Evaluation of General Toxicity and Genotoxicity of the Silkworm Extract Powder

The silkworm extract powder contain 1-deoxynojirimycin (DNJ), a potent alpha-glycosidase inhibitor, has therapeutic potency against diabetes mellitus. Therefore, natural products containing DNJ from mulberry leaves and silkworm are consumed as health functional food. The present study was performed to evaluate the safety of the silkworm extract powder, a health food which containing the DNJ. The repeated toxicity studies and gentic toxicity studies of the silkworm extract powder were performed to obtain the data for new functional food approval in MFDS. The safety was evaluated by a single-dose oral toxicity study and a 90 day repeated-dose oral toxicity study in Sprague-Dawley rats. The silkworm extract powder was also evaluated for its mutagenic potential in a battery of genetic toxicity test: in vitro bacterial reverse mutation assay, in vitro chromosomal aberration test, and in vivo mouse bone marrow micronucleus assay. The results of the genetic toxicology assays were negative in all of the assays. The approximate lethal dose in single oral dose toxicity study was considered to be higher than 5000 mg/kg in rats. In the 90 day study, the dose levels were wet at 0, 500, 1000, 2000 mg/kg/day, and 10 animals/sex/dose were treated with oral gavage. The parameters that were monitored were clinical signs, body weights, food and water consumptions, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weights, and histopathological examination. No adverse effects were observed after the 90 day administration of the silkworm extract powder. The No-Observed-Adverse-Effect-Level (NOAEL) of silkworm extract powder in the 90 day study was 2000 mg/kg/day in both sexes, and no target organ was identified.

A 6-Week Oral Toxicity Study of Oral Cholera Vaccine in Sprague-Dawley Rats

The present study was carried out to examine the toxicity and target organs of oral cholera vaccine (OCV) after repeated oral administration in Sprague-Dawley rats for 6 weeks (3 administrations, once every 2 weeks). OCV is an inactivated oral cholera vaccine that contains Vibrio cholerae and confers protection against cholera caused by V. cholera serogroups O1 (Inaba and Ogawa serotypes) and O139 (strain 4260B). The animals were orally administered either OCV placebo (negative control) or OCV at a dose equivalent to 240 times the anticipated human dose. Throughout the administration period, no significant change was detected in clinical signs, body weight, food or water consumption, urinalysis results, hematological and clinical biochemistry test results, organ weights, necropsy, or histopathological examination results. Minor changes were found in hematological and clinical biochemistry tests; however, these changes were within normal ranges. The above results suggest that oral administration of OCV in rats did not induce any toxicologically meaningful changes, and the target organs could not be determined. This study was conducted in accordance with the guidelines established by Good Laboratory Practice (2009-183, KFDA, December 22, 2009) and the OECD Principles of Good Laboratory Practice (1997).

Antifungal Effects of New Synthetic Materials, KAF-200522 and KAF-200522-HCl, on in vitro and in vivo Models / 한국실험동물학회지

KAF-200522 and its chloride form, KAF-200522-HCl, were invented in Chemon inc. as new triazole antifungal agents with excellent activities in vivo and in vitro against wide range of fungi. As a result of in vitro susceptibility measurements, 80% minimum inhibitory concentrations (MIC80) of both test articles against Candida albican sp. and Aspergillus fumigatus sp. were below 0.0156 microg/mL, which were over 4,100 times lower than those of fluconazole against fluconazole resistant C. albican sp. and A. fumigatus sp., and were over 16 times lower than those of amphotericin B against above same fungi. Additionally, against representative dermatophytes, Trichophyton sp., the MIC80s of both test articles were below 0.0156 microg/mL which were over 64 times lower than those of fluconazole and amphotericin B. As in vivo antifungal activities in A. fumigatus sp. infected mouse models, KAF-200522 treatment group at 600 mg/kg showed 80% survival rate which was 2 times higher than that of amphotericin B and showed 13.7 days in the mean survival time (MST) which was about 2.1 times higher than that of amphotericin B. But in KAF-200522-HCl treatment groups, all animals were found dead in contrast to 40% survival rate in amphotericin B treatment group, however dose dependent increases in MST was revealed. In conclusion, antifungal activities of KAF-200522 and its mimics, KAF-200522-HCl in vitro and in vivo were confirmed in this study, therefore the potentiality of the present compounds to be developed into new antifungal drug was expected.

