Abstract:
The increasing global demand for herbal medicines and dietary supplements, while
offering potential health benefits, has also raised concerns about product quality and
authenticity. Herbal products, often derived from traditional knowledge and practices,
are susceptible to adulteration due to factors like species similarity and the surge in
demand for specific therapeutic properties. This study focuses on three traditionally and
economically important medicinal species, Terminalia bellirica (TB), Terminalia
chebula (TC), and Phyllanthus emblica (PE), known for their therapeutic benefits and
often subjected to adulteration. DNA-based methods tend to be more reliable, accurate
and cost-effective for authentication. The isolating of high-quality amplifiable DNA
from these plant species, especially in processed products, remains challenging. This is
primarily due to the presence of polyphenols, which interfere with DNA extraction and
amplification. To address this, the study developed an optimized DNA isolation
protocol. This protocol incorporated specific buffer modifications to stabilize pH
during extraction and introduced polyvinylpyrrolidone as a phenolic compound
scavenger to minimize interference during cell lysis. The effectiveness of this optimized
protocol was evaluated using the species-specific ITS-based SCAR markers, digital
PCR and ITS2 metabarcode on six of each Baheda (TB fruit), Harde (TC fruit), Amala
(PE fruits) and Triphala (containing three fruits of TB, TC, and PE) market formulation.
Results demonstrated a significant improvement in DNA quality and quantity, leading
to successful species identification. Furthermore, the study employed digital PCR
(dPCR) to enhance sensitivity, achieving a two-fold increase compared to conventional
PCR. This marks the first reported instance of a dPCR application for authenticating
TB, TC, and PE. This research underscores the critical role of optimized DNA isolation
protocols in ensuring the quality and authenticity of herbal products. By effectively
addressing the challenges posed by polyphenols and employing sensitive detection
methods like dPCR, this study provides a robust framework for authenticating herbal
materials, ultimately contributing to consumer safety and confidence in the herbal
medicine market.
