Identification of Bupleurum Seeds by ITS2 Genetic Barcoding and Seed Morphology / 中国实验方剂学杂志

Objective:To accurately identify Bupleurum seeds by traditional morphological identification method combined with DNA barcoding technique. Method:A total of 41 seed samples on the market were collected and 75 ribosomal DNA internal transcribed spacer 2 (ITS2) sequences of 15 varieties were downloaded from the GenBank database as experimental materials. The seeds were measured and observed by stereomicroscope and vernier caliper, and their 1 000-grain weights were calculated. Genomic DNA was extracted from the seeds and used as a template, and ITS2 sequences were amplified using polymerase chain reaction (PCR) and bidirectional sequencing. Species identification was conducted based on BLAST method, neighbor-joining (NJ) phylogenetic tree method, Kimura two-parameter model (K2P) genetic distance method, and secondary structure of ITS2 sequence. Result:There were slight differences in the length, width, cross-section, and 1 000-grain weight among Bupleurum seeds from different origins. The ITS2 sequences of B. chinense seeds had 2 intraspecific variable sites and 3 haplotypes, the maximum intraspecific genetic distance (0.009) was far smaller than the minimum interspecific genetic distance (0.032). B. chinense and B. scorzonerifolium in the NJ phylogenetic tree were clustered into independent branches with good monophyletic property. The secondary structure of ITS2 sequences could make up for the shortcomings of NJ tree in identifying variants. The collected 41 seeds included 30 B. chinense seeds, 3 B. scorzonerifolium seeds, 5 B. falcatum seeds, 2 B. marginatum var. stenophyllum seeds, and 1 B. smithii var. parvifolium seeds. Conclusion:The B. chinense seeds on the market have problems of diverse sources and chaotic origins. Based on the combination of ITS2 gentic barcoding and seed morphological identification, the Bupleurum seeds can be accurately identified, which provides scientific bases for establishing the quality standard of Bupleurum seeds, standardizing the cultivation of B. chinense, and solving the quality problems of B. chinense from the source, and provides a reference for the accurate identification of other medicinal plant seeds or seed medicinal materials.

Advances in Bioculture Technology of Bupleuri Radix and Biosynthesis Pathways of Saikosaponins / 中国实验方剂学杂志

Synthetic biology is an emerging discipline that analyzes the biosynthesis pathways of active constituents in traditional Chinese medicine and explores genes involved in biosynthesis. Bupleuri Radix is one of the most commonly used Chinese medicinal materials with remarkable medicinal value, its index component is saikosaponins, which has significant anti-inflammatory, anti-viral and anti-tumor activities. However, the current wild resources of Bupleuri Radix have been destroyed, and there were some problems in the process of artificial cultivation. The application of biological culture technology and synthetic biology can expand the sources of saikosaponins and protect resources of Bupleuri Radix. The culture conditions of different plants can be followed without a fixed pattern, and the biosynthetic pathways of different medicinal active ingredients are also inconsistent. At present, there is no review report on the culture technology of Bupleuri Radix and the research on the biosynthesis pathway of saikosaponins. This paper introduces the research progress of biological culture techniques, such as callus culture, adventitious root culture, hairy root culture and suspension cell culture used in synthetic biology, and the biosynthesis pathway of saikosaponins and its key enzyme functional genes. It is suggested to optimize the biological culture technology of Bupleuri Radix by referring to the tissue culture technology of other traditional root medicinal materials, so as to provide a reference for the in-depth study on the biosynthesis pathway and metabolic regulation of saikosaponins.

Characteristics of cell cycle and metabolism in microencapsulated K562 cell culture / 生物工程学报

Human K562 leukemia cells were cultured under free and microencapsulated condition, respectively. The cell cycles in the two kinds of cultures were investigated by flow cytometry. Moreover, mathematical model was established to simulate the cell viability and metabolized characteristic in different cultures. It was found that the cell percent in S phase was higher and the cell viability was better when cultured in microcapsule than that in free culture. The results showed that the model successfully described the substrate consumption and product formation in microencapsulated culture as well as in suspension culture. Based on the model, it was indicated that not only there was a higher proliferation and metabolic activity but also the time of the high activity could keep longer in microencapsulated culture. The parameters of the model showed that there was no significant difference between the two kinds of cultures when the influence of the glucose on the cell viability was concerned (kA(free) approximately = kA (APA)) but lactate had a obvious suppression effect on cell viability in free culture, and neglectable suppression in microencapsulated culture (kL(free) > kL(APA)).