Publicação
Development of a DNA-based methodology for the identification of Pfaffia glomerata in herbal products
| Resumo: | Pfaffia glomerata (Brazilian ginseng) is a medicinal plant widely recognized for its adaptogenic, anti-inflammatory, and immunomodulatory properties. Due to its growing commercial value, as well as to its common name that includes the word “ginseng”, and the morphological similarity to other ginsengs, it is increasingly prone to adulteration. This study aimed to develop and validate a species-specific real-time PCR method for the identification and quantification of P. glomerata in commercial herbal products. Primers targeting the ITS1 region were designed and evaluated both in silico and experimentally. Specificity was assessed against 51 medicinal plant samples, including other species known for their adaptogenic properties. Sensitivity assays confirmed an absolute detection limit of 0.001 ng of P. glomerata DNA. Quantitative analysis using binary mixtures with Withania somnifera and the ∆Cq normalization method reliably detected P. glomerata at levels as low as 0.1% (w/w) and allowed the accurate estimate of the percentage of P. glomerata material in the range of 50% to 0.1% (m/m). The method was applied to 25 commercial products labeled as P. glomerata, Pfaffia paniculata, Pfaffia, Brazilian ginseng, or other possibly adulterant species of Brazilian ginseng, seven samples showed inconsistencies with the label and were considered as adulterated. P. glomerata DNA was also found to be present in nine other samples, but only at trace amounts (<LOQ of 0.1%), suggesting a cross-contamination rather than adulteration. These findings highlight the high sensitivity of the developed method but also evidence the importance of using the ∆Cq normalization method to estimate the amounts of P. glomerata in mixtures. The results also showed that the molecular strategy developed was effective and sensitive for the authentication of P. glomerata and confirmed the method’s capacity to authenticate P. glomerata and distinguish it from other adulterant species. The results reveal a high rate of adulteration (3 out of 6) among products marketed under the name P. glomerata or “Brazilian ginseng,” with recurrent substitution of P. glomerata by P. paniculata. In addition, two samples labeled as P. paniculata were found to be P. glomerata, indicating a high level of mislabeling among the two Pfaffia species. These findings highlight weaknesses in labeling practices and support the need for molecular tools to ensure botanical authenticity, for a reliable traceability within the adaptogenic plant market and Pfaffia genus in particular. |
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| Autores principais: | Richter, Camila Palacio |
| Assunto: | Pfaffia glomerata Medicinal plants Authenticity Real-time PCR |
| Ano: | 2025 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Pfaffia glomerata (Brazilian ginseng) is a medicinal plant widely recognized for its adaptogenic, anti-inflammatory, and immunomodulatory properties. Due to its growing commercial value, as well as to its common name that includes the word “ginseng”, and the morphological similarity to other ginsengs, it is increasingly prone to adulteration. This study aimed to develop and validate a species-specific real-time PCR method for the identification and quantification of P. glomerata in commercial herbal products. Primers targeting the ITS1 region were designed and evaluated both in silico and experimentally. Specificity was assessed against 51 medicinal plant samples, including other species known for their adaptogenic properties. Sensitivity assays confirmed an absolute detection limit of 0.001 ng of P. glomerata DNA. Quantitative analysis using binary mixtures with Withania somnifera and the ∆Cq normalization method reliably detected P. glomerata at levels as low as 0.1% (w/w) and allowed the accurate estimate of the percentage of P. glomerata material in the range of 50% to 0.1% (m/m). The method was applied to 25 commercial products labeled as P. glomerata, Pfaffia paniculata, Pfaffia, Brazilian ginseng, or other possibly adulterant species of Brazilian ginseng, seven samples showed inconsistencies with the label and were considered as adulterated. P. glomerata DNA was also found to be present in nine other samples, but only at trace amounts (<LOQ of 0.1%), suggesting a cross-contamination rather than adulteration. These findings highlight the high sensitivity of the developed method but also evidence the importance of using the ∆Cq normalization method to estimate the amounts of P. glomerata in mixtures. The results also showed that the molecular strategy developed was effective and sensitive for the authentication of P. glomerata and confirmed the method’s capacity to authenticate P. glomerata and distinguish it from other adulterant species. The results reveal a high rate of adulteration (3 out of 6) among products marketed under the name P. glomerata or “Brazilian ginseng,” with recurrent substitution of P. glomerata by P. paniculata. In addition, two samples labeled as P. paniculata were found to be P. glomerata, indicating a high level of mislabeling among the two Pfaffia species. These findings highlight weaknesses in labeling practices and support the need for molecular tools to ensure botanical authenticity, for a reliable traceability within the adaptogenic plant market and Pfaffia genus in particular. |
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