Reproductive toxicity studies in rats with rimexolone, a corticoid ophthalmic suspension.

Rimexolone is a potent anti-inflammatory corticosteroid with a lower potential for elevating intraocular pressure, relative to other ophthalmic steroids, and is indicated for postsurgical inflammation and uveitis. Fertility and peri/postnatal toxicities were evaluated at oral gavage doses of 50, 150 or 500 mg/kg, and developmental toxicity at 100, 500, or 1000 mg/kg. In the fertility study, male rats were treated daily beginning 4 weeks prior to mating and females were treated daily beginning 2 weeks prior to mating, and through gestation day 6. Females were necropsied on gestation day 15 and males were necropsied after 10 weeks of exposure. In males, dose-related reductions in mean body weights, body weight gains, and food consumption occurred in all groups. In the 500 mg/kg females, mean body weights were reduced during gestation, and there was an increase in early resorptions and concomitant decrease in viable fetuses at this level. There were no effects on copulation or fertility indices, or on the number of corpora lutea and implantation sites. The no-observed-effect level (NOEL) for fertility and reproductive effects was 150 mg/kg. In the developmental toxicity study, female rats were treated daily from gestation days 6 through 17, necropsied on gestation day 20 and fetuses were evaluated. Maternal toxicity occurred at 500 and 1000 mg/kg as indicated by reduced maternal body weights and body weight gains. However, there was no indication of a developmental effect on fetuses due to rimexolone. The NOEL was 1000 mg/kg for the developing fetuses. In the peri/postnatal toxicity study, female rats were treated daily from gestation day 6 through lactation day 20 and necropsied. F1 developmental and behavioral parameters were evaluated. Selected F1 animals were mated at 12 weeks, allowed to deliver, and necropsied on lactation day 21. At 500 mg/kg, F0 maternal body weights were reduced during gestation and lactation, and F1 pup weights were reduced during lactation and the growth phase. There were no effects on the F1 fertility or reproductive capabilities, or on F2 developmental parameters. The NOEL for the F0 females and F1 offspring was 150 mg/kg. Together, these studies indicate that, unlike some corticosteroids, rimexolone does not produce developmental or reproductive toxicity in rats.     

Effects of valproic acid on fertility and reproductive organs in male rats

Crj:CD(SD)IGS rats were orally administered valproic acid at doses of 250, 500 or 1000 mg/kg/day for 4, 7 or 10 weeks. At each dose, one group of male rats was euthanized after 4-week dosage (4-week dose group) and the other two were mated with untreated females after 4 (7-week dose group) or 7 (10-week dose group) weeks of treatment with valproic acid and their fertility was evaluated. Females were euthanized on day 14-17 of gestation, and numbers of corpora lutea, implantations and live and dead fetuses were recorded. After 4, 7 or 10 weeks of treatment, males were euthanized, genital organs were weighed, the number of sperm in the cauda epididymis was counted, sperm motion analyzed, and histopathological examination of testes performed. The male rats of the 1000 mg/kg dose group died or were moribund 3 or 4 days after the start of treatment. No effects on fertility of male rats were observed up to the 500 mg/kg 10-week dose group. Treatment for 4 weeks at 500 mg/kg/day decreased epididymis weight. After 7 weeks at 500 mg/kg/day, the weights of epididymis, seminal vesicles and prostate were decreased, and the number of sperm heads per cauda epididymis and percentage of motile sperm were reduced. In the 500 mg/kg 10-week dose group, the weight of testis was decreased. On histopathological examination of the testis, degeneration of seminiferous tubules and loss or exfoliation of spermatids were observed, and the ratio of retention of step 19 spermatids in stage IX-XI was increased in the 500 mg/kg 4-, 7- and 10-week dose groups. These results suggest that analysis of sperm motion and histopathological evaluation of testes are sensitive methods for assessing toxicity of valproic acid on male reproductive organs.     

A 40-week male fertility study of the anticancer agent sulofenur (LY186641) administered orally to rats.

Sulofenur was evaluated for fertility effects on rats. Five-week old male rats (20/group) received 0, 5, 30, or 60 mg Sulofenur/kg/day for 14 weeks. Fertility was evaluated five times. Treated males were mated with untreated females at 10 weeks. Half the males from each group were necropsied after the 14-week treatment period and the remainder were mated four additional times during a 26-week posttreatment period. Following each mating, females were killed on gestation-day 20 and examined for evidence of pregnancy. Six weeks after mating trial 5, the remaining males were necropsied. Testes and epididymides were collected, weighed, and examined microscopically. All rats mated in each mating trial, and all control and low-dose animals were fertile. A significant reduction in fertility occurred in the middle- and high-dose males. This was consistent with testicular hypospermatogenesis in these groups. Fertility recovered in the high-dose group following cessation of treatment, but remained reduced in the middle-dose group. Preimplantation and postimplantation loss in mating trial 1 were higher in the middle- and high-dose groups. Abnormal fetuses were present in the high-dose group in mating trial 3, but not in mating trials 4 or 5. In conclusion, male rats given doses of 30 and 60 mg/kg/day of Sulofenur showed hypospermatogenesis and decreased fertility. Spermatogenesis and fertility recovered in the high-dose group. A dose of 5 mg/kg/day did not produce any effect on testes or fertility.     

