Electrochemical treatment of mouse Ehrlich tumor with direct electric current

Ameliorative effects of vitamin B17 on the kidney against Ehrlich ascites carcinoma induced renal toxicity in mice

Cancer is the major cause of death and many factors that lead to its occurrences, such as environmental pollution and pesticides and other factors. Ehrlich carcinoma development depends on many things associated with the environment, nutrition, personal habits, and family history. The present study aimed to evaluate the potential protective effects of vitamin B17 (VB17) against Ehrlich ascites carcinoma (EAC) that induced kidney toxicity in female mice. The mice were divided into five groups (first group, control group; second group, VB17 group; third group, EAC group; fourth group, pretreated EAC with VB17; fifth group, cotreated EAC with VB17). Results showed the VB17 in pretreated (G4) and cotreated (G5) groups lead to an improvement in DNA damage and cytological examination, in addition significantly (P < .05) increase in Na⁺ , red blood cell, hemoglobin, hematocrit value, mean corpuscular hemoglobin (MCH), and MCH concentration, whereas significantly (P < .05) decrease in urea, creatinine, K⁺ , platelets, and white blood cells while insignificant (P < .05) changes in mean corpuscular volume when compared to the EAC group. Many histopathological changes were observed in kidney sections in EAC as marked damage and degenerated, glomerular atrophy, the Malpighian corpuscles that lost their characteristic configuration. On the other hand, a moderate improvement and arrangement in the kidney histological structure in pretreated VB17 + EAC, while a mild enhancement and arrangement of the kidney structure in cotreated EAC + VB17. In addition, depletion in renal P53 and PCNA protein expression compared with the EAC group. It could be concluded that VB17 has a potential renal protective effect against EAC cells induced kidney injury.

Vaccination with gamma radiation-attenuated Toxoplasma gondii protects against ovarian infiltration in mice-bearing Ehrlich ascites carcinoma

Purpose: Cancer is one of the most common causes of mortality and morbidity worldwide. Vaccines have been emerged as an attractive approach for their capacity of eliciting long-term immune response targeting cancer cells. Attenuated avirulent Toxoplasma gondii stimulate immunity and activate antitumor cells thereby eliciting rejection of some established cancer. The purpose of this study was to evaluate the antitumor-protective capacity of vaccination with gamma radiation-attenuated T. gondii against ovarian penetration in Ehrlich ascites carcinoma (EAC)-bearing mice.Materials and methods: Forty-five mice were randomly divided into three groups as follows: nontumor-bearing (normal control); EAC-bearing group (EAC); and mice vaccinated orally with gamma radiation-attenuated T. gondii then inoculated 2 weeks later with EAC (TG + EAC). Survival rate, serum interleukin-12 (IL-12), and levels of IFN-γ mRNA, CD4, and CD8 in ovarian tissues homogenate were assessed. Also, ovarian histopathology and immunohistochemical expressions of metalloproteinase-2, CD34, and vimentin were determined.Results: The group vaccinated with attenuated T. gondii showed significantly increased survival rates, serum IL-12, and levels of IFN-γ, CD4, and CD8 in ovarian tissue homogenates as well as an enhancement of histopathological and immunohistochemical changes compared to EAC-bearing group.Conclusion: Vaccination with gamma radiation-attenuated T. gondii has the capacity to supply immunoprotective impact against ovarian invasion in EAC-bearing mice.

Impact of autologous whole blood administration upon experimental mouse models of acute Trypanosoma cruzi infection

Background

Autologous whole blood (AWB) administration is described as alternative/complementary medical practice widely employed in medical and veterinary therapy against infections, chronic pathologies and neoplasias. Our aim is to investigate in vivo biological effect of AWB using healthy murine models under the course of Trypanosoma cruzi acute infection.

