Rapid separation of four main taxoids inTaxus species by a combined LLP-SPE-HPLC (PAD) procedure

Linum corymbulosum Protects Rats against CCl4-Induced Hepatic Injuries through Modulation of an Unfolded Protein Response Pathway and Pro-Inflammatory Intermediates

Liver fibrosis is a major pathological feature of chronic liver disease and effective therapies are limited at present. The present study focuses on the hepatoprotective potential of L. corymbulosum against carbon tetrachloride (CCl4)-induced liver damage in rats. Analysis of Linum corymbulosum methanol extract (LCM) using high-performance liquid chromatography (HPLC) revealed the presence of rutin, apigenin, catechin, caffeic acid and myricetin. CCl4 administration lowered (p < 0.01) the activities of antioxidant enzymes and reduced glutathione (GSH) content as well as soluble proteins, whereas the concentration of H2O2, nitrite and thiobarbituric acid reactive substances was higher in hepatic samples. In serum, the level of hepatic markers and total bilirubin was elevated followed by CCl4 administration. The expression of glucose-regulated protein (GRP78), x-box binding protein-1 total (XBP-1 t), x-box binding protein-1 spliced (XBP-1 s), x-box binding protein-1 unspliced (XBP-1 u) and glutamate-cysteine ligase catalytic subunit (GCLC) was enhanced in CCl4-administered rats. Similarly, the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemo attractant protein-1 (MCP-1) was strongly increased with CCl4 administration to rats. Co-administration of LCM along with CCl4 to rats lowered (p < 0.05) the expression of the above genes. Histopathology of the liver showed hepatocyte injury, leukocyte infiltration and damaged central lobules in CCl4-treated rats. However, LCM administration to CCl4-intoxicated rats restored the altered parameters towards the levels of control rats. These outcomes indicate the existence of antioxidant and anti-inflammatory constituents in the methanol extract of L. corymbulosum.

A simple and efficient sample preparation for taxanes in Taxus chinensis needles with natural menthol-based aqueous deep eutectic solvent

Taxanes are natural anticancer constituents, and the sample preparation from matrix normally depends on organochlorine solvents. In this study, green and natural menthol-based aqueous deep eutectic solvent was synthesized and used for sample preparation for taxanes. Five key parameters were optimized and the optimal preparation conditions were as follows: menthol/1-propanol ratio 1:1 (mol/mol), solid-liquid ratio 1:30 g/mL, extraction time 30 min, ultrasonic power 250 W, and water content 80%. Under the above conditions, the total extraction efficiency of seven main taxanes was 1.25- to 1.44-fold to the conventional methods. In addition, a high-performance liquid chromatography method with C₁₈ column was established for quantitation of seven main taxanes in <25 min, which had excellent linearity (R²  > 0.9986), precision (relative standard deviation < 3.00%), repeatability (relative standard deviation < 3.69%), and recovery (90.26-109.00%). This method performed the extraction, and enrichment processes simultaneously, and it had advantages such as high extraction efficiency, simple operation, low cost, and eco-friendliness. This work indicated that the natural menthol-based deep eutectic solvent aqueous could be an excellent alternative to the sample preparation from Taxus or other plants.

Comparative metabolomic analysis reveals the variations in taxoids and flavonoids among three Taxus species

BACKGROUND

Trees of the genus Taxus are highly valuable medicinal plants with multiple pharmacological effects on various cancer treatments. Paclitaxel from Taxus trees is an efficient and widely used anticancer drug, however, the accumulation of taxoids and other active ingredients can vary greatly among Taxus species. In our study, the metabolomes of three Taxus species have been investigated.

RESULTS

A total of 2246 metabolites assigned to various primary and secondary metabolic pathways were identified using an untargeted approach. Analysis of differentially accumulated metabolites identified 358 T. media-, 220 T. cuspidata-, and 169 T. mairei-specific accumulated metabolites, respectively. By searching the metabolite pool, 7 MEP pathway precursors, 11 intermediates, side chain products and derivatives of paclitaxel, and paclitaxel itself were detected. Most precursors, initiated intermediates were highly accumulated in T. mairei, and most intermediate products approaching the end point of taxol biosynthesis pathway were primarily accumulated in T. cuspidata and T. media. Our data suggested that there were higher-efficiency pathways to paclitaxel in T. cuspidata and T. media compared with in T. mairei. As an important class of active ingredients in Taxus trees, a majority of flavonoids were predominantly accumulated in T. mairei rather than T. media and T. cuspidata. The variations in several selected taxoids and flavonoids were confirmed using a targeted approach.

