Identification and characterization of a new species of Taxus - Taxus qinlingensis by multiple taxonomic methods.

BACKGROUND: The taxonomy of Taxus Linn. remains controversial due to its continuous phenotypic variation and unstable topology, thus adversely affecting the formulation of scientific conservation strategies for this genus. Recently, a new ecotype, known as Qinling type, is mainly distributed in the Qinling Mountains and belongs to a monophyletic group. Here, we employed multiple methods including leaf phenotype comparison (leaf shapes and microstructure), DNA barcoding identification (ITS + trnL-trnF + rbcL), and niche analysis to ascertain the taxonomic status of the Qinling type. RESULTS: Multiple comparisons revealed significant differences in the morphological characters (length, width, and length/width ratio) among the Qinling type and other Taxus species. Leaf anatomical analysis indicated that only the Qinling type and T. cuspidata had no papilla under the midvein or tannins in the epicuticle. Phylogenetic analysis of Taxus indicated that the Qinling type belonged to a monophyletic group. Moreover, the Qinling type had formed a relatively independent niche, it was mainly distributed around the Qinling Mountains, Ta-pa Mountains, and Taihang Mountains, situated at an elevation below 1500 m. CONCLUSIONS: Four characters, namely leaf curvature, margin taper, papillation on midvein, and edges were put forward as primary indexes for distinguishing Taxus species. The ecotype Qingling type represented an independent evolutionary lineage and formed a unique ecological niche. Therefore, we suggested that the Qingling type should be treated as a novel species and named it Taxus qinlingensis Y. F. Wen & X. T. Wu, sp. nov.

HPLC/ESI-QTOF-MS/MS based untargeted metabolomics authentication of Taxus × media six tissues.

INTRODUCTION: Taxus media (Taxus × media Rehder) is renowned for its high paclitaxel content, serving as a major source for industrial paclitaxel production. In addition to paclitaxel, T. media contains a diverse range of metabolites, including flavonoids, alkaloids, and terpenoids, which have been shown to possess antioxidant, antibacterial, anti-inflammatory, and immunomodulatory effects. However, these compounds have not been thoroughly studied as key metabolites in T. media. OBJECTIVE: The untargeted metabolomics analysis of six T. media tissues provides new insights into the development and utilization of T. media metabolites. METHOD: The extracts from six tissues of T. media were analyzed and subjected to analysis using high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS/MS) and chemometric techniques. RESULTS: Using a reliable HPLC-Q-TOF-MS/MS method, we identified 312 compounds in six T. media tissues, including 214 previously unreported in T. media. To identify characteristic compounds across different tissues, 34 metabolites were further screened. KEGG metabolic pathway analysis revealed that these compounds primarily occur in the metabolic pathways of terpene glycosides, flavans, and O-methylated flavonoids. CONCLUSION: This study initially utilized an HPLC-QTOF-MS/MS-based metabolomics approach to assess the metabolites in different tissues of T. media, providing a basis for their utilization and management.

Draft genome of carotenoid-producing endophytic Pseudomonas sp. 102515 from Taxus chinensis.

Here, we report the draft genome sequence of endophytic Pseudomonas sp. 102515 isolated from Taxus chinensis collected from Logan, UT, USA. The genome is composed of 36 contigs and around 4.9 Mbp in size. The GC content is 66% with an N50 length of 918.9 kbp and L50 count of 2.

Effects of Different Doses of sUV-B Exposure on Taxane Compounds' Metabolism in Taxus wallichiana var. Mairei.

