Identification and quality analysis of Panax notoginseng and Panax vietnamensis var. fuscidicus through integrated DNA barcoding and HPLC

DNA barcoding: an efficient technology to authenticate plant species of traditional Chinese medicine and recent advances

Traditional Chinese medicine (TCM) plays an important role in the global traditional health systems. However, adulterated and counterfeit TCM is on the rise. DNA barcoding is an effective, rapid, and accurate technique for identifying plant species. In this study, we collected manuscripts on DNA barcoding published in the last decade and summarized the use of this technique in identifying 50 common Chinese herbs listed in the Chinese pharmacopoeia. Based on the dataset of the major seven DNA barcodes of plants in the NCBI database, the strengths and limitations of the barcodes and their derivative barcoding technology, including single-locus barcode, multi-locus barcoding, super-barcoding, meta-barcoding, and mini-barcoding, were illustrated. In addition, the advances in DNA barcoding, particularly identifying plant species for TCM using machine learning technology, are also reviewed. Finally, the selection process of an ideal DNA barcoding technique for accurate identification of a given TCM plant species was also outlined.

Determination of the Authenticity and Origin of Panax Notoginseng: A Review

Panax notoginseng, a traditional medicinal and edible plant, is widely used in medicine, health care, cosmetics, and other industries. Affected by the discrepancy between market supply and demand and price, the adulteration of P. notoginseng products with other plant-derived ingredients occurs at times. With the continuous development of technologies such as spectroscopy, chromatography, and DNA barcoding, the detection techniques for rapid and sensitive determination of the authenticity identification and origin of P. notoginseng have become more diversified to meet the needs of different regulatory goals and could effectively control practices that mislead consumers and promote false labeling. This review analyzes and summarizes the existing technologies for determining the authenticity and origin of P. notoginseng from these three aspects: morphological, chemical, and molecular biology methods from the literature since 2001; on this basis, the current problems and future research directions are discussed to provide a reference for the establishment of rapid and accurate methods to verify authenticity and origin to promote the further development and improvement of quality control technology systems for P. notoginseng.

Phytoconstituents and Biological Activities of Panax vietnamensis (Vietnamese Ginseng): A Precious Ginseng and Call for Further Research-A systematic review

Panax vietnamensis Ha et Grushv., a Vietnamese ginseng, is a well-known plant, naturally distributed in the Ngoc Linh and Hoang Lien Son mountain areas in Vietnam. It is used as a tonic and medicinal food in traditional folk medicine because it possesses wondrous health benefits. To support its functional attributes, various investigations have been carried out to find out its anti-inflammatory, anti-cancer, anti-stress, anti-nociception, psychomotor and sedative-hypnotic effects and anxiolytic activities. Also similar to other ginsengs, Vietnamese ginseng is a rich source of saponins and it has higher content of protopanaxadiol-, protopanaxatrial- and ocotillol-type saponins compared to other ginsengs in the world. Majonoside R2 is a main saponin in Vietnamese ginseng but this compound does not exist in Panax ginseng. Based on this systematic review, we discussed for future prospects and suggest that thorough scientific scrutiny is necessary in future researches.

Diversity and composition of bacterial endophytes among plant parts of Panax notoginseng

Background

Bacterial endophytes are widespread inhabitants inside plant tissues that play crucial roles in plant growth and biotransformation. This study aimed to offer information for the exploitation of endophytes by analyzing the bacterial endophytes in different parts of Panax notoginseng.

Methods

We used high-throughput sequencing methods to analyze the diversity and composition of bacterial endophytes from different parts of P. notoginseng.

Results

A total of 174,761 classified sequences were obtained from the analysis of 16S ribosomal RNA in different parts of P. notoginseng. Its fibril displayed the highest diversity of bacterial endophytes. Principal coordinate analysis revealed that the compositions of the bacterial endophytes from aboveground parts (flower, leaf, and stem) differed from that of underground parts (root and fibril). The abundances of Conexibacter, Gemmatimonas, Holophaga, Luteolibacter, Methylophilus, Prosthecobacter, and Solirubrobacter were significantly higher in the aboveground parts than in the underground parts, whereas the abundances of Bradyrhizobium, Novosphingobium, Phenylobacterium, Sphingobium, and Steroidobacter were markedly lower in the aboveground parts.

Conclusions

Our results elucidated the comprehensive diversity and composition profiles of bacterial endophytes in different parts of 3-year-old P. notoginseng. Our data offered pivotal information to clarify the role of endophytes in the production of P. notoginseng and its important metabolites.

Integrated Chemical and Transcriptomic Analysis Reveals the Distribution of Protopanaxadiol- and Protopanaxatriol-Type Saponins in Panax notoginseng

Panax notoginseng is famous for its important therapeutic effects and commonly used worldwide. The active ingredients saponins have distinct contents in different tissues of P. notoginseng, and they may be related to the expression of key genes in the synthesis pathway. In our study, high-performance liquid chromatography results indicated that the contents of protopanaxadiol-(Rb1, Rc, Rb2, and Rd) and protopanaxatriol-type (R1, Rg1, and Re) saponins in below ground tissues were higher than those in above ground tissues. Clustering dendrogram and PCA analysis suggested that the below and above ground tissues were clustered into two separate groups. A total of 482 and 882 unigenes were shared in the below and above ground tissues, respectively. A total of 75 distinct expressions of CYPs transcripts (RPKM ≥ 10) were detected. Of these transcripts, 38 and 37 were highly expressed in the below ground and above ground tissues, respectively. RT-qPCR analysis showed that CYP716A47 gene was abundantly expressed in the above ground tissues, especially in the flower, whose expression was 31.5-fold higher than that in the root. CYP716A53v2 gene was predominantly expressed in the below ground tissues, especially in the rhizome, whose expression was 20.1-fold higher than that in the flower. Pearson's analysis revealed that the CYP716A47 expression was significantly correlated with the contents of ginsenoside Rc and Rb2. The CYP716A53v2 expression was associated with the saponin contents of protopanaxadiol-type (Rb1 and Rd) and protopanaxatriol-type (R1, Rg1, and Re). Results indicated that the expression patterns of CYP716A47 and CYP716A53v2 were correlated with the distribution of protopanaxadiol-type and protopanaxatriol-type saponins in P. notoginseng. This study identified the pivotal genes regulating saponin distribution and provided valuable information for further research on the mechanisms of saponin synthesis, transportation, and accumulation.