CONCLUSIONS

Systematic correlativity analysis identifies a number of metabolites associated with paclitaxel biosynthesis, suggesting a potential negative correlation between flavonoid metabolism and taxoid accumulation. Investigation of the variations in taxoids and other active ingredients will provide us with a deeper understanding of the interspecific differential accumulation of taxoids and an opportunity to accelerate the highest-yielding species breeding and resource utilization.

Comparative Transcriptome Analysis Revealed the Tissue-Specific Accumulations of Taxanes among Three Experimental Lines of Taxus yunnanensis

Taxus yunnanensis (Yew) is known for natural anticancer metabolite paclitaxel (Taxol) and its biosynthesis pathway in yew species still needs to be completely elucidated. In the current study, productions of paclitaxel and 10-DAB III from three different tissues (needle, branch, and root) of T. yunnanensis wild type (WT) and two new cultivars Zhongda-1 (Zd1) and Zhongda-2 (Zd2) were determined, and significant tissue differences in contents of the taxanes were observed among the three experimental lines. The much higher 10-DAB III and lower paclitaxel contents in needle of Zd2 when compared with that of Zd1 indicated the low conversion from 10-DAB III to paclitaxel in the needle of Zd2. In order to uncover the mechanisms of the tissue-specific biosynthesis of the taxanes, transcriptome analysis of cultivar Zd2 was conducted, and the previously reported transcriptome data of Zd1 and WT were used to perform a comparison. The enhancement of TDAT and T10βH side biosynthetic pathway in roots of Zd2 in early taxane synthesis might lead to the biosynthesis of other toxoids, while the preference of T13αH route in the needle and branch of Zd2 was mainly responsible for the tissue-specific reinforced biosynthesis of 10-DAB III and paclitaxel in Zd2. Different from Zd1, the tissue-specific pattern of paclitaxel biosynthesis genes in Zd2 was similar to WT. However, the lower transcript abundance of final steps genes (TBT, DBAT, BAPT, and DBTNBT) of the paclitaxel biosynthesis pathway in Zd2 than in Zd1 might further promote 10-DAB III accumulation in Zd2.

Taxus ingredients in the red arils of Taxus baccata L. determined by HPLC-MS/MS

INTRODUCTION

Taxus baccata L. is an evergreen conifer whose plant parts are cardiotoxic. Only the red arils of the berries are described as non-toxic and taxane-free.

OBJECTIVE

Extraction and HPLC-MS/MS methods were developed for the investigation of the Taxus compounds 3,5-dimethoxyphenol, 10-deacetylbaccatin III, baccatin III, cephalomannine, taxol A and taxinine M in the red arils of the yew berries.

METHODOLOGY

A liquid-liquid extraction method for the red arils of the fruits from three yews were developed. An accurate (ESI+) HPLC-MS/MS method was performed for the simultaneous detection and determination of the target compounds in multiple reaction monitoring (MRM) mode.

RESULTS

All Taxus agents obtained were detected in the red arils. Highest concentrations were determined for baccatin III and 10-deacetylbaccatin III.

CONCLUSION

The developed quantitative method is reliable and selective and was successfully applied for quantification of selected Taxus ingredients in red arils of Taxus baccata. It was disproved that the red arils of the berries do not contain the selected Taxus compounds.

Anticancer activity of an extract from needles and twigs of Taxus cuspidata and its synergistic effect as a cocktail with 5-fluorouracil

BACKGROUND

Botanical medicines are increasingly combined with chemotherapeutics as anticancer drug cocktails. This study aimed to assess the chemotherapeutic potential of an extract of Taxus cuspidata (TC) needles and twigs produced by artificial cuttage and its co-effects as a cocktail with 5-fluorouracil (5-FU).

METHODS

Components of TC extract were identified by HPLC fingerprinting. Cytotoxicity analysis was performed by MTT assay or ATP assay. Apoptosis studies were analyzed by H & E, PI, TUNEL staining, as well as Annexin V/PI assay. Cell cycle analysis was performed by flow cytometry. 5-FU concentrations in rat plasma were determined by HPLC and the pharmacokinetic parameters were estimated using 3p87 software. Synergistic efficacy was subjected to median effect analysis with the mutually nonexclusive model using Calcusyn1 software. The significance of differences between values was estimated by using a one-way ANOVA.