Acute and subchronic toxicity of FCD, a soybean extract combined with L-carnitine, in Sprague-Dawley rats

Soy products are primarily composed of proteins, phytochemicals such as isoflavones, soy lipids, and carbohydrates. Recently, soy isoflavones with L-carnitine were reported to exhibit anti-obesity effects in mice. FCD, a combination of soybean extract and L-carnitine, is a newly developed food substance. As a part of its safety assessment, acute and 13-week subchronic toxicity studies were performed in a total of 100 Sprague-Dawley (SD) rats. In the acute study, a single limit dose of 2000 mg/kg was orally administered to five male and five female rats. No adverse effects or mortality was observed during a 14-day period or upon gross pathological examination. In the subchronic study, FCD was orally administered in daily doses of 500, 1000, and 2000 mg/kg for 13 weeks, resulting in no mortality, and no changes in hematological and serum biochemistry parameters, gross pathology or histopathology. However, body weights of females were significantly decreased 10 weeks after treatment at an average of 2000 mg/kg. In addition, a slight decrease in mean food and water consumption was observed at the same dose level for 13 weeks. Therefore, the no-observed-adverse-effect-level (NOAEL) of FCD was considered to be 2000 mg/kg for male and 1000 mg/kg for female SD rats.     

Safety profile of thalidomide after 53 weeks of oral administration in beagle dogs.

Fifty-six adult beagle dogs (28 male, 28 female) were orally administered thalidomide at 43, 200, or 1000 mg/kg/day for 53 weeks. Sixteen (2/sex/dose group) and 32 (4/sex/dose group) dogs were euthanized and necropsied after 26 and 53 weeks of dosing, respectively. The remaining 8 animals (2/sex/group; high-dose and control groups) were dosed for 53 weeks, euthanized, and necropsied at 58 weeks after a 5-week recovery period. There were no deaths during the study. The only observed clinical signs attributable to thalidomide administration were green-colored urine, white-colored fecal residue presumed to be unchanged thalidomide, enlarged and/or blue coloration of female mammary tissue, and prolonged estrus. There were no thalidomide-related changes in body weights, food consumption, electrocardiography, ophthalmoscopy, neurological function, and endocrine function. The mostly slight and/or transient variations observed in some hematology and blood chemistry values of dosed dogs were considered to be toxicologically insignificant and were supported by the lack of histopathologic correlates. The only gross finding attributable to thalidomide was a yellow-green discoloration of the femur, rib, and/or calvarium that was observed at each euthanization interval including recovery. There was no microscopic correlate for this finding. No thalidomide-related microscopic changes were seen in any of the organs and tissues at 26 weeks. Mammary duct dilatation and/or glandular hyperplasia observed in females at 53 and 58 weeks and hepatic bile pigment exhibited by high-dose males at 53 weeks were microscopic changes considered to be thalidomide-related. There was no gross and histopathologic evidence of any tumors. In summary, thalidomide at up to 1000 mg/kg/day for 53 weeks did not induce any major systemic toxicity or tumors in dogs. The NOAEL was 200 mg/kg/day.     

Effect of oral administration of 1,3-diphenylguanidine on sperm morphology and male fertility in mice.

An oral testicular toxicity and male fertility study was carried out in CD-1 mice with 1,3-diphenylguanidine (99.9% purity). 1,3-Diphenylguanidine was administered to male mice by daily gavage at dose levels of 0, 0.06, 0.25, 1, 4 and 16 mg/kg body wt. per day during an 8-week premating period. Females were not dosed at any time during the study. Sperm abnormality evaluation was performed in approximately half the males, randomly selected from the control and 16-mg/kg dose group on completion of dosing. The remaining males in the control, 4- and 16-mg/kg body wt per day groups were mated with non-dosed females. Reproductive performance, necropsy findings and litter data were recorded. No differences were found between control and dosed groups in body weight gain during the dosing period, macroscopic observations and organ weights at necropsy. Microscopic examination of the testes and determination of the frequency of total sperm abnormalities in the 16-mg/kg body wt per day group, did not show any effect due to 1,3-diphenylguanidine dosing when compared to the control group, except for a slight increase in sperm with folded tails but normal heads. Male and female fertility as well as reproduction performance were comparable in the groups examined (0, 4 and 16 mg/kg body wt per day). Maternal necropsy findings and litter data did not reveal any dose-related effect. It was concluded that under the conditions of the present study, 1,3-diphenylguanidine did not exert any significant adverse effects on fertility, reproductive capacity or embryonic/fetal development in CD-1 mice when administered to males at levels up to 16 mg/kg body wt per day.     

