Species Adulteration in the Herbal Trade: Causes, Consequences and Mitigation

Abstract

The global economy of the international trade of herbal products has been increasing by 15% annually, with the raw material for most herbal products being sourced from South and Southeast Asian countries. In India, of the 8000 species of medicinal plants harvested from the wild, approximately 960 are in the active trade. With increasing international trade in herbal medicinal products, there is also increasing concern about the widespread adulteration and species admixtures in the raw herbal trade. The adverse consequences of such species adulteration on the health and safety of consumers have only recently begun to be recognised and documented. We provide a comprehensive review of the nature and magnitude of species adulteration in the raw herbal trade, and identify the underlying drivers that might lead to such adulteration. We also discuss the possible biological and chemical equivalence of species that are used as adulterants and substitutes, and the consequences thereof to consumer health and safety, and propose a framework for the development of a herbal trade authentication service that can help regulate the herbal trade market.

Authentication of Garcinia fruits and food supplements using DNA barcoding and NMR spectroscopy

“…Globalization in the trade of herbal products and an expanding commodity market have resulted in widespread consumption of medicinal plants as drugs, cosmetics and food supplements, both in developing and developed countries 1 , 2 . Quality, safety and efficacy of herbal medicines are key requirements for public health and a major concern for regulatory authorities 3 .…”

“…Several reports suggest that only 10% of medicinal plants traded in India are being cultivated 2 , 4 . Growing commercial demands for raw drug products increases the incentive for adulteration and substitution in the medicinal plants trade, and such adulteration can threaten consumer health, damage consumer confidence, and generally lower the trade value of such products 1 .…”

DNA metabarcoding to unravel plant species composition in selected herbal medicines on the National List of Essential Medicines (NLEM) of Thailand

“…Seventynine Ayurvedic herbal products were authenticated using DNA metabarcoding, and the results revealed that 67% contained a single ingredient, 21% contained multiple ingredients, and some did not contain all of the plant species mentioned on the label 15 . Much evidence supports species adulteration in herbal products, which might adversely affect consumer health and safety 6,22 . Precise and consistent sequences can be obtained for improved species determination using metabarcoding, which generates repeatable results with a reasonable cost and high-throughput sequencing 23 .…”

Assessment of adulteration in raw herbal trade of important medicinal plants of India using DNA barcoding

“…Species substitution may adversely affect consumer health as it could cause severe allergies and will not have the intended effect (Seethapathy et al 2014;Santhosh et al 2015Santhosh et al , 2016Srirama et al 2017). Visual detection of species adulteration in the raw herbal trade is often difficult, as the plants are usually in a dry state and do not retain the original features of the plant (Seethapathy et al 2014;Santhosh et al 2015Santhosh et al , 2016.…”

“…These results are discussed in the light of the increasing concern over safety of raw herbal drug. The need for a national regulatory mechanism that can authenticate medicinal plants used in raw trade is discussed that could offer quality assurance to customers (Srirama et al 2017).…”