Chinese Hamster Lung Cells Research Articles

General and Genetic Toxicology of Enzyme-Treated Ginseng Extract: Toxicology of Ginseng Rh2.

Objectives:Ginseng Rh2+ is enzyme-treated ginseng extract containing high amounts of converted ginsenosides, such as compound k, Rh2, Rg3, which have potent anticancer activity. We conducted general and genetic toxicity tests to evaluate the safety of ginseng Rh2+.Methods:An acute oral toxicity test was performed at a high-level dose of 4,000 mg/kg/day in Sprague-Dawley (SD) rats. A 14-day range-finding study was also conducted to set dose levels for the 90-day study. A subchronic 90-day toxicity study was performed at dose levels of 1,000 and 2,000 mg/kg/day to investigate the no-observed-adverse-effect level (NOAEL) of ginseng Rh2+ and target organs. To identify the mutagenic potential of ginseng Rh2+, we conducted a bacterial reverse mutation test (Ames test) using amino-acid-requiring strains of Salmonella typhimurium and Escherichia coli (E. coli), a chromosome aberration test with Chinese hamster lung (CHL) cells, and an in vivo micronucleus test using ICR mice bone marrow as recommended by the Korean Ministry of Food and Drug Safety.Results:According to the results of the acute oral toxicity study, the approximate lethal dose (ALD) of ginseng Rh2+ was estimated to be higher than 4,000 mg/kg. For the 90-day study, no toxicological effect of ginseng Rh2+ was observed in body-weight changes, food consumption, clinical signs, organ weights, histopathology, ophthalmology, and clinical pathology. The NOAEL of ginseng Rh2+ was established to be 2,000 mg/kg/day, and no target organ was found in this test. In addition, no evidence of mutagenicity was found either on the in vitro genotoxicity tests, including the Ames test and the chromosome aberration test, or on the in vivo in mice bone marrow micronucleus test. Conclusion:On the basis of our findings, ginseng Rh2+ is a non-toxic material with no genotoxicity. We expect that ginseng Rh2+ may be used as a novel adjuvant anticancer agent that is safe for long-term administration.

Genotoxicity biomarkers for airborne particulate matter (PM2.5) in an area under petrochemical influence

The effects of fine inhalable particles (PM2.5) were evaluated in an area under the influence of a petrochemical industry, investigating the sensitivity of different genotoxicity biomarkers. Organic extracts were obtained from PM2.5 samples at two sites, positioned in the first and second preferential wind direction in the area. The extracts were evaluated with Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024. The mammalian metabolization fraction (S9) was used to evaluate metabolite mutagenicity. The Comet Assay (CA) and Micronuclei Test were used in a Chinese hamster lung cell line (V79). All extracts showed mutagenicity in Salmonella, and nitrogenated compounds were strongly present. Genotoxicity were found in CA in almost all extracts and the micronuclei induction at the Site in the first (Autumn 1, Winter 1), and in the second (Spring 2) wind direction. V79 showed cytotoxicity in all samples. The three biomarkers were concordant in characterization Site NO with worse quality, compatible with the greater pollutants dispersion in the first wind direction. All PM2.5 concentrations were lower than those recommended by air quality standards but genotoxic effects were detected in all samples, corroborating that these standards are inadequate as quality indicators. The Salmonella/microsome assay proved sensitive to PM2.5 mutagenicity, with an outstanding influence of nitroarenes and aromatic amines. Analyses using CA and the micronucleus test broadened the levels of response that involve different damage induction mechanisms. Results show that the complex PM2.5 composition can provoke various genotoxic effects and the use of different bioassays is essential to understand its effects.

