Cyanide

Cyanide kills cells by inhibiting cytochrome c oxidase (Complex IV), preventing mitochondria from using oxygen to produce ATP. Apple seeds contain amygdalin, which releases hydrogen cyanide upon metabolism. Methylene blue restores ATP production by capturing electrons leaking from the disrupted mitochondrial electron transport chain. Raw or unprocessed cassava contains linamarin, which converts to cyanide and must be properly processed before consumption. Chronic cyanide exposure causes progressive vision loss, hearing loss, and poor muscle contraction. Cyanide is naturally present in apple seeds, peach pits, apricot pits, bitter almonds, cassava, and tobacco smoke. Methylene blue is used in emergency rooms to treat cyanide poisoning by acting as a redox mediator that restores mitochondrial oxygen utilization.