DNA BARCODING: A TOOL FOR STANDARDIZATION OF HERBAL MEDICINAL PRODUCTS (HMPS) OF LAMIACEAE FROM PAKISTAN

 

NADIA BATOOL ZAHRA¹, ZABTA KHAN SHINWARI^{1, 2} AND MUHAMMAD QAISER³

 

¹Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan

²Pakistan Academy of Sciences, Islamabad, Pakistan

³University of Karachi, Karachi, Pakistan

^*Corresponding author’s email: shinwari2008@gmail.com

 

Abstract

 

There has been a considerable interest worldwide in traditional and alternative medicine, particularly herbal products over the past few decades but the adulteration or contamination of herbal medicinal products (HMPs) is a potential threat to consumer safety. The fact highlights the importance of an effective and accurate science integrated method for taxonomic identification of the medicinal plants and their HMPs. DNA barcoding is a molecular technique which has made it possible to identify the herbs and to find the adulterants in HMPs. The current study was designed on DNA barcoding of medicinal plants of family Lamiaceae for their correct identification and to fix the problem of adulteration for protecting consumers from health risks associated with product substitution and contamination. Many Lamiaceae species are used as traditional medicines, as culinary herbs, spices and as source of essential oils. HMPs representing 32 Lamiaceae plant samples were purchased/collected from three herbal stores (Pansar stores) in Islamabad and a herbal pharmaceutical industry. We selected three plastid loci rbcL, matK and psbA-trnH to barcode these HMPs. MEGABLAST sequence comparison was performed to verify the taxonomic identity of the samples. We found four mislabeled samples and two product substitutions. The overall amplification success for rbcL and matK was 87% and 81% while psbA-trnH showed 69%. matK and psbA-trnH were able to distinguish the species relatively better with 40% success rate than rbcL (16%). On the whole we generated a total of 22 genus-level barcodes (78%) and 12 species-level barcodes (44%). The species-level identification was considerably low due to insufficient reference data and selection of plastid markers. Therefore, it is recommended to develop herbal barcode library for adequate availability of reference sequence data and addition of nuclear markers. DNA barcoding can help the regulatory authorities to devise a mechanism for quality control and can largely support the herbal pharmaceutical industries to restore the eroded consumer confidence.

 

Key words: DNA barcoding, Lamiaceae, Herbal medicinal products, rbcL, matK and psbA-trnH.