Repeated Dose Toxicity Research Articles

Constructing a developmental and reproductive toxicity database of chemicals (DART NIHS DB) for integrated approaches to testing and assessment

Developmental and reproductive toxicity (DART) is an important endpoint, and databases (DBs) are essential for evaluating the risk of untested substances using alternative methods. We have constructed a reliable and transparent DART DB, which we named DART NIHS DB, using the publicly available datasets of DART studies of industrial chemicals conducted by Japanese government ministries in accordance with the corresponding OECD test guidelines (OECD TG421 and TG422). This DB is unique because its dataset chemicals have little overlap with those of ToxRefDB, which compiles large-scale DART data, and it is reliable because the included datasets were created after reviewing the individual study reports. In DART NIHS DB, 171 of 404 substances exhibited signs of DART, which occurred during fertility and early embryonic development (49 substances), organogenesis (59 substances), and the perinatal period (161 substances). When the lowest-observed-adverse-effect level (LOAEL) of DART was compared with that of repeated-dose toxicity (RDT), 15 substances (12%) had a lower LOAEL for DART than for RDT. Of these, five substances displayed significant DART at doses of ≤ 50 mg/kg bw/day. The chemical and toxicity information in this DB will be useful for the development of stage-specific adverse outcome pathways (AOPs) via integration with mechanistic information. The whole datasets of the DB can be implemented in read-across support tools such as the OECD QSAR Toolbox, which will further lead to future integrated approaches to testing and assessment based on AOPs.

Safety assessment of Aconitum-Derived bulleyaconitine A: A 91-day oral toxicity study and a tissue accumulation study in rats

Background: Bulleyaconitine A (BLA) is a diterpenoid alkaloid from the rhizomes of Aconitum bulleyanum Diels and has been clinically used for chronic pain treatment in China for many years. However, the newly reported adverse events of BLA indicated that BLA still has potential safety issues. Materials and Methods: To assess the safety of BLA, analgesic tests, acute toxicity studies, repeated-dose oral toxicity studies, and tissue distribution studies after single and repeated administration of BLA were carried out. Results: Administration of 0.14 mg/kg BLA showed potent analgesic effects in both analgesic tests. In acute toxicity study, the LD50 value of BLA was calculated to be 3.4434 mg/kg. In the subchronic toxicity study, the no observed adverse effect level was 0.25 mg/kg, and the lowest observed adverse effect level was 0.5 mg/kg. The spleen, liver, and kidneys are newly identified target organs of BLA toxicity after long-term administration. Moreover, unlike a single BLA administration, repeated administration showed BLA redistribution from organs with an abundant blood supply to immune and metabolic organs. Conclusions: These results suggested that BLA itself would be nontoxic at a dosage of 0.25 mg/kg in rats and should be carefully used when combining BLA with medications that can cause spleen, liver, or kidney injury.

In vivo and in silico studies of Dennettia tripetala essential oil reveal the potential harmful effects of habitual consumption of the plant seed.

Dennettia tripetala G. Baker (Annonaceae), is a plant with nutritional, social economy, and medicinal values. Its rising medicinal profile makes this plant a prospect in drug discovery. However, the reported strong addictive potential among habitual consumers makes the need to establish its safety imperative. In this report, we evaluated the safety profile of the essential oil of the seed of D. tripetala (EODS) in nulliparous female Wistar rats using in vivo single and repeated dose toxicity profiling, as well as in silico toxicity profiling of its known seed oil derived phytoconstituents. Our results showed consistent significant dose-dependent alterations in relative body weights, organ-body and organ-brain weight ratios, haematological and biochemical indices, as well as liver and kidney histoarchitectures, following single and repeated oral administrations. Significant alterations in liver and kidney histoarchitectures were consistent with the observed significant increase in AST/ALT ratio, suggesting deleterious effects of EODS on the kidney and liver. However, the lack of alterations in the histoarchitectures of the hippocampus and hypothalamus suggests that the brain may not have been adversely affected. Also, the in silico analysis suggests that hepatotoxic effects of EODS may be linked to Benzylnitrile, Humulene, Linalool, (Z)-ß-Ocimene. In addition, the failure of ß-Phenylnitroethane, the most abundant phytoconstituent of EODS, to pass phases I and II in silico toxicity screening, and the presence of Caryophyllene oxide, a known toxic compound, coupled with the predicted binding of both to DNA and protein, low LD50 and high percent mortality at 250 mg/kg of repeated doses, further confirmed the potentially toxic nature of EODS. We concluded that based on our in vivo and in silico observations, there is an urgent need for public education to regulate the excessive consumption of the seeds of D. tripetala.

