Study Of Rosemary Acid Inhibit Ricin Activity

Ricin is known as one of the most poisonous toxin proteins now. It is a plantheterodimer which is combined by A-chain and B-chain through a disulfide bond. TheB-chain can combine with receptors on the cell surface while A-chain can enter thecell and inhibit protein synthesis. Ricin mainly exists in castor oil seeds. Ricin canenter cells by endocytosis and then it can be transported to the target locus where itcan hide from degradation. A minute dose of ricin can significantly inhibit the activityof large number of ribosomes and thus leads to apotosis of the host cells. Due to itsextreme toxicity, scientists are now working on its insecticidal activity and itsanti-tumor effect.In recent years, as there are many unstable elements in our society, the terroristactivities are booming. As ricin is highly avalible from castor oil seeds and has stablebioactivity, many terrorist choose ricin as their preferred toxin. Thus, ricin study is ingreat need.In this study, we used ammonium sulfate precipitation method and affinityformation technology to get highly purified ricin of great bio-activity. We were ableto get purified A-subunit protein through molecular cloning technique and prokaryoticexpression. Through LDH experiment, we found that rosmarinic acid can significantlyinhibit the bioactivity of ricin. We coincubated A-subunit of ricin with rosmarinic acidand found that rosmarinic acid mainly act on the A subunit of ricin. Animal infectionexperiment showed that rosmarinic acid can protect mice from ricin toxin-induceddeath and can prevent mice from ricin-induced hypoglycemia and losing weight. Inaddition, rosmarinic acid can weaken kidney damage in mice injected with ricin bydecreasing inflammatory factors in mice.