Reference Data of the Main Physiological Parameters in Control Sprague-Dawley Rats from Pre-clinical Toxicity Studies / 한국실험동물학회지

The purpose of this paper is to provide reference data related to the body weight, food & water consumptions, urinalysis, hematology and serum biochemistry parameters and absolute & relative organ weights obtained from control Sprague-Dawley rats, used in the 4-week and 13-week repeated-dose toxicity studies conducted in our laboratory between 2005 and 2008. The mean, standard deviation, minimum and maximum range values for hematology and serum biochemistry parameters, data of absolute & relative organ weights, and the difference between sexes and study duration of week 4 versus 13 week are presented. The studies were conducted according to "the standards of Toxicity Study for Medicinal Products" (2005) and The KFDA Notification No. 2000-63 'Good Laboratory Practice (GLP)' (2000) issued by KFDA. These data could be used as reference material of Sprague-Dawley rats by conducting the studies to evaluate the toxicological profile of pre-clinical toxicity studies.

Uterine Adenomyosis in Beagle Dogs / 한국실험동물학회지

Adenomyosis is a nonneoplastic hyperplastic lesion, characterized by invagination of proliferating endometrial glands into myometrium. In dogs, uterine adenomyosis is relatively rare and it is important in Toxicologic Pathology to differentiate other non-neoplastic and neoplastic lesions in uterus. In the present study, we report two cases of adenomyosis in the female beagle dogs used for a chemical toxicity test. Clinically, one out of the two female beagle dogs, 15 months of age, had vaginal bleeding for 2 weeks and the other one, 11 months of age, showed swelling of vulva for a week. At necropsy, the weight of uterus was markedly increased to 27.9 g and 15.8 g, compared with the mean value (4.01+/-2.37, n=6) of that of other normal dogs, respectively. The parameters of hematology and serum chemistry were ranged normal in both of the dogs with enlarged uterus. For differentiation of connective tissue with muscle fibers, Van Gieson stain was also performed in the serial tissue sections. Histopathologically, the lesions of the enlarged uteruses were characterized by proliferating endometrial glands into myometrium, surrounded by connective tissue. The endometrial glands were proliferating downward to myometrium or embedded in multiple clustered glands in deeper myometrium without compressing the adjacent muscle fibers. The gland epithelial cells are uniformly cuboidal shape with a dense and bottom-located nucleus. These gross and histological findings were consistent with adenomyosis.

Pharmacokinetic and Toxicokinetic Studies of Potential Antifungal Compounds, KAF-200522 and KAF-200522 . HCl, in Animal Models / 한국실험동물학회지

Recent researches on clinically used triazole antifungal reagents are focused on their pharmacokinetic disadvantage which increases the probability of inducing adverse effects in patients. For this point, in the present laboratory, Chemon Inc., has investigated new antifungal reactive compounds, KAF-200522 and its chloride form, KAF-200522 . HCl, which has a modified triazole structure. Pharmacokinetic data were measured with LC-MS/MS in male mice which were orally treated with the above compounds at 10 mg/kg. Tmax and t1/2 of KAF-200522 . HCl were comparable to KAF-200522, but AUC and Cmax were 1.4 and 1.6 times higher than those of KAF-200522, respectively. In beagle dogs, AUC and Cmax of KAF-200522 . HCl were 2.7 and 1.4 times higher than those of KAF-200522, and t1/2 was 3.5 times higher than that of KAF-200522. Moreover, in beagle dogs, the oral bioavailability value of KAF-200522 . HCl was revealed as 31.0% to contrast to 6.2% of KAF-200522. In 1-week repeated oral treatment toxicity study of KAF-200522 in male rats, inhibition of body weight gain was observed in 120 mg/kg treatment group, and loss of body weight was observed in 600 mg/kg treatment group. In the toxicokinetic study of KAF-200522, no accumulation after the systemic exposure was observed. In conclusion, as to the new antifungal drug development, KAF-200522 . HCl was considered to be advantageous in pharmacokinetic characteristics compared to KAF-200522.