Podophyllic Aldehyde, a Podophyllotoxin Derivate, Elicits Different Cell Cycle Profiles Depending on the Tumor Cell Line: A Systematic Proteomic Analysis

When new antitumor therapy drugs are discovered, it is essential to address new target molecules from the point of view of chemical structure and to carry out efficient and systematic evaluation. In the case of natural products and derived compounds, it is of special importance to investigate chemomodulation to further explore antitumoral pharmacological activities. In this work, the compound podophyllic aldehyde, a cyclolignan derived from the chemomodulation of the natural product podophyllotoxin, has been evaluated for its viability, influence on the cell cycle, and effects on intracellular signaling. We used functional proteomics characterization for the evaluation. Compared with the FDA-approved drug etoposide (another podophyllotoxin derivative), we found interesting results regarding the cytotoxicity of podophyllic aldehyde. In addition, we were able to observe the effect of mitotic arrest in the treated cells. The use of podophyllic aldehyde resulted in increased cytotoxicity in solid tumor cell lines, compared to etoposide, and blocked the cycle more successfully than etoposide. High-throughput analysis of the deregulated proteins revealed a selective antimitotic mechanism of action of podophyllic aldehyde in the HT-29 cell line, in contrast with other solid and hematological tumor lines. Also, the apoptotic profile of podophyllic aldehyde was deciphered. The cell death mechanism is activated independently of the cell cycle profile. The results of these targeted analyses have also shown a significant response to the signaling of kinases, key proteins involved in signaling cascades for cell proliferation or metastasis. Thanks to this comprehensive analysis of podophyllic aldehyde, remarkable cytotoxic, antimitotic, and other antitumoral features have been discovered that will repurpose this compound for further chemical transformations and antitumoral analysis.

Cytotoxic Cyclolignans Obtained by the Enlargement of the Cyclolignan Skeleton of Podophyllic Aldehyde, a Selective Podophyllotoxin-Derived Cyclolignan

Podophyllotoxin, a cyclolignan natural product, has been the object of extensive chemomodulation to obtain better chemotherapeutic agents. Among the obtained podophyllotoxin derivatives, podophyllic aldehyde showed very interesting potency and selectivity against several tumoral cell lines, so it became our lead compound for further modifications, as described in this work, oriented toward the enlargement of the cyclolignan skeleton. Thus, modifications performed at the aldehyde function included nucleophilic addition reactions and the incorporation of the aldehyde carbon into several five-membered rings, such as thiazolidinones and benzo-fused azoles. The synthesized derivatives were evaluated against several types of cancer cells, and although some compounds were cytotoxic at the nanomolar range, most of them were less potent and less selective than the parent compound podophyllic aldehyde, with the most potent being those having the lactone ring of podophyllotoxin. In silico ADME evaluation predicted good druggability for most of them. The results indicate that the γ-lactone ring is important for potency, while the α,β-unsaturated aldehyde is necessary to induce selectivity in these cyclolignans.

Pinobanksin from peony seed husk: A flavonoid with the potential to inhibit the proliferation of SH-SY5Y

Pinobanksin, as one of the flavonoids, has powerful biological activities but has been under-recognized. In this study, we optimized the extraction method of phragmites from peony seed shells by using organic solvent extraction. The yield of PSMS was 10.54 ± 0.13% under the conditions of ethanol volume fraction 70%, extraction temperature 70°C, material-liquid ratio 1:25 g/mL, and extraction time 60 min; the optimized PSMS could be effectively separated in S-8 macroporous resin coupled with C18. The relative content of PSMS was increased from 0.42% in PSMS to 92.53% after C18 purification; the antioxidant activity test revealed that pinobanksin could exert antioxidant ability by binding catalase (CAT) enzyme. Second, it was found that pinobanksin could effectively inhibit the proliferation of SH-SY5Y cells, mainly by binding to BCL2-associated X (BAX), B-cell lymphoma-2 (BCL-2), and cyclin-dependent Kinase 4/6 (CDK4/6) to produce more hydrogen bonds to inhibit their activities. This study confirms the medicinal potential of pinobanksin and provides the basis for the proper understanding of pinobanksin and the development of related products.

A Zero-Valent Sulfur Transporter Helps Podophyllotoxin Uptake into Bacterial Cells in the Presence of CTAB

Podophyllotoxin (PTOX) is naturally produced by the plant Podophyllum species. Some of its derivatives are anticancer drugs, which are produced mainly by using chemical semi-synthesis methods. Recombinant bacteria have great potential in large-scale production of the derivatives of PTOX. In addition to introducing the correct enzymes, the transportation of PTOX into the cells is an important factor, which limits its modification in the bacteria. Here, we improved the cellular uptake of PTOX into Escherichia coli with the help of the zero-valent sulfur transporter YedE1E2 in the presence of cetyltrimethylammonium bromide (CTAB). CTAB promoted the uptake of PTOX, but induced the production of reactive oxygen species. A protein complex (YedE1E2) of YedE1 and YedE2 enabled E. coli cells to resist CTAB by reducing reactive oxygen species, and YedE1E2 was a hypothetical transporter. Further investigation showed that YedE1E2 facilitated the uptake of extracellular zero-valent sulfur across the cytoplasmic membrane and the formation of glutathione persulfide (GSSH) inside the cells. The increased GSSH minimized oxidative stress. Our results indicate that YedE1E2 is a zero-valent sulfur transporter and it also facilitates CTAB-assisted uptake of PTOX by recombinant bacteria.

Podophyllotoxin: Recent Advances in the Development of Hybridization Strategies to Enhance Its Antitumoral Profile

Podophyllotoxin is a naturally occurring cyclolignan isolated from rhizomes of Podophyllum sp. In the clinic, it is used mainly as an antiviral; however, its antitumor activity is even more interesting. While podophyllotoxin possesses severe side effects that limit its development as an anticancer agent, nevertheless, it has become a good lead compound for the synthesis of derivatives with fewer side effects and better selectivity. Several examples, such as etoposide, highlight the potential of this natural product for chemomodulation in the search for new antitumor agents. This review focuses on the recent chemical modifications (2017-mid-2023) of the podophyllotoxin skeleton performed mainly at the C-ring (but also at the lactone D-ring and at the trimethoxyphenyl E-ring) together with their biological properties. Special emphasis is placed on hybrids or conjugates with other natural products (either primary or secondary metabolites) and other molecules (heterocycles, benzoheterocycles, synthetic drugs, and other moieties) that contribute to improved podophyllotoxin bioactivity. In fact, hybridization has been a good strategy to design podophyllotoxin derivatives with enhanced bioactivity. The way in which the two components are joined (directly or through spacers) was also considered for the organization of this review. This comprehensive perspective is presented with the aim of guiding the medicinal chemistry community in the design of new podophyllotoxin-based drugs with improved anticancer properties.

Improving the Enantioselectivity of CHMOBrevi1 for Asymmetric Synthesis of Podophyllotoxin Precursor

(R)-β-piperonyl-γ-butyrolactones are key building blocks for the synthesis of podophyllotoxin, which have demonstrated remarkable potential in cancer treatment. Baeyer-Villiger monooxygenases (BVMOs)-mediated asymmetric oxidation is a green approach to produce chiral lactones. While several BVMOs were able to oxidize the corresponding cyclobutanone, most BVMOs gave the (S) enantiomer while Cyclohexanone monooxygenase (CHMO) from Brevibacterium sp. HCU1 gave (R) enantiomer, but with a low enantioselectivity (75 % ee). In this study, we use a strategy called "focused rational iterative site-specific mutagenesis" (FRISM) at residues ranging from 6 Å from substrate. The mutations by using a restricted set of rationally chosen amino acids allow the formation of a small mutant library. By generating and screening less than 60 variants, we achieved a high ee of 96.8 %. Coupled with the cofactor regeneration system, 9.3 mM substrate was converted completely in a 100-mL scale reaction. Therefore, our work reveals a promising synthetic method for (R)-β-piperonyl-γ-butyrolactone with the highest enantioselectivity, and provides a new opportunity for the chem-enzymatic synthesis of podophyllotoxin.

