INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY WORLD HEALTH ORGANIZATION TOXICOLOGICAL EVALUATION OF SOME FOOD COLOURS, ENZYMES, FLAVOUR ENHANCERS, THICKENING AGENTS, AND CERTAIN FOOD ADDITIVES WHO FOOD ADDITIVES SERIES 6 The evaluations contained in this publication were prepared by the Joint FAO/WHO Expert Committee on Food Additives which met in Rome, 4-13 June 19741 World Health Organization Geneva 1975 1 Eighteenth Report of the Joint FAO/WHO Expert Committee on Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 557. FAO Nutrition Meetings Report Series, 1974, No. 54. CALCIUM AND SODIUM-5'-RIBONUCLEOTIDES BIOLOGICAL DATA BIOCHEMICAL ASPECTS The biochemistry of the constituent nucleotides has already been discussed and their relationship to purine biosynthesis and uric acid and allantoin formation in mammals is clear (Kojima, 1973). Mice given i.v. 500 mg/kg DSRN showed initial behavioural depression followed by excitation, no muscular relaxation, depressed rotating activity, did not have modified electroshock convulsions, decreased dose-dependency (200 and 500 mg/kg i.v.) the convulsive dose of metrazol. Doses of 50, 125 and 500 mg/kg i.v. all prolonged loss of righting reflex (Kojima, 1973). 10, 25 and 50 mg/kg DSRN i.v. in cats produced transient dose dependent hypotension and increased blood flow to hind limb. 10 mg/kg intra-arterially increased transiently blood flow to hind limbs without affecting ECG. Concentrations up to 10-5 g/ml had no effect on isolated guinea-pig atrium, 10-4g/ml showed positive ino- and chronotropic effects. 100 mg/kg s.c. had no effect on intestinal transport in mice as shown by charcoal transportation. Concentrations below 10-4g/ml had no effect on isolated guinea-pig ileum regarding response to acetyl chlorine, histamineor barium chloride 100 mg/kg s.c. in rats had no effect on gastric juice secretion, pH or total acidity. 100 mg/kg s.c. in mice depressed salivary secretion. 100 mg/kg orally had no diuretic effects in rats. 500 mg/kg orally did not affect the analgesic response of mice and carrageenin oedema in rats (Kojima, 1973). Mice given i.v. 500 mg/kg disodium 5'-ribonucleotide showed initial behavioural depression followed by excitation, no muscular relaxation, depressed rotating activity, did not have modified electroshock convulsions, decreased dose-dependency (200 and 500 mg/kg i.v.) the convulsive dose of metrazol. Doses of 50, 125 and 500 mg/kg i.v. all prolonged loss of righting reflex (Kojima, 1974). 10, 25 and 50 mg/kg disodium 5'-ribonucleotide i.v. in cats produced transient dose dependent hypotension and increased blood flow to hind limb. 10 mg/kg intra-arterially increased transiently blood flow to hind limbs without affecting ECG. Concentrations up to 10 mg/l had no effect on isolated guinea-pig atrium, 100 mg/l showed positive ino- and chronotropic effects. 100 mg/kg s.c. had no effect on intestinal transport in mice as shown by charcoal transportation. Concentrations below 0.1 g/l had no effect on isolated guinea-pig ileum regarding response to acetyl choline, histamine or barium chloride. 100 mg/kg s.c. in rats had no effect on gastric juice secretion, pH or total acidity. 100 mg/kg s.c. in mice depressed salivary secretion, 100 mg/kg orally had no diuretic effects in rats. 500 mg/kg orally did not affect the analgesic response of mice and carrageenan oedema in rats (Kojima, 1973). Three healthy volunteers (males) were given low purine diets containing 250-4 000 mg disodium 5'-ribonucleotide daily. The higher level raised the serum uric acid level and urinary uric acid output but the 2 g level did not raise serum uric acid level above the accepted normal range. No adverse effects were reported (Cooper et al., 1972). TOXICOLOGICAL STUDIES Special studies on reproduction Rat Four groups of 10 male and 20 females were given 0, 0.1%, 1% and 2% DSRN daily in their diet over three generations. No adverse effects have been noted in parent animals as regards mortality, mating performances, body weight change, food consumption, pregnancy rate, duration of gestation and at autopsy. Litter parameters as assessed by loss, size, pup weights, pup mortality and incidence of abnormalities were unaffected by any dose level. Organ weights and skeletal staining and histology of F3 