UV-B is an important environmental factor that differentially affects plant growth and secondary metabolites. The effects of supplemental ultraviolet-B (sUV-B) exposure (T1, 1.40 kJ·m-2·day-1; T2, 2.81 kJ·m-2·day-1; and T3, 5.62 kJ·m-2·day-1) on the growth biomass, physiological characteristics, and secondary metabolites were studied. Our results indicated that leaf thickness was significantly (p < 0.05) reduced under T3 relative to the control (natural light exposure, CK); The contents of 6-BA and IAA were significantly reduced (p < 0.05); and the contents of ABA, 10-deacetylbaccatin III, and baccatin III were significantly (p < 0.05) increased under T1 and T2. The paclitaxel content was the highest (0.036 ± 0.0018 mg·g-1) under T3. The cephalomannine content was significantly increased under T1. Hmgr gene expression was upregulated under T1 and T3. The gene expressions of Bapt and Dbtnbt were significantly (p < 0.05) upregulated under sUV-B exposure, and the gene expressions of CoA, Ts, and Dbat were significantly (p < 0.05) downregulated. A correlation analysis showed that the 6-BA content had a significantly (p < 0.05) positive correlation with Dbat gene expression. The IAA content had a significantly (p < 0.05) positive correlation with the gene expression of Hmgr, CoA, Ts, and Dbtnbt. The ABA content had a significantly (p < 0.05) positive correlation with Bapt gene expression. Dbat gene expression had a significantly (p < 0.05) positive correlation with the 10-deacetylbaccatin content. Hmgr gene expression was positively correlated with the contents of baccatin III and cephalomannine. Bapt gene expression had a significantly (p < 0.01) positive correlation with the paclitaxel content. A factor analysis showed that the accumulation of paclitaxel content was promoted under T2, which was helpful in clarifying the accumulation of taxane compounds after sUV-B exposure.

An Integrated Strategy Based on 10-DAB Extraction and In Situ Whole-Cell Biotransformation of Renewable Taxus Needles to Produce Baccatin III.

Baccatin III is a crucial precursor in the biosynthesis pathway of paclitaxel. Its main sources are extraction from Taxus or chemical synthesis using 10-deacetylbaccatin III (10-DAB) as substrate. However, these preparation approaches exhibit serious limitations, including the low content of baccatin III in Taxus and the complicated steps of chemical synthesis. Heterologous expression of 10-deacetylbaccatin III-10-O-acetyltransferase (TcDBAT) in microbial strains for biotransformation of 10-DAB is a promising alternative strategy for baccatin III production. Here, the promotion effects of glycerol supply and slightly acidic conditions with a low-temperature on the catalysis of recombinant TcDBAT strain were clarified using 10-DAB as substrate. Taxus needles is renewable and the content of 10-DAB is relatively high, it can be used as an effective source of the catalytic substrate 10-DAB. Baccatin III was synthesized by integrating the extraction of 10-DAB from renewable Taxus needles and in situ whole-cell catalysis in this study. 40 g/L needles were converted into 20.66 mg/L baccatin III by optimizing and establishing a whole-cell catalytic bioprocess. The method used in this study can shorten the production process of Taxus extraction for baccatin III synthesis and provide a reliable strategy for the efficient production of baccatin III by recombinant strains and the improvement of resource utilization rate of Taxus needles.

Research on the Medicinal Chemistry and Pharmacology of Taxus × media.

Taxus × media, belonging to the genus Taxus of the Taxaceae family, is a unique hybrid plant derived from a natural crossbreeding between Taxus cuspidata and Taxus baccata. This distinctive hybrid variety inherits the superior traits of its parental species, exhibiting significant biological and medicinal values. This paper comprehensively analyzes Taxus × media from multiple dimensions, including its cultivation overview, chemical composition, and multifaceted applications in the medical field. In terms of chemical constituents, this study delves into the bioactive components abundant in Taxus × media and their pharmacological activities, highlighting the importance and value of these components, including paclitaxel, as the lead compounds in traditional medicine and modern drug development. Regarding its medicinal value, the article primarily discusses the potential applications of Taxus × media in combating tumors, antibacterial, anti-inflammatory, and antioxidant activities, and treating diabetes. By synthesizing clinical research and experimental data, the paper elucidates the potential and mechanisms of its primary active components in preventing and treating these diseases. In conclusion, Taxus × media demonstrates its unique value in biological research and tremendous potential in drug development.

Functionalized nano cellulose double-template imprinted aerogel microsphere for the targeted enrichment of taxanes.