Podophyllotoxin reduces the aggressiveness of human oral squamous cell carcinoma through myeloid cell leukemia‑1

Podophyllotoxin (PPT), which is derived from the podophyllum plant, exhibits marked cytotoxic effects against cancer cells; however, the precise molecular mechanism underlying its activity against human oral squamous cell carcinoma (OSCC) has not been elucidated. In the present study, the mechanism by which PPT induced cytotoxicity in two OSCC cell lines, HSC3 and HSC4, was determined. The effects of PPT on cytotoxicity in HSC3 and HSC4 cells were analyzed using Annexin V/PI double staining, Sub‑G1 analysis, soft agar assays, western blotting, and quantitative PCR. The changes in the mitochondrial membrane potential were assessed using a JC‑1 assay and cytosolic and mitochondrial fractionation. A myeloid cell leukemia‑1 (Mcl‑1) overexpression cell lines were also established to study the role of Mcl‑1 on apoptosis. The results showed that PPT inhibited the growth of the two human OSCC cell lines and induced apoptosis, which was accompanied by mitochondrial membrane depolarization. Compared with the control, PPT reduced the expression of Mcl‑1 in both cell lines through a proteasome‑dependent protein degradation process. Overall, these results suggested that targeting of Mcl‑1 protein by PPT induced apoptosis, providing a foundation for further pre‑clinical and clinical study of its value in the management of OSCC.

Tetraphenylethylene-Based Photoluminescent Self-Assembled Nanoparticles: Preparation and Biological Evaluation

The conjugation of tetraphenylethylene (TPE) with podophyllotoxin, N-desacetylthiocolchicine, and cabazitaxel through a sebacic acid linker led to the formation of fluorescent nanoparticles. Dynamic light scattering (DLS) and photoluminescence spectroscopy were used for the identification and characterization of the fluorescent nanoparticles. The biological evaluation was determined in three human ovarian (KURAMOCHI, OVCAR3, OVSAHO) and three human breast (MCF7, SKBR 3, and MDA-MB231) cancer cell lines. In the case of cabazitaxel, the nanoparticles maintained the activity of the parent drug, at the low nanomolar range, while exhibiting high blue fluorescence. The internalization of the fluorescent NPs into cells was detected using immunofluorescence assay.

Design, Synthesis, and Biological Evaluation of SSE1806, a Microtubule Destabilizer That Overcomes Multidrug Resistance

Microtubules are dynamic structures that form spindle fibers during cell division; pharmacological inhibition of microtubule dynamics arrests cells in mitosis, leading to apoptosis, and they have been extensively used to treat various cancers. However, the efficacy of such drugs is often limited by multidrug resistance. This study synthesized and evaluated 30 novel derivatives of podophyllotoxin, a natural antimitotic compound, for their antiproliferative activities. Compound SSE1806 exhibited the most potent antiproliferative activity with GI50 values ranging from 1.29 ± 0.01 to 21.15 ± 2.1 μM in cancer cell lines of different origins; it directly inhibited microtubule polymerization, causing aberrant mitosis and G2/M arrest. Prolonged treatment with SSE1806 increased p53 expression, induced cell death in monolayer cultures, and reduced the growth of mouse- and patient-derived human colon cancer organoids. Importantly, SSE1806 overcame multidrug resistance in a cell line overexpressing MDR-1. Thus, SSE1806 represents a potential anticancer agent that can overcome multidrug resistance.

Natural product inspired leads in the discovery of anticancer agents: an update

Natural products have emerged as major leads for the discovery and development of new anti-cancer drugs. The plant-derived anti-cancer drugs account for approximately 60% and the quest for new anti-cancer agents is in progress. Anti-cancer leads have been isolated from plants, animals, marine organisms, and microorganisms from time immemorial. The process of semisynthetic modifications of the parent lead has led to the generation of new anti-cancer agents with improved therapeutic efficacy and minimal side effects. The various chemo-informatics tools, bioinformatics, high-throughput screening, and combinatorial synthesis are able to deliver the new natural product lead molecules. Plant-derived anticancer agents in either late preclinical development or early clinical trials include taxol, vincristine, vinblastine, topotecan, irinotecan, etoposide, paclitaxel, and docetaxel. Similarly, anti-cancer agents from microbial sources include dactinomycin, bleomycin, mitomycin C, and doxorubicin. In this review, we highlighted the importance of natural products leads in the discovery and development of novel anti-cancer agents. The semisynthetic modifications of the parent lead to the new anti-cancer agent are also presented. Further, the leads in the preclinical settings with the potential to become effective anticancer agents are also reviewed.Communicated by Ramaswamy H. Sarma.

L-Cysteine-Modified Transfersomes for Enhanced Epidermal Delivery of Podophyllotoxin

The purpose of this study was to evaluate L-cysteine-modified transfersomes as the topical carrier for enhanced epidermal delivery of podophyllotoxin (POD). L-cysteine-deoxycholic acid (LC-DCA) conjugate was synthesized via an amidation reaction. POD-loaded L-cysteine-modified transfersomes (POD-LCTs) were prepared via a thin membrane dispersion method and characterized for their particle size, zeta potential, morphology, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and in vitro release. Subsequently, in vitro skin permeation and retention, fluorescence distribution in the skin, hematoxylin-eosin staining and in vivo skin irritation were studied. The POD-LCTs formed spherical shapes with a particle size of 172.5 ± 67.2 nm and a zeta potential of -31.3 ± 6.7 mV. Compared with the POD-Ts, the POD-LCTs provided significantly lower drug penetration through the porcine ear skin and significantly increased the skin retention (p < 0.05). Meaningfully, unlike the extensive distribution of the POD-loaded transfersomes (POD-Ts) throughout the skin tissue, the POD-LCTs were mainly located in the epidermis. Moreover, the POD-LCTs did not induce skin irritation. Therefore, the POD-LCTs provided an enhanced epidermal delivery and might be a promising carrier for the topical delivery of POD.

Comparative efficacy of treatments for molluscum contagiosum: A systematic review and network meta-analysis

BACKGROUND AND OBJECTIVES

Various interventions have been applied to treat molluscum contagiosum, but benefits and efficacy remain unclear. To assess the comparative efficacy and safety of interventions for molluscum contagiosum, a network meta-analysis was performed.

PATIENTS AND METHODS

Embase, PubMed, and the Cochrane Library were searched for articles published between January 1, 1990, and November 31, 2020. Eligible studies were randomized clinical trials (RCTs) of interventions in immunocompetent children and adults with genital/non-genital molluscum contagiosum lesions.

RESULTS

Twelve interventions from 25 RCTs including 2,123 participants were assessed. Compared with the placebo, ingenol mebutate had the most significant effect on complete clearance (odds ratio [OR] 117.42, 95% confidence interval [CI] 6.37-2164.88), followed by cryotherapy (OR 16.81, 95% CI 4.13-68.54), podophyllotoxin (OR 10.24, 95% CI 3.36-31.21), and potassium hydroxide (KOH) (OR 10.02, 95% CI 4.64-21.64). Data on adverse effects were too scarce for quantitative synthesis.

CONCLUSIONS

Ingenol mebutate, cryotherapy, podophyllotoxin, and KOH were more effective than the other interventions in achieving complete clearance, but safety concerns regarding ingenol mebutate have recently been reported. Due to the possibility of spontaneous resolution, observation is also justified for asymptomatic infection. Factors including adverse effects, cost, patient preference, and medical accessibility should be considered.