REPRODUCTION/DEVELOPMENTAL TOXICITY SCREENING TEST IN RATS WITH ORALLY-ADMINISTERED 1-HEXENE

This study was conducted to provide screening information concerning the potential systemic, reproductive and developmental toxicity of 1-hexene when administered orally, by gavage, to male and female rats using a modified OECD 421 protocol. 1-Hexene was administered at doses of 100, 500, and 1000 mg/kg/day in corn oil; the control group received the vehicle at an equivalent volume. The males were treated for 28 days prior to mating and until euthanasia (44 days of dosing). The females were treated for 14 days prior to mating and during mating, gestation, and lactation until euthanasia (41–55 total days of dosing). Females were allowed to deliver and rear their offspring until lactation day 4. The parental rats were subject to a gross and microscopic examination. Viability and development of the pups were followed through lactation day 4. There was no mortality, and there were no clinical signs of toxicity or differences in body weights, weight gain, feed consumption or organ weights. Copulation and fertility indices, precoital intervals, gestation lengths and pregnancy rates were comparable among the groups, and no signs of prolonged delivery or unusual nesting behaviors were noted. Pup viability, body weights, external observations and necropsy data were comparable among the groups. Pitted kidneys were observed at necropsy for two parental males in the 500 mg/kg/day group and three males in the 1000 mg/kg/day group. Microscopic changes in the kidneys of some male rats from the 100, 500, and 1000 mg/kg/day groups consisted of dose-related accumulations of hyaline droplets in the epithelial cells of the proximal convoluted tubules of the kidneys. In summary, the only treatment-related effect noted in this study was hydrocarbon nephropathy in male rats, which is not considered relevant for human health. The NOAEL for systemic and reproductive toxicity was 1000 mg/kg/day, excluding the finding of male rat hydrocarbon nephropathy.     

Reproduction/developmental toxicity screening test in rats with orally-administered 1-hexene

This study was conducted to provide screening information concerning the potential systemic, reproductive and developmental toxicity of 1-hexene when administered orally, by gavage, to male and female rats using a modified OECD 421 protocol. 1-Hexene was administered at doses of 100, 500, and 1000 mg/kg/day in corn oil; the control group received the vehicle at an equivalent volume. The males were treated for 28 days prior to mating and until euthanasia (44 days of dosing). The females were treated for 14 days prior to mating and during mating, gestation, and lactation until euthanasia (41-55 total days of dosing). Females were allowed to deliver and rear their offspring until lactation day 4. The parental rats were subject to a gross and microscopic examination. Viability and development of the pups were followed through lactation day 4. There was no mortality, and there were no clinical signs of toxicity or differences in body weights, weight gain, feed consumption or organ weights. Copulation and fertility indices, precoital intervals, gestation lengths and pregnancy rates were comparable among the groups, and no signs of prolonged delivery or unusual nesting behaviors were noted. Pup viability, body weights, external observations and necropsy data were comparable among the groups. Pitted kidneys were observed at necropsy for two parental males in the 500 mg/kg/day group and three males in the 1000 mg/kg/day group. Microscopic changes in the kidneys of some male rats from the 100, 500, and 1000 mg/kg/day groups consisted of dose-related accumulations of hyaline droplets in the epithelial cells of the proximal convoluted tubules of the kidneys. In summary, the only treatment-related effect noted in this study was hydrocarbon nephropathy in male rats, which is not considered relevant for human health. The NOAEL for systemic and reproductive toxicity was 1000 mg/kg/day, excluding the finding of male rat hydrocarbon nephropathy.     

Subchronic toxicity of plant sterol esters administered by gavage to Sprague-Dawley rats.

The purpose of this study was to investigate the potential subchronic toxicity of plant sterol esters by a 13-week repeated oral dose in Sprague-Dawley rats. The test article was administered once daily by gavage to male and female rats at dose levels of 0, 1000, 3000 and 9000 mg/kg/day for 13 weeks. At the end of treatment period, 10 rats/sex/group were sacrificed, while six rats/sex in the negative control and highest dose groups were sacrificed after a 4-week recovery period. During the test period, clinical signs, mortality, body weights, food and water consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, organ weights and histopathology were examined. Slight decreases in body weight gain were noted at lower doses but were only statistically different from the control animals in the highest dose group. In histopathological examinations, an increase in the incidence of cardiomyopathy with mononuclear cell infiltration was observed in males of the 9000 mg/kg group. Decreased body weight gain and increased incidence of cardiomyopathy observed in the highest dose group were not recovered until the end of the recovery period. There were no adverse effects on mortality, clinical signs, food and water consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, necropsy findings and organ weights in any treatment group. Based on these results, it was concluded that the 13-week repeated oral dose of plant sterol esters resulted in the suppression of body weight gains in both sexes and cardiomyopathy in males at a dose level of 9000 mg/kg/day. The target organ was determined to be heart in males, but not in females. The no-observed-adverse-effect level (NOAEL) was considered to be 3000 mg/kg/day for both sexes.     

