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Description of key information

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation
Remarks:
other: in silico prediction
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
2013
Reliability:
2 (reliable with restrictions)
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Reference:
Composition 0
Qualifier:
no guideline available
Principles of method if other than guideline:
QSAR approach: Different tools were used, when possible, in order to apply a consensus approach and thus enhance the reliability of the predictions. In fact, a single in silico prediction model may provide acceptable results. However, by definition all models are simulation of reality, and therefore they will never be completely accurate; sometimes a single model will not work. When multiple models and multiple approaches are combined in a single consensus score, more accurate predictions can be achieved.
If two prediction methods that use data and different approaches are consistent, the reliability of prediction is better. The errors of a model/approach should be different from another, and therefore compensate.

Several computational tools are nowadays available for applying in silico approaches. Among them, for QSAR predictions the following was selected and used for the endpoint:
Toxtree (Ideaconsultant, version 2.5.0) is a flexible and user-friendly open-source application that places chemicals into categories and predicts various kinds of toxic effect by applying decision tree approaches. The following decision trees are currently implemented: the Cramer classification scheme, Verhaar scheme for aquatic modes of action, rulebases for skin and eye irritation and corrosion, Benigni-Bossa rulebase for mutagenicity and carcinogenicity, structural alerts for identification of Michael Acceptors, START rulebase for persistance / biodegradation potential.
Vega Application (Virtual Models for evaluating the properties of chemicals within a global architecture) (VegaNIC application, Laboratory of Environmental Chemistry and Toxicology of Mario Negri Institute of Pharmacological Research, version 1.0.8) is a platform developed on the basis of contributions from the EU projects CAESAR, ORCHESTRA and ANTARES. It includes CAESAR QSAR model for mutagenicity based on a data set that includes 4225 compounds. It is an integrated model made of two complementary techniques: a machine learning algorithm (SVM), to build an early model with the best statistical accuracy, equipped with an expert facility for false negatives removal based on known structural alerts, to refine its predictions. Thus, the mutagenicity model could classify a compound as mutagen even if it is formally out of the applicability domain. This behaviour is normal for this model and it is related to the use of structural alerts. It also include the CAESAR skin sensitization model, which provides a qualitative prediction of skin sensitisation on mouse (local lymph node assay). The model consists in an Adaptive Fuzzy Partition (AFP) based on 8 descriptors. The AFP produces as output two values positive and negative that represent the belonging degree respectively to the sensitiser and non-sensitise classes. The applicability domain of predictions is assessed using an Applicability Domain Index (ADI) that has values from 0 (worst case) to 1 (best case). The ADI is calculated by grouping several other indices, each one taking into account a particular issue of the applicability domain..
GLP compliance:
no
Type of study:
not specified
Test material information:
Composition 1

Name

Toxtree

Vega

Vega

reliability

CONSENSUS

Eye irritation

Methyl 3-α,7-α-diacetoxy-12-oxo-5-β-cholan-24-oate

NO SKIN SENSITIZER

NO SKIN SENSITIZER

Low reliability

NO SKIN SENSITIZER

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The methyl 3-α,7-α-diacetoxy-12-oxo-5-β-cholan-24-oate is NOT SKIN SENSITIZERS.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:
Methyl 3-α,7-α-diacetoxy-12-oxo-5-β-cholan-24-oate is NOT a SKIN SENSITIZER.

Justification for selection of skin sensitisation endpoint:
Tools involved in the prediction are two validated profilers relevant for skin sensitization.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the results of a QSAR prediction, methyl 3-α,7-α-diacetoxy-12-oxo-5-β-cholan-24-oate is not classified for skin seinsitization, according to Regulation 1272/2008/EC.