4-Hydroxybenzoic acid

4-ヒドロキシ安息香酸

[CAS No. 99-96-7]

p-Hydroxybenzoic acid

p-ヒドロキシ安息香酸

Molecular formula: C7H6O3　Molecular weight: 138.13

ABSTRACT

No animals died as a result of the treatment.

Rale and temporary salivation were observed in males and females in the 200 and 1000 mg/kg groups. In males, suppression of body weight gain was noted in the 1000 mg/kg group. Decrease in the percentage of lymphocytes and blood glucose in the 200 mg/kg or more groups and decrease in total protein, and increase in A/G ratio, GPT and GOT in the 1000 mg/kg group were observed. No adverse effects of the compound were found in females.

With regard to reproductive and developmental toxicity, the compound did not demonstrate any adverse effects on reproduction, as well as viability, sex ratio, body weight change and morphological appearance of pups at any of the dose levels tested.

In conclusion, the NOEL for toxicity was suggested to be 40 mg/kg/day in males and females, and that for reproductive and developmental toxicity was 1000 mg/kg/day in males and females.

4-Hydroxybenzoic acid was not mutagenic in Salmonella typhimurium TA100, TA1535, TA98, TA1537 and Escherichia coli WP2 uvrA, with or without an exogenous metabolic activation system.

Genotoxicity of 4-hydroxybenzoic acid was studied by chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells. Structural chromosomal aberrations were induced at 0.70 mg/ml (high concentration) with short-term treatment and exogenous metabolic activation and with continuous treatment. Polyploidy was also induced with 48 h continuous treatment at 0.70 mg/ml. However, no chromosomal aberrations were observed under pH-adjusted conditions in the confirmation test.

Therefore, it was suggested that the chromosome aberrations induced by 4-hydroxybenzoic acid were not caused by the direct effects on DNA.

SUMMARIZED DATA FROM THE STUDIES

1. Repeat Dose and Reproductive/Developmental Toxicity 1)

Purity	:	99.7%
Test species/strain	:	Rat/Crj:CD (Sprague-Dawley)
Test method	:	OECD Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test
Route	:	Oral (Gavage)
Doses	:	40, 200, 1000 mg/kg/day
Number of animals/group	:	Males, 13; Females, 13
Vehicle	:	0.5% CMC Na
Administration period	:	Males, 42 days; Females, from 14 days prior to mating to day 3 of lactation
Terminal killing	:	Males, day 43; Females, day 4 of lactation
GLP	:	Yes

　Test results:

<Repeated dose toxicity>

No animals died in any of the groups. Rale and temporary salivation (sometimes accompanied by rhinorrhea) were intermittently observed throughout the administration period in males and females of the 200 and 1000 mg/kg groups. In males, suppression of body weight gain was noted in the 1000 mg/kg group. Decrease in the percentage of lymphocytes and the blood glucose in the 200 mg/kg or more groups and decrease in total protein and increase in A/G ratio, GPT and GOT in the 1000 mg/kg group were observed. No adverse effects of the compound were found on body weight change in females, food consumption, organ weights, autopsy and histopathological finding in males and females.

<Reproductive and developmental toxicity>

The compound did not demonstrate any adverse effects on copulation, fertility, maintenance of pregnancy, parturition and lactation, as well as viability, sex ratio, body weights and morphological appearance of pups, at any of the dose levels tested.

The NOEL for toxicity was suggested to be 40 mg/kg/day in males and females, and that for reproductive and developmental toxicity was 1000 mg/kg/day in males and females.

