The antitumor effects of tetrodotoxin and/or doxorubicin on Ehrlich ascites carcinoma-bearing female mice

Phytochemical Modulation of Ion Channels in Oncologic Symptomatology and Treatment

Modern chemotherapies offer a broad approach to cancer treatment but eliminate both cancer and non-cancer cells indiscriminately and, thus, are associated with a host of side effects. Advances in precision oncology have brought about new targeted therapeutics, albeit mostly limited to a subset of patients with an actionable mutation. They too come with side effects and, ultimately, 'self-resistance' to the treatment. There is recent interest in the modulation of ion channels, transmembrane proteins that regulate the flow of electrically charged molecules in and out of cells, as an approach to aid treatment of cancer. Phytochemicals have been shown to act on ion channels with high specificity regardless of the tumor's genetic profile. This paper explores the use of phytochemicals in cancer symptom management and treatment.

Potential cardioprotective and anticancer effects of carvedilol either free or as loaded nanoparticles with or without doxorubicin in solid Ehrlich carcinoma-bearing mice

AIM

The aim of this study was to investigate the potential cardioprotective and anti-cancer effects of carvedilol (CAR) either free or as loaded nano-formulated with or without doxorubicin (DOX) in solid Ehrlich carcinoma (SEC)-bearing mice. It focused on assessment of cardiac damage, drug resistance, apoptosis, oxidative stress status, angiogenesis and proliferation.

METHODS

CAR was loaded into poly-D,L lactic-co-glycolic acid)PLGA(or Niosomes. SEC was induced in female albino mice as an experimental model of breast cancer. Seventy-two mice were randomly divided into 9 equal groups (Normal control, Untreated-SEC, SEC + DOX, SEC + CAR-free, SEC + CAR-PLGA, SEC + CAR-Niosomes, SEC + DOX + CAR-free, SEC + DOX + CAR-PLGA and SEC + DOX + CAR-Niosomes). Tumor volume and survival rate were recorded. On day 28 from tumor inoculation, mice were sacrificed, and blood samples were collected for determination of serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB). One part from tumor tissues was prepared for assessment of multidrug resistance protein-1 (MDR-1), caspase-3, reduced glutathione (GSH) and malondialdehyde (MDA), while the other part was processed for histopathological examination and immunohistochemical expression of vascular endothelial growth factor (VEGF) and Ki-67.

RESULTS

There was non-significant difference between CAR-free, CAR-PLGA and CAR-Niosomes as anticancer either alone or when combined with DOX. However, CAR-free demonstrated potential cardioprotective effects against cardiac damage mediated by cancer or DOX that have been enhanced using CAR-PLGA or CAR-Niosomes, but that of Niosomes outperformed them both.

CONCLUSION

CAR could be used as an adjuvant therapy with DOX, especially when nanoformualted with PLGA and even better with Niosomes, without compromising its cytotoxicity against cancer cells and preventing its cardiotoxic impacts.

Synthesis, characterisation and enhanced apoptotic effect of gemcitabine-loaded albumin nanoparticles coating with chitosan

Gemcitabine was loaded in albumin nanoparticles then coated with chitosan. The diameter of GEM-ANPs/CS was 200 ± 4 nm. Gemcitabine was loaded in GEM-ANPs/CS with an efficacy of 75%. The IC₅₀ of GEM-ANPs/CS was found to be 12.98 and 6.08 μg/ml after incubation for 48 and 72 h with MCF-7 cells, respectively. Treatment of MCF-7 cells with IC₅₀ of GEM-ANPS, and GEM-ANP_S/CS resulted in membrane damage which led to elevated LDH activity of 4 and 3.4, and increasing GSH level of 4.6 and 9.3, respectively, when compared with untreated cells. DNA fragmentation and up-regulated of caspase-3 and p53 had illustrated the apoptotic effect of MCF-7 treated with GEM-ANP_S/CS. The tumour suppressor RRM1 gene expression was down-regulated in MCF-7 cells treated with GEM-ANP_S/CS. The modified ANPs coated with chitosan may be used as a promising nanomatrix for gemcitabine delivery and targeting to improve its therapeutic index against MCF-7 cells.