Paclitaxel, a diterpenoid isolated from the bark of Taxus wallichiana var. chinensis (Pilger) Florin, is currently showing significant therapeutic effects against a variety of cancers. Baccatin III (Bac) and 10-Deacetylbaccatin III (10-DAB) are in great demand as important precursors for the synthesis of paclitaxel. This work aims to develop a simple, rapid and highly selective, safe, and non-polluting molecularly imprinted material for 10-DAB and Bac enrichment. In this study, we innovatively prepared molecularly imprinted materials with nanocellulose aerogel microspheres and 2-vinylpyridine (2-VP) as a bifunctional monomer, and 10-DAB and Bac as bis-template molecules. In particular, functionalized nanocellulose dual-template molecularly imprinted aerogel microsphere (FNCAG-DMIM) were successfully synthesized by the bifunctional introduction of functional nanocellulose aerogel microsphere (FNCAG) modified with Polyethyleneimine (PEI) as a carrier and functional monomer, which provided a large number of recognition sites for bimodal molecules. FNCAG-DMIM showed high specificity for 10-DAB and Bac specific assays. Under the optimal experimental conditions, the adsorption capacities of FNCAG-DMIM for 10-DAB and Bac reached 52.27 mg g-1 and 53.81 mg g-1, respectively. In addition, it showed good reliability and practicality in the determination of real samples. The present study extends the research on the synthesis of natural functional monomers by molecularly imprinted materials and opens up new horizons for the targeted isolation of plant compounds by dual-template molecularly imprinted materials.

Altitudinal Impact on Phytochemical Composition and Mycorrhizal Diversity of Taxus Contorta Griff in the Temperate Forest of Shimla District.

Taxus contorta (family Taxaceae) is a native plant of temperate region of western Himalaya. The current study investigated the effect of altitude on the phytochemical composition and mycorrhizal diversity, associated with distribution of T. contorta in Shimla district, Himachal Pradesh, India. Quantitative phytochemical analysis of the leaf extracts indicated that alkaloid levels decreased with altitude, with the highest value in Himri's methanol extracts (72.79 ± 1.08 mg/g) while phenol content increased with altitude, peaking in Nankhari's methanol extracts (118.83 ± 5.90 mg/g). Saponin content was higher in methanol extracts (78.13 ± 1.66 mg/g in Nankhari, 68.06 ± 1.92 mg/g in Pabbas, and 56.32 ± 1.93 mg/g in Himri). Flavonoid levels were notably higher in chloroform extracts, particularly in Nankhari (219.97 ± 2.99 mg/g), and positively correlated with altitude. Terpenoids were higher in chloroform extracts at Himri (11.34 ± 0.10 mg/g) and decreased with altitude. Taxol content showed minimal variation between solvents and altitudes (4.53-6.98 ppm), while rutin was only detected in methanol extracts (1.31-1.46 ppm). Mycorrhizal spore counts in T. contorta's rhizosphere varied with altitude: highest at Himri (77.83 ± 2.20 spores/50 g soil), decreasing to Pabbas (68.06 ± 1.96 spores/50 g soil) and lowest at Nankhari (66.00 ± 2.77 spores/50 g soil), with 17 AMF species identified overall, showing significant altitudinal influence on spore density. The rhizosphere of T. contorta was shown to be dominated by the Glomus species. The rhizospheric soil of the plant was found to be slightly acidic. Organic carbon and available potassium content decreased contrasting with increasing available nitrogen and phosphorus with altitude. Correlation data showed strong negative links between organic carbon (-0.83), moderate positive for nitrogen (0.46) and phosphorus (0.414), and moderate negative for potassium (-0.56) with the altitude. This study provides a comprehensive insight into changes in phytochemical constituents, mycorrhizal diversity and soil composition of T. contorta along a range of altitude.

[Advances in paclitaxel biosynthesis and transcriptional regulation mechanisms].

