Medicinal plants and active phytochemicals targeting MAPK9 (JNK2) in neurodegenerative diseases.
| Medicinal plant | Active phytochemical(s) | Neurodegenerative model/Disease | Effect on MAPK9/JNK signalling | Neuroprotective mechanism | Key references |
|---|---|---|---|---|---|
| Curcuma longa (Turmeric) | Curcumin | Alzheimer’s disease (AD), Parkinson’s disease, cerebral ischemia | Inhibits JNK phosphorylation and c-Jun activation | Anti-inflammatory, antioxidant, anti-apoptotic | [84] |
| Camellia sinensis (Green Tea) | Epigallocatechin gallate (EGCG) | AD, Parkinson’s disease | Suppresses JNK activation and downstream inflammatory signalling | Inhibits amyloid aggregation, mitochondrial protection | [85, 97] |
| Vitis vinifera (Grape) | Resveratrol | Parkinson’s disease, cerebral ischemia, AD models | Reduces oxidative stress-mediated JNK activation | Activates SIRT1, antioxidant, anti-inflammatory | [3, 99] |
| Berberis vulgaris | Berberine | Neuroinflammation, AD models | Attenuates MAPK/JNK and NF-κB signalling | Reduces reactive oxygen species (ROS) production and cytokine release | [98, 100] |
| Ginkgo biloba | Ginkgolides, Bilobalide, Flavonoids | AD, vascular dementia | Modulates MAPK-mediated inflammatory pathways | Antioxidant, anti-apoptotic, improves cerebral blood flow | [86, 101] |
| Withania somnifera (Ashwagandha) | Withanolides | AD, Parkinson’s disease | Downregulates stress-induced MAPK activation | Anti-inflammatory, mitochondrial protection | [80, 102] |
| Bacopa monnieri | Bacosides A and B | Cognitive impairment, AD models | Suppresses oxidative stress-associated JNK signalling | Enhances synaptic function and antioxidant defences | [103] |
| Panax ginseng | Ginsenosides (Rg1, Rb1, Rd) | Parkinson’s disease, ischemic injury | Regulates MAPK/JNK-mediated apoptosis | Mitochondrial stabilisation and neuronal survival | [104] |
| Scutellaria baicalensis | Baicalein, Baicalin | Parkinson’s disease, neuroinflammation | Inhibits JNK phosphorylation and microglial activation | Antioxidant and anti-inflammatory activity | [105] |
| Allium cepa (Onion) | Quercetin | AD, oxidative stress models | Suppresses JNK/c-Jun signalling | ROS scavenging and apoptosis inhibition | [96] |
| Glycyrrhiza glabra (Licorice) | Liquiritigenin, Glycyrrhizin | Neuroinflammation and ischemic injury | Modulates MAPK-mediated inflammatory responses | Anti-inflammatory and antioxidant effects | [17] |
| Centella asiatica | Asiaticoside, Madecassoside | Cognitive impairment, AD models | Reduces stress-induced MAPK activation | Neurogenesis promotion and antioxidant activity | [18] |
The authors would like to acknowledge the University of the Witwatersrand’s Research Office for awarding Dr. Otun a postdoctoral fellowship.
SO: Investigation, Writing—original draft. IA: Conceptualization, Supervision, Writing—review & editing. Both authors read and approved the submitted version.
The authors declare no conflicts of interest.
Not applicable.
Not applicable.
Not applicable.
Not applicable.
Open access funding provided by the University of the Witwatersrand, and the authors would like to acknowledge the National Research Foundation (NRF) of South Africa for awarding Prof. Achilonu the CPRR research grant (Grant number CPRR23042899244). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
© The Author(s) 2026.
Open Exploration maintains a neutral stance on jurisdictional claims in published institutional affiliations and maps. All opinions expressed in this article are the personal views of the author(s) and do not represent the stance of the editorial team or the publisher.