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

Microscopic distribution of taxanes in freeze-fixed stems of Taxus cuspidata

Introduction

Taxus species contain the anticancer alkaloid paclitaxel, as well as other taxanes similar in structure and potentially in effect to paclitaxel. Tissue-specific distribution patterns and seasonal variations of taxanes in some Taxus species have been reported; however, it is still under-presented for the taxanes in Taxus cuspidata.

Methods

The radial distributions of eight taxanes in the transverse surface of freeze-fixed T. cuspidata stems from the late summer and the spring seasons were investigated by cryo-time-of-flight secondary ion mass spectrometry and scanning electron microscopy (cryo-TOF-SIMS/SEM) visualization and liquid chromatography-mass spectrometry (LC-MS) quantitative analysis. By optical microscopic observation, seasonal differences in the amounts and distribution patterns of target taxanes were further characterized in specific tissues.

Results and Discussion

The overall amount of taxanes was higher in the late summer than in the spring. Also, taxanes' radial distribution was generally found at higher concentration in the phloem, the cambium and lower level in the periderm, the latest-forming xylem, with different taxanes showing several patterns with distinction between seasons, which were considered related to seasonal plant physiological behaviors. In addition, the distribution of baccatin III (BAC) was investigated at the cellular level, which was regarded in specific cells suggesting its transport in the radial and axial directions in the T. cuspidata stem. Characterizing the microscopic distribution of taxanes in the T. cuspidata stem is expected to play a role in the further study of their biosynthesis and in planta behaviors.

Anticancer Potential of Valencia Peanut (Arachis hypogaea L.) Skin Extract against Cervical Cancer Cells In Vitro and in Nude Mouse Xenograft Models

This study investigated the impact of Valencia KK4-type peanut skin ethanolic extract (KK4-PSE) combined with cisplatin or 5-fluorouracil (5-FU) on HeLa cells in vitro and in xenograft models. At exposure times of 24, 48 and 72 h, KK4-PSE inhibited the growth of HeLa cells with a half maximal inhibitory concentration (IC50) of 79.43 ± 0.54, 55.55 ± 1.57 and 41.32 ± 0.74 µg/mL, respectively. Drug interactions evaluated by the Chou-Talalay method demonstrated that KK4-PSE enhanced antiproliferative activity of 5-FU against HeLa cells with combination index (CI) values of 0.49 (48 h) and 0.60 (72 h), indicating a synergistic effect, while KK4-PSE combined with cisplatin exhibited an additive effect (CI = 1.02) at 72 h, and an antagonistic effect at 24 and 48 h exposures (CI = 1.12 and 1.18, respectively). In nude mouse xenograft models, the combination of 5-FU and KK4-PSE markedly reduced HeLa tumor weights compared with the control and single agent treatments groups. The combination of KK4-PSE and 5-FU achieved greater tumor growth inhibition than that of the KK4-PSE-cisplatin combination. KK4-PSE mitigated hepatotoxicity induced by both cisplatin and 5-FU in nude mice. The spleen hyaloserositis was significantly reduced in the combination treatment of 5-FU and KK4-PSE. These results suggest that KK4-PSE has the potential to limit cervical cancer cell proliferation while reducing the toxicity of cisplatin and 5-FU.

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.

Chitosan-decorated and tripolyphosphate-crosslinked pH-sensitive niosomal nanogels for Controlled release of fluoropyrimidine 5-fluorouracil

In the present study, 5-fluorouracil-loaded niosomal nanoparticles were successfully prepared and coated with chitosan and subsequently crosslinked by tripolyphosphate to form niosomal nanogels. The prepared niosomal formulations were fully characterized for their particle size, zeta potential, particle morphology, drug entrapment efficiency, and in vitro drug release profile. The prepared niosomal nanocarriers exhibited nanoscale particle sizes of 165.35 ± 2.75-322.85 ± 2.75 nm. Chitosan-coated and TPP-crosslinked niosomes exhibited a slightly decreased in particle size and a switch of zeta potential from negative to positive values. In addition, high yield percentage, drug encapsulation efficiency, and drug loading values of 92.11 ± 2.07 %, 66.59 ± 6.06, and 4.65 ± 0.5 were obtained for chitosan-coated formulations, respectively. Moreover, lowering the rate of 5-FU in vitro release was achieved within 72 h by using chitosan-coated formulations. All prepared formulations revealed hemocompatible properties in hemolysis assay with less than 5 % hemolysis percentage at their higher possible concentrations (500 µM and 1 mM). The cell viability by MTT assay showed higher anticancer activity against B16F10 cancerous cells and lower cytotoxicity toward NIH3T3 normal cells than control and pure 5-FU in the studied concentration range (10-100 µM). Investigating the cell migration inhibition properties of fabricated formulations revealed similar results with in vitro cell viability assay with a higher migration inhibition rate for B16F10 cells than NIH3T3 cells, controls, and free 5-FU.