Methods

The first set of studies consisted of injecting different volumes of AWB and saline (SAL) into the posterior region of quadriceps muscle of healthy male Swiss mice under distinct therapeutic schemes evaluating: animal behavior, body and organ weight, hemogram, plasmatic biochemical markers for tissue damage and inflammatory cytokine levels and profile. To assess the impact on the experimental T. cruzi infection, different schemes (prior and post infection) and periods of AWB administration (from one up to 10 days) were conducted, also employing heterologous whole blood (HWB) and evaluating plasma cytokine profile.

Results

No major adverse events were observed in healthy AWB-treated mice, except gait impairment in animals that received three doses of 20 μL AWB in the same hind limb. AWB and SAL triggered an immediate polymorphonuclear response followed by mononuclear infiltrate. Although SAL triggered an inflammatory response, the kinetics and intensity of the histological profile and humoral mediator levels were different from AWB, the latter occurring earlier and more intensely with concomitant elevation of plasma IL-6. Inflammatory peak response of SAL, mainly composed of mononuclear cells with IL-10, was increased at 24 h. According to the mouse model of acute T. cruzi infection, only minor decreases (< 30%) in the parasitemia levels were produced by AWB and HWB given before and after infection, without protecting against mortality. Rises in IFN-gamma, TNF-alpha and IL-6 were detected at 9 dpi in all infected animals as compared to uninfected mice but only Bz displayed a statistically significant diminution (p = 0.02) in TNF-alpha levels than infected and untreated mice.

Conclusions

This study revealed that the use of autologous whole blood (AWB) in the acute model employed was unable to reduce the parasitic load of infected mice, providing only a minor decrease in parasitemia levels (up to 30%) but without protecting against animal mortality. Further in vivo studies will be necessary to elucidate the effective impact of this procedure.

Dose-response study for the highly aggressive and metastatic primary F3II mammary carcinoma under direct current

Electrochemical treatment has been suggested as an effective alternative to local cancer therapy. Nevertheless, its effectiveness decreases when highly aggressive primary tumors are treated. The aim of this research was to understand the growth kinetics of the highly aggressive and metastatic primary F3II tumor growing in male and female BALB/c/Cenp mice under electrochemical treatment. Different amounts of electric charge (6, 9, and 18 C) were used. Two electrodes were inserted into the base, perpendicular to the tumor's long axis, keeping about 1 cm distance between them. Results have shown that the F3II tumor is highly sensitive to direct current. The overall effectiveness (complete response + partial response) of this physical agent was ≥75.0% and observed in 59.3% (16/27) of treated F3II tumors. Complete remission of treated tumors was observed in 22.2% (6/27). An unexpected result was the death of 11 direct current-treated animals (eight females and three males). It is concluded that direct current may be addressed to significantly affect highly aggressive and metastatic primary tumor growth kinetics, including the tumor complete response. Bioelectromagnetics. 39:460-475, 2018. © 2018 Wiley Periodicals, Inc.

Tissue Damage, Temperature, and pH Induced by Different Electrode Arrays on Potato Pieces (Solanum tuberosum L.)

One of the most challenging problems of electrochemical therapy is the design and selection of suitable electrode array for cancer. The aim is to determine how two-dimensional spatial patterns of tissue damage, temperature, and pH induced in pieces of potato (Solanum tuberosum L., var. Mondial) depend on electrode array with circular, elliptical, parabolic, and hyperbolic shape. The results show the similarity between the shapes of spatial patterns of tissue damage and electric field intensity, which, like temperature and pH take the same shape of electrode array. The adequate selection of suitable electrodes array requires an integrated analysis that involves, in a unified way, relevant information about the electrochemical process, which is essential to perform more efficiently way the therapeutic planning and the personalized therapy for patients with a cancerous tumor.

