Objective: To investigate the irritation stability of raphides from Pinellia ternata and the contribution of raphides proteins on irritation.
Methods: The irritation of raphides and tubers from P. ternata treated with different solvents or protease digestion were evaluated by the Draize test. The shape and appearance of raphides treated with immersion in different solvents were showed by scanning electron microscopy, and protein bands from raphides before and after protease digestion were showed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).
Results: The raphides gradually lost the irritation when immersed in methanol and ethanol, while scanning electron micrograph showed the fragility of the methanol and ethanol treated raphides. The crude tubers of P. ternata immersed in 75% solution of ethanol also lost the acridity. When treated with protease digestion, raphides lost the irritation as well as the many protein bands on the SDS-PAGE gel gradually disappeared.
Conclusion: Protein of the raphides could be involved in the raphides irritation.