Synthesis and anticancer activity of podophyllotoxin derivatives with nitrogen-containing heterocycles

Three series of podophyllotoxin derivatives with various nitrogen-containing heterocycles were designed and synthesized. The antitumor activity of these podophyllotoxin derivatives was evaluated in vitro against a panel of human tumor cell lines. The results showed that podophyllotoxin-imidazolium salts and podophyllotoxin-1,2,4-triazolium salts a1-a20 exhibited excellent cytotoxic activity. Among them, a6 was the most potent cytotoxic compound with IC₅₀ values of 0.04-0.29 μM. Podophyllotoxin-1,2,3-triazole derivatives b1-b5 displayed medium cytotoxic activity, and podophyllotoxin-amine compounds c1-c3 has good cytotoxic activity with IC₅₀ value of 0.04-0.58 μM. Furthermore, cell cycle and apoptosis experiments of compound a6 were carried out and the results exhibited that a6 could induce G2/M cell cycle arrest and apoptosis in HCT-116 cells.

Late-Stage functionalization for the divergent synthesis of novel podophyllotoxin derivatives by rhodium catalysis

A divergent synthesis of novel podophyllotoxin derivatives was here reported from simple and readily available starting materials via Late-Stage functionalization strategy by rhodium catalysis. This strategy utilizes the ketone and oxime in substrates as internal direacting groups and requires no external ligand or removable directing group. 75 podophyllotoxin derivatives have been obtained without any erosion of the enantiopurity, indicating the broad substrate scope of this method. Additionally, by using the newly developed strategy, 9aa can be prepared via sequential transformation, which exhibited excellent anticancer activity against eight cancer cell lines. In particularly, 9aa suppressed Hela cells with IC50 values of 74.5 nM, which provides a promising lead compound for future drug discovery.

Anticancer Podophyllotoxin Recovery from Juniper Leaves at Atmospheric and High Pressure Using Eco-Friendly Solvents

Podophyllotoxin (PPT) is a precursor for the synthesis of drugs against cancer and other diseases. The present sources of PPT (Sinopodophyllum hexandrum and Podophyllum peltatum) are endangered species, with PPT production highly dependent on their growing conditions. In connection with the identification of new sources of PPT, the present study aimed to recover PPT from Juniperus virginiana leaves via atmospheric or high pressure extraction methods with a focus on using eco-friendly solvents. PPT quantification was determined by UHPLC/HRMS/MS. A thorough study of conventional extraction was carried out to reveal the optimal conditions (solvent ethyl acetate at room temperature and a duration of 1 h) for maximizing the PPT recovery (about 30 mg/g of dry extract and 3 mg/g of dry initial plant material). Peleg's equation was applied for process kinetics modeling. The best PPT content in the final dry extract (42-45 mg/g of dry extract) was obtained by high pressure methods under supercritical (scCO₂ with ethanol or ethyl acetate, 30 MPa, 50 °C and 100 min) or accelerated solvent extraction conditions (solvent ethyl acetate, 10.35 MPa, 20 °C and 3 cycles for 15 min). Seasonal stability and storage stability of the raw material were also determined. The present results have potential applications in the pharmacy for the delivery of PPT from juniper leaves.

Chemistry and Biological Activities of Naturally Occurring and Structurally Modified Podophyllotoxins

Plants containing podophyllotoxin and its analogues have been used as folk medicines for centuries. The characteristic chemical structures and strong biological activities of this class of compounds attracted attention worldwide. Currently, more than ninety natural podophyllotoxins were isolated, and structure modifications of these molecules were performed to afford a variety of derivatives, which offered optimized anti-tumor activity. This review summarized up to date reports on natural occurring podophyllotoxins and their sources, structural modification and biological activities. Special attention was paid to both structural modification and optimized antitumor activity. It was noteworthy that etoposide, a derivative of podophyllotoxin, could prevent cytokine storm caused by the recent SARS-CoV-2 viral infection.

Chemical Constituents of the Leaves of Thujopsis dolabrata and Their Cytotoxicity

Five podophyllotoxin derivatives (1-5), two diterpenoids (6 and 7), three diterpenoid xylosides (8-10), a flavanonol glycoside (11), flavonol (12), and biflavonoid (13) were isolated from the leaves of Thujopsis dolabrata (Cupressaceae). Compounds 1, 6, and 8 were named (-)-β-isopeltatin, epi-nootkastatin 2, and acetoxyanticopalol 15-O-β-D-xylopyranoside, respectively. The structures of the isolated compounds were determined based on a detailed analysis of NMR spectroscopic data and through chromatographic and spectroscopic analyses following specific chemical transformations. The isolated compounds (1-5 and 7-11) were evaluated for their cytotoxicity toward HL-60 human promyelocytic leukemia cells and Caki-1 human kidney carcinoma cells. The podophyllotoxin derivatives (1-5) exhibited cytotoxicity against both HL-60 and Caki-1 cells with IC₅₀ values ranging from 0.00069 to 5.4 µM, and the diterpenoid derivatives (7-10) demonstrated cytotoxicity against HL-60 cells with IC₅₀ values ranging from 4.5 to 11 µM. HL-60 cells treated with 8 exhibited apoptosis characteristics, such as accumulation of sub-G₁ cells and nuclear chromatin condensation.

Isolation and Cytotoxic Potency of Endophytic Fungi Associated with Dysosma difformis, a Study for the Novel Resources of Podophyllotoxin

Endophytic fungi are promising sources for the production of podophyllotoxin-an important anticancer compound, replacing depleted medical plants. In this study, the endophytes associated with Dysosma difformis-an ethnomedicinal plant species were isolated to explore novel sources of podophyllotoxin. Fifty-three endophytic fungi were isolated and identified by morphological observation and ITS-based rDNA sequencing, assigning them to 27 genera in 3 divisions. Fusarium was found the most prevalent genus with a colonization frequency of 11.11%, followed by Trametes (9.26%) and Penicillium (7.41%). Phylogenetic trees were constructed for the endophytic fungi community in two collection sites, Ha Giang and Lai Chau, revealing the adaptation of the species to the specific tissues and habitats. Cytotoxic activity of endophytic fungal extracts was investigated on cancer cell lines such as SK-LU-1, HL-60, and HepG2, demonstrating strong anti-cancer activity of six isolates belonging to Penicillium, Trametes, Purpureocillium, Aspergillus, and Ganoderma with IC₅₀ value of lower than 10 µg/mL. The presence of podophyllotoxin was indicated in Penicillium, Trametes, Aspergillus and for the first time in Purpureocillium and Ganoderma via high-performance liquid chromatography, which implied them as a potential source of this anti-cancer compound.

Cationic Nanoparticulate System for Codelivery of MicroRNA-424 and Podophyllotoxin as a Multimodal Anticancer Therapy

Because of the complexity of cancer ecosystems, the efficacy of single-agent chemotherapy is limited. Herein, we report the use of cationic nanoparticles (designated PPCNs) generated from a chemically modified form of the chemotherapeutic agent podophyllotoxin (PPT) to deliver both microRNA-424 (miR-424) and PPT to tumor cells, thus combining chemotherapy and gene therapy. We evaluated the optimal loading ratio of miR-424─which targets programmed cell death ligand 1 (PD-L1) mRNA and reduces PD-L1 production, thus promoting the attack of tumor cells by T cells─for effective delivery of miR-424 and PPCNs into nonsmall-cell lung cancer cells (H460). Because miR-424 can reverse chemotherapy resistance, treatment of the tumor cells with the combination of miR-424 and PPT enhanced their sensitivity to PPT. Because miR-424 and the PPCNs regulated PD-L1 production in different ways, the miR-424@PPCN complexes were significantly more efficacious than either miR-424 or PPCNs alone. We also demonstrated that treatment of tumor-bearing mice with these complexes significantly inhibited tumor growth and extended survival. Moreover, additional in vitro experiments revealed that the complexes could remodel the tumor immune microenvironment, relieve immunosuppression, and achieve immune normalization. This novel system for delivering a combination of PPT and miR-424 shows great potential for the multimodal treatment of lung cancer.