Safety of water extract of Cistanche tubulosa stems as a Novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on water extract of Cistanche tubulosa stems as a novel food (NF) for its use in food supplements (FS) and foods for special medical purposes (FSMP). The target population is the general adult population excluding pregnant and lactating women. The applicant proposes a maximum daily intake of 2 g for FS and a maximum use level of 10% in FSMP. The characteristic components of the extract are phenylethanoid glycosides (at least 70% of the NF), in particular, echinacoside (25–45% of the NF). The NF has been authorised as a prescription drug in China in 2005 for the treatment of vascular dementia. The Panel notes that an integrated analysis of three studies covering 1,076 patients with vascular dementia treated with the proposed NF at a daily dose of 1,800 mg, reported that 12 adverse events (AEs) were classified to be ‘definitely’, ‘probably’ or ‘possibly related’ to the exposure to the NF. Two of these AE were classified as severe (cerebral haemorrhage and epilepsy). The Panel considers that the reported AEs raise safety concerns. The Panel also notes the limitations of the provided toxicological studies, in particular the non‐compliance with the EFSA approach on the genotoxicity testing strategy and the non‐compliance with good laboratory practice (GLP) and the respective OECD Guidance documents of the repeated dose toxicity studies. In view of the AEs in the human studies, the Panel considers that additional toxicological studies, following testing guidelines would not be able to overcome the concerns raised from the human studies. The Panel concludes that the safety of the NF has not been established.

Association between in vitro nuclear receptor-activating profiles of chemical compounds and their in vivo hepatotoxicity in rats.

The liver plays critical roles to maintain homeostasis of living organisms and is also a major target organ of chemical toxicity. Meanwhile, nuclear receptors (NRs) are known to regulate major liver functions and also as a critical target for hepatotoxic compounds. In this study, we established mammalian one-hybrid assay systems for five rat-derived NRs, namely PXR, PPARα, LXRα, FXR and RXRα, and evaluated a total of 326 compounds for their NR-activating profiles. Then, we assessed the association between their NR-activating profile and hepatotoxic endpoints in repeated-dose toxicity data of male rats from Hazard Evaluation Support System. In the in vitro cell-based assays, 68, 38, 20, 17 and 17 compounds were identified as positives for PXR, PPARα, LXRα, FXR and RXRα, respectively. The association analyses demonstrated that the PXR-positive compounds showed high frequency of endpoints related to liver hypertrophy, such as centrilobular hepatocellular hypertrophy, suggesting that PXR activation is involved in chemical-induced liver hypertrophy in rats. It is intriguing to note that the PXR-positive compounds also showed statistically significant associations with both prolonged activated partial thromboplastin time and prolonged prothrombin time, suggesting a possible involvement of PXR in the regulation of blood clotting factors. Collectively, our approach may be useful for discovering new functions of NRs as well as understanding the complex mechanism for hepatotoxicity caused by chemical compounds.

