The scientific world has witnessed multiple outstanding breakthroughs in the field of traditional Chinese medicine and natural product derived drugs during 2015-2020. The research by Prof. Tu Youyou on artemisinin gained her as one of the winners of Nobel Prize in Physiology or Medicine in 2015, has also aroused profound impetus in the investigation of traditional Chinese medicine and natural product drugs. Mori ramulus alkaloids tablets and GV-971 capsules have been approved by National Medical Products Administration (NMPA) for clinical application. Some of the important research findings were selected as "Top 10 major medical advances" in China, and a plenty of research articles were accepted by world top publications such as Nature, Science, New England Journal of Medicine, as well as Lancet, etc. The current review summarized and commented on the research highlights of traditional Chinese medicine and natural drugs published in world top journals from 2015 to 2020, including the major progresses in the sub-divided areas of chemistry, molecular pharmacognosy, pharmacology and toxicology, as well as pharmaceutics. This report aims to follow and review the leading research and hot spots in fields of traditional Chinese medicine and natural drugs, and to provide prospects and inspirations in the interdisciplinary areas based on our preliminary analyses.

In recent years the interaction between host and gut microbiota has attracted increasing attention. However, intestinal flora dysbiosis may lead to many diseases, and there is increasing evidence that the intestinal microbiota in patients with chronic kidney disease (CKD) is associated with the pathophysiological status of the host. "Gut-kidney axis" provides a better explanation of the two-way communication between intestinal flora and CKD. Impaired kidney function leads to dysbiosis of intestinal flora and an altered intestinal flora can damage the intestinal mucosal barrier and facilitate the entry into the bloodstream of harmful bacteria, which can induce chronic inflammation and thus accelerate renal injury. In addition, the accumulation of nephrotoxic metabolites from an altered intestinal flora can aggravate CKD in the "gut-kidney axis". Among them, p-cresol sulfate, indoxyl sulfate and trimethylamine oxide are the most widely studied metabolites of nephrotoxicity, and their renal toxicity has been widely confirmed in basic research and clinical studies. Current studies show that the intestinal microbiota-metabolite network is closely related to the occurrence and development of chronic kidney disease. Thus, intervention in the intestinal microbiota may provide a new approach to the prevention and treatment of chronic kidney disease.

Reactive nitrogen species (RNS) affects intracellular redox balance and induces post-translational modification of proteins. Moreover, RNS, as the signal molecule, participates in the transduction of cellular signals under physiological conditions. However, excessive RNS can induce nitrosative stress and then damage cells, and thereby may play a role in the tumor initiation and progression. Thus, we discussed the role of RNS under physiological conditions and the tumor microenvironment, which may provide some novel ideas for the development of new drugs and the treatment of diseases.

Long non-coding RNA (lncRNA) has a wide range of biological functions in epigenetic, cell cycle, cell differentiation and other life activities, and that affect the development and differentiation of immune cells and the maintenance of homeostasis in the immune system. CD4⁺ T cell subsets are heterogeneous cells with different functions, including promoting the proliferation and differentiation of T cells, B cells and other immune cells, and coordinating related functions between immune cells. Autoimmune disease (AID) is a chronic inflammatory disease caused by an autoantigen immune reaction. lncRNA and CD4⁺ T cell subsets are involved in the occurrence and progression of the disease. This article reviews the relationship between lncRNA and the differentiation of AID CD4⁺ T cell subsets.

Cannabis sativa, one of the ancient medicinal plants, has been used to alleviate pain and seizures. However, cannabinoids are often addictive, which limits their clinical use. Cannabidiol (CBD) as a non-psychoactive component of Cannabis sativa, has much weaker adverse effects than Δ9-tetrahydrocannabinol (THC) and therefore has received widespread attention. CBD has been found to ameliorate a variety of neuropsychiatric diseases, but the precise mechanism(s) of action are still unclear. Due to its low affinity for classical cannabinoid receptors current studies are focusing on other targets outside the endocannabinoid system. In the present review we mainly summarize the effects and molecular mechanisms of CBD in neuropsychiatric disorders, including epilepsy, neuropathic pain, anxiety, and depression.

