Black Walnut Juglans nigra

Black walnut is often applied to treating cases of diphtheria, leukemia and syphilis, and to kill and expel intestinal worms (1).


The chief known constituent of black walnut is juglone, which has demonstrated both antibacterial and antifungal properties (2) (3). James Duke lists juglone as being anti-parasitic, antiviral and a fungicide (4), while Martindale claims some efficiency of juglans in treating lymphatic disorders such as scrofula (5).
 

TRADITIONAL USE
Black walnut has been used in folk medicine as an astringent, laxative and a vermifuge. It is used to expel tapeworms and other internal and external parasites (3). The American Medical Ethnobotany Reference Dictionary claims that the juice from black walnut hull is effective against ringworm (6), but some warnings have been issued regarding the topical use of this herb (see below). Black walnut is traditionally regarded as being anti-parasitic and a vermifuge (kills worms) (7) (8).

Black walnut is listed as safe for short term oral use (typical oral dose is 1,000 mg three times daily with water), but is regarded as possibly unsafe for topical application. Due to the lack of reliable studies on the use of black walnut during periods of pregnancy or lactation it is not recommended for use during these times (1).