Mutagenic,cytogenetic and teratogenic studies on thiophanate-methyl

Graded single doses of thiophanate-methyl (8–500 mg/kg) were injected ip into male mice, which were then mated with untreated females over a subsequent 8-week period. Thiophanate-methyl administered to male mice acutely produced no mutagenic effect in the dominant lethal assay, as measured directly by increased early fetal deaths or indirectly by increased preimplantation losses. In rats injected with this chemical there was no direct relation between dosage levels and percentage of spermatogonial and bone marrow cells showing chromosomal breaks.Thiophanate-methyl was given po (1000, 500 200 and 40 mg/kg/day) to pregnant mice from day 1 to day 15 of gestation. The highest dosage level effected a small difference in the number of living fetuses from the control group but the other groups dosed with 500 mg/kg/day or less presented no differences in implantation sites, number of living fetuses, body weight of living fetuses and number of dead fetuses from the control group. Investigation of cleared skeletons showed no significant difference in the incidence of malformations in all treated groups as compared to the control group. It is concluded that thiophanate-methyl did not exert significant mutagenic, cytogenic and teratogenic effects under the present experimental conditions.     

Thirteen-week oral toxicity study of synthetic lycopene products in rats.

Synthetic crystalline lycopene provides an alternative to extracts of naturally occurring lycopene for use in dietary supplements and functional foods. BASF Lycopene 10 CWD and Lyco Vit 10% formulated products each contain approximately 10% synthetic lycopene. These products were evaluated for toxicological and behavioral effects during a 13-week oral dosing study with male and female Wistar rats. Doses of 0, 500, 1500 and 3000 mg/kg body weight/day Lycopene CWD and 3000 mg/kg body weight /day Lyco Vit, as well as 3000 mg/kg body weight /day of the matrices used to formulate and stabilize each product, were administered by gavage to 10 rats/sex/day. A satellite group of five rats/sex received 0 or 3000 mg/kg body weight /day of each formulated product for an interim evaluation at 4 weeks of feeding. No statistically significant, dose-related effects on body weight, body weight gain, food consumption, hematology, urinalysis, clinical chemistry or ophthalmoscopic parameters were seen in any of the lycopene product or lycopene formulation matrix groups in comparison to the vehicle control group after 4 or 13 weeks of dosing. No deaths attributed to the test articles occurred during the study and the only clinical finding and at necropsy was the presence of red pigment in the feces and gastrointestinal tract that was associated with the red-pigmented test materials. No significant or dose-related abnormalities were found at necropsy or in microscopic evaluations of tissues collected at termination. Rats evaluated in home cages or in open field tests for behavioral and sensorimotor effects during the final week of the study showed no signs of treatment-related effects. The no-observed-adverse-effect level (NOAEL) for this study was concluded to be 3000 mg/kg body weight/day for both Lycopene CWD and Lyco Vit. The results of this study thus demonstrate the absence of any significant toxicological findings with Lycopene CWD and Lyco Vit products even at very high dose levels.     

Subchronic and chronic safety studies with genistein in dogs.

