A retrospective analysis of adverse effects of an in vivo fluoroquinolone antibiotic enrofloxacin treatment on oocyte quality in the common marmoset.

Here we report a retrospective analysis of negative effects of routine enrofloxacin treatment of recurrent diarrhea on the ovary and the developing oocytes of the common marmoset, a small New World primate. The most deleterious effect on oocytes was observed about two months post treatment suggesting that the enrofloxacin effect is on early growing follicles. Manifestations of toxicity included decreased numbers of growing follicles and recovered culturable oocytes, as well as signs of early atresia of granulosa cells. In addition, increased amounts of holed stroma after treatment strongly suggested increased death of the early growing follicles. Of the oocytes judged to be of adequate quality for culture, maturation rates were not affected but fertilization of in vitro matured MII oocytes and subsequent cleavage rates were severely reduced in the enrofloxacin treated animals. Further, the arrested oocytes, which failed to mature or fertilize, showed obvious meiotic spindle abnormalities.

Proarrhythmic risk assessment using conventional and new in vitro assays.

Drug-induced QT prolongation is a major safety issue in the drug discovery process. This study was conducted to assess the electrophysiological responses of four substances using established preclinical assays usually used in regulatory studies (hERG channel or Purkinje fiber action potential) and a new assay (human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs)-field potential). After acute exposure, moxifloxacin and dofetilide concentration-dependently decreased IKr amplitude (IC50 values: 102 µM and 40 nM, respectively) and lengthened action potential (100 µM moxifloxacin: +23% and 10 nM dofetilide: +18%) and field potential (300 µM moxifloxacin: +76% and 10 nM dofetilide: +38%) durations. Dofetilide starting from 30 nM induced arrhythmia in hiPSC-CMs. Overnight application of pentamidine (10 and 100 µM) and arsenic (1 and 10 µM) decreased IKr, whereas they were devoid of effects after acute application. Long-term pentamidine incubation showed a time- and concentration-dependent effect on field potential duration. In conclusion, our data suggest that hiPSC-CMs represent a fully functional cellular electrophysiology model which may significantly improve the predictive validity of in vitro safety studies. Thereafter, lead candidates may be further investigated in patch-clamp assays for mechanistic studies on individual ionic channels or in a multicellular Purkinje fiber preparation for confirmatory studies on cardiac conduction.

Protective role of biogenic selenium nanoparticles in immunological and oxidative stress generated by enrofloxacin in broiler chicken.

Presently most bacteria are becoming antibiotic resistant. Due to this there is a deficiency of potent antibiotics, therefore we have to preserve and improve the efficiency of existing antibiotics by mitigating the side effects. Enrofloxacin (EFX) is an important antimicrobial used in veterinary practice but it is known to exert immune suppression antioxidant stress. In the present study, we report on: (a) the biosynthesis of selenium nanoparticles (Se NPs), and (b) their protective effect in reducing adverse effects of EFX on broiler chicken. A potent bacterial strain, isolated from farm soil, has been identified as Pantoea agglomerans (GenBank: KU500622). It tolerates a high concentration of selenium dioxide (9 mM) and produces Se NPs under aerobic conditions. The obtained Se NPs are amorphous in structure and spherical in shape with sizes of less than 100 nm. The activity of cellular, humoral immune response and enzymatic and non-enzymatic antioxidants, has significantly been decreased as a result of EFX treatment. We investigated that Se NP supplementation greatly restores these values towards the control, and to even higher than those of the control. Adverse effects of EFX are prevented by simultaneous exposure to Se NPs (0.6 mg per kg of feed) in the diet of poultry chicken.

Evaluation of ameliorative potential of supranutritional selenium on enrofloxacin-induced testicular toxicity.

The study was designed to assess the ameliorative potential of selenium (Se) on enrofloxacin-induced testicular toxicity in rats. There was a significant decrease in body weight and non-significant decrease in mean testicular weight of enrofloxacin treated rats. In enrofloxacin treated rats, total sperm count and viability decreased where as sperm abnormalities increased. Testicular histopathology revealed dose dependent dysregulation of spermatogenesis and presence of necrotic debris in seminiferous tubules which was marginally improved with Se. Enrofloxacin also produced a dose dependent decrease in testosterone level. The activity of testicular antioxidant enzymes decreased where as lipid peroxidation increased in a dose-dependent manner. Se supplementation partially restored oxidative stress and sperm damage and did not affect the plasma concentrations of enrofloxacin or ciprofloxacain. The results indicate that enrofloxacin produces a dose-dependent testicular toxicity in rats that is moderately ameliorated with supranutritional Se.

