Although the origin of the papaya plant is uncertain, many believe the plant to be native of tropical regions of Mexico and Central America. It is believed that seeds of the papaya plant were taken to Panama and then the Dominican Republic before 1525 and cultivation spread to warm elevations throughout South and Central America, southern Mexico, the West Indies, the Bahamas, and to Bermuda in the earlier 17th century. Today the papaya plant is found in nearly all tropical regions of the Old World and the Pacific Islands, and in Florida.

The latex of the papaya plant and its green fruits contains two proteolytic enzymes, papain and chymopapain.

The presence and effects of proteinases (now termed proteases) in papaya fruit (Carica papaya) latex have been well known since the 1750s (Brocklehurst et al. 1983). But it was not until the 1870's that the importance of papaya latex as a source of enzymes was recognized.

Papain extracted from the papaya plant is now the most widely studied of the cysteine enzymes because of its commercial value. Besides being used as a meat tenderizer, the medicinal uses of papain include:

• Defibrinating wounds in hospitals
• Prevents cornea scar deformation
• Used in treatments of jellyfish and insect sings
• Dsed to treat edemas, inflammatory processes, and in the acceleration of wound healing