Genistein is a phytoestrogen that occurs naturally in the diet, especially in soy-based foods. There is widespread interest in phytoestrogens as chemopreventive agents for a variety of diseases and cancers based on epidemiologic evidence. Although soy and its constituents, such as genistein, have been consumed at high levels in several Asian populations without apparent adverse effects, concern has been raised about potential adverse effects due to estrogenic and other activities. The subchronic and chronic safety of genistein were evaluated in the beagle dog including a 4-week study and a 52-week safety study with a 13 week interim sacrifice and a 4 week recovery period. In both studies at doses of 50, 150 and 500 mg/kg/day, genistein was well tolerated. In the 4 week study, except for an increase in uterine weights in female dogs at 500 mg/kg/day, there were no other treatment related findings. In the 52-week study, the primary effects of genistein were observed on the reproductive tract, which included for male dogs: reduced size and/or weight of the testes, epididymus and prostate of 2/2 dogs after 13 weeks of treatment and in 1/4 dogs after 52 weeks of treatment at 500 mg/kg/day. The histological changes observed in the affected dogs at 500 mg/kg/day indicated atrophy of the testes and prostate gland and absent spermatozoa in the epididymus. At the mid-dose of 150 mg/kg/day, although there was a reduction to a lesser extent in testes weight after 13, but not 52 weeks, there were no histopathological changes. In female dogs, the reproductive tract effects included increased uterine weight at 500 mg/kg/day after 13 weeks of treatment, but not after 52 weeks of treatment. There was also a small decrease in ovarian weights at 150 and 500 mg/kg/day after 13 weeks and at 500 mg/kg/day after 52 weeks of treatment. There were no histopathological correlates to the changes in organ weights in female dogs. In the 4-week recovery group dogs, no changes were observed in dogs previously treated for 52 weeks with 500 mg/kg/day of genistein. It is concluded that the administration of genistein to dogs for a period of 4-52 weeks was well tolerated and did not result in systemic toxicity. Effects of genistein on the reproductive tract at very high doses were functional in nature and are of a type that would be expected in view of the relatively weak estrogenic activity of genistein and were considered not adverse effects. In the 4-week study, the no observed adverse effect level (NOAEL) for genistein was considered to be >500 mg/kg/day and the no observed effect level (NOEL) was considered to be 150 mg/kg/day. For the 52-week study, the NOAEL is considered to be >500 mg/kg/day and the NOEL is considered to be 50 mg/kg/day.     

Subchronic and chronic toxicity of ingested 1,3-dichloropropene in dogs

The potential toxicologic effects to dogs of 1,3-dichloropropene (1, 3-D), a soil fumigant used for the control of nematodes, were investigated. The 13-week subchronic toxicity study consisted of male and female beagle dogs (4/sex/dose group) given approximately 0, 5, 15, or 41 mg 1,3-D/kg body wt/day (approximately equivalent amounts of cis and trans isomers) via their diets. The 1-year chronic toxicity study consisted of male and female beagle dogs (4/sex/dose group) provided diets delivering approximately 0, 0.5, 2. 5, or 15 mg/kg body wt/day. The test material was stabilized in the feed by microencapsulation in a starch/sucrose matrix (80/20). In both the 13-week and the 1-year studies, the primary effect of 1,3-D in male and female dogs ingesting a dosage of >/=15 mg/kg/day was hypochromic, microcytic anemia. The anemia was regenerative, with increased erythropoietic activity characterized by polychromasia of erythrocytes and increased numbers of reticulocytes in peripheral blood. In the 13-week study, the anemia in dogs given 41 mg/kg/day progressively worsened over time, while the anemia in dogs given 15 mg/kg/day remained relatively constant between 42 and 90 days of dosing. Partial reversal of the anemia of high-dose animals occurred during a 5-week recovery period following the 13-week dosing regimen. In the 13-week study, terminal fasted body weights of males given 15 or 41 mg/kg/day were decreased 3 and 28%, respectively, and body weights of females given 5, 15, or 41 mg/kg/day were decreased 4.5, 12, and 24%, respectively, relative to controls. Males given 5 mg/kg/day for 13 weeks had no change in body weights relative to controls. In the 1-year study, the hypochromic microcytic anemia in dogs given 15 mg/kg/day remained relatively constant in severity between 3 and 12 months of treatment. Histopathologic alterations associated with anemia in the 1-year study consisted of increased hematopoiesis of the bone marrow and increased extramedullary hematopoiesis of the spleen. Body weights of males given 15 mg/kg/day were 5-12% lower than controls during the first 13 weeks of the study and 13-19% lower than controls during the remaining 9 months. Body weights of females given 15 mg/kg/day were 5-14% lower than controls over the majority of the dosing period. Males and females given 0.5 or 2.5 mg/kg/day for 1 year had no change in body weights relative to controls. A no-observed-effect level of 2.5 mg/kg/day was established for male and female dogs from the 1-year study.     

