Related Experiment Video

Updated: Feb 2, 2026

Regular Care and Maintenance of a Zebrafish Danio rerio Laboratory: An Introduction
11:47

Regular Care and Maintenance of a Zebrafish Danio rerio Laboratory: An Introduction

Published on: November 18, 2012

91.9K

Thymol exposure mediates pro-oxidant shift by regulating Nrf2 and apoptotic events in zebrafish (Danio rerio) embryos

Manigandan Krishnan1, Dae Kwang Kim2, Se Gie Kim3

  • 1Department of Biotechnology, College of Engineering, Daegu University Kyoungsan, Kyoungbook 712-714, Republic of Korea.

Environmental Toxicology and Pharmacology
|November 23, 2018
PubMed

Insights

Thymol (THY) exposure causes toxicity and teratogenic effects in zebrafish embryos by increasing reactive oxygen species (ROS) and disrupting cellular defense mechanisms and apoptosis. This study highlights ROS as a key mediator of THY-induced oxidative damage.

Area of Science:

  • Biochemistry
  • Toxicology
  • Developmental Biology

Background:

  • Oxidative stress is a key mechanism in chemical toxicity and disease.
  • Thymol (THY) has therapeutic uses, but its signaling pathways require further elucidation.
  • Understanding THY's impact on reactive oxygen species (ROS) is crucial for its mechanism of action.

Purpose of the Study:

  • To investigate the impact of Thymol (THY) on zebrafish embryos, focusing on ROS production.
  • To assess THY's toxicity, including teratogenic effects, survival rates, and cardiac function.
  • To analyze the molecular mechanisms underlying THY's effects on cellular defense and apoptotic pathways.

Main Methods:

  • Zebrafish embryos were exposed to varying concentrations of THY (25, 50, 100μM) for 96 hours post-fertilization.
  • Assessed survival rate (LC50), hatching, morphology, and cardiac function.
  • Measured ROS levels, mitochondrial membrane potential (ΔΨm), and expression of Nrf2, SOD-1, CAT, CYP450, and apoptotic markers (AIF, p53, Bax, Bcl-2, Casp-3, Casp-9).

Main Results:

  • THY exhibited significant toxicity, causing teratogenic effects and reducing survival rates (LC50 = 42.35μM).
  • THY exposure altered ROS levels, mitochondrial membrane potential, and the expression of key antioxidant and apoptotic proteins.
  • Significant modulatory effects were observed on cellular defense and apoptotic pathways.

Conclusions:

  • Reactive oxygen species (ROS) are identified as the primary mediators of Thymol (THY)-induced oxidative damage in zebrafish embryos.
  • THY disrupts cellular defense mechanisms and induces apoptotic events.
  • Findings provide insights into the toxicological mechanisms of THY and its impact on embryonic development.
Keywords:
Thymolantioxidantsapoptosisdevelopmental toxicityreactive oxygen specieszebrafish

More Related Videos

Heart Dissection in Larval, Juvenile and Adult Zebrafish, Danio rerio06:43

Heart Dissection in Larval, Juvenile and Adult Zebrafish, Danio rerio

Published on: September 30, 2011

22.4K
Testing the Vascular Invasive Ability of Cancer Cells in Zebrafish Danio Rerio07:31

Testing the Vascular Invasive Ability of Cancer Cells in Zebrafish Danio Rerio

Published on: November 3, 2016

12.7K

Related Concept Videos

Oxidation Numbers03:14

Oxidation Numbers

In redox reactions, the transfer of electrons occurs between reacting species. Electron transfer is described by a hypothetical number called the oxidation number (or oxidation state). It represents the effective charge of an atom or element, which is assigned using a set of rules.
42.6K
Epigenetic Regulation01:46

Epigenetic Regulation

Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
33.8K
Regulated Protein Degradation02:58

Regulated Protein Degradation

It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
8.9K
Pyruvate Oxidation01:15

Pyruvate Oxidation

After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
168.8K
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
8.4K
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
8.5K