Wound healing is a complex and highly regulated process to maintaining the skin barrier function. Wounds of diabetic patients are hard or even not healing. Non-healing diabetic foot ulcers can lead to lower-extremity amputations. Diabetic wound healing problem is the main complication that leads to high disability rate of diabetes and can threaten the lives in severe cases. The healing of skin wounds requires the synergy of multiple factors to restore the injured skin to its barrier function. The mechanisms that cause it difficult to heal diabetic wounds are complex, including oxidative stress, chronic inflammation, decreased neovascularization, peripheral neuropathy, and imbalance of extracellular matrix accumulation and remodeling. This review classifies mechanisms of diabetic wound healing and provides a reference for its further research.

Circadian rhythm is an internal regulatory mechanism that allows organisms to adapt to circadian changes in the external environment, and can regulate the body's steady state by affecting the metabolic pathways of multiple organs. When exogenous factors such as eating time, worktime changes, and sleep disturbances cause the body's circadian rhythm to be disrupted, the risk of developing metabolic syndrome is significantly increased. This article explores the relationship between circadian rhythm and body metabolism and summarizes the molecular mechanisms by which circadian rhythm regulates the digestive system, liver and bile acid production, and kidney function. We review research progress on intervention in the circadian rhythm by traditional Chinese medicine and provide a reasonable and valuable basis for follow-up studies on the role of traditional Chinese medicine in research on the molecular mechanisms of regulation of circadian rhythm.

Macrophages play an important role in the pathogenesis of rheumatoid arthritis (RA). Previously, studies have shown that changes in the metabolism of glucose, choline, amino acids and lipids in macrophages of patients with RA can lead to the accumulation of metabolic intermediates which can act as inflammatory signaling molecules to aggravate the inflammation and cause complications. Therefore, a full understanding of the metabolic process of macrophages in RA patients will lay the foundation for macrophage-targeted therapy of RA. In this review, not only the role of macrophage abnormal metabolism in the pathogenesis of RA but also the research progress on macrophage-targeted drugs in RA treatment will be discussed.

G protein-coupled receptor 119 (GPR119) has been a promising target for the treatment of type 2 diabetes. It can not only directly promote insulin secretion, but also indirectly increase insulin secretion by stimulating the release of glucose-dependent GIP/CLP-1 without causing hypoglycemia. The remarkable advantages of small molecule GPR119 agonists make it one of the research hotspots for the development of type 2 diabetes drugs. This article reviews the anti-diabetic small molecules based on the GPR119 target in the past five years.

The research and development of monoclonal antibodies (mAbs) is a rapidly developing field. From the first generation of murine mAbs to the fourth generation of fully human mAbs, the efficacy and safety of mAbs in the treatment of various diseases have been continuously improved. In order to regulate the development and evaluation of mAbs, drug regulatory agencies and pharmacopeias of America and China have tried to issue feasible test procedures and acceptance criteria for quality evaluation of mAbs and biosimilars. Mass spectrometry (MS) technique with high sensitivity, resolution, selectivity, and specificity has become an important tool to evaluate the quality characteristics of monoclonal antibody-related products or specify mAb quality. The research of MS-based monoclonal antibody study involves structure characterization, impurity analysis, pharmacokinetics/pharmacodynamics (PK/PD), etc. This review focuses on the current quality control requirements of mAb related products and the development of MS technique for mAb quality characterization and specification. It is expected to provide information and references for evaluating the quality of monoclonal antibodies under research and development.

With the in-depth study of related substances and the development of consistency evaluation of generic drugs, relative correction factors are gaining increasing attention. By analyzing the domestic and foreign literature on correction factors in recent years, this paper describes the correction factor component, the current measurement method and its application. The rules and key points of use of an impurity correction factor and its determination and application are described, and some problems in its determination and application are discussed, providing a reference and basis for the standardization of research on impurity correction factors in the future.