Prechronic Toxicity Studies on 2-Ethylhexanol in F334 Rats and B6C3F1 Mice

Data on the subchronic toxicity of 2-ethylhexanol (2EH) wererequired to establish the dose vehicle and dose levels for oncogenicitystudies. In preliminary studies 2EH was given subacutely (11days) to male and female Fischer 344 rats and B6C3F1 mice asan aqueous emulsion by oral gavage (0, 100, 330, 1000, and 1500mg/kg/day). Clinical observations were made, body weights, foodconsumption, clinical chemistries, hematologies, and selectedorgan weights were measured, and gross and micropathologieswere performed. Target organs were the central nervous system,liver, forestomach, spleen, thymus, and kidney in rats and thecentral nervous system, liver, and forestomach in mice. 2EHwas then administered by oral gavage to male and female F344rats and B6C3F1 mice as an aqueous emulsion (0, 25, 125, 250,and 500 mg/kg/day) for 13 weeks. At 500 mg/kg/day in the ratthere was reduced body weight gain (6% male, 7% female), increasedrelative liver (29% male, 15% female), kidney (16% male, 6%female), stomach (11% male, 16% female), and testes (6%) weights,and moderate gross and microscopic changes in the liver andforestomach. There were no behavioral effects or effects onthe spleen or thymus. A no-effect level for target organ effectsin the rat was 125 mg of 2EH/kg/day. At 500 mg of 2EH/kg/dayin the mouse the only effects were increased relative stomachweights in males (13%) and a low incidence of gross and microscopicfindings in the forestomach (male and female) and liver (female).A no-effect level for target organ effects in the mouse was125 mg of 2EH/kg/day. 2EH was a peroxisome proliferator in therat but not in the mouse at subchronic dose levels of 500 mg/kg/day.Dose levels in oncogenicity studies were set at 50 mg/kg/dayfor the absence of treatment-related effects in rats and mice,and 500 and 750 mg/kg/day, respectively, in rats and mice ashigh doses producing minimal toxicity without altering the lifespan.     

Subchronic toxicity study of the total flavonoids from Rosa laevigata Michx fruit in rats

The total flavonoids (TFs) from Rosa laevigata Michx fruit showed hepatoprotective and antioxidant activities. However, the safety of this natural product has not been investigated. In the present paper, a 90-day subchronic toxicity study was conducted, and the tested TFs was orally administered to rats at the doses of 500, 1000 and 2000mg/kg/day. The toxicity of the TFs was evaluated on base of ophthalmic examination, body weight, feed/water consumption, urinalysis, hematology, clinical biochemistry and pathology. No toxic signs of the TFs at the doses of 500 and 1000mg/kg/day were observed. However, decreased PLT was found in the 2000mg/kg/day groups and increased intercellular space of myocardial cells was observed in the male 2000mg/kg/day group compared with control. A significant increase in the relative cardiac weight was observed in the male 1000 and 2000mg/kg/day groups. And the significant decrease in the absolute and relative weight of adrenals in the female 1000 and 2000mg/kg groups was happened. The TFs could cause mild side effects at the dose of 1000mg/kg/day in males and females. Thus, the dose of 500mg/kg/day for male and female were selected as the no-observed-adverse-effect level (NOAEL). The present study provides useful data for subsequent researches and new drug exploration of the TFs from R. laevigata Michx fruit.     

Reproductive Toxicity Evaluation of Methylethyl Ketoxime by Gavage in CD Rats

Methylethyl ketoxime (CAS No. 96-29-7; MEKO; 2-butanone oxime),an antioxidant agent used in paints, resins, and adhesives,was tested for reproductive toxicity in a two-generation studywith CD (Sprague-Dawley) rats. Thirty-eight-week-old rats/sex/group(F0) were administered MEKO in water, by gavage, at 0, 10, 100,or 200 mg/kg/day (at a dosing volume of 2 ml/kg), 5 days/weekfor 10 weeks with vaginal cytology evaluation (VCE) of F0 femalesduring the last 3 weeks of the prebreed period. Animals weremated within groups for 3 weeks with dosing during mating, gestation,and lactation for 7 days/week. F0 parents and F1 weanlings,10/sex/dose, were necropsied (after a 2-week postwean VCE inF0 females) with hematologic evaluation (including methemoglobin)and histology of adult livers, spleens, and reproductive organs.F1 weanlings, 30/sex/dose, were dosed for 11 weeks and matedas described above. Because of poor reproductive performance,not treatment related, F1 animals with no F2a litters were rebredto produce F2b litters. F1 parents and F2a weanlings, 10/sex/dose,were necropsied and evaluated as described above. Inguinal mammaryglands were examined histologically from all nonselected F1and F2 (a and b) female weanlings. Adult toxicity was observedin both generations and both sexes at all doses. Treatment-relatedparental deaths occurred at 200 mg/kg/day. At 100 and 200 mg/kg/day,parents exhibited dose-related reduced body weights and weightgains, reduced feed consumption, clinical signs of toxicity,and anemia with concomitant extramedul-lary hematopoiesis andhemosiderosis in livers and spleens (and increased spleen weights).At 10 mg/kg/day, only adult liver and spleen histologic effectswere present. There was no evidence of reproductive organ ormammary gland pathology or of reproductive or postnatal toxicityat any dose tested. There was no adult "no observable adverseeffect level" (NOAEL) established; the NOAEL for reproductiveand postnatal toxicity was at least 200 mg/kg/day for rats inthis study.     

