Coenzyme Q10 (also known as CoQ10, Q10, vitamin Q10, ubiquinone, and ubidecarenone) is a benzoquinone compound synthesized naturally by the human body. The “Q” and the “10” in the name refer to the quinone chemical group and the 10 isoprenyl chemical subunits, respectively, that are part of this compound’s structure. The term “coenzyme” denotes it as an organic (contains carbon atoms), nonprotein molecule necessary for the proper functioning of its protein partner (an enzyme or an enzyme complex). Coenzyme Q10 is used by cells of the body in a process known variously as aerobic respiration, aerobic metabolism, oxidative metabolism, or cell respiration. Through this process, energy for cell growth and maintenance is created inside cells in compartments called mitochondria. Reviewed in [1-4] Coenzyme Q10 is also used by the body as an endogenous antioxidant. Reviewed in [1,2,4-8] An antioxidant is a substance that protects cells from free radicals, which are highly reactive chemicals, often containing oxygen atoms, capable of damaging important cellular components such as DNA and lipids. In addition, the plasma level of coenzyme Q10 has been used, in studies, as a measure of oxidative stress (a situation in which normal antioxidant levels are reduced).[9,10]
Coenzyme Q10 is present in most tissues, but the highest concentrations are found in the heart, the liver, the kidneys, and the pancreas. The lowest concentration is found in the lungs. Tissue levels of this compound decrease as people age, due to increased requirements, decreased production, or insufficient intake of the chemical precursors needed for synthesis. Reviewed in  In humans, normal blood levels of coenzyme Q10 have been defined variably, with reported normal values ranging from 0.30 to 3.84 µg/mL.[13,14] Reviewed in [2,4]
Given the importance of coenzyme Q10 to optimal cellular energy production, use of this compound as a treatment for diseases other than cancer has been explored. Most of these investigations have focused on coenzyme Q10 as a treatment for cardiovascular disease. Reviewed in [2,4] In patients with cancer, coenzyme Q10 has been shown to protect the heart from anthracycline-induced cardiotoxicity (anthracyclines are a family of chemotherapy drugs, including doxorubicin, that have the potential to damage the heart)[3,16-18] and to stimulate the immune system. Reviewed in  Stimulation of the immune system by this compound has also been observed in animal studies and in humans without cancer.[21-27] In part because of its immunostimulatory potential, coenzyme Q10 has been used as an adjuvant therapy in patients with various types of cancer.[17,28-30] Reviewed in [20,31-33]
While coenzyme Q10 may show indirect anticancer activity through its effect(s) on the immune system, there is evidence to suggest that analogs of this compound can suppress cancer growth directly. Analogs of coenzyme Q10 have been shown to inhibit the proliferation of cancer cells in vitro and the growth of cancer cells transplanted into rats and mice.[12,34] In view of these findings, it has been proposed that analogs of coenzyme Q10 may function as antimetabolites to disrupt normal biochemical reactions that are required for cell growth and/or survival and, thus, that they may be useful for short periods of time as chemotherapeutic agents.[12,34]
In animal studies, coenzyme Q10 has been administered by injection (intravenous, intraperitoneal, intramuscular, or subcutaneous). In humans, it is usually taken orally as a pill (tablet or capsule), but intravenous infusions have been given. Coenzyme Q10 is absorbed best with fat; therefore, lipid preparations are better absorbed than the purified compound. Reviewed in [2,4] In human studies, supplementation doses and administration schedules have varied, but usually have been in the range of 90 to 390 mg/day.
Study Suggests Coenzyme Q10 Slows Functional Decline in Parkinson's Disease: National Institute of Neurological Disorders and Stroke (NINDS)
Overview Results of the first placebo-controlled, multicenter clinical trial of the compound coenzyme Q10 suggest that it can slow disease progression in patients with early-stage Parkinson's disease (PD). While the results must be confirmed in a larger study, they provide hope that this compound may ultimately provide a new way of treating PD.
Results of the first placebo-controlled, multicenter clinical trial of the compound coenzyme Q10 suggest that it can slow disease progression in patients with early-stage Parkinson's disease (PD). While the results must be confirmed in a larger study, they provide hope that this compound may ultimately provide a new way of treating PD.
The phase II study, led by Clifford Shults, M.D., of the University of California, San Diego (UCSD) School of Medicine, looked at a total of 80 PD patients at 10 centers across the country to determine if coenzyme Q10 is safe and if it can slow the rate of functional decline. The study was funded by the National Institute of Neurological Disorders and Stroke (NINDS) and appears in the October 15, 2002, issue of the Archives of Neurology.
"This trial suggested that coenzyme Q10 can slow the rate of deterioration in Parkinson's disease," says Dr. Shults. "However, before the compound is used widely, the results need to be confirmed in a larger group of patients." PD is a chronic, progressive neurological disease that affects about 500,000 people in the United States. It results from the loss of brain cells that produce the neurotransmitter dopamine and causes tremor, stiffness of the limbs and trunk, impaired balance and coordination, and slowing of movements. Patients also sometimes develop other symptoms, including difficulty swallowing, disturbed sleep, and emotional problems. PD usually affects people over the age of 50, but it can affect younger people as well. While levodopa and other drugs can ease the symptoms of PD, none of the current treatments has been shown to slow the course of the disease.
The investigators believe coenzyme Q10 works by improving the function of mitochondria, the "powerhouses" that produce energy in cells. Coenzyme Q10 is an important link in the chain of chemical reactions that produces this energy. It also is a potent antioxidant - a chemical that "mops up" potentially harmful chemicals generated during normal metabolism. Previous studies carried out by Dr. Shults, Richard Haas, M.D., of UCSD and Flint Beal, M.D., of Cornell University have shown that coenzyme Q10 levels in mitochondria from PD patients are reduced and that mitochondrial function in these patients is impaired. Animal studies have shown that coenzyme Q10 can protect the area of the brain that is damaged in PD. Dr. Shults and colleagues also conducted a pilot study with PD patients which showed that consumption of up to 800 mg/day of coenzyme Q10 was well-tolerated and significantly increased the level of coenzyme Q10 in the blood.
