Antifertility experiments have been made on mice for short-term and long-term observation with castor bean extract and ricin,and which showed apparent effects of antifertility. 利用蓖麻提取物对昆明种小鼠进行了短期与长期的抗生育实验,研究发现蓖麻提取物(蓖麻油和蓖麻蛋白)对小鼠有明显的抗生育作用。
Ricin/ˈraɪsɪn/ is a highly toxic, naturally occurring lectin (a carbohydrate-binding protein) produced in the seeds of the castor oil plant, Ricinus communis. A dose of purified ricin powder the size of a few grains of table salt can kill an adult human. The median lethal dose (LD50) of ricin is around 22 micrograms per kilogram of body weight if the exposure is from injection or inhalation (1.78milligram for an average adult). For comparison, a standard paracetamol (acetaminophen) tablet contains 500mg of acetaminophen and a low dose aspirin contains 81mg of aspirin. Oral exposure to ricin is far less toxic as some of the poison is inactivated in the stomach. An estimated lethal oral dose in humans is approximately 1milligram per kilogram.