RESUMO
The Chinese cordyceps, a complex of the fungus Ophiocordyceps sinensis and its species-specific host insects, is also called "DongChongXiaCao" in Chinese. Habitat degradation in recent decades and excessive harvesting by humans has intensified its scarcity and increased the prices of natural populations. Some counterfeits are traded as natural Chinese cordyceps for profit, causing confusion in the marketplace. To promote the safe use of Chinese cordyceps and related products, a duplex PCR method for specifically identifying raw Chinese cordyceps and its primary products was successfully established. Chinese cordyceps could be precisely identified by detecting an internal transcribed spacer amplicon from O. sinensis and a cytochrome oxidase c subunit 1 amplicon from the host species, at a limit of detection as low as 32 pg. Eleven commercial samples were purchased and successfully tested to further verify that the developed duplex PCR method could be reliably used to identify Chinese cordyceps. It provides a new simple way to discern true commercial Chinese cordyceps from counterfeits in the marketplace. This is an important step toward achieving an authentication method for this Chinese medicine. The methodology and the developmental strategy can be used to authenticate other traditional Chinese medicinal materials.
Assuntos
Cordyceps/genética , Medicamentos Falsificados/análise , Medicamentos de Ervas Chinesas/análise , Fraude/prevenção & controle , Reação em Cadeia da Polimerase , Animais , Cordyceps/química , Medicamentos Falsificados/química , Medicamentos Falsificados/economia , DNA Fúngico/isolamento & purificação , Medicamentos de Ervas Chinesas/economia , Medicamentos de Ervas Chinesas/normas , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fraude/economia , Genes Fúngicos/genética , Genes de Insetos/genética , Proteínas de Insetos/genética , Insetos/genética , Insetos/microbiologiaRESUMO
Ophiocordyceps sinensis is a valuable traditional Chinese medicine with a high market price. In this study, a polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method based on 2 enzymes was developed to distinguish O. sinensis from 6 common counterfeit species. To verify the applicability of this method, we experimentally tested O. sinensis organisms, tablet preparations made from O. sinensis, and cultured mycelia isolated from O. sinensis. To validate the results from this PCR-RFLP method, all real samples were identified by internal transcribed spacer sequencing. This is, to our knowledge, the first time the PCR-RFLP method has been applied to identify O. sinensis. The selection of 2 restrictive enzymes for identification dramatically improved the accuracy and efficiency of this method. It is the great advantage of this method that sampling from either of 2 parts of O. sinensis-the fruiting body or the caterpillar body-would not cause any difference in the final experimental results. Therefore, this method is not only feasible for testing crude drugs of O. sinensis but it is also useful when the crude drugs are broken down into powder or made into tablets, demonstrating the promising prospect of application in quality control.