Effects of combined administration of doxorubicin and chloroquine on lung pathology in mice with solid Ehrlich ascites carcinoma

Combined use of a chemotherapeutic agent and an autophagy inhibitor is a novel cancer treatment strategy. We investigated the effects of chloroquine (CQ) on lung pathology caused by both solid Ehrlich ascites carcinoma (EAC) and doxorubicin (DXR). A control group and eight experimental groups of adult female mice were inoculated subcutaneously with 2.5 × 10⁶ EAC cells. DXR (1.5 mg/kg and 3 mg/kg) and CQ (25 mg/kg and 50 mg/kg) alone or in combination were injected intraperitoneally on days 2, 7 and 12 following inoculation with EAC cells. Lung tissue samples were examined using immunohistochemistry (IHC) for endothelial (eNOS), inducible nitric oxide synthase (iNOS) and neutrophil gelatinase-associated lipocalin (NGAL). Serum catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured using ELISA. We found decreased levels of iNOS and eNOS in the groups that received 1.5 mg/kg DXR alone and in combination with 25 mg/kg and 50 mg/kg CQ. Combined administration of DXR and CQ partially prevented disruption of alveolar structure. Levels of antioxidant enzymes and MDA were lower in all treated groups; the greatest reduction was observed in mice that received the combination of 25 mg/kg CQ + 1.5 mg/kg DXR. Levels of NGAL were elevated in all treated groups. We found that CQ ameliorated both EAC and DOX induced lung pathology in female mice with solid EAC by reducing oxidative stress.

An Updated Review of Tetrodotoxin and Its Peculiarities

Tetrodotoxin (TTX) is a crystalline, weakly basic, colorless organic substance and is one of the most potent marine toxins known. Although TTX was first isolated from pufferfish, it has been found in numerous other marine organisms and a few terrestrial species. Moreover, tetrodotoxication is still an important health problem today, as TTX has no known antidote. TTX poisonings were most commonly reported from Japan, Thailand, and China, but today the risk of TTX poisoning is spreading around the world. Recent studies have shown that TTX-containing fish are being found in other regions of the Pacific and in the Indian Ocean, as well as the Mediterranean Sea. This review aims to summarize pertinent information available to date on the structure, origin, distribution, mechanism of action of TTX and analytical methods used for the detection of TTX, as well as on TTX-containing organisms, symptoms of TTX poisoning, and incidence worldwide.

From Poison to Promise: The Evolution of Tetrodotoxin and Its Potential as a Therapeutic

Tetrodotoxin (TTX) is a potent neurotoxin that was first identified in pufferfish but has since been isolated from an array of taxa that host TTX-producing bacteria. However, determining its origin, ecosystem roles, and biomedical applications has challenged researchers for decades. Recognized as a poison and for its lethal effects on humans when ingested, TTX is primarily a powerful sodium channel inhibitor that targets voltage-gated sodium channels, including six of the nine mammalian isoforms. Although lethal doses for humans range from 1.5-2.0 mg TTX (blood level 9 ng/mL), when it is administered at levels far below LD₅₀, TTX exhibits therapeutic properties, especially to treat cancer-related pain, neuropathic pain, and visceral pain. Furthermore, TTX can potentially treat a variety of medical ailments, including heroin and cocaine withdrawal symptoms, spinal cord injuries, brain trauma, and some kinds of tumors. Here, we (i) describe the perplexing evolution and ecology of tetrodotoxin, (ii) review its mechanisms and modes of action, and (iii) offer an overview of the numerous ways it may be applied as a therapeutic. There is much to be explored in these three areas, and we offer ideas for future research that combine evolutionary biology with therapeutics. The TTX system holds great promise as a therapeutic and understanding the origin and chemical ecology of TTX as a poison will only improve its general benefit to humanity.