Exposure to 50Hz-sinusoidal electromagnetic field induces DNA damage-independent autophagy

As electromagnetic field (EMF) is commonly encountered within our daily lives, the biological effects of EMF are of great concern. Autophagy is a key process for maintaining cellular homeostasis, and it can also reveal cellular responses to environmental stimuli. In this study, we aim to investigate the biological effects of a 50Hz-sinusoidal electromagnetic field on autophagy and we identified its mechanism of action in Chinese Hamster Lung (CHL) cells. CHL cells were exposed to a 50Hz sinusoidal EMF at 0.4mT for 30min or 24h. In this study, we found that a 0.4mT EMF resulted in: (i) an increase in LC3-II expression and increased autophagosome formation; (ii) no significant difference in the incidence of γH2AX foci between the sham and exposure groups; (iii) reorganized actin filaments and increased pseudopodial extensions without promoting cell migration; and (iv) enhanced cell apoptosis when autophagy was blocked by Bafilomycin A1. These results implied that DNA damage was not directly involved in the autophagy induced by a 0.4mT 50Hz EMF. In addition, an EMF induced autophagy balanced the cellular homeostasis to protect the cells from severe adverse biological consequences.

In Vitro Photochemical Induction of Kojic Acid-DNA Adducts

Objective: Kojic Acid (KA) is a natural substance which inhibits skin melanin production and, when used alone or in combination with other compounds, is effective in reducing pigmentation in melasma patients. KA was classified by IARC as presenting limited evidence of carcinogenicity based largely on a single study showing thyroid neoplasms. More recently KA has been shown to be carcinogenic in rat liver, but not mouse skin. KA has produced positive and negative results in both in vivo and in vitro genotoxicity tests and was considered to be genotoxic in vitro by IARC. KA is photochemically unstable causing in vitro breakage of DNA. Consistent with this, photochemically KA is weakly mutagenicity in bacteria and induced chromosome aberrations in Chinese hamster lung cells, although it was negative on mouse epidermis in a photo-micronucleus assay. To assess the potential of KA to photochemically induce formation of DNA adducts, we investigated effects of irradiating KA and DNA with 320 nm light and analyzing for DNA adducts by the nucleotide 32P-postlabeling (NPL) method. Methods: The ability of KA irradiated at 320 nm to induce formation of DNA adducts was compared to direct chemical reaction of chloro-KA with DNA. To ascertain the reliability of this approach, we also studied adduct formation by the photoactivated 8-mehtoxy-(8-MOP) and 4.5`, 8-trimethyl-(TMP) psoralens. Results: All compounds in the presence of UV irradiation produced DNA adducts assessed by one or more of the NPL enhancement methods used. The pattern of major adducts formed photochemically with KA and directly with chloro-KA were similar, but could represent residual KA in chloro-KA samples. Psoralens produced different pattern of adducts. Conclusions: Thus, KA may have the potential to be photoactivated to DNA-damaging products in skin.

Genotoxicity evaluation of alpha-linolenic acid-diacylglycerol oil.

The alpha-linolenic acid (ALA)-diacylglycerol (DAG) oil is an edible oil enriched with DAG (>80%) and ALA (>50%). Although DAG oil, which mainly consists of oleic and linoleic acids has no genotoxic concerns, the fatty acid composition could affect the chemical property of DAG. Therefore, the purpose of this study was to evaluate the genotoxicity of ALA-DAG oil using standard genotoxicity tests in accordance with the OECD guidelines. ALA-DAG oil showed negative results in the bacterial reverse mutation test (Ames test) and in vitro micronucleus test in cultured Chinese hamster lung cells with and without metabolic activation, and in the in vivo bone marrow micronucleus test in mice. Our results did not show any genotoxicity, suggesting that the fatty acid composition had no deleterious effects. We conclude that ALA-DAG oil had no genotoxicity concerns under the testing conditions.