Hematologic Toxicity of AZT and ddC Administered as Single Agents and in Combination to Rats and Mice

Hematologic Toxicity of AZT and ddC Administered as Single Agentsand in Combination to Rats and Mice. THOMPSON, M. B., DUNNICK,J. K., SUTPHIN, M. E., GILES, H. D., IRWIN, R. D., AND PREJEAN,J. D. (1991). Fundam. Appl. Toxicol. 17, 159-176. Toxicity studiesof 3'-azido-2',3'-dideoxythymidine (AZT) and 2',3'-dideoxycytidine(ddC) were conducted in F344/N rats and B6C3F, mice. The drugswere administered as single agents and in combination. In allstudies, animals were treated by oral gavage twice a day, 7days a week. In studies of the individual compounds, each wasadministered for 13 weeks at the following concentrations; AZTin rats, 0, 125, 250, 500, 1000 mg/kg and in mice, 0, 25, 50,100, 400, 1000 mg/kg; ddC in rats and mice, 0, 250, 1000, 2000mg/kg. Additional male rats and female mice that were treatedwith 0, 250, 1000, or 2000 mg/kg ddC and male and female micetreated with 0, 50, 400, 1000 mg/kg AZT were maintained for30 days after treatment was stopped (at 94 days) to evaluatethe reversibility of toxic effects. Hematologic variables weremeasured on Days 5, 23, and 94 (last day of dosing), and onDay 123 (after a 30-day period without treatment). AZT and ddCproduced dose-related, poorly regenerative, macrocytic anemiasas evidenced by decreases in erythrocyte counts, he-matocrits,and hemoglobin concentrations and increases in mean corpuscularhemoglobin and mean corpuscular volume. Bone marrow samplesin rats treated with AZT were hyperplastic whereas those inmice treated with AZT and rats and mice treated with ddC werehypoplastic. The hematologic toxicity of AZT was more severethan that of ddC. Generally, toxic effects of either chemicalwere greater in mice than in rats and more pronounced in femalethan in male animals. After 30 days without dosing, hematologiceffects either resolved or dramatically improved. In studiesin which ddC and AZT were administered in combination for 4weeks at concentrations of 0/0, 0/500, 500/0, 10/500, 100/500,500/500, and 500/1000 mg/kg ddC/AZT, there was macrocytic anemiain animals in the lower doses and marked microcytic anemia insurviving male mice in higher dose groups. Most female micedied in the 500/500 and 500/1000 mg/kg ddC/ AZT dose groups.At lower concentrations (100/500, 500/1000 mg/kg ddC/AZT), effectsof the two drugs were similar to those in the single drug studies.At higher concentrations (500/500 and 500/1000 mg/kg ddC/AZT),the combination treatment produced enhanced hematopoietic toxicity.These studies demonstrated the early and progressive time courseof toxicity of AZT and ddC, species differences in sensitivitiesand responses, and reversibility of effects after terminationof treatment. Based on these findings, a chronic toxicity studyis being conducted with AZT in mice.     

Effects of di-isononyl phthalate (DINP) on peroxisomal markers in the marmoset-DINP is not a peroxisome proliferator.

In the present study the systemic toxic potential of di-isononyl phthalate (DINP) was assessed in a 13-week study in marmosets. Particular attention was given to its potential for hepatic peroxisome proliferation. Three groups of four male and four female marmosets received DINP, by oral gavage administration, at dosages of 100, 500 or 2500 mg/kg/day for 13 weeks. A fourth group served as a concurrent Control group and received the vehicle (1% methylcellulose and 0.5% Tween) only. A fifth group received clofibrate at a dosage of 500 mg/kg/day to provide a positive Control for liver peroxisome activity. At the end of the treatment period, the animals were killed and their livers were removed. 3000 x g supernatant and microsomal subcellular fractions were prepared from homogenised liver by differential centrifugation. The peroxisomal marker enzyme activity, cyanide-insensitive palmitoyl CoA oxidase, was assayed in the former, while cytochrome P450 concentration and lauric acid 11- and 12-hydroxylase activities (selective for CYP2E1 and 4A, respectively) were assayed in the microsomes. No statistically significant changes were seen in any of these parameters measured following DINP treatment, compared with the Control. Clofibrate treatment resulted in an approximately 100% increase (p < 0.01) in both male and female marmoset cyanide-insensitive palmitoyl CoA oxidase activity and a similar increase (p < 0.05) in male (only) lauric acid 11-hydroxylase activity. No other changes were statistically significant at the 5% level. These data provide no evidence that DINP was acting as a peroxisome proliferator when administered to marmosets under the conditions of the study.     