A 90-day oral repeated-dose toxicity study of Monascus Color Y-001 in rats

Monascus Color Y-001, a natural food dye produced from Monascus purpureus fermentation, was administered orally by gavage to male and female SD rats for 90 days at doses of 0 (vehicle: 0.1% Tween 80, 10 mL/kg bw), 100, 300 and 1000 mg/kg/day. During the treatment period, there was no death, and test article effects on clinical signs were limited to reddish feces, soiled perineal region (reddish color) and salivation that were observed in both sexes at 300/1000 mg/kg/day. Prolongation in PT and APTT occurred in males at 1000 mg/kg/day, and the changes were without any evidence suggesting hemorrhage and/or hepatic dysfunction. Treatment-related histopathological findings were noted in thymus, liver and kidney, and were limited to the females at 1000 mg/kg/day. These findings included decreased cellularity in thymus with decreased thymus weights attributed to nonspecific stress, centrilobular hepatocellular hypertrophy with increase of liver weights attributed to adaptive change, and vacuolation of proximal tubules in kidneys accompanied with related parameter changes in urinalysis. From these results, the no-observed-adverse-effect level (NOAEL) was judged to be 300 mg/kg/day both in male and female rats.

Toxicity of diclofenac sodium salt in Yucatan minipigs (Sus scrofa) following 4 weeks of daily intramuscular administration.

Diclofenac sodium salt (DSS) is a widely used nonsteroidal anti-inflammatory drug. The present study was performed under good laboratory practice (GLP) regulations to investigate the toxicity of DSS after 4 weeks of repeated intramuscular administration at doses of 0, 2, 10, or 20 mg/kg/day in 32 minipigs and to evaluate the DSS effect following a 2-week recovery period. Dose-related clinical signs and alterations of hematological or clinical chemistry parameters, organ weight, and macroscopic as well as histopathological findings in hepatic, renal, gastrointestinal, skin and injection sites were observed in both sexes' animals of the 10 or 20 mg/kg/day group. With the exception of the skin-related findings, most symptoms showed a tendency to resolve after the 2-week recovery period. The systemic exposure (AUClast) of DSS in plasma showed similar pattern to the increase rate of the dose and similar values between males and females except for the female 20 mg/kg dose group (56 %) on Day1. The systemic exposure showed a decreasing trend in the 10 or 20 mg/kg group after 4-week of repeated administration compared to Day1. The no-observed-adverse-effect level of DSS in this study was considered to be 2 mg/kg/day in both male and female minipigs.

Incorporating lines of evidence from New Approach Methodologies (NAMs) to reduce uncertainties in a category based read-across: A case study for repeated dose toxicity

A group of triazole compounds was selected to investigate the confidence that may be associated with read-across of a complex data gap: repeated dose toxicity. The read-across was evaluated using Assessment Elements (AEs) from the European Chemicals Agency's (ECHA's) Read-Across Assessment Framework (RAAF), alongside appraisal of associated uncertainties. Following an initial read-across based on chemical structure and properties, uncertainties were reduced by the integration of data streams such as those from New Approach Methodologies (NAM) and other existing data. In addition, addressing the findings of the ECHA RAAF framework, complemented with specific questions concerning uncertainties, increased the confidence that can be placed in read-across. Although a data rich group of compounds with a strong mechanistic basis was analysed, it was clearly demonstrated that NAM data available from publicly available resources could be applied to support read-across. It is acknowledged that most read-across studies will not be so data rich or mechanistically robust, therefore some targeted experimentation may be required to fill the data gaps. In this sense, NAMs should constitute new experimental tests performed with the specific goal of reducing the uncertainties and demonstrating the read-across hypothesis.

Acute and repeated-dose toxicity of Echinops kebericho Mesfin essential oil.