2. Genetic Toxicity

2-1. Bacterial test 1)

Purity	:	99.7 wt%
Test species/strains	:	Salmonella typhimurium, TA100, TA1535, TA98, TA1537, Escherichia coli WP2 uvrA
Test method	:	Guidelines for Screening Mutagenicity Testing of Chemicals (Japan) and OECD Guideline No. 471 and 472
Procedure	:	Pre-incubation method
Solvent	:	DMSO
Positive controls	:	-S9 mix, 2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide (TA100, TA98, WP2), Sodium azide (TA1535) and 9-Aminoacridine (TA1537) +S9 mix, 2-Aminoanthracene (five strains)
Doses	:	-S9 mix; 0, 78.1, 156, 313, 625, 1250, 2500, 5000 μg/plate (TA98, TA1537) 0, 313 - 5000 μg/plate (TA100, TA1535, WP2) +S9 mix; 0, 78.1 - 5000 μg/plate (TA1537) 0, 313 - 5000 μg/plate (TA100, TA1535, TA98, WP2)
S-9	:	Rat liver, induced with phenobarbital and 5,6-benzoflavone
Plates/test	:	3
Number of replicates	:	2
GLP	:	Yes

This chemical did not induce mutations in the S. typhimurium and E. coli strains. Toxicity was observed at 5000 μg/plate (TA100, TA98, TA1537) without an S9 mix, and at 1500 μg/plate (TA1537) with an S9 mix. Toxicity was not observed in the other cases.

Genotoxic effects:
Salmonella typhimurium TA100, TA1535, TA98, TA1537

	+	?	-
with metabolic activation:	[ ]	[ ]	[*]
without metabolic activation:	[ ]	[ ]	[*]

Escherichia coli WP2 uvrA

	+	?	-
Without metabolic activation:	[ ]	[ ]	[*]
With metabolic activation:	[ ]	[ ]	[*]

3-2 Non-bacterial in vitro test (chromosomal aberration test) 1)

Purity	:	99.7 %
Type of cell used	:	Chinese hamster lung (CHL/IU) cells
Test method	:	Guidelines for Screening Mutagenicity Testing of Chemicals (Japan) and OECD Guideline No. 473
Solvent	:	Dimethylsulfoxide
Positive controls	:	-S9 mix, Mitomycin C +S9 mix, Cyclophosphamide
Doses	:	-S9 mix (continuous treatment):0, 0.18, 0.35, 0.70 mg/ml -S9 mix (short-term treatment):0, 0.18, 0.35, 0.70 mg/ml +S9 mix (short-term treatment):0, 0.18, 0.35, 0.70 mg/ml
S-9	:	Rat liver, induced with phenobarbital and 5,6-benzoflavone
Plates/test	:	2
GLP	:	Yes

　Test results:

Cytogenetic effects were seen as follows.

Structural chromosomal aberrations (including gap) were induced under the following conditions: with 24 h continuous treatment (0.70 mg/ml: high concentrations, 30.5%); 48 h continuous treatment (0.70 mg/ml, 19.5%); short-term treatment with an exogenous metabolic activation system (0.70 mg/ml: high concentration, 28.2%). Polyploidy was induced under the following conditions: 48 h continuous treatment (0.70 mg/ml, 12.62%); short-term treatment with an exogenous metabolic activation system (0.18 and 0.70 mg/ml: low and high concentrations, 1.13 and 1.18%, respectively). However a, trend test showed no dose dependency of the polyploidy with short-term treatment and the metabolic activation system. A confirmation test was conducted, because 4-hydroxybenzoic acid decreased pH in the medium. After pH-adjustment, no significant structural chromosomal aberrations or polyploidy were observed. Therefore, it was suggested that the chromosome aberrations induced with 4-hydroxybenzoic acid were not caused by direct effects on DNA.

Genotoxic effects:

	clastogenicity			polyploidy
	+	?	-	+	?	-
Without metabolic activation:	[ ]	[ ]	[*]	[ ]	[ ]	[*]
With metabolic activation:	[ ]	[ ]	[*]	[ ]	[ ]	[*]

1)	The tests were performed by the Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano-shi, Kanagawa, 257, Japan. Tel +81-463-82-4751 Fax +81-463-82-9627