Photoelectric Bacteria Enhance the In Situ Production of Tetrodotoxin for Antitumor Therapy

Engineered bacteria are promising bioagents to synthesize antitumor drugs at tumor sites with the advantages of avoiding drug leakage and degradation during delivery. Here, we report an optically controlled material-assisted microbial system by biosynthesizing gold nanoparticles (AuNPs) on the surface of Shewanella algae K3259 (S. algae) to obtain Bac@Au. Leveraging the dual directional electron transport mechanism of S. algae, the hybrid biosystem enhances in situ synthesis of antineoplastic tetrodotoxin (TTX) for a promising antitumor effect. Because of tumor hypoxia-targeting feature of facultative anaerobic S. algae, Bac@Au selectively target and colonize at tumor. Upon light irradiation, photoelectrons produced by AuNPs deposited on bacterial surface are transferred into bacterial cytoplasm and participate in accelerated cell metabolism to increase the production of TTX for antitumor therapy. The optically controlled material-assisted microbial system enhances the efficiency of bacterial drug synthesis in situ and provides an antitumor strategy that could broaden conventional therapy boundaries.

Triaryl dicationic DNA minor-groove binders with antioxidant activity display cytotoxicity and induce apoptosis in breast cancer

Despite advances in cancer treatment modalities, DNA still stands as one of the targets for anticancer agents. DNA minor groove binders (MGBs) represent an important investigational chemotherapeutic class with promising cytotoxic capacity. Herein this study reports the potent cytotoxic effect of a series of repurposed flexible bis-imidamides 1-4, triaryl bis-guanidine 5 and bis-N-substituted guanidines 6,7 having a 1,4-diphenoxybenzene scaffold backbone on MCF-7 and MDA-MB-231 breast cancer cell lines. Of these compounds, imidamide 4 was chosen for further in-vitro, in-vivo and molecular dynamics (MD) studies owing to its promising anti-tumor activity, with IC₅₀ values on MCF-7 and MDA-MB-231 breast cancer cell lines of 1.9 and 2.08 μM, respectively. Annexin V/propidium iodide apoptosis assay revealed apoptosis induction on imidamide 4 treated MCF-7 cells. RT-PCR assay results demonstrated the proapoptotic effect of compound 4 through increase of mRNA levels of the pro-apoptotic genes; p53, PUMA, and Bax, and inhibiting the anti-apoptotic Bcl-2 gene expression in MCF-7 cells. Moreover, compound 4 induced a G₀/G₁ cell-cycle arrest in MCF-7 in a dose-dependent manner. Corroborating in-vivo experiments on Ehrlich ascites carcinoma (EAC)-bearing mice, reflected the anticancer strength of derivative 4. For further target validation, molecular dynamics (MD) studies demonstrated an energetically favorable binding of imidamide 4 with the DNA minor groove AT rich site. In effect, imidamide 4 can be viewed as a promising hit dicationic compound with good cytotoxic and apoptotic inducing activity against breast cancer that can be adopted for future optimization.

Voltammetric Detection of Tetrodotoxin Real-Time In Vivo of Mouse Organs using DNA-Immobilized Carbon Nanotube Sensors

Background:

Tetrodotoxin (TTX) is a biosynthesized neurotoxin that exhibits powerful anticancer and analgesic abilities by inhibiting voltage-gated sodium channels that are crucial for cancer metastasis and pain delivery. However, for the toxin’s future medical applications to come true, accurate, inexpensive, and real-time in vivo detection of TTX remains as a fundamental step.

Methods:

In this study, highly purified TTX extracted from organs of Takifugu rubripes was injected and detected in vivo of mouse organs (liver, heart, and intestines) using Cyclic Voltammetry (CV) and Square Wave Anodic Stripping Voltammetry (SWASV) for the first time. In vivo detection of TTX was performed with auxiliary, reference, and working herring sperm DNA-immobilized carbon nanotube sensor systems.

Results:

DNA-immobilization and optimization of amplitude (V), stripping time (sec), increment (mV), and frequency (Hz) parameters for utilized sensors amplified detected peak currents, while highly sensitive in vivo detection limits, 3.43 µg L-1 for CV and 1.21 µg L-1 for SWASV, were attained. Developed sensors herein were confirmed to be more sensitive and selective than conventional graphite rodelectrodes modified likewise. A linear relationship was observed between injected TTX concentration and anodic spike peak height. Microscopic examination displayed coagulation and abnormalities in mouse organs, confirming the powerful neurotoxicity of extracted TTX.

Conclusion:

These results established the diagnostic measures for TTX detection regarding in vivo application of neurotoxin-deviated anticancer agents and analgesics, as well as TTX from food poisoning and environmental contamination.

