The present study was aimed to investigate the effect of lime and licorice processing of Pinelliae Rhizoma on its toxic lectin protein and clarify the scientific detoxification connotation of lime and licorice processing of Pinelliae Rhizoma. Western blot was used to semi-quantitatively analyze the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum. Raw products and lectin were treated by soaking in licorice juice, lime solution or mixture solution of these two to investigate the different processing time on the content of toxic lectin protein. SDS-PAGE gel electrophoresis was used to analyze the changes of lectin protein bands in the solution and precipitates before and after processing. MALDI-TOF technology was used to qualitatively analyze and compare the protein molecular weight before and after processing. The results showed that the contents of lectin in Pinelliae Rhizoma and Pinelliae Rhizoma Praeparatum were 5.01% and 0.04% respectively, indicating that processing could significantly reduce the content of active lectin in raw products. The results also showed that the content of lectin in raw drugs decreased significantly after soaking in lime solution for one day or in licorice juice for three day, and the effect was greatest in mixture solution. Qualitative analysis showed that after being treated by soaking in lime solution, the lectin protein was decomposed into small peptide segments, while after being treated by soaking in licorice juice, the lectin protein was denatured and precipitated. The structure of lectin protein in Pinelliae Rhizoma was broken after being processed with licorice juice and lime solution, which significantly reduced the content of toxic lectinprotein. This is one of the detoxification mechanisms of Pinelliae Rhizoma processing.
Keywords: Pinelliae Rhizoma; lectin protein; processing; toxic component.