DNA Damage Effect of Botanical Insecticides Using Chinese Hamster Lung Cells

BACKGROUND: Botanical insecticides, especially Azadirachta Indica extract (AIE) and Sophorae radix extract (SRE) are widely used in Agriculture field. In our previous studies on genotoxicity test of AIE and SRE samples, a suspicious clastogenic properties was shown. Herein, we investigated the DNA damage effect of these botanical insecticide samples through the in vitro comet assay. METHODS AND RESULTS: Chinese hamster lung (CHL) fibroblast cell line was used, and methyl methanesulphonate was as positive control. Respective two samples of AIE and SRE were evaluated using Single Cell Gel Electrophoresis (Comet) assay and measured as the Olive tail moment (OTM). Results from this study indicated that all tested AIE and SRE samples did not show DNA damage in comet assay using CHL cells, compared with control. CONCLUSION: AIE and SRE samples used in this study were not cause genetic toxicity and are suitable for use as organic materials.

Lactobacillus plantarum AF1와 Lactobacillus plantarum HD1이 생성한 조항균 물질의 유전학적 독성평가

1)ABSTRACTThis study investigates the genotoxicity of crude antifungal co mpounds produced by Lactobacillus plantarum AF1 (L.plantarum AF1) and Lactobacillus plantarum HD1 (L. plantarum HD1) isolated from kimchi. The genetic toxicity of crude antifungal compounds was evaluated in bacterial reverse mutation in Salmonella and Escherichia spp., chromosome aberrations in Chinese hamster lung cells, and micronucleous formations in mic e. In bacterial reversion assays with Salmonella Typhimurium TA98, TA100, TA1535, TA1537, and WP2uvrA, crude antifungal compounds did not increase the number of revertant colonies in both the absence and presence of the 59 metabolic activation system. In the chromosome aberra tion test with Chinese hamster lung cells, crude antifungal compounds showed no increase in th e frequency of chromosome aberrations in the short-period test with/without the S9 mix or in the continuos test. In the in vivo mouse micronucleus assay, crude antifungal compounds sh owed no increase in the frequency of polychromatic erythrocytes with micronuclei. The r esults show that crude antifungal compounds produced by L. plantarum AF1 and L. plantarum HD1 did not induce any genotoxicity.Keywords: crude antifungal compounds, genotoxicity, reverse mutation, chr omosomal aberration, micronucleus test

Investigating the Glucagon Receptor and Glucagon-Like Peptide 1 Receptor Activity of Oxyntomodulin-Like Analogues in Male Wistar Rats

AimsTo investigate the effect of Glu-3 OXM-like analogues on food intake and bodyweight in male rats. BackgroundOxyntomodulin (OXM) is a natural agonist at both the glucagon receptor (GCGr) and the glucagon-like peptide 1 receptor (GLP-1r), and peripheral administration reduces food intake and increases energy expenditure in rodents and humans. Substituting the native glutamine (Gln) at amino acid position 3 of OXM for glutamate (Glu) has previously been shown to diminish GCGr activity without affecting GLP-1r activity. The effects of Glu-3 OXM analogues have not been investigated in rats. MethodsThe effect of 2 Glu-3-substituted OXM-like analogues (eg, OXM14E3 and OXM15E3) on food intake and body weight was investigated in male Wistar rats during 6 days of daily subcutaneous (SC) administration. The effects of Glu-3 substitution on analogue binding and activity at the rat GCGr and rat GLP-1 receptor were investigated in vitro using Chinese hamster ovary or Chinese hamster lung cells. ResultsWe report the novel finding that 2 5-nmol/kg Glu-3 OXM-like analogues (OXM14E3 and OXM15E3) significantly increased rat body weight by up to 4% compared with the equivalent non-Glu-3 analogues (OXM14 and OXM15), without affecting food intake. The effect of OXM15E3 on body weight was dose–dependent. Glu-3 analogues, including Glu-3 OXM, decreased glucagon-mediated cyclic adenosine monophosphate accumulation in Chinese hamster ovary cells expressing the rat GCGr, suggesting they may be acting as antagonists. ConclusionsThe results indicate Glu-3 OXM-like analogues might not be suitable tools to investigate the mechanism of OXM analogue action in a rat model because they significantly increase body weight independent of food intake. Glu-3 OXM analogues are partial agonists at the rat GCGr and may also act as antagonists, possibly resulting in the observed increase in body weight.