pups on 2% showed no evidence of treatment related effects (Palmer et al., 1971). Special studies on teratogenicity Mouse One group of 14 pregnant mice received daily 2 g/kg bw DSRN during the 8-13th day of pregnancy. No significant effects on the fetuses were noted (Kaziwara et al., 1971). Rat One group of 9 pregnant rats received daily 2 g/kg bw DSRN during days 9-15 of pregnancy. No significant effects on the fetuses were noted (Kaziwara et al., 1971). Monkey Two pregnant cynomolgus monkeys received daily 500 mg/kg bw DSRN and another three pregnant animals received daily 1000 mg/kg DSRN during days 21-31 of pregnancy. No significant effects were noted on fetuses (Kaziwara et al., 1971). Acute toxicity LD50 Animal Route mg/kg bw Reference Mouse Oral and 10 000 Usui et al., 1971 Rat parenteral Short-term studies Rat Five groups of 10 male rats were given 0, 0.2%, 0.4%, 0.8% and 2% disodium 5'-ribonucleotide in their diet daily for six months. No significant abnormalities were seen regarding behaviour, body weight gain, food intake, haematology, urinalysis, macroscopic and histological findings (Usui et al., 1971). Dog Three groups of one male and one female beagle were given 2%, 5% and 10% of disodium 5'-ribonucleotide in their diet for 4-6 weeks without adverse effects (Noel et al., 1970). Long-term studies Rat Three groups of 10 male and 10 female rats each received 0, 1% and 2% DSRN in their diet daily for 24 months. No significant abnormalities were noted regarding behaviour, body weight gain, food intake, haematology, urinalysis, macroscopic and histological findings (Usui et al., 1971). Dog Four groups of four male and four female beagles received 0, 0.1%, 1% and 2% DSRN in their diet daily for two years. No dog died nor were any significant abnormalities noted as regards body weight gain, haematology, clinical biochemistry, ophthalmoscopy and urinalysis. Terminal macroscopy, histology or organ weight studies showed no adverse effects (Rivett et al., 1971). OBSERVATIONS IN MAN Three healthy volunteers (males) were given low purine diets containing 250-4000 mg DSRN daily. The higher level raised the serum uric acid level and urinary uric acid output but the 2 g level did not raise serum uric acid level above the accepted range. No adverse effects were reported (Kojima, 1973). Comments: Inosinates, guanylates and ribonucleotides are substances normally present in all tissues and their role in purine metabolism as well as their breakdown in the majority of mammals, but not man, to uric acid and allantoin is well known. The various products have been studied adequately in long-term, reproduction and teratology tests. Ingestion of large amounts of these compounds by man can increase the serum uric acid level and urinary uric acid excretion and this needs to be considered in relation to people with gouty diathesis and those taking uric-acid retaining diuretics. Hence specific mention of the addition of these substances on the label may be indicated. The changes in dietary purine intake from the use of flavour enhancers are no greater than those likely to be occasioned by changes in consumption of those dietary items, which are the main contributors of purine. EVALUATION Acceptable daily intake not specified1 REFERENCES Cooper, A. J. et al. (1972) Huntingdon Research Centre, Unpublished report Kaziwara, K., Mizutani, M. & Ihara, T. (1971) J. Takeda Res. Lab., 30 (2), 314 Kojima, K. (1973) Toxicology, 2, (In press) 1 The statement "ADI not specified" means that, on the basis of the available data (toxicological, biochemical, and other), the total daily intake of the substance, arising from its use or uses at the levels necessary to achieve the desired effect and from its acceptable background in food, does not, in the opinion of the Committee, represent a hazard to health. For this reason, and for the reasons stated in individual evaluations, the establishment of an acceptable daily intake (ADI) in mg/kg bw is not deemed necessary. Noel et al. (1970) Personal Communication from HRC Palmer, A. K., Lovel, M. R. & Spicer, E. J. F. (1971) Report No. 4554/71/710 by HRC to Takeda Rivett, K. F. et al. (1971) Report No. 4500/71/656 by HRC to Takeda Usui, T. et al. (1970) Personal communication from HRC
See Also: Toxicological Abbreviations