RESULTS

TC extract reached inhibition rates of 70-90% in different human cancer cell lines (HL-60, BGC-823, KB, Bel-7402, and HeLa) but only 5-7% in normal mouse T/B lymphocytes, demonstrating the broad-spectrum anticancer activity and low toxicity to normal cells of TC extract in vitro. TC extract inhibited cancer cell growth by inducing apoptosis and G(2)/M cell cycle arrest. Most interestingly, TC extract and 5-FU, combined as a cocktail, synergistically inhibited the growth of cancer cells in vitro, with Combination Index values (CI) ranging from 0.90 to 0.26 at different effect levels from IC50 to IC90 in MCF-7 cells, CI ranging from 0.93 to 0.13 for IC40 to IC90 in PC-3M-1E8 cells, and CI < 1 in A549 cells. In addition, the cocktail had lower cytotoxicity in normal human cell (HEL) than 5-FU used alone. Furthermore, TC extract did not affect the pharmacokinetics of 5-FU in rats.

CONCLUSIONS

The combinational use of the TC extract with 5-FU displays strong cytotoxic synergy in cancer cells and low cytotoxicity in normal cells. These findings suggest that this cocktail may have a potential role in cancer treatment.

Analysis of biosynthetic fluctuations of cultured Taxus seedlings using a metabolomic approach

Fluctuations in the biosynthesis of taxoids in 1-5 year old cultured seedlings of Taxus chinensis var. mairei were investigated using LC-IT-TOF-MS and a metabolomics approach. In the total ion chromatogram (TIC) of the extracts, 16 prominent peaks were observed. Ten compounds were identified by comparison of retention times and MS/MS spectra with those of reference compounds. An additional 6 taxoids were isolated by preparative HPLC and identified by comparison of their spectroscopic data with those reported in the literature. It was clarified that the relative concentrations of taxoids with 4(20) double bonds are high at early stages of cultivation. On the other hand, relatively higher amounts of 5-acetoxy taxoids oxidized at the 4- and 10- positions and taxoids having 5(20)-oxetane rings were found at later stages of cultivation. This approach provides practical information on the biosynthetic flow of taxoids in cultured yew seedlings.

Quantitative structure-retention relationship studies for taxanes including epimers and isomeric metabolites in ultra fast liquid chromatography

Seven pairs of epimers and one pair of isomeric metabolites of taxanes, each pair of which have similar structures but different retention behaviors, together with additional 13 taxanes with different substitutions were chosen to investigate the quantitative structure-retention relationship (QSRR) of taxanes in ultra fast liquid chromatography (UFLC). Monte Carlo variable selection (MCVS) method was adopted to choose descriptors. The selected four descriptors were used to build QSRR model with multi-linear regression (MLR) and artificial neural network (ANN) modeling techniques. Both linear and nonlinear models show good predictive ability, of which ANN model was better with the determination coefficient R(2) for training, validation and test set being 0.9892, 0.9747 and 0.9840, respectively. The results of 100 times' leave-12-out cross validation showed the robustness of this model. All the isomers can be correctly differentiated by this model. According to the selected descriptors, the three dimensional structural information was critical for recognition of epimers. Hydrophobic interaction was the uppermost factor for retention in UFLC. Molecules' polarizability and polarity properties were also closely correlated with retention behaviors. This QSRR model will be useful for separation and identification of taxanes including epimers and metabolites from botanical or biological samples.

Separation of 7-xylosyl-10-deacetyl paclitaxel and 10-deacetylbaccatin III from the remainder extracts free of paclitaxel using macroporous resins

The separation and enrichment of 10-deacetylbaccatin III (10-DAB III) and 7-xylosyl-10-deacetyl paclitaxel were studied on seven macroporous resins with special structures. The performance of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III on macroporous resins including AB-8, ADS-17, ADS-21, ADS-31, ADS-8, H1020 and NKA-II was compared according to their adsorption and desorption properties. AB-8 provided a much higher adsorption capacity for 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III than other resins, and its adsorption data fitted well to the Langmuir and Freundlich isotherm. According to the adsorption and desorption capacities and the adsorption isotherms, AB-8 demonstrated a remarkable capability for the preparative separation of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III from the remainder extracts free of paclitaxel. In order to optimize parameters of separation, dynamic adsorption and desorption experiments were carried out on the columns packed with AB-8 resin. The optimal conditions were: the processing volume 15 BV; concentrations of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III in feed solution 0.0657 mg/mL and 0.1494 mg/mL; flow rate 1 mL/min; temperature 35 degrees C. The gradient elution program was as follows: 30% ethanol for 3 BV, then 80% of ethanol for 6 BV, flow rate 1 mL/min. After the AB-8 resin treatment, the contents of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III in the product had increased from 0.053% and 0.2% to 3.34% and 1.69%, which were 62.43-fold and 8.54-fold of those in the untreated extracts, respectively, and the recoveries of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III were 85.85% and 52.78%. The performance achieved good separation and higher recovery of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III from remainder extracts free of paclitaxel by using AB-8 resin. It is a fast and effective method for the separation and enrichment of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III.