Extraction, Purification, and Biological Activities of Polysaccharides from Branches and Leaves of Taxus cuspidata S. et Z

Taxus cuspidata S. et Z. is an excellent natural source of bioactive polysaccharides and has various biological activities. The objective of this study was to evaluate the effect of antidiabetic and antitumor activities of polysaccharides from Taxus cuspidata branches and leaves (TCBL) and to determine the optimum extraction technology of TCBL using a low-temperature and high-efficiency enzyme and ultrasound-assisted coupled extraction (EUCE) method. Optimal technology parameters were determined as follows: an extraction temperature of 51 °C, an extraction time of 33 min, a ratio of material to liquid of 1:19 (g:mL), and an enzyme concentration of 0.10 mg·mL⁻¹. Under the optimized conditions, the polysaccharide yield from TCBL obtained by EUCE was 4.78% ± 0.18%. The four purified polysaccharides (Pe1, Pe2, Pe3, Pe4) from TCBL are mainly composed of arabinose, galactose, glucose, a small amount of xylose, and mannose. This composition was assessed by HPIC analysis. The antidiabetic activity and antitumor activity of polysaccharides from TCBL were assayed in vitro. Among the four purified polysaccharides from TCBL, purified Pe4 had the highest inhibitory capacity against α-glucosidase, and its IC₅₀ value was 123.0 µg·mL⁻¹. Pe1 had the highest antitumor capacity against MCF7 cells and HepG2 cells, with IC₅₀ values of 169.0 and 132.0 µg·mL⁻¹. Pe4 had the highest antitumor effect on human cervical cancer cells (Hela), and its IC₅₀ value was 89.9 µg·mL⁻¹. Pe4 polysaccharide demonstrated a good α-glucosidase inhibitory activity and antitumor capacity against Hela cells. Therefore, Pe4 polysaccharide from TCBL is a beneficial source of potential inhibitors of type II diabetes and human cervical cancer activity.

Differential Expression of MicroRNAs During Root Formation in Taxus Chinensis Var. mairei Cultivars

MicroRNAs (miRNAs) have been shown to play key roles in the regulation of plant growth and development by modifying the expression of their target genes. However, the influence of miRNAs on root formation and development in woody plants, such as Taxus chinensis, remains largely unknown. In the current study, we explored the phytohormone-response and nutrition-response miRNA expression profiles during T. chinensis rooting by quantitative real-time PCR (qPCR). We identified six phytohormone-response miRNAs, namely, miR164a, miR165, miR167a, miR171b, miR319, and miR391, and eight nutrition-response miRNAs, namely, miR169b, miR395a, miR399c, miR408, miR826, miR827, miR857, and miR2111a, that were differentially expressed at different rooting phases of T. chinensis. Using northern blot analysis of the putative target genes of these miRNAs, we detected the relative gene expression changes of the target genes. Taken together, our results suggest that miRNAs are involved in root formation of T. chinensis and that miRNAs may play important regulatory roles in primary root, crown root, and root hair formation by targeting phytohormone and/or nutrition response genes in T. chinensis. For the first time, these results expand our understanding of the molecular mechanisms of plant root formation and development in a conifer species.

Phenolic Compounds of Catalpa speciosa, Taxus cuspidate, and Magnolia acuminata have Antioxidant and Anticancer Activity

Tree bark represents an important source of medicinal compounds that may be useful for cancer therapy. In the current study, high-performance liquid chromatography with diode-array detection (HPLC-DAD) was used to determine the profile of the phenolic compounds of Catalpa speciosa, Taxus cuspidata, and Magnolia acuminata bark extracts. The antioxidant and anticancer bioactivities against different cancer cell lines were investigated. M. acuminata exerted significantly higher antioxidant activities in the diphenyl picrylhydrazine and β-carotene-linoleic acid assays than the other species. In C. speciosa, novel profiles of phenolic acids (ferulic acid was the predominant compound) and catechin were detected. In T. cuspidata, six phenolic acids were detected; the predominant compounds were hydroxycaffeic acid and protocatechuic acid. In M. acuminata, two phenolic acids and three catechins were detected; catechin was the predominant compound. The three species exerted clear anticancer activity against MCF-7, HeLa, Jurkat, T24, and HT-29 cells, with the strongest activity found in the extracts from M. acuminata. No antiproliferative activity against normal cells was found. Flow cytometry revealed greater accumulation of necrotic and early/late apoptotic cells in various treated cancer cells than in untreated control cells, and protocatechuic acid induced a similar accumulation of necrotic cells to that of the bark extracts. Caspase-3 and -7 activity was increased in cancer cells treated with different bark extracts; the highest activity was found in the M. acuminata treatment. Our results suggested that the treatment of cancer cells with bark extracts of M. acuminata, C. speciosa, and T. cuspidata, and protocatechuic acid induced apoptosis, suggesting an association between anticancer activities and individual phenolic compounds.

Green synthesis of anisotropic silver nanoparticles with potent anticancer activity using Taxus baccata extract

Highly stable colloidal silver nanoparticles with potent anticancer activity against MCF-7 cells were synthesized using Taxus baccata extracts.