Effects of group housing on ECG assessment in conscious cynomolgus monkeys.

INTRODUCTION: Assessing the cardiovascular safety of new chemical or biological entities is important during pre-clinical development. Electrocardiogram (ECG) assessments in non-human primate (NHP) toxicology studies are often made using non-invasive telemetry systems. We investigated whether ECG recording was feasible during group housing of NHPs, rather than the usual single housed arrangement, and whether it would impact the data collected or affect the ability to detect drug-induced changes in QTc interval. METHODS: Following a period of acclimatisation to jackets, cynomolgus monkeys (3 males and 3 females) were housed in same sex groups of 3. Female monkeys were administered 4 doses of vehicle while male monkeys were administered vehicle, 15, 45, and 135mg/kg moxifloxacin. Each dose was administered on a separate dosing day. The same dosing protocol was repeated with the animals singly housed and the results from the two phases were compared including assessment of statistical power. RESULTS: Heart rate (HR) was significantly lower, and PR and QT intervals were significantly higher, at multiple time points when the animals were group housed compared with the singly housed phase. QRS duration and QTc interval were less affected. Moxifloxacin increased QT and QTc intervals but had no consistent effect on HR, QRS duration or PR interval under group housed or singly housed conditions. Power analysis suggested that group housing did not adversely affect the magnitude of detectable changes of ECG parameters. In general, detection of slightly smaller changes was achieved under conditions of group housing. DISCUSSION: The current study shows group housing to be technically possible during non-invasive ECG recording, resulting in lower resting heart rates and small improvements in sensitivity of detection of drug-induced effects. Given the psychological benefits of group housing for NHPs, it is a refinement that should be considered when conducting ECG assessments in NHP toxicology studies.

The effect of resveratrol on protecting corneal epithelial cells from cytotoxicity caused by moxifloxacin and benzalkonium chloride.

PURPOSE: Moxifloxacin (MOX), a fourth generation fluoroquinolone (FQ), has a wide antibacterial spectrum, but may show cytotoxicity characterized by high productions of reactive oxygen species (ROS). This study investigated the protective role of a common antioxidant agent, resveratrol (trans-3,5,4'-trihydroxystilbene), against the cytotoxicity caused by MOX. METHODS: Experiments were performed with a human corneal epithelial cell line (HCECs; ATCC-CRL-11515). Another commonly used FQ, levofloxacin (LEV), and the most commonly used preservatives, benzalkonium chloride (BAC), were also used for comparison with MOX. Cell viability and morphologic changes after treatment were evaluated with trypan blue exclusion assay, propidium iodine/annexin V-FITC staining, and flow cytometry. Chemiluminescence immunoassay was used for ROS quantification. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, wound healing assay, and intracellular detections of oxidative stress were performed to evaluate the effects of resveratrol. RESULTS: The MOX group, similar to the BAC group, showed significant cell shrinkage and death compared with the LEV group. High ROS production in HCECs of MOX group was observed both by chemiluminescence immunoassay and intracellular images. Within the observations of MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay, live cell images, and wound healing process in vitro, the cytotoxic effects of the MOX and BAC groups were opposed by resveratrol. Human corneal epithelial cells pretreated with resveratrol demonstrated better cell viability and healing rate in the early stage. CONCLUSIONS: The protective effects of antioxidant agents indicate that MOX, similar to BAC, causes oxidative stress-related cell damage. The results also inspired us to think about a "supplementary regimen" to increase safety and decrease the adverse effect in the treatment of corneal infections.

Evaluation of gatifloxacin for its potential to induce antioxidant imbalance and retinopathy in rabbits.