Comet assay of DNA damage in Chinese hamster lung cells exposed to Sophorae radix extract

Comet assay of DNA damage in Chinese hamster lung cells exposed to Sophorae radix extract

Genotoxicity evaluation of Oryeong-san water extract using in vitro and in vivo tests.

BackgroundOryeong-san, a mixture of five herbal plants, is a well-known therapy for renal-associated diseases such as those manifesting edema, dysuria, and oliguria.MethodsIn the present study, we investigatee the potential genotoxic effects of a water extract of Oryeong-san (ORSE) in three mutagenicity assays (an in vitro bacterial reverse mutation assay (Ames test) with Salmonella typhimurium and Escherichia coli strains, an in vitro mammalian chromosomal aberration test using Chinese hamster lung cells, and an in vivo micronucleus test using ICR mice bone marrow).ResultsORSE showed no genotoxicity in the Ames test up to 5000 μg/plate; the in vitro chromosome aberration test showed no significant structural aberrations with and without the S9 mix up to 5000 μg/mL, or the in vivo micronucleus test up to 2000 mg/kg body weight.ConclusionsIn conclusion, under the current test conditions, ORSE seems safe for use; however, other genotoxicity tests (e.g. sister-chromatid exchange or Comet) or chronic toxicity tests are warranted.

Evaluation of a water extract of So-Cheong-Ryong-Tang for acute toxicity and genotoxicity using in vitro and in vivo tests.

BackgroundSo-Cheong-Ryong-Tang, a traditional Korean medicine, has been used empirically for the treatment of asthma, allergic rhinitis, and colds for hundreds of years. However, its genotoxicity has been rarely examined.MethodsWe therefore investigated the genotoxicity of an aqueous extract of So-Cheong-Ryong-Tang (SCRT) in two in vitro and one in vivo assays: a bacterial reverse mutation assay (Ames test), a chromosomal aberration assay, and a micronucleus assay, respectively.ResultsIn the bacterial reverse mutation assay, SCRT did not increase revertant colony numbers in Salmonella. typhimurium strains (TA98, TA100, TA1535, and TA1537) or an Escherichia coli strain (WP2 uvrA) regardless of metabolic activation or the duration of treatment. However, statistically significant differences in the incidence of chromosomal aberrations following SCRT >4000 μg/mL were observed in Chinese hamster lung cells exposed with or without an S9 enzyme and cofactor mixture.ConclusionsThese results suggest further genotoxic testing of SCRT, such as a comet assay, to ascertain its generally recognized safety.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-015-0737-x) contains supplementary material, which is available to authorized users.

Preclinical safety evaluation of low molecular weight heparin-deoxycholate conjugates as an oral anticoagulant.

The preclinical safety of a newly developed oral anticoagulant, the low molecular weight heparin-deoxycholate conjugate (OH09208), was evaluated by a comprehensive evaluating program in compliance with standard guidelines. The single dose oral toxicity study in rats receiving 2000 and 5000 mg kg(-1) of OH09208 did not reveal any mortality, unusual body weight changes or necropsy findings. The results of the 4-week oral toxicity study with a 4-week recovery program in rats receiving OH09208 in doses of 100, 300 and 1000 mg kg(-1) day(-1) did not reveal any mortality, or indicate any unusual clinical signs, or show any toxicokinetic relationships to the administration of OH09208. Although the increase in liver enzymes in one male dog treated with 300 mg kg(-1) day(-1) and one female dog treated with 1000 mg kg(-1) day(-1) could not be excluded from the effect of the test substance, no other toxicologically significant changes were observed in the 4-week oral toxicity study with a 4-week recovery in beagle dogs. Thus, while the no-observed-adverse-effect level value from the 4-week study in both male and female rats was 1000 mg kg(-1) day(-1), those from the 4-week study in male and female beagle dogs were 300 and 1000 mg kg(-1) day(-1), respectively. Furthermore, OH09208 did not induce anaphylactic reactions in guinea pigs, micronucleated bone marrow cells in male ICR mice, chromosomal aberration in Chinese hamster lung cell lines, bacterial reverse mutation, and any abnormalities in hERG current assay, mouse central nervous system and dog cardiovascular studies. Overall, there were no unexpected toxicities in this preclinical study that might have precluded the safe administration of OH09208 to humans.

