Hazard characterization of Alternaria toxins to identify data gaps and improve risk assessment for human health.

Fungi of the genus Alternaria are ubiquitous plant pathogens and saprophytes which are able to grow under varying temperature and moisture conditions as well as on a large range of substrates. A spectrum of structurally diverse secondary metabolites with toxic potential has been identified, but occurrence and relative proportion of the different metabolites in complex mixtures depend on strain, substrate, and growth conditions. This review compiles the available knowledge on hazard identification and characterization of Alternaria toxins. Alternariol (AOH), its monomethylether AME and the perylene quinones altertoxin I (ATX-I), ATX-II, ATX-III, alterperylenol (ALP), and stemphyltoxin III (STTX-III) showed in vitro genotoxic and mutagenic properties. Of all identified Alternaria toxins, the epoxide-bearing analogs ATX-II, ATX-III, and STTX-III show the highest cytotoxic, genotoxic, and mutagenic potential in vitro. Under hormone-sensitive conditions, AOH and AME act as moderate xenoestrogens, but in silico modeling predicts further Alternaria toxins as potential estrogenic factors. Recent studies indicate also an immunosuppressive role of AOH and ATX-II; however, no data are available for the majority of Alternaria toxins. Overall, hazard characterization of Alternaria toxins focused, so far, primarily on the commercially available dibenzo-α-pyrones AOH and AME and tenuazonic acid (TeA). Limited data sets are available for altersetin (ALS), altenuene (ALT), and tentoxin (TEN). The occurrence and toxicological relevance of perylene quinone-based Alternaria toxins still remain to be fully elucidated. We identified data gaps on hazard identification and characterization crucial to improve risk assessment of Alternaria mycotoxins for consumers and occupationally exposed workers.

RIFM fragrance ingredient safety assessment, 5-hydroxy-7-decenoic acid δ-lactone, CAS Registry Number 25524-95-2.

The existing information supports the use of this material as described in this safety assessment. 5-Hydroxy-7-decenoic acid δ-lactone was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from read-across material tetrahydro-6-(3-pentenyl)-2H-pyran-2-one (CAS # 32764-98-0) show that 5-hydroxy-7-decenoic acid δ-lactone is not expected to be genotoxic. The repeated dose, 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 5-hydroxy-7-decenoic acid δ-lactone is below the TTC (0.03 mg/kg/day, 0.03 mg/kg/day, and 1.4 mg/day, respectively). Data show that there are no safety concerns for 5-hydroxy-7-decenoic acid δ-lactone for skin sensitization under the current declared levels of use. The phototoxicity/photoallergenicity endpoints were evaluated based on ultraviolet/visible (UV/Vis) spectra; 5-hydroxy-7-decenoic acid δ-lactone is not expected to be phototoxic/photoallergenic. The environmental endpoints were evaluated; 5-Hydroxy-7-decenoic acid δ-lactone 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.

Alternariol monomethyl ether toxicity and genotoxicity in male Sprague-Dawley rats: 28-Day in vivo multi-endpoint assessment.

Alternariol monomethyl ether (AME), a typical Alternaria toxin, has often been detected in grains. We have measured the general toxicity and genotoxicity of AME with a 28-day multi-endpoint (Pig-a assay + in vivo micronucleus [MN] test + comet assay) platform. Male Sprague-Dawley rats were administered AME (1.84, 3.67, or 7.35 µg/kg body weight/day), N-Ethyl-N-nitrosourea (40 mg/kg body weight/day), or corn oil by gavage for 28 consecutive days. Another group (AME-high-dose + recovery) was maintained for a further 14 days after the end of the AME administration. Hematology and serum biochemistry results suggested that AME might compromise the immune system. The histopathology results indicated that AME can cause liver (inflammatory cell infiltration, steatosis, and edema), kidney (renal glomerular atrophy), and spleen (white pulp atrophy) damage. The genotoxicity results showed that AME can induce gene mutations, chromosome breakage, and DNA damage, but the effects were diminished after the recovery period. According to point-of-departure analysis (BMDL10), the risk to the population of exposure to AME cannot be ignored and further assessment is needed.

Assessment of the genotoxic potential of mintlactone.

Mintlactone (chemical name 3,6-dimethyl-5,6,7,7a-tetrahydro-1-benzofuran-2(4H)-one, CAS Number 13341-72-5) is a fragrance and flavor ingredient with reported uses in many different cosmetics, personal care, and household products. In order to evaluate the genotoxic potential of mintlactone, in vitro and in vivo genotoxicity tests were conducted. Results from bacterial mutagenicity tests varied across different batches of differing purity with positive results observed in TA98 only. An in vivo comet assay was also considered to be positive in livers of female mice but negative in male mice. In contrast, in vitro and in vivo micronucleus tests, as well as 3D skin comet/micronucleus tests, were negative, indicating no chromosomal or DNA damage. The underlying causes for these contradictory results are not clear. It appears that the purity and/or stability of the test material may be an issue. In the absence of dependable scientific information on the purity and/or storage stability of mintlactone, its safety for use as a fragrance ingredient cannot be substantiated.

RIFM fragrance ingredient safety assessment, hexadeca-1,5-lactone, CAS Registry Number 7370-44-7.

The existing information supports the use of this material as described in this safety assessment. Hexadeca-1,5-lactone was evaluated for genotoxicity, repeated dose toxicity, reproductive toxicity, local respiratory toxicity, phototoxicity/photoallergenicity, skin sensitization, and environmental safety. Data from the target material and read-across analog hydroxynonanoic acid, δ-lactone (CAS # 3301-94-8) show that hexadeca-1,5-lactone is not expected to be genotoxic. Data from analog δ-decalactone (CAS # 705-86-2) provide a calculated Margin of Exposure (MOE) > 100 for the repeated dose and reproductive toxicity endpoints. Data from analog δ-octalactone (CAS # 698-76-0) 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; hexadeca-1,5-lactone 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). For the hazard assessment based on the screening data, hexadeca-1,5-lactone is not Persistent, Bioaccumulative, and Toxic (PBT) as per the International Fragrance Association (IFRA) Environmental Standards. Hexadeca-1,5-lactone could not be risk screened as there were no reported volumes of use for either North America or Europe in the 2015 IFRA Survey.