https://ntp.niehs.nih.gov/go/tr554abs

Abstract for TR-554

Toxicology and Carcinogenesis Studies of 5-(Hydroxymethyl)-2-Furfural in F344/N Rats and B6C3F1 Mice (Gavage Studies)

CASRN: 67-47-0
Chemical Formula: C6H6O3
Molecular Weight: 126.11
Synonyms/Common Names: 5-Hydroxymethyl-2-formylfuran; 5-(hydroxymethyl)-2-furaldehyde; 5-(hydroxymethyl)-2-furancarbonal; 5-(hydroxymethyl)-2-furancarboxaldehyde (9CI); hydroxymethyl furfuraldehyde; 5-oxymethylfurfurole
Report Date: June 2010

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Abstract

5-(Hydroxymethyl)-2-furfural is formed when reducing sugars such as fructose and sucrose are heated in the presence of amino acids. 5-(Hydroxymethyl)-2-furfural is ubiquitous in the human diet and occurs at concentrations greater than 1 g/kg in dried fruits, caramel products, certain types of fruit juices, and up to 6.2 g/kg in instant coffee. 5-(Hydroxymethyl)-2-furfural also occurs naturally and has been identified in honey, apple juice, citrus juices, beer, brandy, milk, breakfast cereal, baked foods, tomato products, and home cooking of sugar and carbohydrates. Industrially, 5-(hydroxymethyl)-2-furfural is used in the synthesis of dialdehydes, glycols, ethers, aminoalcohols, acetals, and phenol/furfural novolak-type resins. 5-(Hydroxymethyl)-2-furfural was nominated by the National Institute of Environmental Health Sciences for study because of extensive human exposure and the lack of adequate data characterizing its toxicity and carcinogenicity. Male and female F344/N rats and B6C3F1 mice were administered 5-(hydroxymethyl)-2-furfural (at least 99% pure) by gavage in deionized water for 3 weeks, 3 months, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Escherichia coli and mouse peripheral blood erythrocytes.

Three-week study in rats

Core study groups of five male and five female rats were administered 0, 94, 188, 375, 750, or 1,500 mg 5-(hydroxymethyl)-2-furfural/kg body weight in deionized water by gavage for a total of 13 doses over a 22-day period. Special study groups of five male and five female rats designated for neuropathology were administered 0 or 1,500 mg/kg on the same schedule. Except for one 1,500 mg/kg core study male rat, all rats survived to the end of the study. The final mean body weight of 1,500 mg/kg males was significantly less than that of the vehicle control group. No chemical-related histopathologic lesions were observed in core or special study animals.

Three-week study in mice

Groups of five male and five female mice were administered 0, 94, 188, 375, 750, or 1,500 mg 5-(hydroxymethyl)-2-furfural/kg body weight in deionized water by gavage for a total of 13 doses over a 22-day period. Three male and three female mice administered 1,500 mg/kg died before the end of the study. Mean body weights of 1,500 mg/kg males were significantly less than those of the vehicle control group. Heart weights of 1,500 mg/kg females were significantly greater than those of the vehicle controls. No chemical-related lesions were observed.

Three-month study in rats

Core groups and special study groups (for clinical pathology and neuropathological evaluation) of 10 male and 10 female rats were administered 0, 94, 188, 375, 750, or 1,500 mg 5-(hydroxymethyl)-2-furfural/kg body weight in deionized water by gavage for 3 months. One male and three female rats administered 1,500 mg/kg died before the end of the study; the male died as a result of gavage trauma. Mean body weights of 750 and 1,500 mg/kg males were significantly less than those of the vehicle control group. Female rats had elongated estrous cycles; fewer 750 and 1,500 mg/kg females had regular cycles, and 375, 750, and 1,500 mg/kg females had a significantly increased probability of extended diestrus. No chemical-related lesions were observed in core or special study animals.