3D printing technology has the advantages of accurate spatial distribution, accurate drug release and personalized drug dosage, which can make up for the shortcomings of traditional pharmaceutical technology. In recent years drop-on powder (DoP) 3D printing technology has been widely used in pharmaceutical preparation. Compared with other types of 3D printing technology, it is more simple, flexible and easy to operate. In 2015, Aprecia Pharmaceuticals announced that the US Food and Drug Administration (FDA) approves the launch of its first instant tablet Spritam^® (levetiracetam) made with DoP 3D printing. After the first 3D printed medicine was launched, people also saw the unique advantages and broad prospects of DoP 3D printing technology platform in pharmaceutical preparation. This review focuses on the technical principles and key factors of DoP 3D printing, its application in the preparation field and its future development challenges.

In recent years, non-viral gene vectors have attracted great attention for efficient gene delivery due to the advantages, including low toxicity, low immunogenicity and simple preparation. Polyethylenimine (PEI) is one of the typical non-viral gene carriers that have been widely utilized for gene delivery owing to its superior capabilities in gene compression and buffering capacity. This article discusses the processes of gene delivery and the barriers of PEI-based carrier during the gene delivery, such as low biocompatibility, cytotoxicity, lack of specific targeting and insufficient gene release, etc. Therefore, we summarize the multiple approaches for the modifications of PEI in terms of improved biocompatibility, degradability, specific targeting and buffering capacity. Furthermore, we also review on the recent impressive progresses of smart stimuli-responsive PEI carriers, including endogenous stimuli (pH, reactive oxygen species, glutathione, biomolecular, etc), exogenous stimuli (light, temperature, magnetic field, etc) and dual-responsive strategies, which might provide guidance for the development of more efficient and safer non-viral gene vectors.

The solubility/dissolution, hygroscopicity and mechanical properties of drug candidates have a profound effect on oral bioavailability, processability and stability. The physicochemical properties of crystalline drug are closely related to inner crystal structure. Crystal engineering technologies, as strategies of altering the crystal structure and tailoring physicochemical properties at molecular level, possess the potential of enhancing the pharmaceutical performance of product. The current article reviewed the modification of drug solubility/dissolution, hygroscopicity and mechanical properties by crystal engineering technologies through polymorphic selection, amorphization/co-amorphization, as well as co-crystallization, which provided a reference for the applications of pharmaceutical crystallography in improving physicochemical properties and druggability.

Salvia miltiorrhiza Bge. is one of the most important traditional Chinese medicinal plants and is used for a variety of diseases and disorders, including cardiovascular diseases, hepatocirrhosis, chronic renal failure, Alzheimer's disease, angina pectoris, myocardial ischemia, liver diseases, and diabetic nephropathy. In recent years, with the shortage of uncultivated resources and uneven product quality of cultivated germplasm, the biosynthesis and regulation of its main active ingredient has become a topic of interest. The use of a multi-omics approach with Salvia miltiorrhiza may provide genetic information as well as insights into the synthesis and regulation of the active ingredient at the molecular level. The paper presented a systematic review of the genomics, transcriptomics, proteomics and metabolomics associated with Salvia miltiorrhiza, summarized the advances in biosynthesis, regulation and related functional genes, and also put forward some scientific problems of Salvia miltiorrhiza that need to be further studied in the future.