Gatifloxacin, a fluoroquinolone antibiotic, has been reported to produce several adverse reactions. In the present investigation, gatifloxacin administered at the dose rate of 10 and 20 mg kg(-1) body weight per day, respectively, for 21 consecutive days, was evaluated for its potential to induce antioxidant status alterations and retinal damage in rabbits. A significant alteration in the antioxidant status of rabbits particularly in the high-dose group was observed which is indicated by decreased activity of superoxide dismutase and levels of blood glutathione with a concomitant increase in the activity of catalase, glutathione peroxidase, and glutathione S-transferase enzymes. The activity of glutathione reductase differed nonsignificantly between groups throughout the study period. The levels of malondialdehyde were elevated in the high-dose group. The histopathological examination of eyeball tunics revealed clumping of nuclei of the retinal outer nuclear layer in the gatifloxacin-treated groups. The results from this study indicate that repeated gatifloxacin administration produces a dose-dependent oxidative stress and retinopathy.

Intravitreal administration of known phototoxicants in the rabbit fails to produce phototoxicity: implications for phototoxicity testing of intravitreally administered small molecule therapeutics.

CONTEXT: Intravitreal (ITV) dosing has become a clinically important route of administration for the treatment of uveitis, endophthalmitis, retinal vein occlusion, diabetic macular edema and age-related macular degeneration. Despite this, there are no validated non-clinical models of phototoxicity for ITV products. OBJECTIVE: The objective of this study was to develop an ITV rabbit model of phototoxicity for use in assessing the photosafety of small molecules therapeutics. MATERIALS AND METHODS: Dutch Belted rabbits were intravitreally injected bilaterally with four known phototoxicants: 8-methoxypsoralen, lomefloxacin, doxycycline and stannsoporfrin. Triescence(®), a non-phototoxic triamcinolone acetonide steroid formulation designed for ITV administration, was used as a negative control. One eye was then irradiated with solar-simulated ultraviolet radiation for 30 min, 1 h after dosing, while the other eye was occluded, serving as a non-irradiated control. RESULTS: Despite the direct administration of known phototoxicants into the vitreous, no evidence of ocular phototoxicity was observed in any dose group. Direct (non-phototoxic) retinal toxicity was observed in the doxycycline dose group only. CONCLUSION: These data suggest that the posterior segment of the rabbit eye is protected against phototoxicity by anatomical and/or physiological mechanisms, and is not a useful model for the assessment of phototoxicity of intravitreally administered molecules.

Acute and twenty-eight days repeated oral dose toxicity study of besifloxacin in Wistar albino rats.

The purpose of this study was to investigate the potential acute and 28-day repeated oral toxicities of besifloxacin (BAF) in Wistar albino rats. In oral acute and repeated dose study, BAF was administered to both sex of rats, at dose levels of 0, 300, 600, 900 mg/kg/day and 0, 100, 200, 500 mg/kg/day, respectively. In the acute study, total white blood cell (WBC) (male, 43.74%; female, 42.60%) and total bilirubin (T-BIL) (male, 80%; female, 60%) were significantly increase, total protein (TP) (male, 23.24%; 27.80%) was significantly decreased, and significant incidence of pericholangitis (male, 83.33%; female, 75%) was shown in males and females of high-dose groups. In repeated oral dose toxicity study, similar type effects were also observed after serum hematological and serum biochemical analysis, whereas additionally sever hepatic injury and focal ulceration in gastric mucosa also observed in high dose groups of both sexes after histopathological analysis. However these toxic effects of besifloxacin were transient and reversible and no-observed adverse effect level (NOAEL) were 300 mg/kg/day for acute and 100 mg/kg/day for repeated dose toxicity study, respectively.

Comparative study of skin phototoxicity with three drugs by an in vivo mouse model.

Photosafety evaluation is becoming important during the drug development process in pharmaceutical companies. Both in vitro and in vivo test systems have been developed for the evaluation of phototoxic potential of chemicals. In the present study, we conducted an in vivo phototoxicity test using BALB/c mice. The mice were treated with sparfloxacin, lomefloxacin, or a quinoline derivative orally followed by the irradiation of simulated sunlight, and resulting phototoxic reactions of the ears were assessed. Sparfloxacin and lomefloxacin, but not the quinoline derivative, are well known to cause photoirritation in humans. All three drugs exhibited positive reaction in the 3T3 neutral red uptake phototoxicity test (3T3 NRU PT). In the in vivo test, sparfloxacin and lomefloxacin exhibited positive skin reaction in mice, but the quinoline derivative did not. The results of in vivo phototoxicity test in the mice coincided with phototoxic potential of these drugs in humans. The exposure levels of sparfloxacin or lomefloxacin at the minimum effective dose that exhibited phototoxic reaction in the mice were comparable with those in humans treated with the recommended therapeutic dose.

