Authentication of important medicinal herbal species through DNA-based molecular characterization

DNA-based molecular markers have great importance among other methods used for the authentication, detection, and identification of medicinal herbal species. Currently, it is more common to identify the medicinal herbal species (monoherbal or polyherbal forms) morphologically by using sensory, macroscopic, and microscopic methods. DNA-based markers made an easy for accurate detection of herbal species by using the polymerase chain reaction (PCR) which involves in vitro amplification of a particular region of DNA sequence.

In the current study, we used heterogenic parts for isolation of DNA from twelve important medicinal herbal species followed by purity determination, and yield calculation. We optimized a PCR reaction using universal primer sets to amplify the target DNA followed by DNA sequencing, and species identification. We also performed phylogenetic analysis for determining the evolutionary relationship between the herbal species, by using MEGAX32 software. Further, we prepared adulterated herbal species samples to validate the method.

The method was able to amplify the target gene through PCR in 11 out of 12 herbal species samples (sensitivity 91.66%).The DNA from cinnamon could not yield a truly amplified product. On DNA sequencing, all the amplified products were identified as true herbal species (specificity 100%). In the adulterated samples, non-specific DNA bands were observed after performing the PCR reaction, indicating the mixing of more than one herbal species.

To conclude, DNA sequencing-based molecular analysis is advantageous for the correct identification, and detection of adulterated herbal species.