Echinops kebericho Mesfin is used for the management of various diseases and fumigation during child birth. This study investigated acute and repeated-dose toxicity of E. kebericho M. essential oils (EOs). The study was conducted in Swiss albino mice. Organ weight, histopathology and clinical chemistry were analyzed. The dose and duration of treatment were defined in accordance with Organization for Economic Co-operation and Development (OECD) guideline. No mortality was observed in acute oral dose toxicity study up to 2000 mg/kg per body weight. Compared to control group, treated groups did not show significant abnormalities in body weight and most parameters of clinical chemistry parameters and relative organ weight in repeated-dose toxicity study. However, urea, albumin, aspartate aminotransferase, and relative organ weight of right kidney showed variations in treated groups compared to control group. All treated groups and control group showed normal histology except lymphocytic infiltrates observed on the kidney with 200 mg/kg treated female group. The current study revealed that EO of E. kebericho M. could be considered well tolerated in acute and repeated-dose exposure. Further, teratogenic, mutagenic, carcinogenic, and sub-chronic and chronic toxicity studies are warranted.

Development of a Battery of In Silico Prediction Tools for Drug-Induced Liver Injury from the Vantage Point of Translational Safety Assessment.

Drug-induced liver injury (DILI) remains a challenge when translating knowledge from the preclinical stage to human use cases. Attempts to model human DILI directly based on the information from drug labels have had some success; however, the approach falls short of providing insights or addressing uncertainty due to the difficulty of decoupling the idiosyncratic nature of human DILI outcomes. Our approach in this comparative analysis is to leverage existing preclinical and clinical data as well as information on metabolism to better translate mammalian to human DILI. The human DILI knowledge base from the United States Food and Drug Administration (U.S. FDA) National Center for Toxicology Research contains 1036 pharmaceuticals from diverse therapeutic categories. A human DILI training set of 305 oral marketed drugs was prepared and a binary classification scheme applied. The second knowledge base consists of mammalian repeated dose toxicity with liver toxicity data from various regulatory sources. Within this knowledge base, we identified 278 pharmaceuticals containing 198 marketed or withdrawn oral drugs with data from the U.S. FDA new drug application and 98 active pharmaceutical ingredients from ToxCast. From this collection, a set of 225 oral drugs was prepared as the mammalian hepatotoxicity training set with particular end points of pathology findings in the liver and bile duct. Both human and mammalian data sets were processed using various learning algorithms, including artificial intelligence approaches. The external validations for both models were comparable to the training statistics. These data sets were also used to extract species-differentiating chemotypes that differentiate DILI effects on humans from mammals. A systematic workflow was devised to predict human DILI and provide mechanistic insights. For a given query molecule, both human and mammalian models are run. If the predictions are discordant, both metabolites and parents are investigated for quantitative structure-activity relationship and species-differentiating chemotypes. Their results are combined using the Dempster-Shafer decision theory to yield a final outcome prediction for human DILI with estimated uncertainty. Finally, these tools are implementable within an in silico platform for systematic evaluation.

The methanolic extract of Garcinia atroviridis (MeGa) reduces body weight and food intake, and improves lipid profiles by altering the lipid metabolism: a rat model.

Garcinia species are widely used for their slimming effects via increased fat burning and suppression of satiety. However, scientific evidence for the biological effects of Garcinia atroviridis (GA) is lacking. We investigated the phytochemical composition, safety profiles, and antioxidant and antiobesity effects of methanolic extracts of Garcinia atroviridis (MeGa) in obese female rats. Repeated dose toxicity studies were conducted according to the OECD guidelines. Upon sacrifice, haematological, biochemical, lipid profile, and serum-based metabolomics analyses were performed to evaluate metabolic expression changes and their related pathways. MeGa contains several phytochemical groups and GA fruit acids. MeGa was found to be nontoxic in both male and female rats with an oral lethal dose (LD50) of 2000 mg/kg. After 9 weeks of treatment, MeGa-treated obese rats had lower weight gain and better lipid profiles (cholesterol and triglyceride), which correlated with the altered metabolic pathways involved in the metabolism of lipid (glycerophospholipid) and biosynthesis of unsaturated fatty acid. In addition, MeGa caused differential metabolism pathways of arachidonic acid and tryptophan that affect the inflammatory response and suppression of appetite. We concluded that MeGa is safe, and its slimming effects are due to the differential metabolism of lipids.