Evaluation of toxicity of commercial ophthalmic fluoroquinolone antibiotics as assessed on immortalized corneal and conjunctival epithelial cells.

PURPOSE: To evaluate the toxicity of a variety of the fluoroquinolone antibiotics on the ocular surface by using tissue culture models of corneal epithelial cells and conjunctival epithelial cells. METHODS: Immortalized conjunctival (CCC) and human corneal (HCE) epithelial cells were grown and when confluent the cells allowed to air dry for 1 hour. Medium was then replaced with 100 microL of one of the following: 1) Vigamox [moxifloxacin (0.5%: MX)]; (2) Zymar [gatifloxacin (0.3%: GA)]; 3) Quixin [levofloxacin (0.5%: LE)]; 4) Ocuflox [ofloxacin (0.3%: OF)]; 5) Ciloxan [ciprofloxacin (0.3%: CP)]; 6) medium (viable control); 7) "normal"/physiologic saline; 8) formalin (dead control). After one hour, 150 microL of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazonium bromide was added and incubated for 4 hours. After decanting, precipitate was dissolved in 150 microL of isopropanol. Absorbance was determined at 572 nm. RESULTS: The lowest amount of cell death was associated with the viable control. All ophthalmic preparations showed both corneal and conjunctival cell toxicity. Aside from the viable control, normal saline showed the next lowest amount of toxicity. Of the topical ocular antibiotics tested, MX showed the least amount of toxicity. All of the other antibiotics tested were statistically indistinguishable from each other. CONCLUSIONS: All of the topical ocular antibiotics tested showed evidence of both corneal and conjunctival toxicity (MX < OF < or = LE < or = CP < or = GA), although only MX was statistically significant. Whether this finding reflects on in vivo wound healing remains to be determined. This model provides a rapid and cost-effective method to screen for surface toxicity of topical agents.

Calmodulin antagonist W-7 prevents sparfloxacin-induced early afterdepolarizations (EADs) in isolated rabbit purkinje fibers: importance of beat-to-beat instability of the repolarization.

INTRODUCTION: The occurrence of early afterdepolarizations (EADs) has been related to the incidence of torsades de pointes in drug-induced long QT (LQT). The generation of EADs may be facilitated by Ca(2+)/calmodulin-dependent protein kinase II (CaM kinase). METHODS AND RESULTS: In the present study, we investigated a possible involvement of Ca(2+)/Calmodulin dependent protein kinase in the generation of sparfloxacin-induced EADs in isolated rabbit Purkinje fibers by means of a calmodulin antagonist W-7. EADs were evident in 8 of the 10 preparations perfused with sparfloxacin at 1 x 10(-4) M and stimulated at 0.2 Hz. The induction of EADs by sparfloxacin was associated with a large prolongation of the duration of the action potential (APD), an increase in the triangulation, and the short-term instability of the repolarization. CaM kinase blockade with the calmodulin antagonist W-7 inhibited sparfloxacin-induced EADs in a concentration-dependent manner (EADs were induced in 3 of 10, 1 of 10, and 0 of 8 preparations in the presence of W-7 at 5 x 10(-7) M, 5 x 10(-6) M, and 5 x 10(-5) M, respectively; P < 0.01 at 5 x 10(-6) M and 5 x 10(-5) M). The inhibition of sparfloxacin-induced EADs by W-7 at 5 x 10(-7) M and 5 x 10(-6) M was associated with a significant decrease in the beat-to-beat instability but not associated with a significant shortening of the APD and reduction of V(max). CONCLUSION: The present findings support the hypothesis that CaM kinase may be a proarrhythmic signaling molecule and demonstrate that CaM kinase may be involved in the generation of EADs in drug-induced LQT and enhanced beat-to-beat instability of repolarization is essential for the genesis of EADs in rabbit in vitro.

Intravitreal toxicity of garenoxacin.