Self-Assembly of Podophyllotoxin-Loaded Lipid Bilayer Nanoparticles for Highly Effective Chemotherapy and Immunotherapy via Downregulation of Programmed Cell Death Ligand 1 Production

Low drug delivery efficiency elevates the cost of medication, lowers the therapeutic efficacy, and appears as a leading reason for unmet needs in anticancer therapies. Herein, we report the development of self-assembled podophyllotoxin-loaded lipid bilayer nanoparticles that inhibit the production of programmed cell death ligand 1 in lung cancer cells and promote tumor-specific immune responses, thus offering a strategy for regulating the immunosuppressive microenvironment of tumors. In addition, encapsulation of podophyllotoxin in the nanoparticles reduced its systemic toxicity, enhanced its penetration into tumors, and increased its antitumor efficacy. Systemic injection of the nanoparticles into tumor-bearing mice not only prevented tumor immune escape but also significantly inhibited tumor growth and extended survival. In general, the podophyllotoxin-loaded nanoparticles exhibited both immunological effects and antitumor effects in addition to having better targeting activity and fewer side effects than free podophyllotoxin. We expect our findings to facilitate the development of therapies for lung cancer.

Immediate severe hypersensitivity reaction to etoposide phosphate: Case report and review of the literature

INTRODUCTION

Hypersensitivity reactions from intravenous (IV) etoposide have been rarely reported, with these being seen more commonly with etoposide than with etoposide phosphate. This is generally explained by the need for polysorbate 80, a known cause of hypersensitivity, as a solubiliser, in the etoposide formulation.

CASE REPORT

We report a 22-year-old male, being treated with adjuvant BEP (bleomycin/etoposide phosphate/cisplatin) for a testicular germ cell tumour. Bleomycin and cisplatin were administered without incident. Within one minute of etoposide phosphate commencement he experienced a severe hypersensitivity reaction, consisting of widespread erythematous rash, facial swelling, and nausea. Observations included unrecordable blood pressure, tachycardia, hypoxia, and loss of consciousness, confirming a diagnosis of anaphylactic shock.

MANAGEMENT AND OUTCOME

Etoposide phosphate was ceased immediately. He was successfully managed with IV hydrocortisone, IV promethazine, intramuscular adrenaline, IV fluids and oxygen. Following admission for observation, significant improvement occurred over 48 h.

DISCUSSION

Hypersensitivity reactions to etoposide were first reported in the 1980s. Following reactions to etoposide, substituting etoposide phosphate into chemotherapy regimens has commonly allowed treatment to continue without incidence. Anaphylactic reactions to etoposide phosphate were first documented in 2012, with further cases reported subsequently. Unlike etoposide, etoposide phosphate is highly soluble in aqueous solutions and doesn't require adjuvants in the formulation. Hypersensitivity reactions to etoposide phosphate are therefore likely related to the etoposide drug molecule itself. Clinicians should be aware of this rare, but potentially life-threatening, toxicity when using etoposide-based treatments and have procedures in place to urgently manage any hypersensitivity reactions that may occur.

Podophyllotoxin-combined 5-aminolevulinic acid photodynamic therapy significantly promotes HR-HPV-infected cell death

BACKGROUND

Human papillomavirus (HPV) infection and related diseases are difficult clinical challenges. The efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in treating condyloma acuminata is remarkable, with high virus clearance and low recurrence rates. Podophyllotoxin (POD) is the first-line drug with a significant therapeutic effect on condyloma acuminata. However, no studies have determined whether POD-combined ALA-PDT improves high-risk (HR)-HPV-infected cell killing. We aimed to investigate whether POD-combined ALA-PDT could promote HPV-infected cell death more effectively than the single treatment and explore the underlying mechanism.

METHODS

In HeLa and SiHa cells, flow cytometry, EdU assay and LDH release test were used to detect apoptosis, cell proliferation change and necrosis, respectively. To investigate whether the combined therapy might activate apoptosis and induce endoplasmic reticulum (ER) stress, flow cytometry was used to determine intracellular levels of ROS and calcium, and Western blotting was used to determine the expression of related proteins. Mitochondrial membrane depolarization was detected by JC-1 assay. Immunofluorescence staining and Western blotting were used to detect the activation of autophagy.

RESULTS

Podophyllotoxin -combined ALA-PDT inhibited the proliferation and promoted apoptosis and necrosis more effectively than the single treatment at the same intensity and concentration. The activation of the caspase-dependent apoptosis pathway, ER stress and autophagy was more substantial in POD-combined ALA-PDT than with single treatments.

CONCLUSION

Podophyllotoxin -combined ALA-PDT effectively promoted cell death through several pathways in HeLa and SiHa cells. This combination might be a promising therapeutic strategy for the HR-HPV infection.

ameliorate podophyllotoxin-induced myelosuppression and gastrointestinal toxicity

Podophyllotoxin (POD), a natural lignan distributed in podophyllum species, possesses significant antitumor and antiviral activities. But POD often causes serious side effects, such as myelosuppression, gastrointestinal toxicity, neurotoxicity, hepatic and renal dysfunction, and even death, which not only hinder its clinical application but also threaten the patient's health. Therefore, an effective treatment against POD-induced toxicity is important. Our preliminary study found that the total saponins from the stems and leaves of Panax quinquefolius L. (PQS) could significantly reduce the death of mice caused by POD. To reveal how PQS can alleviate POD-induced toxicity, further study was needed. Peripheral blood cell analysis, diarrhea score, and histological examination demonstrated that PQS could relieve myelosuppression and gastrointestinal side effects induced by POD. Then, metabolomics was performed to investigate the possible protective mechanism of PQS on POD-induced myelosuppression and gastrointestinal toxicity. Metabolomics analysis showed that metabolic changes caused by POD could be reversed by PQS to some extent; 23 metabolites altered significantly after POD exposure, and 11 metabolites significantly reversed by PQS pretreatment. Metabolic pathway analysis suggested that PQS might exhibit its protective effects by rebalancing disordered arginine, glutamine, and unsaturated fatty acid metabolism.

Junipers of Various Origins as Potential Sources of the Anticancer Drug Precursor Podophyllotoxin

Juniper representatives are natural sources of plenty of bioactive metabolites and have been used since ancient times as folk remedies against tapeworms, warts, cancer, etc. The antiproliferative activities of junipers are attributed to podophyllotoxin (PPT), which is a precursor for the synthesis of efficient anticancer drugs. However, the natural sources of PPT, Sinopodophyllum hexandrum (Royle) T. S. Ying and Podophyllum peltatum L., are already endangered species because of their intensive industrial exploitation. Therefore, identification of other sources of PPT is necessary. This study is a broad comparative investigation of junipers, for which original sources have been accessed from different continents of the world. The present research is aimed at the identification of species, producing PPT and other lignans at concentrations that are sufficient for the high antiproliferative activity of the corresponding extracts. Cytotoxic juniper leaf extracts demonstrated a broad spectrum of activity on a panel of cancer cell lines. The antiproliferative properties of junipers were attributed to the combined activity of great diversity of lignans (podophyllotoxin, deoxypodophyllotoxin, β-peltatin, yatein, matairesinol, anhydropodorhizol, etc.), detected by UHPLC-HRMS and LC-ESI-MS/MS in the corresponding extracts. Several species of the genus Juniperus L. were outlined as perspective sources of drug precursors with potential pharmaceutical applications.

