of rats fed at 25%. Myrj 45 produced bladder stones in about one-third of the 25% male rats (27 of 87) with associated bladder tumors in nearly half of these (13 of 27). One female also had bladder stones. Bladder stones did not occur below the 25% feeding level. The incidence of spontaneous tumors was affected in male rats at the 2% and 5% levels. Livers were significantly heavier at 5% and 10% and slight fatty changes occurred in some livers, the numbers increasing with dosage. Dogs exhibited no distinct effect due to the feeding of 5% Myrj 45. Myverol 18-00 used as a control at 25% (the only level fed) caused a mild degree of renal tubular calcification.

Chronic toxicity of two food colors, Brilliant Blue FCF and Indigotine

Abstract Brilliant Blue FCF (FD & C Blue No. 1) and Indigotine (FD & C Blue No. 2) were fed to groups of 24 Osborne-Mendel rats for two years at dietary levels of 0.5, 1.0, 2.0, and 5.0%. Growth inhibition occurred in the male animals fed Indigotine at the 2.0 and 5.0% levels. No effect was observed on survival, hematology, or organ weights. No significant pathologic changes were observed in animals fed either color. Five beagle dogs received a dietary level of 2.0%, and three dogs a level of 1.0% of Brilliant Blue FCF for one year. One dog died after 17 days on the 2% dietary level and another died after 46 weeks on the 1% level. Indigotine was fed to beagle dogs for periods up to two years at dietary levels of 1.0 and 2.0%. Four of the six dogs at the 2.0% level died during the two years, and one of the four at the 1.0% level was sacrificed in a moribund condition. All the deaths were attributed to intercurrent virus infections. No clinical signs, gross lesions, or microscopic pathology were attributed to intercurrent virus infections. No clinical signs, gross lesions, or microscopic pathology were attributed to ingestion of Brilliant Blue FCF or Indigotine; however, because of deaths from intercurrent virus infections a no-effect level has not been established for Indigotine. Subcutaneous injections of 30 mg of Brilliant Blue FCF or 20 mg of Indigotine into rats weekly for two years produced fibrosarcomas at the site of injection. Other than acute convulsive deaths of some of the test mice immediately after injection, no deleterious effects attributable to the weekly subcutaneous injection of 2.5 mg of Indigotine were observed over a two-year period.

Chronic oral toxicity of Ponceau 3R.

The results of two-year oral toxicity studies with Ponceau 3R using two strains of rats have been presented. Dosage levels were 5.0, 2.0, 1.0, and 0.5% for Osborne-Mendel rats and one dosage level of 2.0% for Bethesda Black rats. Preliminary results of the continuing dog and mouse studies are reported. Ponceau 3R at 5.0, 2.0, 1.0, and 0.5% of the diet produced high mortality, growth inhibition, and increased weight of the liver and kidneys. Malignant liver tumors occurred in both strains of rats at all dietary levels of Ponceau 3R, statistically significant (P < 0.01) in comparison with the controls at the 5.0% level of the Osborne-Mendel rats and the 2.0% level of the Bethesda Black animals. Incidence of benign liver tumors was also significant for all test levels. Marked weight loss and high mortality have been observed in dogs fed Ponceau 3R at dosage levels of 2.0% and 1.0%. After a feeding period of 32 weeks, changes in the liver were the most pronounced tissue changes. Increased mortality of C3HeBFe mice has been observed on 2.0% and 1.0% feeding levels. Hepatic adenomas and carcinomas have been observed on the 2.0% level.

Chronic rat and dog toxicity studies on tartrazine

Rats. Five groups of 24 Osborne-Mendel weanling rats, evenly divided by sex, were fed 5.0, 2.0, 1.0, 0.5, and 0.0% tartrazinemixed in their Purina laboratory chow diet for 2 years. Growth effect was negligible, and there was no effect on survival, hematology, or organ weights. The rats evidenced diarrhea at the 5% dosage level, slight diarrhea at the 2% level, and no diarrhea at the 1% level. The incidence of tumors and of the common incidental diseases was unaffected. No organ pathology attributable to treatment was noted except at the highest dosage level, where the feeding of tartrazine may have influenced the deposition of small amounts of gritty material in the renal pelvis of some of the surviving male rats. Dogs. Three groups of two male and two female beagles each were fed diets containing 2, 1, and 0% tartrazine for 2 years. No clinical symptoms of toxicity or hematologic abnormalities were noted during the study. No gross lesions were noted at autopsy. Histopathology was limited to the usual incidental lesions which, with the possible exception of pyloric gastritis in one high dose level dog, were not attributable to tartrazine toxicity.