To study the anti-tumor activities and the related mechanisms of dicumarol, the CCK-8 method was used to identify anti-tumor activities of dicumarol. HepG2 cells were used to explore the anti-tumor mechanisms by measuring several physiological and biochemical indexes. The results show that dicumarol can significantly inhibit the growth of HepG2, Hccc-9810 and MDA-MB-231 cell lines in a dose-dependent and time-dependent manner, with HepG2 cells showing the greatest sensitivity to dicumarol (with an IC₅₀ value of 3.19±0.68 µmol·L^-1 at 48 h). Dicumarol arrested the cell cycle at S phase and down-regulated the expression of anti-apoptotic protein Bcl-2 while promoting the expression of the pro-apoptotic proteins Bax and cleaved caspase-9. Dicumarol significantly decreased the levels of glutathione (GSH) and superoxide dismutase (SOD) in HepG2 cells, and increased the levels of malonaldehyde (MDA) and reactive oxygen species (ROS). Dicumarol also down-regulated the protein levels of NAD(P)H quinone oxidoreductase 1, 3-phosphoinositide-dependent protein kinase 1, and hypoxia inducible factor-1α under hypoxic conditions. The above results show that dicumarol can inhibit the proliferation of HepG2 cells and induce cycle arrest and apoptosis. Dicumarol may down-regulate the expression of HIF-1α by inhibiting the activity of NQO1 and PDK1, which leads to the accumulation of ROS, thereby generating oxidative stress and inducing apoptosis in HepG2 cells.

Zika virus (ZIKV) is an emerging mosquito-borne virus that is associated with severe congenital brain malformations in the fetus and Guillain-Barré syndrome in adults. However, there are currently no drugs or preventive vaccines approved for ZIKV infection. Here, ciclesonide has been found significantly against ZIKV activity by plaque and cytotoxicity assays in vitro, and its 50% effective concentration (EC₅₀) to ZIKV SZ01 and MR766 are (0.40±0.22) and (1.59±1.08) μmol·L^-1, respectively. Its 50% cytotoxic concentration (CC₅₀) to Vero cells are (64.70±7.33) μmol·L^-1; Virus yield reduction and Western blot assays showed that ciclesonide can inhibit replication of ZIKV. In addition, ciclesonide can also inhibit the replication of ZIKV in A549 cells; the results of time of drug addition analysis indicated that ciclesonide mainly acts on the ZIKV RNA synthesis stage. Ciclesonide can also inhibit the internalization of ZIKV. These results indicated that ciclesonide is a potential drug against ZIKV.

High expression of Bcl-2 is associated with the development of pancreatic cancer, and downregulation of Bcl-2 is an effective approach for the treatment of pancreatic malignancy. In the present study exosomes were isolated from the cultured medium of human embryonic kidney cells (HEK293) by ultracentrifugation and exosome-coated Bcl-2 siRNA (exosiBcl-2) was synthesized using electroporation. The results showed that the particle size of exosiBcl-2 was 67.3±9.7 nm and the morphology of exosomes displayed a concave ring structure as determined by transmission electron microscopy (TEM). Western blot analysis indicated that exosomal proteins including CD9, CD81, CD63 and TSG101 were highly expressed. Confocal microscopy revealed that exosiBcl-2 was widely distributed in Miapaca-2 cells, and the transfection efficiency of exosiBcl-2 in Miapaca-2 was 77.2% as determined by flow cytometry. Treatment with exosiBcl-2 at a concentration of 100 nmol·L^-1 resulted in an inhibitory effect on the growth of Miapaca-2 cells with an inhibition rate of 63%. ExosiBcl-2 treatment can downregulate Bcl-2 and upregulate Bax protein. This study provides evidence that exosiBcl-2 is able to inhibit the growth of pancreatic cancer cells and the nanoparticles have potential to be developed as a novel anticancer agent.

