Using Molecular Phylogenetics to Authenticate the Active Fungal Ingredient Used in Herbal Supplements
Tess A. Gunnels,
Faculty Mentor: Justen B. Whittall
The herbal supplement industry is a growing enterprise, expected to reach a value of 86.74 billion dollars by 2022, yet, a recent study revealed that up to 60% of herbal supplements have substituted ingredients not listed on their labels, some with harmful contaminants. Threats to consumer health make rigorous quality control testing a necessary aspect in the production of supplements. Traditionally, species have been verified morphologically or using distinctive microscopic features, but this is not possible for all species (e.g., reishi and Cordyceps mushrooms). One way to verify the plant and fungal species in these supplements is through DNA barcoding complemented with a molecular phylogenetic analysis. This method provides an objective, efficient and repeatable method for unambiguous species identification. We designed a molecular phylogenetic analysis for species authentication of a commonly used fungal supplement by amplifying and sequencing the nuclear ribosomal internal transcribed spacer (ITS) region using species specific primers. Initial PCR results using powdered reishi mushrooms (Ganoderma lucidum) produced a single, strong product in the expected size-range for Ganoderma. Preliminary DNA sequence analysis indicates the predominant fungal DNA is likely to be the unadulterated species advertised. Our data suggest a successful and cost-effective method for DNA-based species authentication that could be used in the herbal supplement industry for other fungal and plant species that are difficult to identify.