Is nitrous oxide a genotoxic carcinogen?

Nitrous oxide (N2O) has been widely used as a dental and surgical anaesthetic for over 150 years. However, results from a recent study suggested that increased DNA damage was seen in lymphocytes from surgical patients and this led to its continued clinical use to be questioned. The data can be challenged on technical grounds and must be considered with other studies in order to assess any possible risk. There are other studies indicating that N2O has weak genotoxicity in man, but these are confused by exposure of the populations to other anaesthetic gases including isoflurane and sevoflurane, both of which have also been reported to increase DNA damage. It should be noted that the suggested genotoxic mechanisms are all indirect, including folate deficiency, oxidative stress and homocysteine toxicity. Further, results from in vitro studies indicate that N2O has no direct DNA reactivity as negative results were obtained in a bacterial mutation (Ames) test and an assay for mutation at the hprt locus in Chinese hamster lung cells. Although not performed to definitive study designs, no evidence of carcinogenicity was seen in two long-term tests in mice and another in rats. Although there is some evidence that N2O is weakly genotoxic in humans, this appears to be similar to that reported for isoflurane and sevoflurane and all the postulated mechanisms have clear thresholds with no evidence of direct DNA reactivity. Because any potential genotoxic mechanism would have a threshold, it seems reasonable to conclude that neither occasional high exposure to patients as an anaesthetic nor low-level exposure to staff within published recommended exposure limits presents any significant carcinogenic risk.

Abstract W P70: Pharmacokinetic Properties and Toxicity/safety Profiles of SP-8203, a Novel Neuroprotectant for Treatment of Cerebral Ischemic Stroke

We recently identified a multi-target directed neuroprotectant SP-8203, which is now undergoing phase 1 clinical trial. Here we report the preclinical and clinical toxicity/safety profiles and pharmacokinetic properties of SP-8203. Single-dose and 28-day repeated-dose toxicity tests in Sprague Dawley rats, Beagle dogs, and Cynomolgus monkeys were performed by Chemon (Korea), MPI Research (USA), and Toxikon (USA) and Phase 1 clinical trial by ASAN medical center (korea). The genotoxicity was examined by the bacterial reverse mutation assay (AMES test), the chromosome aberration assay using Chinese hamster ovary and lung cells, and the micronucleus test in rat bone-marrow erythrocytes. The safety pharmacology studies evaluate acute neurobehavioral toxicities and pulmonary functions in male rats and cardiovascular toxicities in male Cynomolgus monkeys. Following a single-dose intravenous administration, the minimum lethal dose of SP-8203 was estimated to 60 mg/kg and the lethal dose 50 (LD50) was 83.3 mg/kg in rats. The No-Observable-Adverse-Effect-Level (NOAEL) of 4 week repeated dose of SP-8203 was 20 mg/kg/day in rats and 12 mg/kg/day in monkeys, when administered as an intravenous slow bolus injection for 5 min. However, when administered as an intravenous infusion for 30 min, the NOAEL in rats increased to 80 mg/kg/day or more. SP-8203 did not exert any genotoxicity. Safety pharmacology studies showed that NOAELs of neurobehavioral toxicity, pulmonary functions, and cardiovascular effects were 30 mg/kg, 30 mg/kg, and 10 mg/kg, respectively. In a single accelerating dose study in phase 1 clinical trial, no toxic responses were observed at doses up to 240mg in healthy subjects. Pharmacokinetics of SP-8203 evaluated after its intravenous administration in humans and rats showed that the AUCs and half-lives of SP-8203 were dose-dependently increased; thus the dose-normalized AUCs and half-lives were significantly elevated with increasing doses. However, the nonlinear PK properties are within safe ranges in humans and rats. Taken together, a series of toxicity/safety assessments showed that SP-8203 is quite safe and non-toxic at the doses for the treatment of cerebral ischemic stroke in humans.

