Juglans nigra, known as black walnut, is a hardwood tree that grows naturally in North America and some European countries. The tree produces edible fruits that contain flavonoids, quinones, and polyphenols, which are known for their antineoplastic, anti-inflammatory, antioxidant, and neuroprotective properties. Today the hulls are used to help with numerous conditions. One of the key active components of the black walnut hull is juglone. Juglone is known for its antifungal and antimicrobial properties, which exerts its effects by inhibiting certain enzymes needed for metabolic function. Its highly toxic to many insect herbivores; making it a great natural pesticide for organic farmers.
The juice from unripe black walnut hulls has been used in folk medicine for many years as a treatment for internal and topical fungal infections. It is also quite effective against parasites such as: ringworm, tapeworm, pin or thread worm, and other parasites in the intestine. One of my personal favorite uses for black walnut hulls is for promoting healthy skin. The tannins within the hulls have an astringent effect, which is used to relieve irritation and tighten the epidermis. Making it a great candidate for skin issues such as: eczema, psoriasis, viral worts, acne, and poison ivy.