Amorphous liquid metal electrodes enabled conformable electrochemical therapy of tumors

Electrochemical treatment of tumors (EChT) has recently been identified as a very effective way for local tumor therapy. However, hindered by the limited effective area of a single rigid electrode, multiple electrodes are often recruited when tackling large tumors, where too many electrodes not only complicate the clinical procedures but also aggravate patients' pain. Here we present a new conceptual electric stimulation tumor therapy through introducing the injectable liquid metal electrodes, which can adapt to complex tumor shapes so as to achieve desired therapeutic performance. This approach can offer evident merits for dealing with the complex physiological situations, especially for those irregular body cavities like stomach, colon, rectum or even blood vessel etc., which are hard to tackle otherwise. As it was disclosed from the conceptual experiments that, Unlike traditional rigid and uncomfortable electrodes, liquid metal possesses high flexibility to attach to any crooked biological position to deliver and adjust targeted electric field to fulfill anticipated tumor destruction. And such amorphous electrodes exhibit rather enhanced treatment effect of tumors. Further, we also demonstrate that EChT with liquid metal electrodes produced more electrochemical products during electrolysis. Transformations with the shapes of liquid metal provided an easily regulatable strategy to improve EChT efficiency, which can conveniently aid to achieve better output compared to multiple electrodes. In vivo EChT of tumors further clarified the effect of liquid metal electrodes in retarding tumor growth and increasing life spans.

Mutagenic and genotoxic potential of direct electric current in Escherichia coli and Salmonella thyphimurium strains

Direct electric current has several therapeutic uses such as antibacterial and antiprotozoal action, tissues scarring and regeneration, as well as tumor treatment. This method has shown promising results in vivo and in vitro, with significant efficacy and almost no side effects. Considering lack of studies regarding direct electric current mutagenic and/or genotoxic effects, the present work evaluated both aspects by using five different bacterial experimental assays: survival of repair-deficient mutants, Salmonella-histidine reversion mutagenesis (Ames test), forward mutations to rifampicin resistance, phage reactivation, and lysogenic induction. In these experimental conditions, cells were submitted to an approach that allows evaluation of anodic, cathodic, and electro-ionic effects generated by 2 mA of direct electric current, with doses ranging from 0.36 to 3.60 Coulombs. Our results showed these doses did not induce mutagenic or genotoxic effects.

Antitumor effects of electrochemical treatment

Electrochemical treatment is an alternative modality for tumor treatment based on the application of a low intensity direct electric current to the tumor tissue through two or more platinum electrodes placed within the tumor zone or in the surrounding areas. This treatment is noted for its great effectiveness, minimal invasiveness and local effect. Several studies have been conducted worldwide to evaluate the antitumoral effect of this therapy. In all these studies a variety of biochemical and physiological responses of tumors to the applied treatment have been obtained. By this reason, researchers have suggested various mechanisms to explain how direct electric current destroys tumor cells. Although, it is generally accepted this treatment induces electrolysis, electroosmosis and electroporation in tumoral tissues. However, action mechanism of this alternative modality on the tumor tissue is not well understood. Although the principle of Electrochemical treatment is simple, a standardized method is not yet available. The mechanism by which Electrochemical treatment affects tumor growth and survival may represent more complex process. The present work analyzes the latest and most important research done on the electrochemical treatment of tumors. We conclude with our point of view about the destruction mechanism features of this alternative therapy. Also, we suggest some mechanisms and strategies from the thermodynamic point of view for this therapy. In the area of Electrochemical treatment of cancer this tool has been exploited very little and much work remains to be done. Electrochemical treatment constitutes a good therapeutic option for patients that have failed the conventional oncology methods.

Analytical and numerical solutions of the potential and electric field generated by different electrode arrays in a tumor tissue under electrotherapy

BACKGROUND

Electrotherapy is a relatively well established and efficient method of tumor treatment. In this paper we focus on analytical and numerical calculations of the potential and electric field distributions inside a tumor tissue in a two-dimensional model (2D-model) generated by means of electrode arrays with shapes of different conic sections (ellipse, parabola and hyperbola).

METHODS

Analytical calculations of the potential and electric field distributions based on 2D-models for different electrode arrays are performed by solving the Laplace equation, meanwhile the numerical solution is solved by means of finite element method in two dimensions.