Restoration of Mitochondrial Gene Expression Using a Cloned Human Gene in Chinese Hamster Lung Cell Mutant.

Gal-32 is a Chinese hamster lung cell nuclear mutant that is unable to grow in galactose due to a defect in mitochondrial protein synthesis. Since the product of the Gal-32 gene was unknown, it was imperative to use phenotypic complementation to clone a human gene that corrected the Gal-32 mutation. Recessive Gal-32 cells were co-transformed with pSV2-neo plasmid DNA and recombinant DNA from a human genomic library containing the dominant human Gal+ gene and a chloramphenicol-resistance (camr ) gene present in the pSV13 vector. Primary transformants were selected by growth in galactose and the neomycin analog G418. In order to rescue the human Gal+ gene, a genomic library was constructed with primary transformant DNA and the pCV108 cosmid vector. The camr gene was used to identify clones with the nearby human sequences. DNA from two camr , Alu-hybridizing clones was able to transform the recessive Gal-32 cells to the Gal+ phenotype and to restore mitochondrial protein synthesis. These data demonstrate the isolation of two pCV108-transformant recombinant clones containing a human gene that complements the Chinese hamster Gal-32 mutation and restores galactose metabolism.

Safety Evaluation of Rare Sugar Syrup: Single-dose Oral Toxicity in Rats, Reverse Mutation Assay, Chromosome Aberration Assay, and Acute Non-Effect Level for Diarrhea of a Single Dose in Humans

The safety of rare sugar syrup obtained from high-fructose corn syrup under slightly alkaline conditions was studied. Mutagenicity of rare sugar syrup was assessed by a reverse mutation assay using Salmonella typhimurium and Escherichia coli, and an in vitro chromosomal aberration assay using Chinese hamster lung cell line (CHL/IU). No mutagenicity of rare sugar syrup was detected under these experimental conditions. Oral administration of single dose (15,000 mg/kg) of rare sugar syrup to rats caused no abnormalities, suggesting no adverse effect of rare sugar syrup. In humans, the acute non-effect level of rare sugar syrup for causing diarrhea was estimated as 0.9 g/kg body weight as dry solid base in both males and females.

Hep-2 cell based indirect immunofluorescence assay for antinuclear antibodies as a potential diagnosis of drug-induced autoimmunity in nonclinical toxicity testing

Antinuclear antibodies (ANAs) are important biomarkers in the diagnosis of autoimmune diseases in humans; however, the diagnostic performance of ANA in nonclinical safety studies are not well understood. Here, we studied the use of ANAs as potential nonclinical biomarkers for drug-induced autoimmunity (DIA) using a Hep-2 based indirect immunofluorescence assay (IFA). Initially, MRL-faslpr/J mice and HgCl2-treated rats were used as SLE-positive models. Serum samples obtained from 94 normal mice or 204 normal rats aged one to four months served as the negative control. The IFA effectively distinguished ANAs-positive samples in both species with a cut-off titer of 1:100. Brown Norway rats were treated with 450mg/kg d-penicillamine for 30 consecutive days. ANAs were generated and corresponded with DIA development. Human Hep-2 cells, mice Neuro 2A cells, and Chinese Hamster Lung cells served as antigen from different species, which were found cross-reactive with ANA-positive serum samples from mice, rats, and humans without any differences in diagnosis. This methodology showed no species-specificity for ANA detection. Furthermore, we found approximately 20 percentage of the mice aged seven to eight months demonstrated age-related ANAs, which was consistent with humans. Overall, our findings demonstrated the use of ANA detection using IFA in the nonclinical diagnosis of murine drug-induced autoimmunity, and age-related ANAs should be considered when aged animals are used.

