A review of the literature on the potential therapeutic significance of papain.

TLDR: The term papain will be restricted to designate the whole dried product from the latex from the unripe fruit of Carica papaya, which contains proteolytic enzymes and other possible components.

Abstract: The digestant action of the juice from papaya, a fruit of the melon tree, C U T ~ C U papaya, Linn., has been known for centuries.‘ The results of the experimental investigation of its action first appeared in 1874.2 In 1878, Wittmack in Germany also reported the digestive properties of the milky juice of the papaya3 When he saw these reports in 1879, Peckolt reexamined a precipitate he had made years before from the fresh juice of the unripe papaya in Brazil and confirmed the digestion of meat in a solution of that precipitate, “papay~tin.”~ Later in the same year, Wurtz and Bouchut5 also published their results of experiments on a puritied product from the sap of papaya, designated as “papain.” These well-controlled experiments have been referred to as the first scientific investigation of the enzyme.fi Since that time, the term papain has referred either to the crude dried powdered whole latex from the green papaya’s or to the same material after purification to various degrees by different methods. Other names, such as papaotin, Caroid, and papoid, have also been used for similar products by different manufacturers. The inadequacy of using the term papain to denote only the proteinase component of the whole preparations is made apparent by the thorough investigation of the complicated enzyme system in this preparation during recent years. The term papain used in this review, unless otherwise specified, will be restricted to designate the whole dried product from the latex from the unripe fruit of Carica papaya, which contains proteolytic enzymes and other possible components.