Paclitaxel, a rare diterpene extracted from the bark of Chinese yew (Taxus chinensis), is renowned for its anti-cancer activity and serves as a primary drug for treating cancers. Due to the exceptionally low content of paclitaxel in the bark, a semi-synthetic method that depletes Chinese yew resources is used in the production of paclitaxel, which, however, fails to meet the escalating clinical demand. In recent years, researchers have achieved significant progress in heterologous biosynthesis and metabolic engineering for the production of paclitaxel. This article comprehensively reviews the advancements in paclitaxel production, encompassing chemical synthesis, heterologous biosynthesis, and cell engineering. It provides an in-depth introduction to the biosynthetic pathway and transcriptional regulation mechanisms of paclitaxel, aiming to provide a valuable reference for further research on paclitaxel biosynthesis.

A leading-edge scenario in the phylogeography and evolutionary history of East Asian insular Taxus in Taiwan and the Philippines.

The cool temperate origin of gymnosperm Taxus species in East Asia is specifically diverse and widespread. Certain lineages have managed to extend their distribution further south to subtropical and tropical islands such as Taiwan and the Philippines. To address questions including whether these insular lineages, recently identified as T. phytonii, have become genetically distinct from each other and from their continental relatives, and when and how they colonized their residing islands, we sampled over 11 populations, covering 179 Taxus individuals from Taiwan and the Philippines. Using four cpDNA and one nuclear marker, we showed in population genetic and genealogical analyses that the two insular lineages were genetically distinct from each other and also from other continental Taxus and that they represented each other's closest relative. Estimated with the coalescent-based multi-type tree (MTT) analyses, we inferred an origin of Taiwanese T. phytonii more ancient than 2.49 Mya and that of Philippine T. phytonii more ancient than 1.08 Mya. In addition, the divergence demographic history revealed by both MTT and isolation with migration (IM) analyses indicated the presence of recent post-split migrations from a continental taxon, T. mairei, to Taiwanese T. phytonii, as well as from Taiwanese T. phytonii to Philippine T. phytonii. Overall, this study suggests Taiwan as a stepping stone through which the temperate-origin yew trees can extend their distributions to tropical regions such as the Philippines.

Regulatory microRNAs and phasiRNAs of paclitaxel biosynthesis in Taxus chinensis.

Paclitaxel (trade name Taxol) is a rare diterpenoid with anticancer activity isolated from Taxus. At present, paclitaxel is mainly produced by the semi-synthetic method using extract of Taxus tissues as raw materials. The studies of regulatory mechanisms in paclitaxel biosynthesis would promote the production of paclitaxel through tissue/cell culture approaches. Here, we systematically identified 990 transcription factors (TFs), 460 microRNAs (miRNAs), and 160 phased small interfering RNAs (phasiRNAs) in Taxus chinensis to explore their interactions and potential roles in regulation of paclitaxel synthesis. The expression levels of enzyme genes in cone and root were higher than those in leaf and bark. Nearly all enzyme genes in the paclitaxel synthesis pathway were significantly up-regulated after jasmonate treatment, except for GGPPS and CoA Ligase. The expression level of enzyme genes located in the latter steps of the synthesis pathway was significantly higher in female barks than in male. Regulatory TFs were inferred through co-expression network analysis, resulting in the identification of TFs from diverse families including MYB and AP2. Genes with ADP binding and copper ion binding functions were overrepresented in targets of miRNA genes. The miRNA targets were mainly enriched with genes in plant hormone signal transduction, mRNA surveillance pathway, cell cycle and DNA replication. Genes in oxidoreductase activity, protein-disulfide reductase activity were enriched in targets of phasiRNAs. Regulatory networks were further constructed including components of enzyme genes, TFs, miRNAs, and phasiRNAs. The hierarchical regulation of paclitaxel production by miRNAs and phasiRNAs indicates a robust regulation at post-transcriptional level. Our study on transcriptional and posttranscriptional regulation of paclitaxel synthesis provides clues for enhancing paclitaxel production using synthetic biology technology.

Gapless biosynthetic pathway enables sustainable paclitaxel production.

A recent leading-edge study by Jiang et al. identified two enzymes that are responsible for key reactions in the biosynthesis of baccatin III. The authors successfully reconstructed the baccatin III synthesis pathway with a minimal number of synthetic enzymes in tobacco leaves, laying the foundation for industrial-scale sustainable production of the anticancer drug paclitaxel.