RESULTS

Both analytical and numerical solutions reveal significant differences between the electric field distributions generated by electrode arrays with shapes of circle and different conic sections (elliptic, parabolic and hyperbolic). Electrode arrays with circular, elliptical and hyperbolic shapes have the advantage of concentrating the electric field lines in the tumor.

CONCLUSION

The mathematical approach presented in this study provides a useful tool for the design of electrode arrays with different shapes of conic sections by means of the use of the unifying principle. At the same time, we verify the good correspondence between the analytical and numerical solutions for the potential and electric field distributions generated by the electrode array with different conic sections.

Electrochemical treatment: An investigation of dose-response relationships using an isolated liver perfusion model

BACKGROUND/AIM

Ablative techniques such as radiofrequency ablation or non-thermal electrochemical treatment (ECT) are used to manage unresectable liver metastases. Although ECT is not affected by the cooling effect from adjacent vessels, there is a paucity of data available on ECT.

MATERIALS AND METHODS

We used porcine livers to establish an organ model with portal venous and hepatic arterial blood flow for a standardized analysis of the relationship between dose (electric charge) and response (volume of necrosis).

RESULTS

This model allowed us to study pressure-controlled perfusion of portal venous and hepatic arterial circulation in the absence of a capillary leak. A specially designed guiding template helped us place platinum electrodes at reproducible locations. With two electrodes, there was a linear relationship between charges of no more than 200 C and necrosis. The relationship was logarithmic at charges of 400-600 C. Larger electrode spacing led to a significant increase in necrosis. We measured pH values of 0.9 (range: 0.6-1.3) at the anode and 12.6 (range: 11.6-13.4) at the cathode.

CONCLUSIONS

Using a perfusion model, we established an experimental design that allowed us to study ECT in the liver of large animals without experiments on living animals. An electrode template helped us improve the standardized analysis of dose-response relationships. ECT created reproducible and sharply demarcated areas of necrosis, the size of which depended on the charge delivered as well as on the number and spacing of electrodes. Doses higher than 600 C require longer treatment times but do not increase the area of necrosis (logarithmic dose-response relationship).

Modified Gompertz equation for electrotherapy murine tumor growth kinetics: predictions and new hypotheses

BACKGROUND

Electrotherapy effectiveness at different doses has been demonstrated in preclinical and clinical studies; however, several aspects that occur in the tumor growth kinetics before and after treatment have not yet been revealed. Mathematical modeling is a useful instrument that can reveal some of these aspects. The aim of this paper is to describe the complete growth kinetics of unperturbed and perturbed tumors through use of the modified Gompertz equation in order to generate useful insight into the mechanisms that underpin this devastating disease.

METHODS

The complete tumor growth kinetics for control and treated groups are obtained by interpolation and extrapolation methods with different time steps, using experimental data of fibrosarcoma Sa-37. In the modified Gompertz equation, a delay time is introduced to describe the tumor's natural history before treatment. Different graphical strategies are used in order to reveal new information in the complete kinetics of this tumor type.

RESULTS

The first stage of complete tumor growth kinetics is highly non linear. The model, at this stage, shows different aspects that agree with those reported theoretically and experimentally. Tumor reversibility and the proportionality between regions before and after electrotherapy are demonstrated. In tumors that reach partial remission, two antagonistic post-treatment processes are induced, whereas in complete remission, two unknown antitumor mechanisms are induced.

CONCLUSION

The modified Gompertz equation is likely to lead to insights within cancer research. Such insights hold promise for increasing our understanding of tumors as self-organizing systems and, the possible existence of phase transitions in tumor growth kinetics, which, in turn, may have significant impacts both on cancer research and on clinical practice.