In vitro Antimutagenic and Genotoxic Effects of Azadirachta indica Extract

Azadirachta indica extract (AIE) has been regarded as a promising source of environment-friendly organic materials owing to their low mammalian toxicity. However, quite a bit of research has been reported that AIE may cause clastogens in human lymphocytes. Therefore, this study was conducted to evaluate the antimutagenic and genotoxicity of two samples of AIE. Antimutagenic test was experimented by using bacterial reverse mutation test. In the bacterial reverse mutation test, five strains Salmonella Typhimurim of two samples of AIE in order to evaluate its mutagenic potential. Bacterial reverse mutation test was also performed on positive control and negative control groups in the presence of the metabolic activation system (S-9 mix) and metabolic non-activation system. In the chromosome aberration test, Chinese hamster lung cells were exposed to AIE for 6 or 24 h with BPS, or for 6 h with S-9 mix. Negative and positive control groups were experimented for chromosome aberration test. As a result, the number of mutated colonies induced by 4-NQO were reduced by AIE treatment in all strains, indicating that AIE may have antimutagenic effects. Bacterial reverse mutation and chromosomal aberration were not shown at all concentration of AIE, regardless of activation of the metabolic system. we concluded that two AIE samples used in this study have no genotoxic effects to human, according to the genotoxicity battery system suggested by ICH (International Conference on Harmonization).

In Vitro Genotoxicity Assessment of a Novel Resveratrol Analogue, HS-1793.

Resveratrol has received considerable attention as a polyphenol with various biological effects such as anti-inflammatory, anti-oxidant, anti-mutagenic, anti-carcinogenic, and cardioprotective properties. As part of the overall safety assessment of HS-1793, a novel resveratrol analogue free from the restriction of metabolic instability and the high dose requirement of resveratrol, we assessed genotoxicity in three in vitro assays: a bacterial mutation assay, a comet assay, and a chromosomal aberration assay. In the bacterial reverse mutation assay, HS-1793 did not increase revertant colony numbers in S. typhimurium strains (TA98, TA100, TA1535 and TA1537) or an E. coli strain (WP2 uvrA) regardless of metabolic activation. HS-1793 showed no evidence of genotoxic activity such as DNA damage on L5178Y Tk+/− mouse lymphoma cells with or without the S9 mix in the in vitro comet assay. No statistically significant differences in the incidence of chromosomal aberrations following HS-1793 treatment was observed on Chinese hamster lung cells exposed with or without the S9 mix. These results provide additional evidence that HS-1793 is non-genotoxic at the dose tested in three standard tests and further supports the generally recognized as safe determination of HS-1793 during early drug development.

Genotoxicity evaluation of Guibi-Tang extract using an in vitro bacterial reverse mutation assay, chromosome aberration assay, and in vivo micronucleus test.

BackgroundGuibi-Tang is a traditional herbal prescription made from 12 different herbs that is used in the treatment of amnesia and poor memory.MethodsIn the present study, we evaluated the acute oral toxicity and genotoxic potential of Guibi-Tang water extract (GBT) at doses up to 2000 μg/plate an using a bacterial reverse mutation test (Ames test) with Salmonella typhimurium strains TA100, TA1535, TA98, and TA1537, and Escherichia coli strain WP2uvrA. Acute toxicity and genotoxic potential were measured in the presence and absence of an exogenous source of metabolic activation, in an in vitro chromosome aberration assay with Chinese hamster lung (CHL) cells, and in an in vivo micronucleus test using ICR mice bone marrow as recommended by the Korean Food and Drug Administration. An acute oral toxicity test of GBT was performed in Sprague Dawley rats. The Ames test showed that GBT did not induce gene mutations in S. typhimurium or in E. coli in the presence or absence of S9 activation.ResultsGBT did not significantly increase the number of structural aberrations in CHL cells with or without S9 activation. The oral administration of GBT at a dose of up to 2000 mg/kg caused no significant increase in the number of micronucleated polychromatic erythrocytes or in the mean ratio of polychromatic to total erythrocytes.ConclusionsHowever, as we did not identify the components of GBT responsible for these effects, other assays are needed to confirm its genotoxicity.