Insight Into the Molecular Mechanism of Podophyllotoxin Derivatives as Anticancer Drugs

Podophyllotoxin (PTOX) is a biologically active compound derived from the podophyllum plant, and both it and its derivatives possess excellent antitumor activity. The PTOX derivatives etoposide (VP-16) and teniposide (VM-26) have been approved by the U.S. Food and Drug Administration (FDA) for cancer treatment, but are far from perfect. Hence, numerous PTOX derivatives have been developed to address the major limitations of PTOX, such as systemic toxicity, drug resistance, and low bioavailability. Regarding their anticancer mechanism, extensive studies have revealed that PTOX derivatives can induce cell cycle G2/M arrest and DNA/RNA breaks by targeting tubulin and topoisomerase II, respectively. However, few studies are dedicated to exploring the interactions between PTOX derivatives and downstream cancer-related signaling pathways, which is reasonably important for gaining insight into the role of PTOX. This review provides a comprehensive analysis of the role of PTOX derivatives in the biological behavior of tumors and potential molecular signaling pathways, aiming to help researchers design and develop better PTOX derivatives.

[Research progress in biosynthesis of podophyllotoxin and its derivatives]

Podophyllotoxin (PTOX) is an aryl-tetralin lignan of plant origin found in some species of Podophyllum such as Dysosma versipellis, Diphylleia sinensis, and Sinopodophyllum hexandrum. Etoposide and teniposide are produced semisynthetically from PTOX and used clinically to treat several forms of cancer. As a typical representative of new drug discovery from natural products, the production of PTOX solely depends on extraction from plants, resulting in severe contradiction between supply and demand. With the advantages of unconstrained resources and eco-friendly reaction conditions, biosynthesis method has become a trend in the production of PTOX and its derivatives. In this review, we summarize the research progress of PTOX biosynthesis in plants and expound the functions of the key enzymes as well as their subcellular location. The synthetic biology for production of PTOX intermediates in a tobacco chassis is also introduced. Finally, the heterologous expression and biotransformation of PTOX in microorganisms is summarized, which sets the foundation for the efficient microbial production of PTOX using cell factories.

[Conjugate of podophyllotoxin with chlorambucil: synthesis, biological testing and molecular modeling]

In the present work we have studied a novel conjugate of the DNA alkylating agent chlorambucil with podophyllotoxin, a ligand of the colchicine binding site in tubulin. The target compound was obtained by Steglich esterification of podophyllotoxin with the percentage yield of 41%. Results of biotesting carried out on the carcinoma A549 cell line revealed that at a concentration of 2 μM the conjugate caused full depolymerization of microtubules without any other effect on free tubulin. The conjugate inhibited proliferation (IC50=135±30 nM) and growth (EC50=240±30 nM) of A549 cells. The data of computer molecular docking of the novel compound into the 3D model of the colchicine binding site in α,β-tubulin and molecular dynamics modelling allowed to explain the observed difference in effects of chlorambucil-podophyllotoxin and chlorambucil-colchicine conjugates on microtubules.

Essential Oil Composition and Bioactivity of Two Juniper Species from Bulgaria and Slovakia

Juniperus excelsa M. Bieb and J. sabina L. contain essential oil (EO), while J. sabina also contains podophyllotoxin, which is used as a precursor for anti-cancer drugs. Two studies were conducted. The first assessed the variability in the EO profile and podophyllotoxin concentration of the two junipers, depending on the location and tree gender. The main EO constituents of J. excelsa were α-cedrol, α-limonene and α-pinene, while the constituents in J. sabina were sabinene, terpinen-4-ol, myrtenyl acetate and α-cadinol. The podophyllotoxin yield of 18 J. sabina accessions was 0.07–0.32% (w/w), but this was not found in any of the J. excelsa accessions. The second study assessed the effect of hydrodistillation (Clevenger apparatus) and steam distillation (in a semi-commercial apparatus) on the EO profile and bioactivity. The extraction type did not significantly alter the EO composition. The EO profiles of the two junipers and their accessions were different and may be of interest to the industry utilizing juniper leaf EO. Breeding and selection programs could be developed with the two junipers (protected species) in order to identify chemotypes with (1) a high EO content and desirable composition, and (2) a high concentration of podophyllotoxin in J. sabina. Such chemotypes could be established as agricultural crops for the commercial production of podophyllotoxin and EO.

Synthesis and antitumor activity of new tetrahydrocurcumin derivatives via click reaction

Three new derivatives of tetrahydrocurcumin 6, 7 and 9 have been prepared as potent antitumor agents using copper(II)-catalyzed 'click chemistry'. Their structures were identified using ¹H-NMR, ¹³C-NMR and HRMS techniques. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay has been carried out to investigate the in vitro cytotoxicity against human cervical carcinoma (HeLa), human lung adenocarcinoma (A549), human hepatoma carcinoma (HepG2) and human colon carcinoma (HCT-116). Compound 6 has showed significant inhibitory activity against HCT-116 cell line with an IC₅₀ value of 17.86 μM compared to tetrahydrocurcumin (50.96 μM) and positive control etoposide (19.48 μM) while showed no inhibitory activity against NCM460 cell line. Compounds 7 showed moderate inhibitory activity compared to tetrahydrocurcumin and etoposide while compound 9 showed no obvious inhibitory activity. The results suggested further structure modifications of tetrahydrocurcumin to improve its anticancer activity.

Podophyllotoxin Exposure Affects Organelle Distribution and Functions in Mouse Oocyte Meiosis

Podophyllotoxin (POD) is one of the most characterized lignans that is commonly found in podophyllum, and its preparations and derivatives are widely used in clinical treatment due to strong antitumor and antivirus activities. POD has been reported for its neurotoxicity, liver toxicity, and potential reproductive toxicity. In the present study, we investigated the effects of POD on the organelles of mouse oocytes during meiosis. Our results showed that exposure to POD significantly reduced the developmental competence of mouse oocytes. Further analysis revealed that the endoplasmic reticulum (ER) failed to accumulate to the spindle periphery, suggesting that POD exposure might affect protein synthesis during oocyte meiotic maturation. Similarly, abnormal Golgi apparatus distribution was found after POD exposure, which could be confirmed by the aberrant localization of Rab11a-related vesicles, indicating that POD induced vesicle-based protein transport disorder. We also found the aberrant accumulation of lysosomes in the cytoplasm of POD-exposed oocytes, which implied that POD might lead to aberrant protein degradation. Moreover, the perinuclear distribution of mitochondria was also significantly disturbed, indicating the mitochondrial dysfunction after POD exposure. In all, our study illustrated that exposure to POD might disrupt protein synthesis, transport, degradation, and ATP production by its effects on the distribution and functions of organelles during mouse oocyte meiotic maturation.

Novel Hybrids of Podophyllotoxin and Coumarin Inhibit the Growth and Migration of Human Oral Squamous Carcinoma Cells

Oral squamous cell carcinoma is the most common malignancy of oral tumor. In this study, two novel hybrids of podophyllotoxin and coumarin were designed using molecular hybridization strategy and synthesized. Pharmacological evaluation showed that the potent compound 12b inhibited the proliferation of three human oral squamous carcinoma cell lines with nanomolar IC₅₀ values, as well as displayed less toxicity on normal cells. Mechanistic studies indicated that 12b triggered HSC-2 cell apoptosis, induced cell cycle arrest, and inhibited cell migration. Moreover, 12b could disturb the microtubule network via binding into the tubulin. It was noteworthy that induction of autophagy by 12b was associated with the upregulation of Beclin1, as well as LC3-II. Furthermore, 12b significantly stimulated the AMPK pathway and restrained the AKT/mTOR pathway in HSC-2 cells. These results indicated that compound 12b was a promising candidate for further investigation.

