what's the use of Castor oil

The source of castor oil

Castor oil is a vegetable oil obtained by pressing the seeds of the castor oil plant (Ricinus communis L.) mainly cultivated in China, South America, Africa, and India.

Castor oil is a rich source of Ricinoleic acid, which represents up to 90% of the total castor oil content. It also consists up to 4% linoleic, 3% oleic, 1% stearic, and less than 1% linolenic fatty acids.Ricinoleic acid has a hydroxyl group that provides a functional group location for various chemical reactions, making it a favourable substance in industrial applications. 

Castor oil does not contain ricin, which is a natural poison found in the castor oil plant; the toxic lectin remains in the bean pulp following oil isolation. Due to its renewability and high versatility in addition to being the only commercial source of a hydroxylated fatty acid, castor oil has been used as a vital raw material for the chemical industry. 

Castor oil is a mix of triglycerides consisting of mainly ricinolein, linoleic acid, oleic acid, palmitic acid, stearic acid, dihydroxystearic acid, and traces of other fatty acids.

Uses of castor oil

Castor oil was mainly used in the manufacturing of soaps, lubricants, and coatings . It is an FDA-approved food additive directly added to food products for human consumption. It can also be found in hard candies as a release agent and anti-sticking agent, or supplementary vitamins and mineral oral tablets as an ingredient for protective coatings. Castor oil is found in over-the-counter oral liquids as a stimulant laxative, and is also added in commercial cosmetic, hair, and skincare products. 

The main pharmacodynamic effects of castor oil are mediated by ricinoleic acid, a hydroxylated fatty acid released from castor oil by intestinal lipases. It was believed that ricinoleic acid acts as an anionic surfactant that reduces net absorption of fluid and electrolytes, and stimulates intestinal peristalsis.However, a recent study suggests that ricinoleic acid interacts with EP3 prostanoid receptors expressed on intestinal and uterine smooth muscles. Via activating EP3 prostanoid receptors on intestinal and uterine smooth muscle cells, ricinoleic acid promotes laxation and uterus contraction, respectively. EP3 receptor act as the major prostanoid receptor in the intestine mediating propulsive effects on gut motility, and activation of EP3 receptors has been demonstrated to evoke contraction of uterine smooth muscle.