Laboratory work on coenzyme Q₁₀ has focused primarily on its structure and its function in cell respiration. Studies in animals have demonstrated that coenzyme Q₁₀ is capable of stimulating the immune system, with treated animals showing increased resistance to protozoal infections [1,2] and to viral and chemically induced neoplasia.[1-3] Reviewed in [4] Early studies of coenzyme Q₁₀ showed increased hematopoiesis (the formation of new blood cells) in monkeys, Reviewed in [4,5] rabbits,[6] and poultry. Reviewed in [5] Coenzyme Q₁₀ demonstrated a protective effect on the heart muscle of mice, rats, and rabbits given the anthracycline anticancer drug doxorubicin.[7-12] Although another study confirmed this protective effect with intraperitoneal administration of doxorubicin in mice, it failed to demonstrate a protective effect when the anthracycline was given intravenously, which is the route of administration in humans.[13] Researchers in one study sounded a cautionary note when they found that coadministration of coenzyme Q₁₀ and radiation therapy decreased the effectiveness of the radiation therapy.[14] In this study, mice inoculated with human small cell lung cancer cells (a xenograft study), and then given coenzyme Q₁₀ and single- dose radiation therapy, showed substantially less inhibition of tumor growth than mice in the control group that were treated with radiation therapy alone. Since radiation leads to the production of free radicals, and since antioxidants protect against free radical damage, the effect in this study might be explained by coenzyme Q₁₀ acting as an antioxidant. As noted previously (General Information ¹), there is some evidence from laboratory and animal studies that analogs of coenzyme Q₁₀ may have direct anticancer activity.[15,16]

References

1. Bliznakov EG, Adler AD: Nonlinear response of the reticuloendothelial system upon stimulation. Pathol Microbiol (Basel) 38 (6): 393-410, 1972.  [PUBMED Abstract]
   
   
2. Bliznakov EG: Coenzyme Q in experimental infections and neoplasia. In: Folkers K, Yamamura Y, eds.: Biomedical and Clinical Aspects of Coenzyme Q. Vol 1. Amsterdam, The Netherlands: Elsevier/North-Holland Biomedical Press, 1977, pp 73-83. 
   
   
3. Bliznakov EG: Effect of stimulation of the host defense system by coenzyme Q 10 on dibenzpyrene-induced tumors and infection with Friend leukemia virus in mice. Proc Natl Acad Sci U S A 70 (2): 390-4, 1973.  [PUBMED Abstract]
   
   
4. Folkers K, Osterborg A, Nylander M, et al.: Activities of vitamin Q10 in animal models and a serious deficiency in patients with cancer. Biochem Biophys Res Commun 234 (2): 296-9, 1997.  [PUBMED Abstract]
   
   
5. Folkers K, Brown R, Judy WV, et al.: Survival of cancer patients on therapy with coenzyme Q10. Biochem Biophys Res Commun 192 (1): 241-5, 1993.  [PUBMED Abstract]
   
   
6. Ludwig FC, Elashoff RM, Smith JL, et al.: Response of the bone marrow of the vitamin E-deficient rabbit to coenzyme Q and vitamin E. Scand J Haematol 4 (4): 292-300, 1967.  [PUBMED Abstract]
   
   
7. Choe JY, Combs AB, Folkers K: Prevention by coenzyme Q10 of the electrocardiographic changes induced by adriamycin in rats. Res Commun Chem Pathol Pharmacol 23 (1): 199-202, 1979.  [PUBMED Abstract]
   
   
8. Combs AB, Choe JY, Truong DH, et al.: Reduction by coenzyme Q10 of the acute toxicity of adriamycin in mice. Res Commun Chem Pathol Pharmacol 18 (3): 565-8, 1977.  [PUBMED Abstract]
   
   
9. Folkers K, Choe JY, Combs AB: Rescue by coenzyme Q10 from electrocardiographic abnormalities caused by the toxicity of adriamycin in the rat. Proc Natl Acad Sci U S A 75 (10): 5178-80, 1978.  [PUBMED Abstract]
   
   
10. Lubawy WC, Dallam RA, Hurley LH: Protection against anthramycin-induced toxicity in mice by coenzyme Q10. J Natl Cancer Inst 64 (1): 105-9, 1980.  [PUBMED Abstract]
    
    
11. Shinozawa S, Gomita Y, Araki Y: Protective effects of various drugs on adriamycin (doxorubicin)-induced toxicity and microsomal lipid peroxidation in mice and rats. Biol Pharm Bull 16 (11): 1114-7, 1993.  [PUBMED Abstract]
    