PURPOSE: To assess the retinal toxicity of varying concentrations of intravitreally injected garenoxacin. METHODS: Twenty eyes of 20 New Zealand albino rabbits were used for this study. The animals were anesthetized with ketamine (35-50 mg/kg) and xylazine (3-5 mg/kg). Garenoxacin was titrated using distilled water to the following concentrations: 4,000, 2,000, 1,000, 400, 200, and 100 microg/0.1 mL. Each concentration was injected intravitreally (0.1 mL) into three rabbit eyes. Three control eyes were injected with 0.1 mL of balanced saline solution. All animals were examined before and after injection by indirect ophthalmoscopy and slit-lamp biomicroscopy. Electroretinography was performed on all animals before intravitreal injection and 14 days after injection. The animals were examined by indirect ophthalmoscopy and slit-lamp biomicroscopy before they were killed; the eyes were enucleated and examined with light microscopy. RESULTS: No electroretinographic changes or signs of retinal toxicity by slit-lamp examination, indirect ophthalmoscopy, or light microscopy were seen in any eyes 14 days after intravitreal injection of garenoxacin (< or =4,000 microg/0.1 mL). CONCLUSIONS: Garenoxacin injected intravitreally appeared safe at concentrations of < or =4,000 microg/0.1 mL.

Acute hypokalemia may not be an effective way to sensitize the in situ canine heart for sparfloxacin-induced long QT syndrome.

Extents of the sparfloxacin (3 - 10 mg/kg, i.v.)-induced QT interval prolongation under normokalemic and hypokalemic conditions were assessed in halothane-anesthetized beagle dogs (n = 5). The hypokalemic condition was induced by an oral administration of furosemide (200 mg/kg per day) for 3 days, which decreased the serum potassium concentration from 3.65 +/- 0.13 to 2.35 +/- 0.13 mM (P < 0.05). However, the decrease of potassium concentration by itself did not affect the extent of the sparfloxacin-induced QT interval prolongation. These results indicate that acute hypokalemia may not severely sensitize the in situ heart for drug-induced long QT syndrome as previously thought.

Synthesis and in-vitro cytotoxicity evaluation of gatifloxacin Mannich bases.

Mannich bases of gatifloxacin were synthesized by reacting them with formaldehyde and several isatin derivatives. Their chemical structures have been confirmed by means of their IR, 1H-NMR data and by elemental analysis. The compounds were tested in-vitro against a panel of 58 human tumour cell lines derived from nine neoplastic diseases. Among them compound 1-cyclopropyl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-7[[N4-(3'-sulphadoximino)-1'-(5-bromoisatinyl) methyl]-3-methyl N1-piperazinyl]-3-quinoline carboxylic acid (6) emerged as a potent anticancer agent being more active than standard DNA topoisomerase II inhibitor, etoposide against 30 cancer cell lines.

Relación estructura-fotoestabilidad u fototoxicidad de fluoroquinolonas / Structure-photostability and phototoxicity relationship in fluoroquinolones

Las quinolonas constituyen una familia de antibióticos de amplio uso en la actualidad, debido a su gran eficacia clínica en el tratamiento de infecciones del tracto respiratorio, urinario, tejidos blandos y enfermedades de transmisión sexual. De acuerdo a su estructura base se pueden clasificar en quinolonas naftiridínicas (enoxacino y ácido nalidíxico), quinolínicas (ciprofloxacino, norfloxacino, ácido oxolínico, rosoxacino) y pirimido-pirimidinicas (ácido pipemídico). Las quinolonas se caracterizan por presentar reacciones de fotosensibilidad y fotolabilidad. El ácido nalidíxico, quinolona de primera generación, presenta reacciones de fototoxicidad, evaluadas en el modelo del glóbulo rojo y en cultivos celulares. El ácido nalidíxico, exento del sustituyente piperazínico presenta una fotolabilidad disminuida. Las fluoroquinolonas, a diferencia del ácido nalidíxico, presentan un anillo piperazínico o metil piperazínico en posición 7, incorporado con el fin de mejorar las propiedades antibacterianas. En este trabajo se investiga la influencia del anillo piperazínico en posición 7 sobre la fotolabilidad y fototoxicidad, demostrándose que las fluoroquinolonas que poseen este sustituyente presentan una fotolabilidad aumentada y una fototoxicidad disminuída, en relación a quinolonas carentes de éste grupo. Es probable que la fotodegradación de quinolonas transcurra mediante un mecanismo radicalario, con la pérdida del grupo carboxílico