Three-month study in mice

Groups of 10 male and 10 female mice were administered 0, 47, 94, 188, 375, or 750 mg 5-(hydroxymethyl)-2-furfural/kg body weight in deionized water by gavage for 3 months. One 750 mg/kg male and one 375 mg/kg female died before the end of the study; the death of the female was attributed to ovarian teratoma. The final mean body weight of 750 mg/kg males and body weight gains of 750 mg/kg males and females were significantly less than those of the vehicle controls. The incidences of minimal to mild cytoplasmic alteration of the kidney were significantly increased in males administered 188 mg/kg or greater.

Two-year study in rats

Groups of 50 male and 50 female rats were administered 0, 188, 375, or 750 mg 5-(hydroxymethyl)-2-furfural/kg body weight in deionized water by gavage for 104 weeks. Survival of 188 and 750 mg/kg males was greater than that of the vehicle control group. Mean body weights of dosed groups of males and females were generally similar to those of the vehicle controls throughout the study.

Incidences of olfactory epithelium degeneration were significantly increased in 750 mg/kg males and 188 and 375 mg/kg females. Incidences of olfactory epithelium respiratory metaplasia and respiratory epithelium squamous metaplasia were significantly increased in 750 mg/kg males and females. Incidences of suppurative inflammation of the nose and chronic active inflammation of the nasolacrimal duct were significantly increased in 750 mg/kg females.

Two-year study in mice

Groups of 50 male and 50 female mice were administered 0, 188, 375, or 750 mg 5-(hydroxymethyl)-2-furfural/kg body weight in deionized water by gavage for 104 weeks. Survival of 750 mg/kg males and females was significantly less than that of the vehicle control groups. Mean body weights of 750 mg/kg males were 14% less than those of the vehicle controls after week 26. Mean body weights of 375 and 750 mg/kg females were 9% and 30% less, respectively, than those of the vehicle controls after week 36. Beginning in month 8 and continuing until the end of the study, 750 mg/kg males and females exhibited clinical signs indicative of neurological effects of 5-(hydroxymethyl)-2-furfural administration. These signs included decreased exploratory behavior, piloerection, salivation, Straub tail, catatonia, excitation, dyspnea, clonic-tonic seizures, and unconsciousness. Because of the reduced survival of this group and the presence of the treatment-related clinical signs, groups of mice that received 750 mg/kg were not included in the evaluation of carcinogenic potential.

The incidences of hepatocellular adenoma were significantly increased in 188 and 375 mg/kg females.

In the nose, the incidences of olfactory epithelium metaplasia, degeneration, and hyaline droplet accumulation; chronic active inflammation; respiratory epithelium hyaline droplet accumulation; and hyperplasia, dilatation, and chronic active inflammation of the glands were significantly increased in 375 and 750 mg/kg males and females. Incidences of olfactory epithelium hyperplasia were significantly increased in 375 and 750 mg/kg females.

Genetic toxicology

5-(Hydroxymethyl)-2-furfural was tested in two independent bacterial mutagenicity assays. In the first study, the chemical was weakly mutagenic in Salmonella typhimurium strain TA100 in the absence of exogenous metabolic activation; no mutagenic activity was detected in TA100 with activation or in strains TA97, TA98, TA102, or TA1535, with or without activation. In the second study, no mutagenicity was detected, with or without activation, in TA98 or TA100 or Escherichia coli WP2 uvrA/pKM101. No increases in the frequencies of micronucleated erythrocytes were observed in peripheral blood of male or female mice administered 5-(hydroxymethyl)-2-furfural by gavage for 3 months.

Conclusions

Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of 5-(hydroxymethyl)-2-furfural in male or female F344/N rats administered 188, 375, or 750 mg/kg. There was no evidence of carcinogenic activity of 5-(hydroxymethyl)-2-furfural in male B6C3F1 mice administered 188 or 375 mg/kg. There was some evidence of carcinogenic activity of 5-(hydroxymethyl)-2-furfural in female B6C3F1 mice based on increased incidences of hepatocellular adenoma in the 188 and 375 mg/kg groups.