Research Progress on Taxus Extraction and Formulation Preparation Technologies.

Taxus, as a globally prevalent evergreen tree, contains a wealth of bioactive components that play a crucial role in the pharmaceutical field. Taxus extracts, defined as a collection of one or more bioactive compounds extracted from the genus Taxus spp., have become a significant focus of modern cancer treatment research. This review article aims to delve into the scientific background of Taxus extracts and their considerable value in pharmaceutical research. It meticulously sifts through and compares various advanced extraction techniques such as supercritical extraction, ultrasound extraction, microwave-assisted extraction, solid-phase extraction, high-pressure pulsed electric field extraction, and enzymatic extraction, assessing each technology's advantages and limitations across dimensions such as extraction efficiency, extraction purity, economic cost, operational time, and environmental impact, with comprehensive analysis results presented in table form. In the area of drug formulation design, this paper systematically discusses the development strategies for solid, liquid, and semi-solid dosage forms based on the unique physicochemical properties of Taxus extracts, their intended medical uses, and specific release characteristics, delving deeply into the selection of excipients and the critical technical issues in the drug preparation process. Moreover, the article looks forward to the potential directions of Taxus extracts in future research and medical applications, emphasizing the urgency and importance of continuously optimizing extraction methods and formulation design to enhance treatment efficacy, reduce production costs, and decrease environmental burdens. It provides a comprehensive set of preparation techniques and formulation optimization schemes for researchers in cancer treatment and other medical fields, promoting the application and development of Taxus extracts in pharmaceutical sciences.

Metabolites isolated from Penicillium HDS-Z-1E, an endophytic fungal strain isolated from Taxus cuspidata and their activation effect of catalase.

Objective: To study the compounds isolated from Penicillium HDS-Z-1E, an endophytic fungal strain isolated from Taxus cuspidata and their activation effect of catalase (CAT). Methods: The chemical constituents were isolated from Penicillium HDS-Z-1E, by using silica gel, Sephadex LH-20 and HPLC. The structural elucidations of five metabolites were elucidated on the basis of spectroscopic including 1H-NMR, 13C-NMR, HMBC and HSQC. Their activation sites of catalase have been investigated by molecular docking. Results: Five metabolites, compounds (1-5) were isolated from Penicillium HDS-Z-1E and identified as 4-hydroxy-4-methyltetrahydro-2H-pyran-2-one (1), 4-hydroxymethyl-5, 6-dihydro-pyran-2-one (2), 5, 6-dihydro-2-oxo-2H-pyran-4-carboxylic (3), N-acetyl-hydrazinobenzoic acid (4), and methyl 2-(2, 5-dihydroxyphenyl) acetate (5). Conclusion: Compound 3 is a new compound. Compounds 3 and 4 may have potential activators of catalase, providing a theoretical basis for the development of CAT activators.

Metabolomics analysis of different diameter classes of Taxus chinensis reveals that the resource allocation is related to carbon and nitrogen metabolism.

Taxus chinensis (Taxus cuspidata Sieb. et Zucc.) is a traditional medicinal plant known for its anticancer substance paclitaxel, and its growth age is also an important factor affecting its medicinal value. However, how age affects the physiological and metabolic characteristics and active substances of T. chinensis is still unclear. In this study, carbon and nitrogen accumulation, contents of active substances and changes in primary metabolites in barks and annual leaves of T. chinensis of different diameter classes were investigated by using diameter classes instead of age. The results showed that leaves and barks of small diameter class (D1) had higher content of non-structural carbohydrates and C, which were effective in enhancing defense capacity, while N content was higher in medium (D2) and large diameter classes (D3). Active substances such as paclitaxel, baccatin III and cephalomannine also accumulated significantly in barks of large diameter classes. Moreover, 21 and 25 differential metabolites were identified in leaves and barks of different diameter classes, respectively. The differential metabolites were enhanced the TCA cycle and amino acid biosynthesis, accumulate metabolites such as organic acids, and promote the synthesis and accumulation of active substances such as paclitaxel in the medium and large diameter classes. These results revealed the carbon and nitrogen allocation mechanism of different diameter classes of T. chinensis, and its relationship with medicinal components, providing a guidance for the harvesting and utilization of wild T. chinensis.

