N-Phenylmaleimide was studied for oral toxicity in rats of both sexes in a single dose toxicity test at doses of 0, 62.5, 125, 250 and 500 mg/kg. The LD50 values were estimated to be 153 mg/kg for males, and 188 mg/kg for females.
N-Phenylmaleimide was studied for oral toxicity in rats in an OECD combined repeat dose and reproductive/developmental toxicity screening test at doses of 0, 2.5, 5, 10 and 20 mg/kg/day (12 animals of each sex per group).
In the males, soiled fur was noted in the 20 mg/kg group. Body weights tended to be decreased in the 20 mg/kg group and transiently lowered food consumption was noted in the 10 and 20 mg/kg groups. On hematological examination, PT and APTT were reduced or tended to be lower than the control in the 20 mg/kg group. On blood chemical analysis, total protein and albumin concentrations were lowered in the 20 mg/kg group. At necropsy, thickened mucosa ulcers and edema in the mucosa of the forestomach were noted at 5 mg/kg or more. Regarding organ weights, the absolute and relative spleen weights tended to be elevated or were increased in the 20 mg/kg group. Histopathological examination, revealed hyperkeratosis, epithelial hyperplasia, erosion and inflammatory cellular infiltration in the mucosa at 5 mg/kg or more. In the 20 mg/kg group, inflammatory cellular infiltration in the mucosa of the glandular stomach were also observed.
In the females, 3 animals died in the 20 mg/kg group. Transiently reduced body weights were noted in the 20 mg/kg group during the pregnancy period along with transiently lowered food consumption. At necropsy, thickening of the mucosa and ulceration in the forestomach were noted in the 10 mg/kg and 20 mg/kg groups. On histopathological examination, hyperkeratosis, epithelial hyperplasia and inflammatory cellular infiltration in the mucosa of the forestomach were noted in all treated groups.
The NOELs for repeat dose toxicity are considered to be 2.5 mg/kg/day for males, and less than 2.5 mg/kg/day for females.
Regarding reproductive/developmental toxicity, no changes caused by the substance were noted in terms of the copulation index, gestation length, delivery conditions, nursing conditions, fertility index, number of corpora lutea, implantation rate, or gestation index.
The NOELs for reproductive performance are considered to be 20 mg/kg/day for both sexes.
Regarding the pups, no changes caused by the substance were noted in terms of the numbers of pups, stillbirths, and live pups born, sex ratio, delivery index, birth index, live birth index, viability index, or body weight.
The NOEL for pup development is considered to be 20 mg/kg/day.
Reverse mutation assays using microorganisms (Salmonella typhimurium, Escherichia coli) were conducted to assess the potential of N-phenylmaleimide to induce gene mutations.
N-Phenylmaleimide induced gene mutations in bacteria under the conditions of this study.
In vitro chromosomal aberration tests using cultured cells (CHL/IU) were conducted to assess the potential of N-phenylmaleimide to induce chromosomal aberrations.
N-Phenylmaleimide induced chromosomal aberrations in cultured cells under the conditions of this study.
| Purity | : | 99.2 % |
| Test species/strain | : | Rat/Crj:CD(SD)IGS |
| Test method | : | OECD Test Guideline 401 |
| Route | : | Oral(gavage) |
| Doses | : | 0(vehicle), 62.5, 125, 250, 500 mg/kg |
| Number of animals/group | : | Males, 5; females, 5 |
| Vehicle | : | Corn oil |
| GLP | : | Yes |
Test results:
The LD50 values were estimated to be 153 mg/kg for males, and 188 mg/kg for females.
| Purity | : | 99.2 % |
| Test species/strain | : | Rat/Crj:CD(SD)IGS |
| Test method | : | OECD Test Guideline 422 |
| Route | : | Oral(gavage) |
| Doses | : | 0(vehicle), 2.5, 5, 10, 20 mg/kg/day |
| Number of animals/group | : | Males, 12; females,12 |
| Vehicle | : | Corn oil |
| Administration period | : | Males, 49 days Females, from 14 days before mating to day 3 of lactation |
| Terminal kill | : | Males, day 50 Females, day 4 of lactation |
| GLP | : | Yes |
Test results:
In the males, soiled fur was noted in the 20 mg/kg group. Body weights tended to be deceased in the 20 mg/kg group and transiently lowered food consumption was noted in the 10 and 20 mg/kg groups. On hematological examination, PT and APTT were lower or tended to be lower than control in the 20 mg/kg group. On blood chemical analysis, total protein and albumin concentrations were reduced in the 20 mg/kg group. At necropsy, ulcers and edema in the mucosa of the forestomach were noted in the 5 mg/kg group, thickened mucosa of the forestomach was noted in the 10 mg/kg group, and thickened mucosa and ulcers of the forestomach were noted in the 20 mg/kg group. Regarding organ weights, the absolute and relative spleen weights tended to be elevated or were increased in the 20 mg/kg group. On histopathological examination, changes were noted in the forestomach as follows: in the 5 mg/kg, 10 mg/kg and 20 mg/kg groups, hyperkeratosis, epithelial hyperplasia and inflammatory cellular infiltration in the mucosa. Inflammatory cellular infiltration in the mucosa of the glandular stomach, and erosion in the forestomach were also noted in the 20 mg/kg group.