Antineoplastic Activity and Curative Role of Avenanthramides against the Growth of Ehrlich Solid Tumors in Mice

Interest is growing in finding natural sources of effective antitumor agents that generate fewer side effects than conventional chemotherapeutic drugs. Avenanthramides (Avns) are such compounds; these phenolic molecules naturally occur in oats and have antioxidant, anti-inflammatory, and antiproliferative effects making them worthy of further research. The aim of this study is to characterise Avns' curative ability and antineoplastic activity on solid-form Ehrlich tumors. For the study, 75 female mice were randomly and equally allocated to five groups (group 1-control, group 2-DMSO, group 3-positive control receiving Avns, group 4-mice with Ehrlich solid tumor, and group 5-Ehrlich solid tumor treated with Avns). Mice with Ehrlich solid tumors exhibit increased tumor volume; elevated expression of AFP, ALT, AST, Bcl2, CEA, cholesterol, creatinine, urea, MDA, PCNA, potassium, triglycerides, TNF-α, and NF-κB; and a concomitant decline in catalase, GSH, P53, and SOD. In the mice with Ehrlich tumors who received Avns, there appeared to be improvement in NF-κB TNF-α, tumor markers (AFP and CEA), electrolytes, liver and kidney function enzymes, and lipid profiles; reduced MDA level; improved antioxidant parameters; normalised liver protein, P53, and PCNA; and reduced Bcl2 expression. Pathological examination of tumor lesions also indicated improvement. These results suggest that Avns exhibit antineoplastic activity and possess antioxidant properties that enhance the antioxidant defence system, thus reducing the oxidative stress caused by Ehrlich solid tumors.

Rutin and orlistat produce antitumor effects via antioxidant and apoptotic actions

Cancer is a broad term used to describe a large number of diseases characterized by uncontrolled cell proliferation that leads to tumor production. Cancer is associated with mutations in genes controlling proliferation and apoptosis, oxidative stress, fatty acid synthase (FAS) expression, and other mechanisms. Currently, most antineoplastic drugs have severe adverse effects and new effective and safe drugs are needed. This study aims to investigate the possible anticancer activity of rutin and orlistat which are both safely used clinically in humans against two breast cancer models (in vivo EAC and in vitro MCF7) and the pancreatic cancer cell line (PANC-1). Our results have shown that both rutin and orlistat exerted an in vivo anticancer activity as evidenced by the decrease in tumor volume, CEA level, cholesterol content, FAS, and the exerted antioxidant action (reduced MDA level and increased GSH content) and through histopathological examination. In addition, both were cytotoxic to MCF-7 and Panc-1 cell lines by promoting apoptosis. In conclusion, the anticancer activity of rutin and orlistat makes them promising candidates for cancer treatment alone or in combination with other anticancer drugs specially that they are used clinically with an acceptable safety profile.

Effect of metformin and adriamycin on transplantable tumor model

Adriamycin is a cytotoxic anthracycline antibiotic used in treatment of many types of cancer. Metformin is antidiabetic drug and is under investigation for treatment of cancer. The aim of this work was to study the effect of each of adriamycin and metformin alone and in combination on solid Ehrlich carcinoma (SEC) in mice. Eighty BALB/C mice were divided into four equal groups: SEC group, SEC+adriamycin, SEC+metformin, SEC+adriamycin+metformin. Tumor volume, survival rate, tissue catalase, tissue reduced glutathione, tissue malondialdehyde, tissue sphingosine kinase 1 activity, tissue caspase 3 activity and tissue tumor necrosis factor alpha were determined. A part of the tumor was examined for histopathological and immunohistochemical study. Adriamycin or metformin alone or in combination induced significant increase in the survival rate, tissue catalase, reduced glutathione and tissue caspase 3 activity with significant decrease in tumor volume, tissue malondialdehyde, tissue sphingosine kinase 1 activity and tumor necrosis factor alpha and alleviated the histopathological changes with significant increase in Trp53 expression and apoptotic index compared to SEC group. In conclusion, the combination of adriamycin and metformin had a better effect than each of these drugs alone against transplantable tumor model in mice.