Green Walnut Husk and Cancer: A 2025 Research Guide
What Is Green Walnut Husk?
Green walnut husk (GWH) is the fresh green outer layer that surrounds the hard walnut shell. It comes from trees like Juglans regia (English walnut) and Juglans nigra (black walnut). Farmers used to throw it away, but research now shows this part of the walnut is rich in special plant compounds. These include juglone, polyphenols, flavonoids, and other natural chemicals that can help fight germs and inflammation.
Traditionally, people used GWH in folk medicine for skin problems and infections. Scientists today study it because its main compound, juglone, can damage cancer cells while leaving healthy cells alone in some lab studies.
Why Study Green Walnut Husk for Cancer?
The key reason is the link between green walnut husk cancer research and its bioactive ingredients. Juglone and other compounds can stop cancer cells from growing and make them self-destruct. Unlike chemo that can hurt healthy cells, GWH targets only cancer cells in some lab tests. It can also lower inflammation in the body, which often helps cancer spread.
For these reasons, researchers see GWH as a possible safe add-on to standard treatments.
How Does Green Walnut Husk Fight Cancer?
Scientists have found several ways GWH fights cancer:
- Triggers Apoptosis: Juglone helps cells die properly. This means it can kill cancer cells while leaving healthy cells alone.
- Stops Growth: GWH can freeze cancer cells in the G0/G1 phase, stopping them from dividing.
- Blocks Spread: It lowers enzymes (MMP-2, MMP-9) that help cancer cells move.
- Antioxidant Action: Its polyphenols fight free radicals that damage DNA.
- Anti-Inflammatory: It calms inflammation by blocking signals like JAK2/STAT3.
- microRNA: It boosts microRNA-144-3p, which slows cancer cell spread.
These actions make GWH a good partner for other treatments.
Key Research Findings (2023–2025)
Recent research highlights:
- Gastric Cancer: GWH extracts killed about half of SCG7901 stomach cancer cells and stopped them from moving.
- Ovarian Cancer: It blocked ovarian cancer cells from multiplying and spreading by changing microRNA levels.
- Liver Cancer: GWH extract killed up to 69% of HepG2 liver cancer cells.
- Prostate Cancer: N-hexane GWH extract caused prostate cancer cells to self-destruct.
- Leukemia: Juglone in GWH triggered cell death in leukemia cells without harming normal ones.
- Osteosarcoma: GWH extracts reduced bone cancer cell growth and triggered cell cleanup (autophagy).
These studies are mostly lab and animal tests, so more human research is needed.
Graph 1: Lab Tests by Cancer Type
This graph shows the % of cancer cell death in lab tests. Gastric: ~50%, Ovarian: ~60%, Liver: ~69%, Prostate: ~65%, Leukemia: ~70%.
This means GWH works on many cancer types in early lab tests.
Cancer Types Studied
Studies so far cover:
- Gastric (Stomach) Cancer: Stops cells from spreading.
- Ovarian Cancer: Lowers growth, blocks spread.
- Liver Cancer: Shows strong cell-killing action.
- Prostate Cancer: Triggers cell death.
- Leukemia: Works at very low doses.
- Osteosarcoma: Slows bone cancer cells.
Early data also suggests possible effects on breast and colon cancers, but more work is needed.
Graph 2: Cancer Cell Lines Tested
A pie chart shows gastric (20%), ovarian (20%), liver (20%), prostate (20%), leukemia (10%), osteosarcoma (10%).
GWH research covers many cancers evenly.
Practical Uses in Cancer Care
Some ways people may use GWH:
- Supplements: Capsules or tinctures standardized for juglone.
- Topical Creams: For skin tumors (rare).
- Diet: Eating walnut kernels gives some polyphenols, but the husk itself isn’t eaten.
- Dosage: In labs, doses range from 10–500 µg/mL. Human safe doses are not clear yet.
Always talk to a doctor first.
Graph 3: Lab Dose Range vs Safe Human Dose
A bar chart shows lab doses (10–500 µg/mL) vs unknown human safe range.
This shows why doctor advice is needed.
Safety and Side Effects
- Toxicity: Too much juglone can hurt the liver or kidneys.
- Skin Irritation: It can blister the skin.
- Interactions: May change how some drugs work.
- Pregnancy: Avoid if pregnant or breastfeeding.
Side effects are rare at low doses, but safety is not well-studied in people.
Limitations and Challenges
- No Human Trials: Most data is from cells and animals.
- Bioavailability: Juglone does not absorb well in the body.
- Variability: Different walnut types have different levels of juglone.
- Fake Claims: Some posts say GWH cures 100 cancers in days — this is not true.
Graph 4: Research vs Clinical Use
A line graph shows a gap between promising lab research and real human testing.
This means GWH needs more studies before use in hospitals.
Future Directions for GWH in Cancer
Scientists want to:
- Run clinical trials for real patients.
- Improve how juglone is absorbed (like nano-capsules).
- Use GWH with chemo to lower side effects.
- Find out the best walnut type for extracts.
Green walnut husk cancer research is growing, but use caution. Always ask your oncologist.
Research Links
Ethnobotanical Review (2022): GWH’s juglone as an anticancer compound. Proceedings of the Indian National Science Academy. https://link.springer.com/article/10.1007/s43538-022-00106-2
Gastric Cancer (2022, revisited 2023): GWH extracts reduced SCG7901 cell viability, migration, and invasion; induced apoptosis. Journal of Cancer. https://www.jcancer.org/v13p1130.htm
Ovarian Cancer (2023): GWH suppressed SKOV3 cell growth via microRNA-144-3p. Indian Journal of Pharmaceutical Sciences. https://www.ijpsonline.com/articles/walnut-green-husk-extract-suppresses-ovarian-cancer-cell-proliferation-migration-and-invasion-via-modulating-microrna1443p-4615.html
Liver Cancer (2023): GWH reduced HepG2 viability by 69.23% at 500 μg/mL. Antioxidants. https://www.mdpi.com/2076-3921/12/1/52
Prostate Cancer (2012, revisited 2023): N-hexane GWH extracts induced PC-3 apoptosis. Evidence-Based Complementary and Alternative Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3291113/
Leukemia (2019): GWH (1 μM juglone) induced HL-60 apoptosis. Electronic Journal of Biotechnology. https://www.sciencedirect.com/science/article/pii/S0717345819300080
Osteosarcoma (2023): Methanol GWH extracts reduced U2OS viability. Journal of Food Biochemistry. https://www.sciencedirect.com/science/article/abs/pii/S0889157522000530
Multiple Cancers (2019): GWH showed cytotoxicity against MCF-7, HCT-116, and others. International Journal of Molecular Sciences. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6722946/
Black Walnut Anticancer (2020): Penta-O-galloyl-β-D-glucose in black walnut inhibited lung, prostate, breast cancers. Molecules. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7587956/
Walnut Consumption (2025): Walnuts reduced colon cancer risk via urolithin A. Cancer Prevention Research. https://today.uconn.edu/2025/04/walnut-consumption-curbs-inflammation-and-colon-cancer-risk/
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