DNA barcodes reveal adulteration in traditional medicines:

DNA barcodes reveal adulteration in traditional medicines:

Context

A genetic study has shown that traditional medicines in the large unorganised market contain spurious plant extracts and heavy metals that pose serious risks to health.

What does the study show?

The studies shows that traditional medicinal markets are replete with unrelated plant materials that substitute for endangered or rare ones, while the final product, in some instances, contains heavy metals, particularly lead. A herbal trade authentication system was needed to address concerns over widespread adulteration.

What are heavy metals?

• Heavy metals are metallic, naturally occurring compounds that have higher density compared to other metals, at least five times the density of water.
• Heavy metals are toxic to humans.
• Examples: Lead, Copper, Mercury, Cadmium, Arsenic, Chromium (Cr), Thallium etc.

Process of tracing the genes and focus on adulteration

• While attempting to trace the genetic history of Phyllanthus (Leaf flower), scientists were surprised to see claims of the plant being used in abundance in herbal medicines, despite its relative rarity.
• Samples and their DNA analysis showed that nearly 25% of samples were not Phyllanthus amarus (used to treat Hepatitis B), but a mixture of other species which did not contain the curative elements of Phyllanthin and hypophyllanthin.
• The focus was then on species adulteration and developed DNA barcodes – short genetic sequences, much like a supermarket barcode, which becomes an identifying mark – for the species commonly used in traditional medicine.
• For example, Ashoka bark, which is used to cure many ailments including leucorrhea, uterine disorders, and as an anti-inflammatory, anti-bacterial drug — whose harvesting is highly regulated under forest laws was found to have 90% adulteration by seven other species, including papaya or drumstick bark.

What are DNA Barcodes?

• DNA barcoding is a taxonomic method that uses a short genetic marker in an organism’s DNA to identify it as belonging to a particular species.
• It differs from molecular phylogeny in that the main goal is not to determine patterns of relationship but to identify an unknown sample in terms of a preexisting classification.
• Although barcodes are sometimes used in an effort to identify unknown species or assess whether species should be combined or separated, the utility of DNA barcoding for these purposes is subject to debate.

Conclusion

There is a need to reduce the adulteration in traditional medicines and develop barcodes as an identifying mark for the medicines.