Recent advances in paclitaxel biosynthesis and regulation.

Paclitaxel (PTX) is a high value plant natural product (PNP) derived from Taxus (yew) species. This plant secondary metabolite (PSM) and its derivatives constitute a cornerstone for the treatment of an increasing variety of cancers. New applications for PTX also continue to emerge, further promoting demand for this WHO designated essential medicine. Here we review recent advances in our understanding of PTX biosynthesis and its cognate regulation, which have been enabled by the development of transcriptomic approaches and the recent sequencing and annotation of three Taxus genomes. Collectively, this has resulted in the elucidation of two functional gene sets for PTX biosynthesis, unlocking new potential for the use of heterologous hosts to produce PTX. Knowledge of the PTX pathway also provides a valuable resource for understanding the regulation of this key PSM. Epigenetic regulation of PSM in plant cell culture (PCC) is a major concern for PTX production, given the loss of PSM production in long-term cell cultures. Recent developments aim to design tools for manipulating epigenetic regulation, potentially providing a means to reverse the silencing of PSM caused by DNA methylation. Exciting times clearly lie ahead for our understanding of this key PSM and improving its production potential.

Mycorrhizal symbiosis in Taxus: a review.

Taxus, a genus of conifers known for its medicinal significance, faces various conservation challenges with several species classified under different threat categories by the IUCN. The overharvesting of bark and leaves for the well-known chemotherapy drug paclitaxel has resulted in its population decline. Exploring the mycorrhizal relationship in Taxus is of utmost importance, as mycorrhizal fungi play pivotal roles in nutrition, growth, and ecological resilience. Taxus predominantly associates with arbuscular mycorrhizal fungi (AM), and reports suggest ectomycorrhizal (EM) or dual mycorrhizal associations as well. This review consolidates existing literature on mycorrhizal associations in Taxus species, focusing on structural, physiological, and molecular aspects. AM associations are well-documented in Taxus, influencing plant physiology and propagation. Conversely, EM associations remain relatively understudied, with limited evidence suggesting their occurrence. The review highlights the importance of further research to elucidate dual mycorrhizal associations in Taxus, emphasizing the need for detailed structural and physiological examinations to understand their impact on growth and survival.

Genome-Wide Identification and Expression Pattern Analysis of BAHD Acyltransferase Family in Taxus mairei.

BAHD acyltransferases are involved in catalyzing and regulating the secondary metabolism in plants. Despite this, the members of BAHD family and their functions have not been reported in the Taxus species. In this study, a total of 123 TwBAHD acyltransferases from Taxus wallichiana var. mairei genome were identified and divided into six clades based on phylogenetic analysis, of which Clade VI contained a Taxus-specific branch of 52 members potentially involved in taxol biosynthesis. Most TwBAHDs from the same clade shared similar conserved motifs and gene structures. Besides the typical conserved motifs within the BAHD family, the YPLAGR motif was also conserved in multiple clades of T. mairei. Moreover, only one pair of tandem duplicate genes was found on chromosome 1, with a Ka/Ks ratio < 1, indicating that the function of duplicate genes did not differentiate significantly. RNA-seq analysis revealed different expression patterns of TwBAHDs in MeJA induction and tissue-specific expression experiments. Several TwBAHD genes in the Taxus-specific branch were highly expressed in different tissues of T. mairei, suggesting an important role in the taxol pathway. This study provides comprehensive information for the TwBAHD gene family and sets up a basis for its potential functions.

Transcriptome and comparative chloroplast genome analysis of Taxus yunnanensis individuals with high and low paclitaxel yield.