Recent advances in the application of podophyllotoxin derivatives to fight against drugresistant cancer cells

Podophyllotoxins including epipodophyllotoxin derivatives can act on a diverse array of drug targets in cancer cells, and thus possess potential activity against various forms of cancer cell lines including drug-resistant forms. Moreover, several podophyllotoxin derivatives which are represented by etoposide and teniposide have already been approved for the cancer therapy, demonstrating podophyllotoxin moiety is a useful pharmacophore for the discovery of novel anticancer agents. This review reports the recent advances in exploitation of podophyllotoxin derivatives to fight against multidrug-resistant cancer cells. The mechanism of action and structure-activity relationship (SAR) studies are also highlighted.

A Novel Cytotoxic Conjugate Derived from the Natural Product Podophyllotoxin as a Direct-Target Protein Dual Inhibitor

Natural products are the ideal basis for the design of novel efficient molecular entities. Podophyllotoxin, a naturally occurring cyclolignan, is an example of natural product which displays a high versatility from a biological activity point of view. Based on its unique chemical structure, different derivatives have been synthesized presenting the original antitumoral properties associated with the compound, i.e., the tubulin polymerization inhibition and arising anti-topoisomerase II activity from structural modifications on the cyclolignan skeleton. In this report, we present a novel conjugate or hybrid which chemically combines both biological activities in one single molecule. Chemical design has been planned based in our lead compound, podophyllic aldehyde, as an inhibitor of tubulin polymerization, and in etoposide, an approved antitumoral drug targeting topoisomerase II. The cytotoxicity and selectivity of the novel synthetized hybrid has been evaluated in several cell lines of different solid tumors. In addition, these dual functional effects of the novel compound have been also evaluated by molecular docking approaches.

A combined prophylactic modality of podophyllotoxin and rutin alleviates radiation induced injuries to the lymphohematopoietic system of mice by modulating cytokines, cell cycle progression, and apoptosis

The present study was conceptualized to delineate radioprotective efficacy of a formulation G-003M (a combination of podophyllotoxin and rutin) against radiation-induced damage to the lymphohematopoietic system of mice. C57BL/6J mice, treated with G-003M 1 h prior to 9 Gy lethal dose, were assessed for reactive oxygen species (ROS)/nitric oxide (NO) generation, antioxidant alterations, Annexin V/PI and TUNEL staining for apoptosis, modulation of apoptotic proteins, cell proliferation, histological alterations in thymus and cell cycle arrest in bone marrow cells. Induction of granulocyte colony-stimulating factor (G-CSF), granulocytes macrophage colony-stimulating factor (GM-CSF), interleukin-IL-6, IL-10, IL-1α, and IL-1β in response to G-003M was also evaluated in different groups of mice. Haematopoietic reconstitution with G-003M was explored by examining endogenous spleen colony-forming units (CFU-S) in irradiated animals. G-003M significantly inhibited ROS/NO, malondialdehyde (MDA) and restored cellular antioxidant glutathione in the thymus of irradiated animals. G-003M pre-treatment significantly (p < 0.001) restrained apoptosis in thymocytes via upregulation of Bcl2 and down-regulation of Bax, p53 and caspase-3. Stimulation of cell proliferation and inhibition of apoptosis by G-003M, restored architecture of thymus in irradiated animals within 30 days as evaluated by histological analysis. G-003M arrested cells at the G2/M phase by inducing reversible cell cycle arrest. Peak expression of G-CSF (45-fold) and IL-6 (60-fold) as well as moderate induction of GM-CSF, IL-10, IL-1α by G-003M helped in haematopoietic recovery of irradiated mice. A higher number of endogenous CFU-S in G-003M pre-treated irradiated mice suggested haematopoietic recovery. Data obtained from the current study affirms that G-003M can be proved as a potential radioprotective agent against radiation damage.

Target Analysis and Mechanism of Podophyllotoxin in the Treatment of Triple-Negative Breast Cancer

Background

As the original compound of many podophyllotoxin derivatives, podophyllotoxin has a beneficial antitumor effect. The mechanism of podophyllotoxin activity in triple-negative breast cancer still needs to be explored.

Methods

We used cell proliferation assay, scratch and transwell experiments, and cell cycle and apoptosis analyses to observe the intervention effect of podophyllotoxin on breast cancer. Furthermore, we analyzed the differences between GSE31448, GSE65194, and GSE45827 in the Gene Expression Omnibus database (GEO) and explored the differential genes using a STRING database. Centiscape2.2, MCODE cluster analysis and KEGG pathway analysis were used to identify the most significant gene differences. Next, we utilized BATMAN-TCM and TCMSP databases for further screening to identify key genes. Finally, quantitative RT-PCR (qRT-PCR) and Western blotting were performed to detect the expression of key targets.

Results

Our research confirmed that podophyllotoxin could not only inhibit the migration and invasion of triple-negative breast cancer but also affect the cell cycle and induce apoptosis. In total, 566 differential genes were obtained by using the GEO database. After topological network analysis, cluster analysis, and molecular docking screening, we finally identified PLK1, CCDC20, and CDK1 as key target genes. The results of the qRT-PCR assay showed that the mRNA levels of PLK1, CDC20, and CDK1 decreased, while the expression of upstream P53 increased, after drug induction. The Gene Set Enrichment Analysis (GSEA) and conetwork analysis showed that PLK1 is a more critical regulatory factor. Further Western blotting analysis revealed that there was a negative regulatory relationship between the key gene PLK1 and P53 on the protein level. The results were presented as the mean ± standard deviation of triplicate experiments and P<0.05 was considered to indicate a statistically significant difference.

Conclusion

Podophyllotoxin has an intervention effect on the development of triple-negative breast cancer. The expression of PLK1, CDC20, and CDK1 in the cell cycle pathway is inhibited by regulating P53. Our research shows that natural drugs inhibit tumor activity by regulating the expression of cyclins, and the combination of natural drugs and modern extensive database analysis has a wide range of potential applications in the development of antitumor therapies.

Combination of podophyllotoxin and rutin modulate radiation-induced alterations of jejunal proteome in mice

Purpose: Gastrointestinal (GI) injuries post ionizing radiation (IR) becomes a crucial factor in survival. Thus, the current study was aimed to explore the molecular mechanisms behind IR produced GI proteome alterations and their amelioration by a safe radioprotective formulation candidate, G-003M (podophyllotoxin+rutin).Materials and method: C57BL/6 mice were administered with G-003M 1 h before 9 Gy whole body γ irradiation. 2DE-MS analysis was conducted to identify differential expression of jejunum proteins with fold change >1.5 (p < .05) at various time-points. Results: G-003M pre-administration decreased total number of differential proteins. It mediated protection to cytoskeleton, modulated stress, apoptosis and inflammatory proteins. Direct effect on eukaryotic translation initiation factor 4H (Eif4h), thioredoxin domain-containing protein 17 (Txndc17) and interferon-induced protein 35 (Ifi35) was observed. Bioinformatics depicted transcription factor-MYC, was also positively modulated by G-003M. Further, it also enhanced level of citrulline (ELISA analysis), and restored crypts and villi lengths (histological analysis) against severe damage caused by lethal irradiation.Conclusion: Current findings reveal that G-003M may be an efficient candidate in protecting key proteins of metabolic and biochemical pathways assisting in the rapid recovery of GI proteome. This fairly improved the chances of animal survival exposed to lethal doses of whole body radiation.

