From Pharmacognosia to DNA-Based Medicinal Plant Authentication – Pharmacognosy through the Centuries

Abstract

For centuries, pharmacognosy was essential for the identification, quality, purity, and, until the end of the 18th century, even for the efficacy of medicinal plants. Since the 19th century, it concentrated on authenticity, purity, quality and the analysis of active substances, and was established as an academic branch discipline within pharmacy and continuously developed into a modern, highly sophisticated science. Even though the paradigm in pharmacy changed in the 19th century with the discovery of morphine and concentrated on single substances that could be synthesized fast by the upcoming industry, medicinal plants always remained an important element of the Materia medica, and during the last decades, medicinal plants continue to be a source of remedies, and natural products are an inspiration for new medicine. In this research, pharmacognostic skills remain an essential element, both with regards to identity, quality assurance of botanicals (both herbal medicines and supplements), and the discovery and development of new medicines. Over the years, the specific pharmacognostical tools have changed dramatically, and most recently, DNA-based techniques have become another element of our spectrum of scientific methods.

Effects of circadian clock and light on melatonin concentration in Hypericum perforatum L. (St. John’s Wort)

“…Melatonin concentration in H. perforatum was the highest in the owers, followed by that in the leavesthus indicating a tissue-organ differential expression. This also re ects both spatial distribution and regulation of the signaling hormone and conventional usage of H. perforatum as "materia medica" for treating minor or moderate forms of depression and a range of mood disorders (Heinrich and Anagnostou 2017). Melatonin acts as a chronobiotic agent, and treatment with melatonin can entrain circadian rhythms in most visually impaired people and night-shift workers who have free-running rhythms (Sack and Lewy 1997;Sack et al 2000); it exerts clinically bene cial effects on circadian rhythm-related sleep disorders, jetlag, and even Alzheimer disease (Zisapel 2018).…”

Benefits and Limitations of DNA Barcoding and Metabarcoding in Herbal Product Authentication

“…One of the core interests of modern pharmacognosy refers to the identification and authentication of drug substances and to the quality of the resulting herbal medicines (Heinrich et al ., ). However, the complex natural formulations, as well as the lack of standardised operating procedures and analytical methods, complicate the quality control of the herbal products.…”

“…Initially used as an identification tool, DNA barcoding is now applied in the industrial quality assurance context to authenticate a wide range of herbal products (de Boer et al ., ; Parveen et al ., ; Sgamma et al ., ). Recently, the British Pharmacopoeia included the first globally general DNA‐based identification method using Ocimum tenuiflorum L. (Lamiaceae), with the focus on plant sampling, barcode regions, DNA extraction, purification and amplification, and the sequences reference database (Heinrich et al ., ; Sgamma et al ., ). Recent investigations applied DNA barcoding to identify and authenticate various marketed herbal products, reporting various degrees of discrepancy between the expected species and the actual identified species.…”

“…Importantly, DNA metabarcoding data is usable for qualitative evaluation only, to determine presence of taxa, and not for quantitative assessment of relative species abundance based on sequence read numbers, as many variables considerably impact the obtained sequence read results (Staats et al, 2016). Clearly, in the context of pharmacognosy and pharmacovigilance, a combination of analytical methods is unavoidable for comprehensive authentication and quality control of raw material and resulting products (Shetti et al, 2011;Mishra et al, 2016;Parveen et al, 2016;Heinrich et al, 2017;Pawar et al, 2017), and DNA-based approaches offer important novel insights.…”

The historical development of pharmacopoeias and the inclusion of exotic herbal drugs with a focus on Europe and Brazil

“…In parallel the presence of chemical preparations increased from 53 in 1872 to 98 in 1910 (Heffter, 1914, p. 33). During the 19th and early 20th century pharmacognosy flourished in Germany (Heinrich and Anagnostou, 2017) resulting in innovative literature mostly published in German, which contextualized history of ethnomedicine with the latest discoveries in chemistry and pharmacology (e.g., Köhler, 1887;Lewin, 1894;Hartwich, 1897;Tschirch, 1909Tschirch, -1925. Similarly, the advancement of organic and natural product chemistry was mainly published in German during the 19th century (e.g., Liebig, 1837;Liebig und Geiger, 1843;von Hofmann, 1843;Kolbe, 1874;Baeyer, 1878).…”