RIFM fragrance ingredient safety assessment, methyl-2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate, CAS Registry Number 81752-87-6

The existing information supports the use of this material as described in this safety assessment. Methyl-2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that methyl-2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate is not genotoxic. Data on methyl-2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate provide a calculated Margin of Exposure (MOE) >100 for the repeated dose toxicity endpoint. The reproductive and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material, and the exposure to methyl-2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate is below the TTC (0.03 mg/kg/day and 1.4 mg/day, respectively). Data show that there are no safety concerns for methyl-2,2-dimethyl-6-methylene-1-yclohexanecarboxylate for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; methyl-2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; methyl-2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.

Two-weeks repeated-dose oral toxicity study of Pediococcus acidilactici J9 in a mice model

BackgroundHelicobacter pylori (H. pylori) is an important pathogen that causes chronic gastritis and peptic ulcer, and is related to the development of gastric carcinoma. Several chemicals, including antibiotics, have been used to eradicate H.pylori. However, more studies are yet requred to accomplish a sufficient therapy. Pediococcus acidilactici (P. acidilactici) J9 were studied for inhibition of binding of H.pylori binding to human gastric cell lines. This study was performed in order to investigate the repeated-dose toxicity of P. acidilactici J9 in male and female mice.ResultsC57BL/6 male and female Mus musculus were divided into four groups (n = 10 in each group). P. acidilactici J9 was administered daily by oral injection of vehicle control at dosage levels to a low-dose group (500 mg/kg/day), middle-dose group (1000 mg/kg/day), and high-dose group (2000 mg/kg/day) for 2 weeks. After 14 days of exposure, the blood biochemistry and hematology were investigated, along with a histopathology exam. There were no bacterial-related deaths or abnormal clinical signs in either gender of mouse. The data was observed during the period in terms of body weight, food intake, and water consumption. Also, no alterations in organ weights upon administration of P. acidilactici J9 alone were observed. The adhesion and growth of H. pylori were inhibited by a 24 h treatment of H. pylori and P. acidilactici J9 on adenocarcinoma gastric (AGS) cells, which are gastric cancer cells. Compared to the control group (AGS cell and H. pylori), the number of H. pylori analyzed by FACS significantly (p < 0.01) decreased after incubation of AGS cell with P. acidilactici J9 for 24 h.ConclusionsThese results suggest that the oral application of P. acidilactici J9, up to a dosage level of 2000 mg/kg/day, causes no adverse effects in both male and female mice. P. acidilactici J9 inhibits the adhesion of H.pylori to AGS cancer cells. When used as probiotics, P. acidilactici J9 may help decrease the occurrence of gastritis and reduce the risk of H.pylori infection with promising safety issues.

Short-term toxicity study of 1-aminobenzotraizole, a CYP inhibitor, in Wistar rats

1-Aminobenzotriazole (ABT) is a pan-specific, mechanism-based inhibitor of CYP P450 enzymes, often used as co-treatment to investigate the metabolism-dependent toxicity of drugs or chemicals. To assess the confounding effects of ABT in such kind of mechanistic studies, a repeated dose toxicity study with ABT following 7 days oral administration at 0, 25, 50 and 100 mg/kg/day was performed in Wistar rats (5 rats/sex/group). Wistar rat is selected as a model being one of the well characterized rodent species, widely used for toxicity and toxicokinetics studies. The standard parameters of general toxicity study viz. clinical signs, body weight, feed consumption, clinical, gross and histopathology were evaluated. The ABT was tolerated up to the highest tested dose of 100 mg/kg/day. No clinical signs, mortality or effect on feed consumption at any dose. Slight increase in body weight gain was noted in ABT treated females. Increased reticulocyte, and decreased triglycerides, BUN, A/G ratio and plasma potassium; increased weight of liver, kidneys, adrenals and thyroid was noted in ABT treated animals. Microscopically, hypertrophic findings were noted in liver, thyroid, adrenal glands, pituitary and uterus. Some of these changes were observed at as low as 25 mg/kg/day, therefore, NOEL could not be established. Based on this study, it is concluded that ABT is tolerable up to 100 mg/kg/day with some variations in clinical pathology, organ weight and histopathology; these changes should be considered during the assessment of any mechanistic study with ABT. Findings of this manuscript were presented at 58th meeting of the Society of Toxicology, Baltimore, 11 March 2019.