[Synthesis and antitumor activity of podophyllotoxin derivatives]

According to drug design flattening principle and using podophyllotoxin or 4'-demethylepipodophyllotoxin and aldehydes as starting material,a series of podophyllotoxin derivatives containing an imine structure with low toxicity were highly effective synthesized. Nine target compounds were successfully synthesized,and their structures were confirmed by ~1H-NMR,HR-ESI-MS and melting point data analysis. Using etoposide as positive control drug,nine target compounds were screened for cytotoxicity against He La cells in vitro by MTT method. The antitumor activity screening results showed that compound 6 b,6 d,6 e,6 f,6 g,6 i exhibited higher inhibitory rate against He La cells than those of control drug VP-16. It provides some practical reference value for the further development on the structure modification of podophyllotoxin and study on anti-tumor activity.

Phospholipid prodrug conjugates of insoluble chemotherapeutic agents for ultrasound targeted drug delivery

The hydrophobicity and high potency of many therapeutic agents makes them difficult to use effectively in clinical practice. This work focuses on conjugating phospholipid tails (2T) onto podophyllotoxin (P) and its analogue (N) using a linker and characterizing the effects of their incorporation into lipid-based drug delivery vehicles for triggered ultrasound delivery. Differential Scanning Calorimetry results show that successfully synthesized lipophilic prodrugs, 2T-P (~28 % yield) and 2T-N(~26 % yield), incorporate within the lipid membranes of liposomes. As a result of this, increased stability and incorporation are observed in 2T-P and 2T-N in comparison to the parent compounds P and N. Molecular dynamic simulation results support that prodrugs remain within the lipid membrane over a relevant range of concentrations. 2T-N's (IC₅₀: 20 nM) biological activity was retained in HeLa cells (cervical cancer), whereas 2T-P's (IC₅₀: ~4 µM) suffered, presumably due to steric hindrance. Proof-of-concept studies using ultrasound in vitro microbubble and nanodroplet delivery vehicles establish that these prodrugs are capable of localized drug delivery. This study provides useful information about the synthesis of double tail analogues of insoluble chemotherapeutic agents to facilitate incorporation into drug delivery vehicles. The phospholipid attachment strategy presented here could be applied to other well suited drugs such as gemcitabine, commonly known for its treatment of pancreatic cancer.

A short, 8-week course of imiquimod 5% cream versus podophyllotoxin in the treatment of anogenital warts: A retrospective comparative cohort study

BACKGROUND

Studies comparing head-to-head treatment modalities for anogenital warts are lacking.

AIM

We sought to compare a short, 8-week course of imiquimod 5% cream to versus the standard 4 week course of podophyllotoxin in the treatment of anogenital warts and to assess factors that may affect response to treatment.

METHODS

This was a retrospective cohort study. We reviewed medical files of otherwise healthy patients with a first episode of anogenital warts who were treated with either a short, 8-week course of imiquimod or the standard 4-week course of podophyllotoxin. Inverse probability of treatment weighted (IPTW). Logistic regression was employed to evaluate factors that may affect response to therapy.

RESULTS

The study included 347 patients. In patients with lesions on dry, keratinized anatomical sites, the complete clearance rates were 7.6% for imiquimod and 27.9% for podophyllotoxin (P < 0.001). In patients with lesions on moist, partially keratinized sites, no difference between the treatments was revealed. Significant predictors of > 50% reduction in wart area were location of lesions [odds ratio (OR) (95% confidence interval (CI)): 3.6 (1.84-7.08), P = 0.0002] for "partially keratinized" versus "keratinized" sites and treatment used [OR (95% CI): 1.79 (1.08-2.97), P = 0.024] for podophyllotoxin versus imiquimod.

LIMITATIONS

The retrospective design of the study was a limitation that we mitigated against with the use of IPTW logistic regression.

CONCLUSION

A standard 4 week course of Podophyllotoxin was more effective than an 8-week course of imiquimod only for lesions on keratinized sites. Treatment with podophyllotoxin and location of lesions on partially keratinized sites were independent predictors of >50% reduction in wart area.

Glucoside Derivatives Of Podophyllotoxin: Synthesis, Physicochemical Properties, And Cytotoxicity

Background

Widespread concern of the side effects and the broad-spectrum anticancer property of podophyllotoxin as an antitumor agent highlight the need for the development of new podophyllotoxin derivatives. Although some per-butyrylated glucosides of podophyllotoxin and 4β-triazolyl-podophyllotoxin glycosides show good anticancer activity, the per-acetylated/free of podophyllotoxin glucosides and their per-acetylated are not well studied.

Methods

A few glucoside derivatives of PPT were synthesized and evaluated for their in vitro cytotoxic activities against five human cancer cell lines, HL-60 (leukemia), SMMC-7721 (hepatoma), A-549 (lung cancer), MCF-7 (breast cancer), and SW480 (colon cancer), as well as the normal human pulmonary epithelial cell line (BEAS-2B). In addition, we investigated the structure–activity relationship and the physicochemical property–anticancer activity relationship of these compounds.

Results

Compound 6b shows the highest cytotoxic potency against all five cancer cell lines tested, with IC₅₀ values ranging from 3.27±0.21 to 11.37±0.52 μM. We have also found that 6b displays higher selectivity than the etoposide except in the case of HL-60 cell line. The active compounds possess similar physicochemical properties: MSA > 900, %PSA < 20, ClogP > 2, MW > 700 Da, and RB > 10.

Conclusion

We synthesized several glucoside derivatives of PPT and tested their cytotoxicity. Among them, compound 6b showed the highest cytotoxicity. Further studies including selectivity of active compounds have shown that the selectivity indexes of 6b are much greater than the etoposide except in the case of HL-60 cell line. The active compounds possessed similar physicochemical properties. This study indicates that active glucoside analogs of podophyllotoxin have potential as lead compounds for developing novel anticancer agents.

Enhanced production of podophyllotoxin, kaempferol, and quercetin from callus culture of Dysosma pleiantha (Hance) Woodson: An endangered medicinal plant

Dysosma pleiantha (Hance) Woodson is one of the endangered traditional Chinese medicinal herbs, highly valued for its medicinal properties by Taiwan's mountain tribes. The present study aims to develop an efficient protocol for callus biomass by optimizing suitable culture medium, carbon source culture condition, and enhanced production of pharmaceutically important podophyllotoxin, kaempferol, and quercetin from callus culture of D. pleiantha under the influence of different additives. Best callus induction was achieved in Gamborg's medium (B5) with 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) along with 0.2 mg/L kinetin under dark condition. Tender leaves of D. pleiantha showed the maximum of 86% callus induction among the different explants tested. Highest leaf callus proliferation was noted in B5 medium with 1 mg/L 2,4-D incubated under complete darkness. In addition, it was found that B5 medium with 1 mg/L 2,4-D along with 2 g/L peptone produced more leaf callus biomass and enhanced production of podophyllotoxin (16.3-fold), kaempferol (12.39-fold), and quercetin (5.03-fold) compared to control. Therefore, D. pleiantha callogenesis can provide an alternative source for enhanced production of secondary compounds regardless of the exploitation of its natural plant population.

[Synthesis and antitumor activity of novel indole podophyllotoxin derivatives]

According to drug design flattening principle,a series of novel indole podophyllotoxin derivatives which were introduced different indole substituents in C-4 position on the basis of podophyllotoxin nucleus were synthesized with the starting material podophyllotoxin and 1 H-indole-5-carboxylic acid. Its anti-tumor activity in vitro was tested in order to screen for high-efficiency and low-toxic compounds. Six target compounds were synthesized,and were confirmed by~1 H-NMR,~(13)C-NMR,HR-ESI-MS and melting point determination analysis. All these target compounds were not reported by previous literature. Using etoposide as positive control drug,all the target compounds were screened for cytotoxicity against He La cells,K562 cells and K562/A02 cell in vitro by MTT method. The antitumor activity screening results showed that compounds 4 b,4 e,4 f exhibited higher inhibitory rate against He La cells and K562 cells than those of control drug VP-16. This route has the advantages on simple operation and reasonable design,provides some practical reference value for the further development on the structure modification of podophyllotoxin and study on anti-tumor activity.

