The ITS region provides a reliable DNA barcode for identifying reishi/lingzhi (Ganoderma) from herbal supplements

Abstract

The dietary supplement industry is rapidly growing yet, a recent study revealed that up to 60% of supplements may have substituted ingredients, some of which can be harmful contaminants or additives. When ingredients cannot be verified morphologically or biochemically, DNA barcoding complemented with a molecular phylogenetic analysis can be a powerful method for species authentication. We employed a molecular phylogenetic analysis for species authentication of the commonly used fungal supplement, reishi (Ganoderma lingzhi), by amplifying and sequencing the nuclear ribosomal internal transcribed spacer regions (ITS) with genus-specific primers. PCR of six powdered samples and one dried sample all sold as G. lucidum representing independent suppliers produced single, strong amplification products in the expected size-range for Ganoderma. Both best-hit BLAST and molecular phylogenetic analyses clearly identified the presence of G. lingzhi DNA in all seven herbal supplements. We detected variation in the ITS sequences among our samples, but all herbal supplement samples fall within a large clade of G. lingzhi ITS sequences. ITS-based phylogenetic analysis is a successful and cost-effective method for DNA-based species authentication that could be used in the herbal supplement industry for this and other fungal and plant species that are otherwise difficult to identify.

The ITS analysis and identification of Actinidia eriantha and its related species

“…Many researchers have reported that ITS region has the advantages of high intra-specific conservation, large inter-specific variation, small fragment, easy amplification, easy analysis and high success rate for species identification [ 20 , 21 ]. Similar results were found in our study.…”

EVALUATION OF DNA QUALITY FROM MODIFIED DNA EXTRACTION AND AMPLIFICATION OF ITS2 FROM Eurycoma longifolia CAPSULE HERBAL PRODUCTS

“…Previous study had shown that ITS2 has ability to discriminate approximately 13307 genus and 5240 species accessed from GenBank and no argument on considering ITS2 as universal barcode for wide taxa range of medicinal plant [13]. In addition, Pang et al, reported that ITS2 was able to distinguish 100% correctly species from adulterants, however, it was not easy to discriminate herbal products, because of degraded DNA and substituted by other species [11,20]. Therefore, high quality of DNA extracted was a crucial step in any DNA molecular techniques.…”

Safety assessment of the fungal immunomodulatory protein from Ganoderma microsporum (GMI) derived from engineered Pichia pastoris: Genetic toxicology, a 13-week oral gavage toxicity study, and an embryo-fetal developmental toxicity study in Sprague-Dawley rats

“…Ganoderma spp. is now marketed as a dietary supplement in the Unites States of America and the European Union [18] . Polysaccharides, triterpenoids, alkaloids, and proteins extracted from Ganoderma spp.…”