Effects of pulsed magnetic stimulation on tumor development and immune functions in mice

We investigated the effects of pulsed magnetic stimulation on tumor development processes and immune functions in mice. A circular coil (inner diameter = 15 mm, outer diameter = 75 mm) was used in the experiments. Stimulus conditions were pulse width = 238 micros, peak magnetic field = 0.25 T (at the center of the coil), frequency = 25 pulses/s, 1,000 pulses/sample/day and magnetically induced eddy currents in mice = 0.79-1.54 A/m(2). In an animal study, B16-BL6 melanoma model mice were exposed to the pulsed magnetic stimulation for 16 days from the day of injection of cancer cells. A tumor growth study revealed a significant tumor weight decrease in the stimulated group (54% of the sham group). In a cellular study, B16-BL6 cells were also exposed to the magnetic field (1,000 pulses/sample, and eddy currents at the bottom of the dish = 2.36-2.90 A/m(2)); however, the magnetically induced eddy currents had no effect on cell viabilities. Cytokine production in mouse spleens was measured to analyze the immunomodulatory effect after the pulsed magnetic stimulation. tumor necrosis factor (TNF-alpha) production in mouse spleens was significantly activated after the exposure of the stimulus condition described above. These results showed the first evidence of the anti-tumor effect and immunomodulatory effects brought about by the application of repetitive magnetic stimulation and also suggested the possible relationship between anti-tumor effects and the increase of TNF-alpha levels caused by pulsed magnetic stimulation.

Antitumor effectiveness of different amounts of electrical charge in Ehrlich and fibrosarcoma Sa-37 tumors

Background

In vivo studies were conducted to quantify the effectiveness of low-level direct electric current for different amounts of electrical charge and the survival rate in fibrosarcoma Sa-37 and Ehrlich tumors, also the effect of direct electric in Ehrlich tumor was evaluate through the measurements of tumor volume and the peritumoral and tumoral findings.

Methods

BALB/c male mice, 7–8 week old and 20–22 g weight were used. Ehrlich and fibrosarcoma Sa-37 cell lines, growing in BALB/c mice. Solid and subcutaneous Ehrlich and fibrosarcoma Sa-37 tumors, located dorsolaterally in animals, were initiated by the inoculation of 5 × 10⁶ and 1 × 10⁵ viable tumor cells, respectively. For each type of tumor four groups (one control group and three treated groups) consisting of 10 mice randomly divided were formed. When the tumors reached approximately 0.5 cm³, four platinum electrodes were inserted into their bases. The electric charge delivered to the tumors was varied in the range of 5.5 to 110 C/cm³ for a constant time of 45 minutes. An additional experiment was performed in BALB/c male mice bearing Ehrlich tumor to examine from a histolological point of view the effects of direct electric current. A control group and a treated group with 77 C/cm³ (27.0 C in 0.35 cm³) and 10 mA for 45 min were formed. In this experiment when the tumor volumes reached 0.35 cm³, two anodes and two cathodes were inserted into the base perpendicular to the tumor long axis.

Results

Significant tumor growth delay and survival rate were achieved after electrotherapy and both were dependent on direct electric current intensity, being more marked in fibrosarcoma Sa-37 tumor. Complete regressions for fibrosarcoma Sa-37 and Ehrlich tumors were observed for electrical charges of 80 and 92 C/cm³, respectively.

Histopathological and peritumoral findings in Ehrlich tumor revealed in the treated group marked tumor necrosis, vascular congestion, peritumoral neutrophil infiltration, an acute inflammatory response, and a moderate peritumoral monocyte infiltration. The morphologic pattern of necrotic cell mass after direct electric current treatment is the coagulative necrosis. These findings were not observed in any of the untreated tumors.

Conclusion

The data presented indicate that electrotherapy with low-level DEC is feasible and effective in the treatment of the Ehrlich and fibrosarcoma Sa-37 tumors. Our results demonstrate that the sensitivity of these tumors to direct electric current and survival rates of the mice depended on both the amount of electrical charge and the type of tumor. Also the complete regression of each type of tumor is obtained for a threshold amount of electrical charge.