It contains a chemical that can be toxic when consumed. Black nightshade contains a chemical called solanine which is poisonous to humans. The green fruits contain the highest amounts of solanine and therefore are the most toxic parts of the plant.
Despite serious safety concerns, black nightshade has been used for stomach irritation, cramps, spasms, pain, and nervousness. Some people apply black nightshade directly to the skin for a skin condition called psoriasis, hemorrhoids, and deep skin infections (abscesses)
