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An Herbalife scientist explains why different DNA technologies are required to trace and qualify botanical materials during manufacturing.
Current good manufacturing practices (cGMPs) require dietary supplement manufacturers to conduct at least one appropriate test to verify the identity of any component used in products. Identification and authentication of botanical materials and processed ingredients present challenges, however, due to close interspecies relationships and increased profile complexity, which can lead to misidentified or adulterated botanical materials. The use of misidentified or adulterated materials can lower a product’s health benefits or even present unexpected health risks.
The Value of DNA-Based Methods in the Complete Botanical Authentication Toolbox
Morphological and chemical methods are widely used in botanical identification and authentication. However, these methods are sometimes compromised by the loss of physical features when botanical materials undergo processing, as well as by variations of chemical profiles due to seasonal and geographical differences.
Because of the fidelity and specificity of DNA sequences in plant species, DNA-based methods are valuable contributions or even required components in the complete toolbox of botanical authentication. In terms of species identification, DNA technology is a viable tool to precisely authenticate the target botanical species, as well as to trace material identity throughout the manufacturing processes. It can also be used to detect potential botanical adulterants in finished products.
A Case Study in DNA-Based Botanical Authentication
Botanical materials are presented in different forms at the different stages of manufacturing-and so is the quantity and quality of their DNA. Therefore, different DNA technologies are required to trace and qualify botanical materials-from starting botanical parts before manufacturing to highly processed botanical extracts and even finished products delivered to the consumers. Below are what have been done in Herbalife Nutrition.
Starting plant parts contain DNA of larger quantity and higher quality and allow us to enrich certain DNA sequences, called DNA barcodes. Like the unique pattern of black and white bars in a UPC barcode that identifies different consumer products, these collected barcodes are compared to an in-house botanical barcode database that is built on hundreds of authenticated botanical reference materials used in the dietary supplement industry. This approach provides a universal solution for the identification of botanical parts from a broad range of plant taxa, without pre-assumptions. This DNA barcoding method, which was validated by the Center of Excellence (COE) Quality Control Laboratory at Herbalife Nutrition and recently became ISO 17025:2008 accredited, has been transferred to the Herbalife Nutrition Botanical Extraction Facility to test starting botanical materials to ensure their correct identity.
The application of DNA-based methods in processed botanicals is more challenging because extensive manufacturing processes, which include heat treatment, solvent extraction, and filtration, significantly degrade and remove DNA. To assess the quantity and quality of DNA in those materials and to generate reliable DNA test results, Herbalife Nutrition developed a novel approach, called LA-DNA (LA stands for adapter Ligation and PCR Amplification), to evaluate the botanical DNA in processed botanical materials1. With this approach, we are able to visualize the previously “invisible” DNA. We find the size of the “invisible” DNA fragments in botanical extracts are around 20-220 base pairs, and they are seen in most of the botanical extracts that have been tested. DNA fragments in this size range are usually missed by the previous mentioned barcoding method, which focuses on much longer DNA fragment pieces (between 400-800 base pairs). However, these degraded DNA can still provide diagnostic information for species identity, if potential tests are designed to target these fragments by PCR (polymerase chain reaction) or NGS (next-generation sequencing). Herbalife Nutrition is exploring those targeted methods to characterize many of our botanical extracts. Designed to detect both the botanicals of interest and their common adulterants, we hope these methods can be used to address the purity of the highly processed botanical materials at species level in the near future.
In addition to analyzing the starting plant parts and botanical extracts with the targeted methods, we also have success in monitoring botanical ingredients in some of our finished products, which have even much higher complex matrices than a single botanical extract.
DNA Test Methods’ Potential in Reducing Risk
Depending on the quantity and quality of DNA present, different DNA testing approaches are required for testing different types of botanical materials, such as starting botanical parts or botanical extracts where DNA is damaged due to processing. Based on our experience at Herbalife Nutrition, we believe that DNA test methods have the potential to be used for all types of botanical materials, not only to fulfill the regulatory requirement for botanical identification, but also to reduce the risks of commercial adulteration to protect consumers and companies.
Zhengfei Lu, PhD, is a Quality Control Analytical Scientist for Herbalife Nutrition.
1. Lu Z et al. “Visualization of DNA in highly processed botanical materials.” Food Chemistry. Published online April 15, 2018. (https://www.sciencedirect.com/science/article/pii/S0308814617318861)