Administration of 5-(hydroxymethyl)-2-furfural was associated with increased incidences of lesions of the olfactory and respiratory epithelium of the nose in male and female rats and mice.

Studies

Summary of the Two-year Carcinogenesis and Genetic Toxicology Studies of 5-(Hydroxymethyl)-2-Furfural
  Male
F344/N Rats
Female
F344/N Rats
Male
B6C3F1 Mice
Female
B6C3F1 Mice
Doses in deionized water administered by gavage 0, 188, 375, or 750 mg/kg 0, 188, 375, or 750 mg/kg 0, 188, 375, or 750 mg/kg 0, 188, 375, or 750 mg/kg
Body weights Dosed groups similar to vehicle control group Dosed groups similar to vehicle control group 750 mg/kg group was 14% less than vehicle control group after week 26 375 mg/kg group 9% less and 750 mg/kg group 30% less than vehicle control group after week 36
Survival rates 22/50, 34/50, 31/50, 35/50 31/50, 32/50, 27/50, 30/50 40/50, 35/50, 43/50, 15/49 39/50, 42/50, 32/50, 22/50
Nonneoplastic effects Nose: olfactory epithelium, degeneration (18/50, 22/49, 26/48, 29/49); olfactory epithelium, metaplasia, respiratory (2/50, 5/49, 3/48, 11/49); respiratory epithelium, metaplasia, squamous (0/50, 2/49, 1/48, 16/49) Nose: olfactory epithelium, degeneration (21/50, 35/49, 36/49, 28/49); olfactory epithelium, metaplasia, respiratory (1/50, 1/49, 0/49, 11/49); respiratory epithelium, metaplasia, squamous (1/50, 1/49, 0/49, 24/49); inflammation, suppurative (0/50, 0/49, 0/49, 8/49); nasolacrimal duct, inflammation, chronic (2/50, 2/49, 3/49, 12/49) Nose: olfactory epithelium, metaplasia (1/50, 7/50, 38/50, 43/47); inflammation, chronic active (0/50, 6/50, 18/50, 45/47); glands, inflammation, chronic active (4/50, 12/50, 34/50, 43/47); glands, hyperplasia (3/50, 7/50, 45/50, 45/47); glands, dilatation (16/50, 22/50, 47/50, 45/47); olfactory epithelium, degeneration (4/50, 2/50, 17/50, 39/47); olfactory epithelium, accumulation, hyaline droplet (13/50, 17/50, 29/50, 27/47); respiratory epithelium, accumulation, hyaline droplet (14/50, 17/50, 23/50, 31/47) Nose: olfactory epithelium, metaplasia (1/49, 5/49, 30/50, 40/50); inflammation, chronic active (0/49, 1/49, 14/50, 41/50); glands, inflammation, chronic active (1/49, 6/49, 21/50, 38/50); glands, hyperplasia (0/49, 7/49, 42/50, 43/50); glands, dilatation (12/49, 36/49, 48/50, 47/50); olfactory epithelium, degeneration (2/49, 1/49, 34/50, 24/50); olfactory epithelium, accumulation, hyaline droplet (1/49, 1/49, 27/50, 25/50); respiratory epithelium, accumulation, hyaline droplet (4/49, 4/49, 36/50, 27/50); olfactory epithelium, hyperplasia (0/49, 0/49, 8/50, 24/50)
Neoplastic effects None None None Liver: hepatocellular adenoma (14/50, 26/49, 26/50, 6/50)
Level of evidence of carcinogenic activity No evidence No evidence No evidence Some evidence
Genetic Toxicology
Assay Results
Salmonella typhimurium gene mutations: Weakly positive in strain TA100 without S9; negative in TA100 with S9; negative in TA97, TA98, TA102, TA1535, and in Escherichia coli strain WP2 uvrA/pKM101 with and without S9
Micronucleated erythrocytes
Mouse peripheral blood in vivo:
Negative in males and females