Quinolones constitute a large class of synthetic antimicrobial agents that are highly effective in the treatment of respiratory, urinary, sexually transmitted diseases and soft tissue infection. In agreement with his structure the quinolones can be classified into naftaridines (enoxacin and nalidixic acid), quinolines (ciprofloxacin, norfloxacin, oxolinic acid, roxosacin) and pyrid-pyrimidin (pipemidic acid). Some quinolones may undergo photodegradation reactions. On the other hand, quinolones can induce cutaneous photosensitivity reactions.and photolability as well. Nalidixic acid, a first quinolone generation, may undergo phototoxic effects on the red blood cells and in cell culture. Nalidixic acid, which has not the piperazine group in position 7, exhibit a moderated photolability. The fluoroquinolones as oppossed to nalidixic acid have a piperazine ring in position 7. We investigated the influence of the piperazine ring on the phototoxicity and photolability of several quinolones. We demonstrated that the fluoroquinolones with piperazinic group present higher photolability and less phototoxicity .It is possible that the photodegradation of quinolones takes place through a radical pathway, with the loss of a carboxylic acid group

Antimicrosporidial activity of (fluoro)quinolones in vitro and in vivo.

Microsporidia are a cause of emerging and opportunistic infections in humans and animals. Although two drugs are currently being used to treat microsporidiosis, concerns exist that albendazole is only selective for inhibiting some species of microsporidia that infect mammals, and fumagillin appears to have been found to be toxic. During a limited sequence survey of the Vittaforma corneae genome, a partial gene encoding for the ParC topoisomerase IV subunit was identified. The purpose of this set of studies was to determine if fluoroquinolones, which target topoisomerase IV, exert activity against Encephalitozoon intestinalis and V. corneae in vitro, and whether these compounds could prolong survival of V. corneae-infected athymic mice. Fifteen fluoroquinolones were tested. Of these, norfloxacin and ofloxacin inhibited E. intestinalis replication by more than 70% compared with non-treated control cultures, while gatifloxacin, lomefloxacin, moxifloxacin, and nalidixic acid (sodium salt) inhibited both E. intestinalis and V. corneae by at least 60% at concentrations not toxic to the host cells. These drugs were tested in vivo also, where gatifloxacin, lomefloxacin, norfloxacin, and ofloxacin prolonged survival of V. corneae-infected athymic mice (P < 0.05), whereas moxifloxacin and nalidixic acid failed to prolong survival. Therefore, these results support continued studies for evaluating the efficacy of the fluoroquinolones for treating microsporidiosis and for characterizing the target(s) of these fluoroquinolones in the microsporidia.

Developmental toxicity assessment of the new fluoroquinolone antibacterial DW-116 in rabbits.

DW-116 is a newly developed fluoroquinolone antibacterial with a broad spectrum against both Gram-positive and Gram-negative bacteria. We have reported recently that DW-116 is embryotoxic and teratogenic in rats. The present study was conducted to investigate the teratogenicity of DW-116, together with maternal toxicity and developmental toxicity using New Zealand White rabbits. The test chemical was administered by gavage to pregnant rabbits from gestational day (GD) 6 through to GD 18 at dose levels of 0, 5, 19.5 and 76.1 mg kg(-1) day(-1). All does were subjected to caesarean section on day 28 of gestation and their foetuses were examined for external, visceral and skeletal abnormalities. In the 76.1 mg kg(-1) group, a minimal maternal toxicity, as evidenced by decreased body weight gain during treatment period, was observed in pregnant rabbits. Significant embryo-foetal toxicity, including increased number of foetal deaths and delayed foetal ossification, was seen. However, no treatment-related morphological changes were detected in foetal external, visceral and skeletal examinations. There were no adverse effects on either pregnant dams or embryo-foetal development at 19.5 and 5 mg kg(-1). It was concluded that administration of DW-116 during the major organogenetic period in rabbits produced decreased maternal body weight gain, increased number of foetal deaths and foetal developmental delay but no evidence of teratogenicity. The no-observed-adverse-effect levels (NOAELs) of DW-116 are considered to be 19.5 mg kg(-1) day(-1) for does and embryo-foetuses, respectively.