Conference Papers in Science

Conference Papers in Science / 2013 / Article
Special Issue

Conference of the International Clinical Hyperthermia Society 2012

View this Special Issue

Conference Paper | Open Access

Volume 2013 |Article ID 386913 | https://doi.org/10.1155/2013/386913

Csaba Kovago, Nora Meggyeshazi, Gabor Andocs, Andras Szasz, "Report of the Pilot Study Done for the Proposed Investigation on the Possible Synergic Effect between High-Dose Ascorbic Acid Application and Oncothermia Treatment", Conference Papers in Science, vol. 2013, Article ID 386913, 2 pages, 2013. https://doi.org/10.1155/2013/386913

Report of the Pilot Study Done for the Proposed Investigation on the Possible Synergic Effect between High-Dose Ascorbic Acid Application and Oncothermia Treatment

Academic Editor: A. Szasz
Received15 Jan 2013
Accepted17 Apr 2013
Published23 May 2013

Abstract

According to recent investigations, the parenteral application of ascorbic acid (vitamin C) at high doses has significant antitumor activity in in vitro assays. The goal of our experiment was to determine the possible potentiating effect of application of high dose pH-neutralized ascorbic acid to the normal oncothermia treatment method. The NMRI mice were inoculated with C26 murine colon carcinoma cell line subcutaneously at both of their femoral regions and were kept till the tumors reached symmetrically 10 mm in diameter. We created four experimental groups, containing 5 male and 5 female animals in each. Both vitamin-C and oncothermia treatments were applied once; ascorbic acid was applied intra-peritoneally. Oncothermia treatment was applied only to the right limb tumor; the other side will be used as internal control. After the treatment, the animals were sacrificed, and all tumors were removed and analyzed histopathologically. Our main question centers on the comparison of the cell destruction ratio of the various applied treatment regimes, and studies the possible synergy or additive cross-potentiating of the methods. The results of this experiment turned out to be controversial, since the ascorbic acid did not change the remission rate of the allografts and showed no synergy with oncothermia.

1. Introduction

According to recent investigations, the parenteral application of ascorbic acid (vitamin C) at high doses has significant antitumor activity in in vitro assays. This fact is very important using ascorbic acid as complementary drug with standard antitumoral therapy or in cases where currently no other potent treatment is possible. Although the beneficial effect of the ascorbic acid on antineoplastic therapy has some controversial reports in the literature [13] and the specific method of action is still unclear: high concentration of ascorbic acid produces oxidative shock by H2O2 lethal for tumor cells beyond a certain level, healthy cells can survive the same stress effect [4]. As for the application, it was reported that intravenous ascorbic acid treatment is much more efficient, since this way more than 70-fold higher plasma concentration is elucidative than in case of oral application [5]. To achieve proper effect, high plasma level of ascorbic acid is required; so in human cases intravenous dosages are considered between 0,15 and 1,5 g/kg doses [6, 7].

2. Objective

The goal of our experiment was to determine the possible potentiating effect of application of high-dose pH-neutralized ascorbic acid to the normal oncothermia treatment method. The dose we used was considered to be 2 g/kg according to human trials [7] and our intraperitoneal acute toxicity test (not reported). We choose the intraperitoneal application because the absorption from abdominal cavity is very fast and complete, nearly equal to intravenous application and it is much easier to perform in mouse than IV application. However, in this case not only irritative materials can be applied, but also neutralization of ascorbic acid by sodium hydroxide is necessary.

3. Method

The NMRI mice were intended to inoculate with C26 murine colon carcinoma cell line subcutaneously at both of their femoral regions and were kept till the tumors reached symmetrically 10 mm in diameter. C26 cells were cultivated in RPMI 1640 Glutamax medium (Invitrogen, Carlsbad, CA, USA). Inoculation was be done by 7500000 cell/mL concentration liquid cell suspension, using 0,1 mL subcutaneously at each side. Incubation time for tumor growth is expected to be around two weeks.

Vitamin C solution of 1 M in concentration was created by using dry ascorbic acid (Sigma Aldrich, St. Louis, MO, USA) and sterilized purified water and neutralized by 10 M sodium hydroxide solution (Sigma Aldrich, St. Louis, MO, USA).

