DNA-Based Approaches for the Discrimination of Medicinal Plants from Their Adulterants

Medicinal herbs are essential to many conventional and contemporary health-care systems around the world. However, the increased demand for these plants has also meant a rise in adulteration, which puts the public’s health and the effectiveness of herbal medicines at grave risk. In response to this difficulty, DNA-based methods have become effective means of validating therapeutic plants and separating them from adulterants. Several research investigations have indicated the potential prevalence of substitution and/or adulteration, collectively stated as substitution, within the raw herbal market for medicinal plants. Such practices could pose risks to the well-being and safety of consumers. The substitution of species could have detrimental effects on consumer health, potentially leading to severe allergies and failing to produce the intended therapeutic effects. Identifying species adulteration visually in the raw herbal trade proves challenging due to the typically dry state of the plants, resulting in the loss of their original characteristics. In recent times, various methods have emerged for the identification of medicinal plants in trade, such as morpho-taxonomical keys, histological techniques, chemical fingerprinting, and DNA-based approaches, each with its own set of advantages and drawbacks. However, a notable limitation of morphological techniques is their inability to identify powdered market samples, while chemical and histological approaches are susceptible to variations based on the age and season of collection. The accuracy, dependability, and cost of DNA barcoding have made it a popular technology for identifying medicinal plant materials in commercial settings. To verify the legitimacy of medicinal plants, this chapter offers a thorough overview of DNA-based methods, such as DNA barcoding, SNP analysis, HRM analysis, digital PCR, next-generation sequencing (NGS), and DNA fingerprinting. It also highlights the methods, benefits, drawbacks, and applications of these methods.