[Effects of exogenous IBA and fungal elicitor on growth of in vitro roots culture of Dysosma versipellis and production of podophyllotoxin]

Using the White as basic medium, the effects of the exogenous IBA and endophytic fungal elicitor on the growth of in vitro roots cultures of Dysosma versipellis and production of podophyllotoxin were investigated in this study. The results showed that the IBA and the endophytic fungus Zasmidium syzygii elicitor could increase the content of podophyllotoxin of in vitro roots of D. versipellis after 3 weeks. The White medium added with 3 mg·L~(-1) IBA induced the highest increase of podophyllotoxin(1 830.86 μg·g~(-1)), which was 2.07 folds greater than the control, and followed by 1.5 mg·L~(-1) IBA, fungal elicitor, 1 mg·L~(-1) IBA, 0.5 mg·L~(-1) IBA and 4.5 mg·L~(-1) IBA, which was 1.82, 1.71, 1.63, 1.43 and 1.1 folds greater than the control, respectively. The results also showed that the growth of roots was certain positively correlated with the change of IBA concentration. Therefore, 3 mg·L~(-1) IBA was the most suitable for the production of podophyllotoxin in the in vitro roots of D. versipellis, and the stimulating effect of Z. syzygii fungal elicitor was between 1.5 mg·L~(-1) and 1 mg·L~(-1) IBA, which was a potential natural elicitor to induce the accumulation of podophyllotoxin in future production.

Synaptic Microtubule-Associated Protein EB3 and SRC Phosphorylation Mediate Structural and Behavioral Adaptations During Withdrawal From Cocaine Self-Administration

Addictive behaviors, including relapse, are thought to depend in part on long-lasting drug-induced adaptations in dendritic spine signaling and morphology in the nucleus accumbens (NAc). While the influence of activity-dependent actin remodeling in these phenomena has been studied extensively, the role of microtubules and associated proteins remains poorly understood. We report that pharmacological inhibition of microtubule polymerization in the NAc inhibited locomotor sensitization to cocaine and contextual reward learning. We then investigated the roles of microtubule end-binding protein 3 (EB3) and SRC kinase in the neuronal and behavioral responses to volitionally administered cocaine. In synaptoneurosomal fractions from the NAc of self-administering male rats, the phosphorylation of SRC at an activating site was induced after 1 d of withdrawal, while EB3 levels were increased only after 30 d of withdrawal. Blocking SRC phosphorylation during early withdrawal by virally overexpressing SRCIN1, a negative regulator of SRC activity known to interact with EB3, abolished the incubation of cocaine craving in both male and female rats. Conversely, mimicking the EB3 increase observed after prolonged withdrawal increased the motivation to consume cocaine in male rats. In mice, the overexpression of either EB3 or SRCIN1 increased dendritic spine density and altered the spine morphology of NAc medium spiny neurons. Finally, a cocaine challenge after prolonged withdrawal recapitulated most of the synaptic protein expression profiles observed at early withdrawal. These findings suggest that microtubule-associated signaling proteins such as EB3 cooperate with actin remodeling pathways, notably SRC kinase activity, to establish and maintain long-lasting cellular and behavioral alterations following cocaine self-administration.SIGNIFICANCE STATEMENT Drug-induced morphological restructuring of dendritic spines of nucleus accumbens neurons is thought to be one of the cellular substrates of long-lasting drug-associated memories. The molecular basis of these persistent changes has remained incompletely understood. Here we implicate for the first time microtubule function in this process, together with key players such as microtubule-bound protein EB3 and synaptic SRC phosphorylation. We propose that microtubule and actin remodeling cooperate during withdrawal to maintain the plastic structural changes initially established by cocaine self-administration. This work opens new translational avenues for further characterization of microtubule-associated regulatory molecules as putative drug targets to tackle relapse to drug taking.

Chemoenzymatic Total Synthesis of Deoxy-, epi-, and Podophyllotoxin and a Biocatalytic Kinetic Resolution of Dibenzylbutyrolactones

Podophyllotoxin is probably the most prominent representative of lignan natural products. Deoxy‐, epi‐, and podophyllotoxin, which are all precursors to frequently used chemotherapeutic agents, were prepared by a stereodivergent biotransformation and a biocatalytic kinetic resolution of the corresponding dibenzylbutyrolactones with the same 2‐oxoglutarate‐dependent dioxygenase. The reaction can be conducted on 2 g scale, and the enzyme allows tailoring of the initial, “natural” structure and thus transforms various non‐natural derivatives. Depending on the substitution pattern, the enzyme performs an oxidative C−C bond formation by C−H activation or hydroxylation at the benzylic position prone to ring closure.

[Podophyllotoxin analogue with bicyclo[3.2.1]octane moiety annelated with indole: synthesis, molecular modeling, and biological testing]

C4-Ester derivatives of the anticancer agent podophyllotoxin with bridged moieties can either inhibit polymerization of alpha,beta-tubulin with the formation of microtubules (analogously to the parent molecule) or cause an unusual effect of "curling and shortening" of the microtubules (MT). In order to predict the effect of bridged podophyllotoxin derivatives on the MT network using computer molecular modeling it is desirable to enhance the structural diversity of their bridged substituents. In the present work we synthesized novel podophyllotoxin ester with bicyclo[3.2.1]octane moiety annelated with indole core. The target compound was obtained by Steglich esterification of podophyllotoxin by rac-exo-(indolo[2,3-b])bicyclo[3.2.1]oct-2-ene-6-carboxylic acid as diastereomeric (6RS,8SR,9RS) mixture, which could not be separated by thin layer or preparative column chromatography on silica gel. Results of biotesting of 4-O-{(6R,8S,9R)-5,6,7,8,9,10-hexahydro-6,9-methanocyclohepto[b]indol-8-ylcarbonyl}-Lpodophyllotoxin on the carcinoma A549 cells proved its ability to cause full depolymerization of microtubules without curling effect at a concentration 10 μM. Cytotoxicity value of the compound estimated in MTT test was in a high nanomolar concentration interval (EC50=710±30 nM). Computer molecular docking of both isomers of novel compound and earlier synthesized podophyllotoxin esters with bridged moieties into the 3D model of the colchicine domain in alpha,beta-tubulin revealed the difference in positions of the bridge moieties of new compound and MT-curling ligands and allowed to hypothesize that the atypical action on MT might be caused by positioning of their bridge groups near the GTP binding site in alpha-tubulin.

Recalcitrant extragenital giant condyloma acuminatum: A need for combination therapy

Giant condyloma acuminatum (GCA), also known as Buschke -Löwenstein tumor, is a huge, rapidly growing variant of condyloma found in the anogenital region. Extragenital GCA is rare and, in most cases, affecting the intertriginous area and treated by excision. We described a case of refractory extragenital GCA involving the large part of the left axilla area successfully treated with immunotherapy and podophyllotoxin. Considering the large size and the location, the lesions were not treated by wide excision because it might result in scar contracture with limitation of shoulder movement or axillary web syndrome. Our case illustrates that combination therapy of podophyllotoxin, imiquimod plus weekly cryotherapy may be an effective and less invasive option for treating GCA of the axilla with good cosmetic and functional outcomes.