Toxicologic, reproductive and teratologic studies of colestipol hydrochloride, a new bile acid sequestrant

Colestipol hydrochloride is a high molecular weight, essentially insoluble, polyethylenepolyamine polymer with 1-chloro-2,3-epoxypropane hydrochloride, developed as a serum cholesterol-lowering agent. This article presents the results of toxicity studies done to determine the safety of colestipol HCl before testing in man. The LD50 in mice and rats ip was >4000 mg/kg; orally in the rat it was >1000 mg/kg. In short-term, high-dose studies, the compound did not affect the rat at a dose of 4000 mg/kg/day for 6 days in the feed, or the rabbit at a dose of 4000 mg/kg/day for 2 weeks by gastric intubation. In dogs 13–14 months old, 3000 mg/kg/day in the diet had no adverse effects during a 30-day period, but in dogs 6–8 months old given 4000 mg/kg/day in a diet of canned horsemeat for 11 days, 3 of 4 developed a possibly significant decrease in serum inorganic phosphorus. Levels of 500, 1000 or 2000 mg/kg/day caused no drug-related abnormalities in dogs for 1 year in the diet, nor in rats at the same levels in the diet for 18 months.In reproduction studies, F₀ and F₁ rats given levels of 500 or 1000 mg/kg/day in the diet did not develop any drug-related abnormalities. Males had received the drug from the age of 40 to 100 days, and females were dosed from 14 days before breeding at 100 days through weaning of the litters at 21 days postparturition. No drug-related malformations developed in rats or rabbits born to females treated with 300 or 1000 mg/kg/day from days 6 to 15 in rats and to day 18 in rabbits.     

Acute, subchronic and chronic safety studies with genistein in rats.

Genistein is a phytoestrogen that occurs naturally in the diet, especially in soy based foods. There is wide spread interest in phytoestrogens as chemopreventive agents for a variety of diseases and cancers based on epidemiologic evidence. Although soy, and its constituents such as genistein, have been consumed at high levels in several Asian populations without apparent adverse effects, concern has been raised about potential adverse effects due to the estrogenic and other activities. Safety studies with genistein were conducted in the Wistar rat including two acute studies, two subchronic (4 weeks and 13 weeks) and a chronic 52-week dietary admix study. In the acute studies, genistein had a low order of toxicity. In the three repeated dose safety studies at doses up to 500 mg/kg/day, genistein was well tolerated. In all of the studies, decreased food consumption and body weight gain were observed at 500 mg/kg/day. The main hematological findings were decreased red blood cell parameters at 500 mg/kg/day with a compensatory increase in reticulocytes. For clinical chemistry, with the exception of a slight increase in gamma glutamyl transferase in male and female rats at the high dose, there were a number of other minor changes considered not toxicologically significant. At necropsy, there were relatively few macroscopic changes; in the 52-week study, dilation of the uterus with fluid at the high dose and cysts of the ovaries in treated animals were observed. Organ weight changes in male rats at the high dose of 500 mg/kg/day included increased kidney, spleen, adrenal and testes weights and for females included, increased liver, kidney, spleen, ovary and uterus weights. After 4 and 13 weeks of treatment with genistein, there were no treatment related histopathologic findings. After 26 and 52 weeks of treatment, histological changes were seen in the female reproductive organs (ovaries and uterus), and in males (epididymides and prostate), and bone, kidneys, heart, liver and spleen in both sexes. After 52 weeks of treatment of males, vacuolation of the epididymal epithelium at 500 mg/kg/day and inflammation of the prostate were recorded at a higher incidence at 50 and 500 mg/kg/day. In females, cytological changes in the uterus, squamous metaplasia at 50 and 500 mg/kg/day and hyperplasia at 500 mg/kg/day were observed. Furthermore, hydrometra of the uterus and findings in the vagina consisting of anestric or diestrus vaginal mucosa with vaginal mucification, hyperplastic epithelium and multifocal cystic degeneration were noted at 500 mg/kg/day. Atrophy of the ovaries increased in severity in animals at 50 and 500 mg/kg/day. Osteopetrosis (hyperostosis) was observed in male and female rats at 50 and 500 mg/kg/day along with a compensatory increase in extramedullary hemopoiesis in the spleen; females were more affected than males. Hepatocellular hypertrophy and minimal bile duct proliferation were recorded at a higher incidence in animals at 500 mg/kg/day. It is concluded that almost all of the treatment related findings in these studies are related to the estrogenic properties of genistein as a phytoestrogen and would be expected to occur with a compound with estrogenic activity. The hormonally related changes were considered to be functional in nature and thus not adverse effects. Most of the findings in these studies were limited to the high dose of 500 mg/kg/day and were reversible. The few findings observed at 50 mg/kg/day were relatively minor and in view of the functional (hormonally mediated) nature of the effects, were considered not adverse effects. The increased incidence of minimal bile duct proliferation and slightly increased gamma glutamyl transferase are indicative of a mild hepatic effect at the high dose of 500 mg/kg/day. The no observed adverse effect level (NOAEL) of genistein is considered to be 50 mg/kg/day based on the presence of mild hepatic effects at the high dose of 500 mg/kg/day. The no observed effect level (NOEL) is considered to be 5 mg/kg/day based on the hormonally induced functional changes at higher doses.