    
12. Usui T, Ishikura H, Izumi Y, et al.: Possible prevention from the progression of cardiotoxicity in adriamycin-treated rabbits by coenzyme Q10. Toxicol Lett 12 (1): 75-82, 1982.  [PUBMED Abstract]
    
    
13. Shaeffer J, El-Mahdi AM, Nichols RK: Coenzyme Q10 and adriamycin toxicity in mice. Res Commun Chem Pathol Pharmacol 29 (2): 309-15, 1980.  [PUBMED Abstract]
    
    
14. Lund EL, Quistorff B, Spang-Thomsen M, et al.: Effect of radiation therapy on small-cell lung cancer is reduced by ubiquinone intake. Folia Microbiol (Praha) 43 (5): 505-6, 1998.  [PUBMED Abstract]
    
    
15. Folkers K: The potential of coenzyme Q 10 (NSC-140865) in cancer treatment. Cancer Chemother Rep 2 4 (4): 19-22, 1974.  [PUBMED Abstract]
    
    
16. Folkers K, Porter TH, Bertino JR, et al.: Inhibition of two human tumor cell lines by antimetabolites of coenzyme Q10. Res Commun Chem Pathol Pharmacol 19 (3): 485-90, 1978.  [PUBMED Abstract]
    
    

Glossary Terms

In chemistry, a substance that is similar, but not identical, to another.

A type of antibiotic that comes from certain types of Streptomyces bacteria. Anthracyclines are used to treat many types of cancer. Anthracyclines damage the DNA in cancer cells, causing them to die. Daunorubicin, doxorubicin, and epirubicin are anthracyclines.

A substance that protects cells from the damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism). Free radicals may play a part in cancer, heart disease, stroke, and other diseases of aging. Antioxidants include beta-carotene, lycopene, vitamins A, C, and E, and other natural and manufactured substances.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

A chemical process in which oxygen is used to make energy from carbohydrates (sugars). Also called aerobic metabolism, aerobic respiration, and oxidative metabolism.

A nutrient that the body needs in small amounts to function and stay healthy. Coenzyme Q10 helps mitochondria (small structures in the cell) make energy. It is an antioxidant that helps prevent cell damage caused by free radicals (highly reactive chemicals). Coenzyme Q10 is fat-soluble (can dissolve in fats and oils) and is found in fatty fish, beef, soybeans, peanuts, and spinach. It is being studied in the prevention and treatment of some types of cancer and heart disease and in the relief of side effects caused by some cancer treatments. Also called CoQ10, Q10, ubiquinone, and vitamin Q10.

In a clinical trial, the group that does not receive the new treatment being studied. This group is compared to the group that receives the new treatment, to see if the new treatment works.

The amount of medicine taken, or radiation given, at one time.

A drug that is used to treat many types of cancer and is being studied in the treatment of other types of cancer. Doxorubicin comes from the bacterium Streptomyces peucetius. It damages DNA and may kill cancer cells. It is a type of anthracycline antitumor antibiotic. Also called Adriamycin PFS, Adriamycin RDF, doxorubicin hydrochloride, hydroxydaunorubicin, and Rubex.

A highly reactive chemical that often contains oxygen and is produced when molecules are split to give products that have unpaired electrons (a process called oxidation). Free radicals can damage important cellular molecules such as DNA or lipids or other parts of the cell.

The formation of new blood cells.

The complex group of organs and cells that defends the body against infections and other diseases.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Within the peritoneal cavity (the area that contains the abdominal organs). Also called IP.

Into or within a vein. Intravenous usually refers to a way of giving a drug or other substance through a needle or tube inserted into a vein. Also called IV.

Research done in a laboratory. These studies may use test tubes or animals to find out if a drug, procedure, or treatment is likely to be useful. Laboratory studies take place before any testing is done in humans.

Abnormal and uncontrolled cell growth.

Research using animals to find out if a drug, procedure, or treatment is likely to be useful. Preclinical studies take place before any testing in humans is done.

Having to do with the simplest organisms in the animal kingdom. Protozoa are single-cell organisms, such as ameba, and are different from bacteria, which are not members of the animal kingdom. Some protozoa can be seen without a microscope.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

An aggressive (fast-growing) cancer that forms in tissues of the lung and can spread to other parts of the body. The cancer cells look small and oval-shaped when looked at under a microscope.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

Having to do with a virus.

The transplant of an organ, tissue, or cells to an individual of another species.