Chronic Toxicity in Wistar Rats of Cytoreg, An Ionic Antineoplastic Therapeutic Mix of Strong and Weak Acids

Introduction

Toxicity tests are today an important stage in the development of new drugs. In the development of new compounds, in order to take them to human consumption, stages of preclinical phases involving experimentation must be completed. In order to answer the question: Is the drug harmful or toxic to cells or organ systems?, research must be conducted using animals to find out if a drug, procedure, or treatment is likely to be useful.

Drugs are used for prevention, diagnosis and treatment of diseases of humans or other living beings; efficacy and safety of new drugs must be shown to in order for these become marketable. It is widely known that no drug is absolutely safe and that there is always risk of adverse reactions, but knowing advantages and disadvantages, therapeutic benefits along with the risks of complications, allow regulators to determine whether the drug should be or not permitted for human consumption.

Among the diseases that affect humans, cancer causes about 13% of all deaths. 7.6 million People died of cancer in the world during the year 2007 [1, 2]. In the research and development of new drugs, different types of pharmacological and toxicological tests must be performed, in order to validate. Among these are preclinical studies, which allow evaluating the safety of any drug under development [3]. In vivo animal testing is an important part of the preclinical phase that precedes the application of the drug in humans [4]. According to WHO experts [3], they recommend attention to three aspects: the drug, the animals used, and operating methods; with respect to the latter, it is proposed to use repeated dosing, which include chronic or long term toxicity studies (three to six months).

Test agent Cytoreg® (Cytorex de Venezuela, S.A.) is being studied as an antineoplastic agent, and has been described that this preparation inhibits the growth and proliferation of many cancer cell lines [7, 8]. It is presented in liquid form, with a mixture of strong and weak acids, with a concentration-HF Hydrofluoric Acid - reported by the supplier, at 55 grams/liter. Hydrofluoric Acid (HF) is the active compound in the acid balanced mix which also includes sulfuric acid (H2SO4), hydrochloric acid (HCl), phosphoric acid (H3PO4), oxalic acid (C2H2O4) and citric acid (C6H8O7). Concentrations of the test agent active compound Cytoreg®, which are referred in this work, are all in terms of hydrofluoric acid (HF). The Jesus RD, et al. Chronic Toxicity in Wistar Rats of Cytoreg, An Ionic Antineoplastic Therapeutic Mix of Strong and Weak Acids. Adv Clin Toxicol 2019, 4(4): 000170.

purpose of this study is to evaluate the chronic toxicity Cytoreg® as part of its preclinical evaluation.

Material and Methods

Animals: female Wistar rats outbred at the animal Vivarium at the University of Los Andes (Merida, Venezuela), 8 weeks old and with an average weight of 222.9 grams, in a range of 215-238 grams. The animals were housed in cubicles under sanitary barriers and sterilization of supplies and maintenance, with 12 hour light / dark, and access to food and drink at will. Material: Pharmacological Cytoreg® compound provided by Cytorex of Venezuela, .A. (a subsidiary of Cytorex International, Inc. ), supplied in liquid form, consisting of a mixture of strong and weak acids having a concentration of hydrofluoric acid (HF), with a concentration of 55 grams/liter, as referred by the supplier. Hydrofluoric acid is the active compound in the acid equilibrium mixture, which also includes 10% sulfuric acid (H2SO4), 10% hydrochloric acid (HCL), 3% phosphoric acid (H3PO4), oxalic acid 0.3% (C2H2O4) and 0.3% citric acid (C6H8O7).

Discussion

In the present study we tested a relatively high dose of Cytoreg®, which is the estimated minimum lethal dose obtained in previous acute toxicology experiment. Daily administration of these doses for 9 months did not cause the death of any animal [4, 7]. There was no weight loss or significant reduction of food intake in both groups of treatment. In the first 5 months, food consumption decreased, although not significantly. After 5 months, a slight increase was observed and it remained stable until the end of the experiment. Statistical analysis showed no differences between the control group and the treated group. This ascending behavior of discrete gain weight in both groups (Control and Treated). From baseline to 9 months occurred, regardless of the conditions to which the animals were subjected. This reflects that there are no adverse effects on this indicator by the daily administration of the compound Cytoreg® for 9 months [7].

When analyzing the behavior of all hematologic variables in the two groups, there was no difference in the mean values. In Table II we see the following values:

Jesus RD, et al. Chronic Toxicity in Wistar Rats of Cytoreg, An Ionic Antineoplastic Therapeutic Mix of Strong and Weak Acids. Adv Clin Toxicol 2019, 4(4): 000170.

hemoglobin 16.50 in the control group and 16.31 in the treated group; hematocrit of 39.0% in the control group and 38.5% in the treated group; and WBCs. 3.63 in the control group and 5.650 in the treated group.

The interpretation of the biochemical data. as well as the results of statistical analysis shows that there is no involvement of the indicators examined, by oral administration of Cytoreg® during 9 months. The existence of a stable performance shows. no evidence for a relationship between administration of the test substance and blood biochemical parameters. In the ninth month of treatment, we observed an increased alanine aminotransferase which is a sign of liver damage, which from the pathological point of view coincides with liver congestion. This would explain an increased transaminase, but without hepatic necrosis, since the levels of SGOT did not increase.

The pathological study revealed some alterations in the organs. Table IV shows the percentage of these injuries. In the stomach no abnormalities were observed, but injuries in the intestines there were a relatively high percentage; in the small intestine 33.33% and in the large intestine 50.00%, being primarily inflammatory, which is compatible with the acidic nature of the compound. These inflammatory lesions tend to disappear after 7 months of treatment. In the liver we observed the same percentage of lesions in both groups, 25%, mainly liver congestion, which seems an injury unrelated to treatment with the compound, because the untreated group has the same effect. In the lung, interstitial pneumonitis was observed in 85.71% of the treated group, however in the control group showed a 100% pneumonitis, so it seems to be a compound-independent factor to explain this interstitial pneumonitis.

Conclusion

• Cytoreg® used at relatively high doses and for 9 months produced no mortality in animals
• No changes were observed in hematology, but there was an increase of liver enzymes (SGPT) in 3 of 4 rats. In the ninth month of treatment, which could be due to liver congestion?
• In general, pathological lesions observed are consistent with the acidic nature of Cytoreg®, at the beginning of the treatment, but showing a tendency to disappear towards the end of the study.