for undecylenic acid, a natural fungicide. Commercially available cold-pressed castor oil is not toxic to humans in normal doses, whether internal or external. Uses Castor oil has many uses in medicine and other applications. An alcoholic extract of the leaf was shown, in laboratory rats, to protect the liver from damage from certain poisons. Methanolic extracts of the leaves of Ricinus communis were used in antimicrobial testing against eight pathogenic bacteria in rats and showed antimicrobial properties. The pericarp of Ricinus showed central nervous system effects in mice at low doses. At high doses mice quickly died. A water extract of the root bark showed analgesic activity in rats. Antihistamine and anti-inflammatory properties were found in ethanolic extract of Ricinus communis root bark. Castor oil and the plant's roots and leaves are used in the ancient Indian medicinal system of Ayurveda for various diseases, and it has been investigated in a few limited studies for its potential as an anti-nociceptive and anti-inflammatory herbal medicine. Modern commercial usage Global castor seed production is around two million tons per year. Leading producing areas are India (with over three-quarters of the global yield), China and Mozambique, and it is widely grown as a crop in Ethiopia. There are several active breeding programmes. Other modern uses include: Whether natural, blended, or chemically altered, castor oil still has many uses. For example, it remains of commercial importance as a non-freezing, antimicrobial, pressure-resistant lubricant for special purposes, either of latex or metals, or as a lubricating component of fuels. Castor products are sources of various chemical feedstocks. In Brazil, castor oil (locally known as mamona oil) is a raw material for some varieties of biodiesel. In rural areas, the abundant seeds are used by children for slingshot balls, as they have the right weight, size, and hardness. Because castor seeds are attractively patterned, they are popular in low-cost personal adornments, such as non-durable necklaces and bracelets. Castor oil has long been used on the skin to prevent dryness. Either purified or processed, it still is a component of many cosmetics. The high percentage of ricinoleic acid residues in castor oil and its derivatives, inhibits many microbes, whether viral, bacterial or fungal. They accordingly are useful components of many ointments and similar preparations. Castor oil is the major raw material for polyglycerol polyricinoleate, a modifier that improves the flow characteristics of cocoa butter in the manufacture of