Rotenone

Rotenone Full Name

Rotenone

Rotenone Introduction

Rotenone is a naturally occurring isoflavonoid widely used in neuroscience as a selective mitochondrial complex I (NADH:ubiquinone oxidoreductase) inhibitor to reproduce key pathological features of Parkinson's disease (PD). Although originally developed as an insecticide and piscicide, rotenone has become one of the most extensively validated experimental tools for investigating mitochondrial dysfunction, oxidative stress, and dopaminergic neurodegeneration. Researchers frequently select the rotenone model because it closely mimics progressive nigrostriatal degeneration, α-synuclein aggregation, impaired energy metabolism, and motor deficits observed in human PD. Rather than acting on a single signaling molecule, rotenone initiates a cascade of molecular events beginning with mitochondrial respiratory inhibition, ATP depletion, and excessive reactive oxygen species (ROS) production, ultimately affecting numerous transcription factors, inflammatory mediators, and cell survival pathways. This broad mechanism makes rotenone an important pharmacological tool for studying disease mechanisms and evaluating neuroprotective therapies targeting mitochondrial homeostasis and neuroinflammation.

At the molecular level, the primary target of rotenone is mitochondrial complex I, whose inhibition disrupts electron transport and accelerates oxidative stress. Elevated ROS subsequently activates multiple signaling pathways, including NF-κB, PI3K/AKT/mTOR, p38 MAPK/JNK, TLR4, Wnt/β-catenin, GSK-3β, and NLRP3 inflammasome-associated networks, leading to increased production of pro-inflammatory mediators such as TNF-α, IL-1β, IL-6, iNOS, and nitric oxide. These events are accompanied by mitochondrial DNA damage, altered expression of antioxidant enzymes including SOD1 and catalase, cytochrome c release, Caspase-3 activation, and an increased Bax/Bcl-2 ratio, promoting apoptotic cell death. Recent transcriptomic and epigenomic studies further demonstrate that rotenone-induced toxicity exhibits remarkable brain-region specificity. In the substantia nigra, genes associated with innate immunity and neuroinflammation, including BCL3, C1QA, C1QB, C1QC, CXCL11, IRF8, STAT family members, and PU.1, are significantly upregulated through H3K27ac-mediated epigenetic regulation, whereas cortical tissues preferentially exhibit dysregulation of synaptic genes such as HOMER1 and GRIN2B. In parallel, rotenone directly impairs midbrain astrocyte function by suppressing the antioxidant proteins Metallothionein-1 (MT-1) and MT-2, enhancing SPARC secretion, activating NFATc3 signaling, and promoting NF-κB nuclear translocation in microglia, thereby amplifying glia-mediated dopaminergic neuron loss. These findings highlight that rotenone toxicity involves coordinated mitochondrial failure, epigenetic remodeling, glial dysfunction, and immune activation rather than isolated neuronal injury.

Because of these diverse molecular effects, rotenone has become a cornerstone model for investigating Parkinson's disease, while also providing valuable insights into Alzheimer's disease, multiple system atrophy, Lewy body disorders, and other neurodegenerative conditions characterized by mitochondrial dysfunction and chronic neuroinflammation. One of the most clinically relevant discoveries is the activation of the Nrf2-mediated antioxidant response, which serves as an endogenous defense mechanism against rotenone-induced oxidative injury. Nrf2 regulates cytoprotective genes such as HO-1, SOD, glutathione peroxidase (GPx), and other antioxidant enzymes, while emerging evidence indicates that the SIRT1/Nrf2/NLRP3 signaling axis plays a critical role in balancing mitochondrial integrity and inflammatory activation. Experimental interventions restoring MT-1 expression, blocking SPARC-mediated astrocyte signaling, inhibiting NF-κB or NLRP3 activation, or enhancing Nrf2 activity have consistently reduced dopaminergic neuron degeneration in rotenone-based models. Consequently, rotenone remains an indispensable experimental compound for target discovery, biomarker identification, and preclinical evaluation of therapies aimed at restoring mitochondrial bioenergetics, suppressing neuroinflammation, and slowing the progression of neurodegenerative diseases.

Alternate Names for Rotenone

Rotenone; Canex; 5'-beta-rotenone; Barbasco; Deril; Derrin; (-)-cis-rotenone; Foliafume; derrisextract,e.c.(2.5%); ethenyl)[1]benzopyrano[3,4-b]furo[2,3-h]benzopyran-6(6ah)-one

• 1.Tsalenchuk M, et al.; Unique nigral and cortical pathways implicated by epigenomic and transcriptional analyses in rotenone Parkinson's model. NPJ Parkinsons Dis. 2025, 11(1):217.
  2.Miyazaki I, et al.; Rotenone targets midbrain astrocytes to produce glial dysfunction-mediated dopaminergic neurodegeneration. Acta Neuropathol Commun. 2025, 13(1):234.