In the females, 3 animals died in the 20 mg/kg group. Transiently lowered body weights were noted in the 20 mg/kg group during the pregnancy period, along with tansiently reduced food consumption. At necropsy, thickened mucosa and ulcers in the forestomach were noted in the 10 mg/kg and 20 mg/kg groups. On histopathological examination, changes were noted in the forestomach as follows: hyperkeratosis, epithelial hyperplasia and inflammatory cellular infiltration in the mucosa in the 2.5 mg/kg, 5 mg/kg, 10 mg/kg and 20 mg/kg groups.
The NOELs for repeat dose toxicity are considered to be 2.5 mg/kg/day for males, and less than 2.5 mg/kg/day for females.
<Reproductive and developmental toxicity>
No changes caused by the substance were noted with regard to the copulation index, gestation length, delivery conditions, nursing conditions, fertility index, number of corpora lutea, implantation rate, or gestation index.
The NOELs for reproductive performance are considered to be 20 mg/kg/day for both sexes.
Regarding the pups, no changes caused by the substance were noted in terms of the number of pups, number of stillbirths, number of live pups born, sex ratio, delivery index, birth index, live birth index, viability index, or body weight.
The NOEL for pup development is considered to be 20 mg/kg/day.
| Purity | : | 99.2 % |
| Test species/strains | : | Salmonella typhimurium TA100, TA1535, TA98, TA1537, Escherichia coli WP2 uvrA |
| Test method | : | Guidelines for Screening Mutagenicity Testing of Chemicals (Chemical Substances Control Law of Japan) and OECD Test Guideline 471 |
| Procedures | : | Pre-incubation method |
| Solvent | : | DMSO |
| Positive controls | : | -S9 mix; 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide (TA100, TA98 and WP2 uvrA), Sodium azide (TA1535) and 9-Aminoacridine hydrochloride (TA1537) +S9 mix; 2-Aminoanthracene (all strains) |
| Doses | : | -S9 mix(1st trial); 0, 0.313, 0.625, 1.25, 2.50, 5.00, 10.0, 20.0 μg/plate(all strains) +S9 mix(1st trial); 0, 1.25, 2.50, 5.00, 10.0, 20.0, 40.0, 80.0 μg/plate(all strains) -S9 mix(2nd trial); 0, 0.313, 0.625, 1.25, 2.50, 5.00, 10.0, 20.0 μg/plate(TA100, TA1535, WP2 uvrA) -S9 mix(2nd trial); 0, 2.62, 3.28, 4.10, 5.12, 6.40, 8.00, 10.0 μg/plate(TA98, TA1537) +S9 mix(2nd trial); 0, 1.25, 2.50, 5.00, 10.0, 20.0, 40.0, 80.0 μg/plate(all strains) -S9 mix(confirmative test); 0, 2.62, 3.28, 4.10, 5.12, 6.40, 8.00, 10.0 μg/plate(TA98, TA1537) |
| S9 | : | Rat liver, induced with phenobarbital and 5,6-benzoflavone |
| Plates/test | : | 3 |
| Number of replicates | : | 2 |
| GLP | : | Yes |
Test results:
Genetic effects:
Salmonella typhimurium TA100, TA1535, TA98, TA1537
| + | ? | - | |
| Without metabolic activation: | [*] | [ ] | [ ] |
| With metabolic activation: | [ ] | [ ] | [*] |
Escherichia coli WP2 uvrA
| + | ? | - | ||
| Without metabolic activation: | [ ] | [ ] | [*] | |
| With metabolic activation: | [ ] | [ ] | [*] |
| Purity | : | 99.2 % |
| Type of cell used | : | Chinese hamster lung (CHL/IU) cells |
| Test method | : | Guidelines for Screening Mutagenicity Testing of Chemicals(Chemical Substances Control Law of Japan) and OECD Test Guideline 473 |
| Solvent | : | DMSO |
| Positive controls | : | -S9 mix; Mitomycin C +S9 mix; Cyclophosphamide |
| Doses | : | -S9 mix(short-term treatment); 0, 0.625, 1.25, 2.50, 5.00 μg/mL +S9 mix(short-term treatment); 0, 3.75, 7.50, 15.0, 30.0 μg/mL -S9 mix(short-term treatment, confirmative test); 0, 2.50, 3.00, 3.50, 4.00, 4.50, 5.00 μg/mL |
| S9 | : | Rat liver, induced with phenobarbital and 5,6-benzoflavone |
| Plates/test | : | 2 |
| GLP | : | Yes |
Test results:
Genetic effects:
| clastogenicity | polyploidy | |||||
| + | ? | - | + | ? | - | |
| Without metabolic activation: | [*] | [ ] | [ ] | [ ] | [ ] | [*] |
| With metabolic activation: | [ ] | [ ] | [*] | [ ] | [ ] | [*] |
| 1) | The test was performed by Nihon Bioresearch Inc., 6-104 Majima, Fukuju-cho, Hashima, Gifu, 501-6251, Japan. Tel +81-58-392-6222 Fax +81-58-392-1284 |
| 2) | The tests were performed by the Biosafety Research Center, Foods, Drugs and Pesticides (An-pyo Center), 582-2 Shioshinden, Fukude-cho, Iwata-gun, Shizuoka, 437-1213, Japan. Tel +81-538-58-1266 Fax +81-538-58-1393 |