We created four experimental groups, containing 4 female animals in each. The formed groups of animals wereGr1: no treatment (control);Gr2: only ascorbic acid treatment;Gr3: only oncothermia (OTM) treatment;Gr4: both ascorbic acid and oncothermia treatments.

Both vitamin C and oncothermia treatments were applied once (“single-shut” treatment regime); ascorbic acid was pH-neutralized and applied intraperitoneally in a dose of 2 g/kg bodyweight. Oncothermia treatment was applied only to the right limb tumor, the other side was used as internal control, and the incubation period between vitamin C application and OTM treatment was 30 minutes. The animals were sacrificed 24 hours after the treatment; all tumors were removed and analyzed histopathologically. The other organs were routinely checked as well.

4. Results

In our pilot study, we discovered that vitamin C as monotherapy did not do any change in tumor remission compared to the control samples. As for OTM as monotherapy, the treated side tumor showed greater dead tissue area than both of untreated side and control animals, same level as experienced in earlier studies. The combinational therapy showed controversial result, as the dead tissue amount in the tumors was the same in both treated and untreated sides, and it was smaller than in case of OTM monotherapy at the treated side.

5. Conclusion

In this pilot study, results are showing that because of some unknown reasons, high-dose ascorbic acid application showed no synergic or adjuvant effect with OTM therapy, even the combination decreased the effectivity of the OTM compared to the results of monotherapy.

When planing the proposed, large-number animal experiment, the results of this current pilot study should be taken into consideration. It is highly probable that “single-shut” ascorbic acid application will not be appropriate to achieve any synergic effect. Also, incubation time between vitamin C application and OTM treatment should be greater than the applied 30 minutes.

According to the results we have got in our experiment, we should turn our interest from ascorbic acid to other possible materials as potentiating agent for oncothermia treatment in the future.

References

  1. E. Cameron and L. Pauling, “Supplemental ascorbate in the supportive treatment of cancer: reevaluation of prolongation of survival times in terminal human cancer,” Proceedings of the National Academy of Sciences of the United States of America, vol. 75, no. 9, pp. 4538–4542, 1978. View at: Google Scholar
  2. E. T. Creagan, C. G. Moertel, and J. R. O'Fallon, “Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer. A controlled trial,” The New England Journal of Medicine, vol. 301, no. 13, pp. 687–690, 1979. View at: Google Scholar
  3. M. Levine, M. G. Espey, and Q. Chen, “Losing and finding a way at C: new promise for pharmacologic ascorbate in cancer treatment,” Free Radical Biology and Medicine, vol. 47, no. 1, pp. 27–29, 2009. View at: Publisher Site | Google Scholar
  4. Q. Chen, J.-H. Lee, L. Zhang et al., “Pharmacologic ascorbate concentrations selectively kill cancer cells: ascorbic acid as a prodrug for ascorbate radical or H2O2 delivery to tissues,” The Journal of Nutrition, vol. 137, no. 1, p. 293s, 2007. View at: Google Scholar
  5. S. J. Padayatty, H. Sun, Y. Wang et al., “Vitamin C pharmacokinetics: implications for oral and intravenous use,” Annals of Internal Medicine, vol. 140, no. 7, pp. 533–I61, 2004. View at: Google Scholar
  6. L. J. Hoffer, M. Levine, S. Assouline et al., “Phase I clinical trial of i.v. ascorbic acid in advanced malignancy,” Annals of Oncology, vol. 19, no. 11, pp. 1969–1974, 2008. View at: Publisher Site | Google Scholar
  7. J. Du, J. J. Cullen, and G. R. Buettner, “Ascorbic acid: chemistry, biology and the treatment of cancer,” Biochimica et Biophysica Acta, vol. 1826, no. 2, pp. 443–457, 2012. View at: Publisher Site | Google Scholar

Copyright © 2013 Csaba Kovago et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


More related articles

804 Views | 208 Downloads | 0 Citations
 PDF Download Citation Citation
 Download other formatsMore
 Order printed copiesOrder

Related articles

We are committed to sharing findings related to COVID-19 as quickly as possible. We will be providing unlimited waivers of publication charges for accepted research articles as well as case reports and case series related to COVID-19. Review articles are excluded from this waiver policy. Sign up here as a reviewer to help fast-track new submissions.