Paclitaxel is a potent anti-cancer drug that is mainly produced through semi-synthesis, which still requires plant materials as precursors. The content of paclitaxel and 10-deacetyl baccatin III (10-DAB) in Taxus yunnanensis has been found to differ from that of other Taxus species, but there is little research on the mechanism underlying the variation in paclitaxel content in T. yunnanensis of different provenances. In this experiment, the contents of taxoids and precursors in twigs between a high paclitaxel-yielding individual (TG) and a low paclitaxel-yielding individual (TD) of T. yunnanensis were compared, and comparative analyses of transcriptomes as well as chloroplast genomes were performed. High-performance liquid chromatography (HPLC) detection showed that 10-DAB and baccatin III contents in TG were 18 and 47 times those in TD, respectively. Transcriptomic analysis results indicated that genes encoding key enzymes in the paclitaxel biosynthesis pathway, such as taxane 10-ß-hydroxylase (T10ßH), 10-deacetylbaccatin III 10-O-acetyltransferase (DBAT), and debenzoyl paclitaxel N-benzoyl transferase (DBTNBT), exhibited higher expression levels in TG. Additionally, qRT-PCR showed that the relative expression level of T10ßH and DBAT in TG were 29 and 13 times those in TD, respectively. In addition, six putative transcription factors were identified that may be involved in paclitaxel biosynthesis from transcriptome data. Comparative analysis of plastid genomes showed that the TD chloroplast contained a duplicate of rps12, leading to a longer plastid genome length in TD relative to TG. Fifteen mutation hotspot regions were identified between the two plastid genomes that can serve as candidate DNA barcodes for identifying high-paclitaxel-yield individuals. This experiment provides insight into the difference in paclitaxel accumulation among different provenances of T. yunnanensis individuals.

Compound Taxus exerts marked anti-tumor activity and radiosensitization effect on hepatocellular carcinoma cells.

Background: Compound Taxus capsule, as an antineoplastic Chinese patent drug, has been increasingly applied as an adjunctive treatment for the management of non-small-cell lung cancer (NSCLC) and some other malignancies, but research about its antitumor activity and radiosensitization effect on hepatocellular carcinoma (HCC) cells is very rare. Purpose: To investigate the antitumor activity and radiosensitization effect of Compound Taxus on HCC cells and to preliminarily explore the possible molecule mechanisms involved. Methods: Cell viability, cell cycle distribution, apoptosis, DNA damage repair and protein expression levels were detected by CCK-8 assay, flow cytometry, immunofluorescence staining, western blotting analysis and immunohistochemical staining, respectively. The migration and invasion activities and vasculogenic mimicry (VM) formation and angiogenesis were evaluated by tube formation and VM formation assay. Radiation survival curves were obtained from the colony formation assay in human HCC cell lines, Smmc7721 and Bel7402 cells, pretreated with or without Compound Taxus before receiving X-ray irradiation. A Bel7402 tumor-bearing mouse model was established and the radiosensitization effect of Compound Taxus in vivo was evaluated by analyzing tumor volume and tumor weight in different groups receiving different treatments. Results: Compound Taxus decreased viability, induced G2/M arrest, promoted apoptosis, suppressed migration and invasion, and inhibited VM formation and angiogenesis in Smmc7721 and Bel7402 cells. Furthermore, Compound Taxus inhibited irradiation-induced DNA damage repair, enhanced the radiosensitivity of Smmc7721 and Bel7402 cells and improved the anti-tumor therapeutic efficacy of irradiation in Bel7402 tumor-bearing mice. Radiotherapy in combination with Compound Taxus showed the best tumor inhibition compared to that of Compound Taxus alone or irradiation alone. In addition, Compound Taxus significantly down-regulated NF-κB p65, p-NF-κB p65 and Bcl-2, and up-regulated Bax in vitro and in vivo, yet NF-κB p65 overexpression reversed the proapoptotic effect of Taxus on HCC cells, indicating that the NF-κB signaling pathway might be an important signal mediator in the Compound-Taxus-modulated biological responses. Conclusion: Our findings suggest that Compound Taxus shows marked antitumor activity and significant radiosensitization effect on HCC cells, making it possible for Compound Taxus to become a promising auxiliary modality for HCC management and a potential radiosensitizer of HCC in the future.