The goal of the present study was to determine the effectiveness and safety of hemoperfusion (HP) in beagle dogs with chronic kidney disease (CKD). The experimental protocol was approved by the Institutional Animal Care and Use Committee of Tianjin Institute of Pharmaceutical Research New Drug Evaluation Research (IACUC2019071501). Twelve CKD model beagles were randomly divided into two groups: a low-frequency treatment group (n=6) and a high-frequency treatment group (n=6). The dogs in the high- and low-frequency groups received HP treatment every 3 days and once per week, respectively, for two treatments, with each session lasting 2 h. The test results showed that high-frequency HP treatment significantly decreased the accumulation of toxins in the CKD beagles. Hematology, coagulation function, electrolytes and liver function indicated that the HP treatment was safe. The body index effects were consistent between the low- and high-frequency treatment groups. Therefore, HP treatment once every 3 days was safe at the animal level. Multiple HP treatments every 3 days were more conducive than weekly treatments to the removal of uremic toxins with better prognosis and had no associated safety hazards.

To identify the composition of iridoids from Hedyotis diffusa Willd and explore the mechanism on its anti-renal fibrosis effect based on network pharmacology, LC-Q/TOF-MS (liquid chromatograpy-quadrupole/time of flight mass spectrometry) was used to analyze the iridoid ingredients and the related targets of renal fibrosis were obtained by DisGeNET database and MalaCards database. The potential targets were screened by SYBYL-X7.3 software. We then imported the identified ingredients and potential target genes into Cytoscape3.7.1 to construct the compound-target network and the protein-protein interaction (PPI) network. Finally, the gene ontology (GO) functional enrichment analysis and KEGG pathway enrichment analysis of the selected core genes were made to explore the mechanism of iridoids against renal fibrosis. There were 10 active iridoid compounds and 111 corresponding targets including dimethylarginine dimethylaminohydrolase 1 (DDAH1), heparanase (HPSE), human kirsten rat sarcoma viral oncogene (KRAS), moesin (MSN), etc. in compound-target network. The GO functional enrichment analysis obtained 211 GO entries. Twenty related signal pathways including Toll-like receptor signaling pathway, transforming growth factor-beta (TGF-β) signaling pathway, renal cell carcinoma signaling pathway, and the Janus kinase/signal transducer and activator of tran-ions (Jak-STAT) signaling pathway were selected by KEGG enrichment analysis. We preliminarily investigated the mechanism of the iridoid compounds on renal fibrosis to provide guide information for the subsequent experimental research and clinical application.

We used the network pharmacology to explore the active ingredients and mechanism of action of Danqi tablets in the treatment of coronary heart disease, providing a theoretical basis for the treatment of clinical coronary heart disease. The TCMSP database was used to screen for active ingredients and targets in Danqi tablets; the predicted targets of coronary heart disease were screened through the GeneCards database; then, the intersection of the two targets was mapped; we used STRING database to construct a protein interaction network map and identified 65 cores targets; then, the DAVID database was used for enrichment analysis of gene ontology (GO) biological processes and KEGG signaling pathways, and finally the Cytoscape-3.6.2 software was used to construct a network diagram of traditional Chinese medicine-active ingredient-key targets-pathway. The H₂O₂-induced H9C2 cells injury model was used for experimental verification. The results suggest that Danqi tablets act on inflammatory factors and apoptosis-related pathways through quercetin, luteolin, tanshinone ⅡA, and other active ingredients, and improve proinflammatory or anti-inflammatory imbalances in the body and protect cardiomyocytes. This study confirms the multi-component and multi-target effects of Danqi tablets in the treatment of coronary heart disease, and provides an objective basis for their use in further experimental research and the clinical diagnosis and treatment of coronary heart disease.

The chemical constituents from ethyl acetate extract of Gleditsiae spina were isolated and purified by various chromatographic methods such as MCI gel CHP-20, ODS, Sephadex LH-20, silica gel and semi-preparative HPLC. Seven lignans were isolated and identified by spectroscopic data analyses as (7R, 8S, 7'E, 7''S, 8''R)-buddlenol P (1), (+)-syringaresinol (2), (+)-isolariciresinol (3), (7S, 8R)-cedrusin (4), (7S, 8R)-4, 9, 9'-trihydroxy-3, 3'-dimethoxy-7, 8-dihydrobenzofuran-1'-propylneolignan (5), 3', 4-O-dimethylcedrusin (6), balanophonin (7). Among them, compound 1 is a new lignan, compounds 2-7 are isolated from the Gleditsia L. for the first time. MTT method was used to investigate the effect of compounds 2-7 on LPS-induced injury of NRK-52e cells. As a result, compounds 2, 3 and 7 exhibit protective effects against LPS-induced damage to NRK-52e cells.