RIFM fragrance ingredient safety assessment, 3,4,4a,5,8,8a(Or 3,4,4a,7,8,8a)-hexahydro-3,3,6,7-tetramethyl-1H-2-benzopyran, CAS Registry Number 72429-08-4

The existing information supports the use of this material as described in this safety assessment. 3,4,4a,5,8,8a (Or 3,4,4a,7,8,8a)-Hexahydro-3,3,6,7-tetramethyl-1H-2-benzopyran was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 3,4,4a, 5,8,8a (Or 3,4,4a, 7,8,8a)-hexahydro-3,3,6,7-tetramethyl-1H-2-benzopyran is not genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the threshold of toxicological concern (TTC) for a Cramer Class III material, and the exposure to 3,4,4a, 5,8,8a (Or 3,4,4a, 7,8,8a)-hexahydro-3,3,6,7-tetramethyl-1H-2-benzopyran is below the TTC (0.0015 mg/kg/day, 0.0015 mg/kg/day, and 0.47 mg/day, respectively). The skin sensitization endpoint was completed using the dermal sensitization threshold (DST) for non-reactive materials (900 μg/cm2); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; 3,4,4a, 5,8,8a (Or 3,4,4a,7,8,8a)-hexahydro-3,3,6,7-tetramethyl-1H-2-benzopyran is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 3,4,4a, 5,8,8a (Or 3,4,4a, 7,8,8a)-hexahydro-3,3,6,7-tetramethyl-1H-2-benzopyran was found not to be persistent, bioaccumulative, and toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.

RIFM fragrance ingredient safety assessment, 2-cyclohexylcyclohexanone, CAS Registry Number 90-42-6

Summary: The existing information supports the use of this material as described in this safety assessment.2-Cyclohexylcyclohexanone was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data and read-across to 2-tert-butylcyclohexanone (CAS # 1728-46-7) show that 2-cyclohexylcyclohexanone is not expected to be genotoxic. Data on read-across material 2-sec-butylcyclohexanone (CAS # 14765-30-1) provide a calculated margin of exposure (MOE) > 100 for the repeated dose toxicity and reproductive toxicity endpoints. The skin sensitization endpoint was completed using the dermal sensitization threshold (DST) for non-reactive materials (900 μg/cm2); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on UV spectra; 2-cyclohexylcyclohexanone is not expected to be phototoxic/photoallergenic. The local respiratory toxicity endpoint was evaluated using the threshold of toxicological concern (TTC) for a Cramer Class II material, and the exposure to 2-cyclohexylcyclohexanone is below the TTC (0.47 mg/day). The environmental endpoints were evaluated; 2-cyclohexylcyclohexanone was found not to be persistent, bioaccumulative, and toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.

RIFM fragrance ingredient safety assessment, 3-octanol, CAS Registry Number 589-98-0

Summary: The existing information supports the use of this material as described in this safety assessment.3-Octanol was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog 3-hexanol (CAS # 623-37-0) show that 3-octanol is not expected to be genotoxic. Data on 3-octanol provide a calculated margin of exposure (MOE) > 100 for the repeated dose toxicity endpoint. Data on read-across analog 2-octanol (CAS # 123-96-6) provide a calculated MOE >100 for the reproductive toxicity endpoint and show that there are no safety concerns for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; 3-octanol is not expected to be phototoxic/photoallergenic. The local respiratory toxicity endpoint was evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material; exposure is below the TTC (1.4 mg/day). The environmental endpoints were evaluated; 3-octanol was found not to be Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., Predicted Environmental Concentration/Predicted No Effect Concentration [PEC/PNEC]), are <1.