Chronic toxicity of three food colourings: Guinea Green B, Light Green SF Yellowish and Fast Green FCF in rats, dogs and mice

Abstract The results of feeding rats, dogs and mice diets containing Guinea Green B, Light Green SF Yellowish or Fast Green FCF for 2 yr are reported. Results of weekly subcutaneous injections of each of the three colourings into rats for 2 yr, as well as thrice-weekly intraperitoneal injections of Light Green SF Yellowish for 2 yr, are also reported. Guinea Green B, Light Green SF Yellowish or Fast Green FCF were fed to groups of weanling Osborne-Mendel rats, 50 per group and evenly divided by sex, at dietary levels of 0·0, 0·5, 1·0, 2·0 and 5·0% for 2 yr. Growth inhibition occurred in male rats fed Light Green SF Yellowish at the 2 and 5% levels and in females at the 5% level. No gross or microscopic lesions could be attributed to the feeding of Light Green SF Yellowish or Fast Green FCF. Rats fed Guinea Green B at the 5% level were mildly anaemic. Growth depression was observed in male animals on both the 2·0 and 5·0% feeding levels. Liver weights, expressed as organ to body weight ratios, were increased in males at the 2 and 5% levels and in females on the 5% level. Pathological effects attributable to ingestion of the colouring were limited to hepatic changes, the most important being increased incidence of total hepatic neoplasms (nine rats on 5% versus none in controls; however, only two were malignant). Intraperitoneal injections of Light Green SF Yellowish for 2 yr in rats did not produce any tumours. A high incidence of injection-site fibrosarcomas was produced in rats given repeated subcutaneous injection of Light Green SF Yellowish or Fast Green FCF. A lesser incidence was obtained with Guinea Green B. The three green colourings, Guinea Green B, Light Green SF Yellowish and Fast Green FCF, were each fed at dietary levels of 0·0, 1·0 and 2·0% to groups of two male and two female beagle dogs for 2 yr. Ten of the 12 dogs fed Guinea Green B survived in good clinical condition. A male at 2% was killed after 1 yr when he became moribund and a female at 1% died after 5 months. Both non-survivors showed generalized inanition-type atrophy of the bone marrow, fat, skeletal muscle, adrenal cortex, lymphatic tissue and the gastric mucosa. Moderate periportal fatty metamorphosis of the liver was observed in a male survivor on 2%. No clinical signs of toxicity were attributable to Light Green SF Yellowish. Gross changes attributable to this compound were greenish coloration of the retropharyngeal lymph nodes, mesenteric lymph nodes, kidney cortices and urine. Livers appeared slightly enlarged in the four dogs at the 2% level. Slight hepatic congestion was observed in two females, one each at the 1 and 2% levels. Slight orange granularity of the hepatic cell cytoplasm appeared in two males at 2%. Ten of the 12 dogs fed Fast Green FCF survived in good clinical condition. A control male died after 3 months and a control female which became moribund was killed after 3·5 months; both had canine distemper. The skin and hair, intestinal contents, lymph nodes, and urine appeared green in the test dogs. Green blobs of pigment in the tubular epithelium of the renal cortex were noted in a male at 2%. Slight interstitial nephritis and slight bone marrow hypoplasia were found in a female at 2%. Mice (strain C 3 HeB/FeJ) were fed Guinea Green B, Light Green SF Yellowish or Fast Green FCF for 2 yr at dietary levels of 0·0, 1·0 and 2·0%. A total of 400 mice was studied for each colouring to determine a possible tumorigenic effect. Mice fed Guinea Green B at the 1% level had a high percentage of tumours; however, there was no statistically-significant difference in tumour incidence between the three dietary-level groups. Increased survival occurred at the 1% feeding level of Light Green SF Yellowish. Compared with control groups, the total tumour incidence of the lungs of all test groups was significantly raised and this indicated a possible mild pulmonary tumorigenic effect, but there was no increase in the incidence of either malignant lung tumours or of tumours in other organs. Mortality was increased at the 2% level of Fast Green FCF at 78 wk but no significant difference in mortality was observed among the three groups at 2 yr.

Oral toxicities of lauric acid and certain lauric acid derivatives

Abstract Subacute toxicity data for lauric acid and sorbitan monclaurate (Span 20) and chronic toxicity data for lauric acid glycerides (S-1062) and polyoxyethylene-20 monolaurate (G-2129) in rats have been presented. Sorbitan monolaurate tested at 25, 20, and 15% levels for 23 weeks caused significant growth depression beginning at the lowest dietary level and significant increase in mortality at the 25% level. There was progressive enlargement of the common bile duct with each increase in dosage, and gangrene of the tail at all feeding levels, with a greater number of rats affected at the 25% dosage. Histologically, liver damage was pronounced and lung changes were present. Polyoxyethylene-20 monolaurate tested at 25, 10, 5, and 2% levels for two years caused growth retardation in male rats at the 25% level. Mortality data showed no significant differences from the controls. There was a progressive increase in incidence of liver cysts and distention of the cecum as the dosage increased. Feeding of lauric acid glycerides at 25% of the diet for two years caused only minor histological changes in the liver. In a group of 5 rats, not microscopically examined, feeding of lauric acid at 10% of the diet for 18 weeks had no deleterious effect.