Four cadinane-type sesquiterpenes were obtained from the petroleum ether of 95% ethanol extract of Eupatorium adenophorum Spreng by using an HP-20 macroporous resin column, silica gel, and semi-preparative HPLC. Their structures were determined by physical, chemical and spectroscopic methods and identified as eupatorinol (1), (+)-(5R, 7S, 9R, 10S)-2-oxocadinan-3, 6(11)-dien-12, 7-olide (2), (1S, 4R)-7-hydroxycalamenen-3-one(3) and (-)-(5R, 6R, 7S, 9R, 10S)-cadinan-3-ene-6, 7-diol (4). Among them, compound 1 is a new cadinane-type sesquiterpene, and compound 3 was isolated from this genus for the first time. In bioassay, none of these compounds displayed obvious cytotoxicity.

The goal of this work was to establish a population pharmacokinetics (PPK) model of tacrolimus in idiopathic membranous nephropathy (IMN) patients and to identify potential covariates that influence pharmacokinetic of tacrolimus. A total of 610 data points on the blood concentration of tacrolimus were collected from 96 IMN patients in routine clinical settings. Nonlinear mixed-effect modeling (NONMEM) was used to investigate the effects of CYP3A5 genotype, age, gender, weight, laboratory tests and co-therapy medications on the pharmacokinetic of tacrolimus. The PPK model was evaluated by the goodness-of-fit (GOT), bootstrap and prediction corrected visual predictive check (pc-VPC). The pharmacokinetic of tacrolimus was described by a one-compartment model. The apparent clearance (CL/F) of CYP3A5*1/*3 and *1/*1 were 1.57 and 1.86 times of that of *3/*3, respectively. The CL/F of tacrolimus was 73.6% in patients undergoing co-therapy with Wuzhi capsules, and 1.2 times than that of the patients undergoing co-therapy with Jinshuibao capsules. The evaluation of the model shows that the model is stable and has satisfactory predictive performance. The clinical trial was approved by the Society of Ethics and conducted in Binzhou Medical University Hospital. The established PPK model can describe the pharmacokinetic characteristics of tacrolimus in Chinese patients with IMN, and can facilitate individualized therapy with tacrolimus.

Characterization of the polysaccharides and monosaccharides of Bupleurum chinense was undertaken to identify differences in the Bupleurum chinense's sugar profiles, so as to provide a basis for the identification of different varieties. High performance liquid chromatography (HPLC) was used to generate chromatograms of the total polysaccharides of Bupleurum using an Evaporation Light Detector (ELSD), and a monosaccharide chromatogram was generated using a UV-detector (UV) following polysaccharide derivatization. The data were analyzed using SIMCA software and SPSS software to distinguish different varieties of Bupleurum. The results show that the yield of polysaccharides from Bupleurum falcatum is the highest, while the yield of polysaccharides from Bupleurum chinense is the lowest. The polysaccharide spectrum shows that the molecular weights of the polysaccharides in different Bupleurum differ, and their percentages of the total peak area are also different. The four Bupleurum polysaccharides are composed of mannose, glucuronic acid, rhamnose, galacturonic acid, glucose, galactose, and arabinose, but differ in length. The ratio of glucose to arabinose in Bupleurum chinense, Bupleurum scorzonerifolium, Bupleurum falcatum and Bupleurum marginatum var. stenophyllum is: 3.0-4.0, 5.5-7.0, 12.0-17.0, 9.0-12.0. In this study, a sugar profile technique was developed to provide a new method for the identification of different varieties of Bupleurum.

