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Event: 1599

Key Event Title

A descriptive phrase which defines a discrete biological change that can be measured. More help

Inflamatory events in light-exposed tissues

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. More help
Inflammatory events
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Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. More help
Level of Biological Organization

Organ term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help

Key Event Components

The KE, as defined by a set structured ontology terms consisting of a biological process, object, and action with each term originating from one of 14 biological ontologies (Ives, et al., 2017; Biological process describes dynamics of the underlying biological system (e.g., receptor signalling).Biological process describes dynamics of the underlying biological system (e.g., receptor signaling).  The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signaling by that receptor).  Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description.  To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons.  If a desired term does not exist, a new term request may be made via Term Requests.  Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE. Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
ROS-mediated chemical phototoxicity AdverseOutcome Satomi Onoue (send email) Under development: Not open for comment. Do not cite EAGMST Under Review

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KE.In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
human Homo sapiens High NCBI

Life Stages

An indication of the the relevant life stage(s) for this KE. More help
Life stage Evidence
All life stages High

Sex Applicability

An indication of the the relevant sex for this KE. More help
Term Evidence
Mixed High

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. More help

Photoirritation is frequently characterized as exaggerated sunburn sometimes mediated by oxidative stress in the cell membrane, and hyperpigmentation and desquamation may occur as a residual effect of a phototoxic reaction. Theoretically, if a high concentration of a phototoxic drug accumulates in the skin and the appropriate wavelength of light is present, any individual will develop a phototoxic reaction. In particular, peroxidation of membrane lipid could be induced by some photosensitizers under photo-irradiation, and this photochemical reaction certainly correlates with damage produced in the cell membrane, leading to the skin photoirritation (Castell et al. , 1994, Onoue et al. , 2009).

How It Is Measured or Detected

A description of the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements.These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA). Do not provide detailed protocols. More help

Inflammatory events induced by photoreactive chemicals can be detected in vivo phototoxicity testing and photopatch test in clinical (Epstein, 1964, ICH, 2014, Onoue et al., 2009). 

Domain of Applicability

A description of the scientific basis for the indicated domains of applicability and the WoE calls (if provided).  More help

Chemicals: This AO applies to a wide range of chemicals.  Phototoxic chemicals are recognized to have following characteristics: (i) absorption of light within the range of natural sunlight (290-700 nm); (ii) generation of a reactive species following absorption of UV-visible light; (iii) distribution to light-exposed tissues (e.g., skin and eye) in ICH S10 guideline for photosafety assessment (ICH, 2014).

Sex: This AO applies to both males and females. 

Life stages: The relevant life stages for this AO are all life stages after born.

Taxonomic: This AO mainly applies to human.

Regulatory Significance of the Adverse Outcome

An AO is a specialised KE that represents the end (an adverse outcome of regulatory significance) of an AOP. More help

Inflammatory events in light-exposed tissues are considered to be the endpoint of ROS-mediated chemical phototoxicity, especially photoirritant reactions (ICH, 2014, Onoue et al., 2009). 


List of the literature that was cited for this KE description. More help

Castell JV, Gomez-Lechon MJ, Grassa C, Martinez LA, Miranda MA, Tarrega P. Photodynamic lipid peroxidation by the photosensitizing nonsteroidal antiinflammatory drugs suprofen and tiaprofenic acid. Photochem Photobiol. 1994;59:35-9.

Epstein S. The Photopatch Test; Its Technique, Manifestations, and Significance. Ann Allergy. 1964;22:1-11.

ICH. ICH Guideline S10 Guidance on Photosafety Evaluation of Pharmaceuticals.: International Council on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use; 2014.

Onoue S, Seto Y, Gandy G, Yamada S. Drug-induced phototoxicity; an early in vitro identification of phototoxic potential of new drug entities in drug discovery and development. Current drug safety. 2009;4:123-36.