RIFM fragrance ingredient safety assessment, 2-thiophenecarboxylic acid, ethyl ester, CAS Registry Number 2810-04-0

The existing information supports the use of this material as described in this safety assessment. 2-Thiophenecarboxylic acid, ethyl ester was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data show that 2-thiophenecarboxylic acid, ethyl ester is not genotoxic. The repeated dose, reproductive, and local respiratory toxicity endpoints were evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class III material, and the exposure to 2-thiophenecarboxylic acid, ethyl ester is below the TTC (0.0015 mg/kg/day, 0.0015 mg/kg/day, and 0.47 mg/day, respectively). The skin sensitization endpoint was completed using the Dermal Sensitization Threshold (DST) for non-reactive materials (900 μg/cm2); exposure is below the DST. The phototoxicity/photoallergenicity endpoints were evaluated based on UV spectra; 2-thiophenecarboxylic acid, ethyl ester is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 2-thiophenecarboxylic acid, ethyl ester was found not to be PBT as per the IFRA Environmental Standards, and its risk quotients, based on its current volume of use in Europe and North America (i.e., PEC/PNEC), are <1.

Subacute toxicity study of the ethanolic extract of Mesua ferrea (L.) flowers in rats

Mesua ferrea Linn. is used traditionally in India and South East Asian countries as an antiseptic, antidote and a brain tonic. Recent pharmacological studies on the plant have highlighted M. ferrea to be a rich source of secondary metabolites, with proven therapeutic applications. Since the toxicity of a plant following repeated exposure is of higher clinical significance, the present investigation was conducted to establish the subacute toxicity profile of the ethanolic extract of Mesua ferrea flowers (MFE). The study was conducted in accordance with the OECD Guideline 407, wherein MFE was administered orally to groups of male and female rats (n = 5/group/sex) at the doses of 100, 500 and 1000 mg/kg, over a period of 28 days. Repeated administration of MFE had no adverse effect on the growth rate and hematological parameters of the animals. There were no changes in the biochemical parameters, except for a slight decrease in the CHOL (total cholesterol) levels, and an increase in the levels of AST (aspartate aminotransferase) and ALT (alanine aminotransferase), at the highest dose. The latter corroborated with the histopathological findings exhibiting mild lymphocytic infiltration and hepatocyte degeneration observed in the liver tissues of both sexes. According to the study, the no-observed-adverse-effect level (NOAEL) of M. ferrea in the 28-day repeated dose toxicity study in rats was 500 mg/kg. Though the overall effects of the extract at the highest dose did not translate into any serious complications, its effect on hepatic function needs to be established over a longer period of study.

RIFM fragrance ingredient safety assessment, hexyl 2-hydroxypropionate, CAS Registry Number 20279-51-0

Summary The existing information supports the use of this material as described in this safety assessment. Hexyl 2-hydroxypropionate was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across analog ethyl lactate (CAS # 97-64-3) show that hexyl 2-hydroxypropionate is not expected to be genotoxic, provide a calculated Margin of Exposure (MOE) >100 for the repeated dose toxicity and reproductive toxicity endpoints, and show that there are no safety concerns for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet (UV) spectra; hexyl 2-hydroxypropionate is not expected to be phototoxic/photoallergenic. The local respiratory toxicity endpoint was evaluated using the Threshold of Toxicological Concern (TTC) for a Cramer Class I material; the exposure is below the TTC (1.4 mg/day). The environmental endpoints were evaluated. For the hazard assessment based on the screening data, hexyl 2-hydroxypropionate is not persistent, bioaccumulative, and toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards. For the risk assessment, hexyl 2-hydroxypropionate was not able to be risk screened as there were no reported volumes of use for either North America or Europe in the 2015 IFRA Survey.