This paper showed bioprinted HepG2 tumor tissues used for studying the sonodynamic anticancer activity of chlorine e6 (Ce6). HepG2 cells were printed by using alginate/gelatin/hydroxyethyl cellulose composite biomaterial as bio ink and cell viability was detected with Live-Dead assay and MTT proliferation. The ultrasonic intensities of self-built micro ultrasonic device under different powers were estimated by using the temperature change caused by the conversion of acoustic energy to heat energy. Ce6 of 14.3 and 28.6 μg·mL^-1 were acted on two-dimensional cultured and three-dimensional printed HepG2 cells, and the antitumor activity of Ce6 was detected by MTT method with ultrasound intensity of 0.15 W·cm² for 60 s. The results showed that the activities of bioprinted HepG2 cells were as high as 95%, and tumor microspheres were formed after 7 days of culture. The ultrasound intensity was lower than 3 W·cm², which belonged to low ultrasound intensity and had no damage to normal hepatocyte LO2 cells. By comparing the antitumor activity of Ce6 on 2D cultured and printed HepG2 cells, it was found that the anticancer activity of Ce6 on bioprinted HepG2 cells was 63.4% lower than that on 2D culture cells, indicating the acoustic drug resistance of three-dimensional tumor model. Bioprinted tumor tissues show the potential in the application of in vitro activity evaluation models for sonodynamic therapy.

To explore the mechanism hydroxysafflor yellow A (HSYA) biosynthesis and regulation, the effect of methyl jasmonate (MeJA) treatment on gene expression related to the biosynthesis of hydroxysafflor yellow A (HSYA) was analyzed, and expression differences in genes involved in HSYA biosynthesis in safflower of different colors was quantified. MeJA at concentrations of 0, 50, 100, and 200 μmol·L^-1 was sprayed onto safflower florets to determine the optimal concentration of MeJA. Safflower was treated with 100 μmol·L^-1 MeJA and florets were harvested 0, 3, 6, 12 and 24 h after treatment. The content of MeJA was determined by high performance liquid chromatography (HPLC). RNA was extracted from safflower florets treated with 100 μmol·L^-1 MeJA for 6 h. The transcription of key genes involved in the biosynthesis of HSYA was quantified by qRT-PCR and differentially expressed genes were identified. The content of HSYA increased after treatment with MeJA, with 100 μmol·L^-1 MeJA treatment for 6 h having the greatest effect on HSYA accumulation. qRT-PCR results showed that MeJA could significantly increase the transcription of HSYA biosynthesis genes including PAL2, PAL4, 4CL2, 4CL4, 4CL5, CHS3, CHS4 and CHI2. The content of HSYA differed between safflowers of different colors with a trend of red > orange-yellow > yellow > white. The results of qRT-PCR showed that the expression of CHS1 and CHI2 in red, orange and yellow safflower was significantly higher than that in white safflower. These results indicate that MeJA promotes the accumulation of HSYA by up-regulating the expression of genes involved in the biosynthesis of HSYA such as PAL2, PAL4, 4CL2, 4CL4, 4CL5, CHS3, CHS4 and CHI2, and the variation of HSYA content in safflower of different colors was related to a difference in the level of expression of CHS1 and CHI2.

The major challenge in the development of recombinant biologics lies in generating and isolating rare high-producing stable single clone in a short period of time. The selection marker is an essential component of the plasmid vector, it plays an important part in the generation and screening of producing cell lines. Engineering the selection marker to enhance the stringency of selection for high producing cells is one of the most effective approaches to improve the cell line development process. Here, using Chinese hamaster overy (CHO) cells as an example, we introduce the application of selection marker for generation of recombinant biologics producing mammalian cell lines, methods of engineering the selection markers to enhance the selection stringency, and propose considerations on cell substrate stability and selection marker safety, in order to provide references for high-efficiency development of recombinant biologics.