Black walnut is a traditional plant medicine used to treat digestive disorders, stimulate the liver and cleanse the digestive tract from intestinal parasites. The American Cancer Society notes that black walnut is a source of compounds that may reduce the risk of cancer. While more research is required on the efficacy and safety of black walnut in patients with liver cancer, its medicinal properties are promising harbingers of new anticancer drugs in the future. Consult your doctor before purchasing black walnut products.
History
According to an article published on the Non-Timber Forest Products website in 2001, researchers from the USDA Forest Service found that black walnut has a long and colorful history of usage as a food, medicine and dye. Native American Indians used the bark of the black walnut for internal cleansing and toothaches, and it is used in Pakistan and Cuba as a treatment for skin conditions and inflammation. The leaves are a source of plant estrogens, the roots, of black dye, and the green fruit hull is used in traditional western herbal medicine as a treatment for ringworm and as a digestive stimulant.
Pharmacology
Black walnut extract provides a range of nutrients and phytochemicals, such as protein, calcium, magnesium, tannins and juglone. According to a review of research published by the USA National Toxicology Program in 1999, scientists found several animal studies supporting the use of black walnut's active compound, juglone, in treating various types of cancer. Juglone reduced the occurance of tumors and of tumor growth and killed human leukemia cells in vitro. However, juglone also promoted skin cancer, allergies and inflammation when applied topically. Researchers concluded that juglone may be an anticancer compound in some forms of cancer, but its usefulness is limited by its high toxicity.
Antioxidant
In a study published in "Phytotherapy Research" in 2002, researchers from Pusan National University in Korea studied 28 herbal extracts for their ability to scavenge free radicals in vitro and protect against damage caused by the chemical peroxynitrite. Black walnut was one of the eight most effective herbal medicines in protecting against peroxynitrate and showed significant antioxidant abilities. Researchers confirmed that black walnut may help to defend cells in the body against damage caused by free radicals and other oxidizing chemicals, such as peroxynitrite, and reduce the related risk of diseases such as cancer and liver damage.
Liver Cancer
Black walnut and its active constituent, juglone, may have a specific action on cancer cells found in the liver. In a study published in "The Journal of Southern Medical University" in 1999, researchers from the Southern Medical University in China studied the effects of juglone on human liver cancer cells in vitro. Juglone had significant effects on liver cancer cells, reducing their size, robustness and leading to their death -- a process called apoptosis. Researchers concluded that juglone had a specific toxic effect on liver cancer cells, and more research is still required to confirm these results in animal and human clinical trials.
Safety
According to Drug Information Online, there have been adverse reactions and side effects from taking black walnut extract internally. Taken internally it may have toxic and cancer-causing properties due to its juglone content -- though this has only been seen in animals and not in humans. No drug interactions have been reported, and it is not considered safe for use during pregnancy and breastfeeding. The German E Commision has not approved the use of black walnut as safe. Consult with a registered medical herbalist and a doctor about the use of this herb.
References
- The American Cancer Society: Black Walnut
- Non-Timber Forest Products; Black Walnut; 2001
- National Toxicology Program; Summary of Data for Chemical Selection: Juglone; 1999
- "Phytotherapy Research"; Peroxynitrite Scavenging Activity of Herb Extracts; H.R. Choi et al.; 2002
- "The Journal of Southern Medical University"; Effect of Juglone on the Ultrastructure of Human Liver Cancer BEL-7402 Cells; L. Chen et al.; 2009
- Drug Information Online: Black Walnut