All of the patients who took part in the new study had the three primary features of PD - tremor, stiffness, and slowed movements - and had been diagnosed with the disease within 5 years of the time they were enrolled. After an initial screening and baseline blood tests, the patients were randomly divided into four groups. Three of the groups received coenzyme Q10 at three different doses (300 mg/day, 600 mg/day, and 1,200 mg/day), along with vitamin E, while a fourth group received a matching placebo that contained vitamin E alone. Each participant received a clinical evaluation 1 month later and every 4 months for a total of 16 months or until the investigator determined that the patient needed treatment with levodopa. None of the participants or the study investigators knew which treatment each patient had received until the study ended.
The investigators found that most side effects of coenzyme Q10 were mild, and none of the patients required a reduction of their dose. The percentage of people receiving coenzyme Q10 who reported side effects was not significantly different from that of the placebo group. During the study period, the group that received the largest dose of coenzyme Q10 (1,200 mg/day) had 44 percent less decline in mental function, motor (movement) function, and ability to carry out activities of daily living, such as feeding or dressing themselves. The greatest effect was on activities of daily living. The groups that received 300 mg/day and 600 mg/day developed slightly less disability than the placebo group, but the effects were less than those in the group that received the highest dosage of coenzyme Q10.
The groups that received coenzyme Q10 also had significant increases in the level of coenzyme Q10 in their blood and a significant increase in energy-producing reactions within their mitochondria.
The results of this study suggest that doses of coenzyme Q10 as high as 1,200 mg/day are safe and may be more effective than lower doses, says Dr. Shults. The findings are consistent with those of a recently published study of patients with early Huntington's disease - another degenerative neurological disorder - that showed slightly less functional decline in groups that received 600 mg/day of coenzyme Q10.
The new study also used an efficient phase II clinical trial design - developed by biostatistician David Oakes, Ph.D., of the University of Rochester, and other study investigators - which should be useful for testing other drugs that might slow the progression of PD, says Dr. Shults. The design allowed the researchers to study the effects of three doses plus a placebo in less than 3 years, and to obtain useful data about the compound's effectiveness.
Dr. Shults and his colleagues strongly caution patients against taking coenzyme Q10 until a larger, definitive trial can be conducted. Because coenzyme Q10 is classified as a dietary supplement, it is not regulated by the U.S. Food and Drug Administration. The versions of the supplement sold in stores may differ, they may not contain potentially beneficial amounts of the compound, and taking coenzyme Q10 over a number of years may be costly, says Dr. Shults. In addition, the current study included only a small number of patients, and the findings may not extend to people in later stages of PD or to those who are at risk but have not been diagnosed with the disorder, he notes. Finally, if many people begin taking coenzyme Q10 because of these early results, it might make it impossible for investigators to find enough patients to carry out definitive studies of the compound's effectiveness and the proper dosages, since patients must not be taking any treatments in order to be considered for enrollment in a definitive trial.
The investigators are now planning a larger clinical trial that will examine the effects of 1,200 mg/day of coenzyme Q10 , and possibly a higher dose as well, in a larger number of patients.
The NINDS is a component of the National Institutes of Health in Bethesda, Maryland, and is the nation's primary supporter of biomedical research on the brain and nervous system.
- Crane FL, Sun IL, Sun EE: The essential functions of coenzyme Q. Clin Investig 71 (8 Suppl): S55-9, 1993. [PUBMED Abstract]
- Pepping J: Coenzyme Q10. Am J Health Syst Pharm 56 (6): 519-21, 1999. [PUBMED Abstract]
- Folkers K, Wolaniuk A: Research on coenzyme Q10 in clinical medicine and in immunomodulation. Drugs Exp Clin Res 11 (8): 539-45, 1985. [PUBMED Abstract]
- Overvad K, Diamant B, Holm L, et al.: Coenzyme Q10 in health and disease. Eur J Clin Nutr 53 (10): 764-70, 1999. [PUBMED Abstract]
- Beyer RE, Nordenbrand K, Ernster L: The role of coenzyme Q as a mitochondrial antioxidant: a short review. In: Folkers K, Yamamura Y, eds.: Biomedical and Clinical Aspects of Coenzyme Q. Vol 5. Amsterdam, The Netherlands: Elsevier Science Publishers B V (Biomedical Division), 1986, pp 17-24.
- Gordon M: Dietary antioxidants in disease prevention. Nat Prod Rep 13 (4): 265-73, 1996. [PUBMED Abstract]
- Palazzoni G, Pucello D, Littarru GP, et al.: Coenzyme Q10 and colorectal neoplasms in aged patients. Rays 22 (1 Suppl): 73-6, 1997 Jan-Mar. [PUBMED Abstract]
- Ernster L, Dallner G: Biochemical, physiological and medical aspects of ubiquinone function. Biochim Biophys Acta 1271 (1): 195-204, 1995. [PUBMED Abstract]
- Yamamoto Y, Yamashita S, Fujisawa A, et al.: Oxidative stress in patients with hepatitis, cirrhosis, and hepatoma evaluated by plasma antioxidants. Biochem Biophys Res Commun 247 (1): 166-70, 1998. [PUBMED Abstract]
- Yamamoto Y, Yamashita S: Plasma ratio of ubiquinol and ubiquinone as a marker of oxidative stress. Mol Aspects Med 18 (Suppl): S79-84, 1997. [PUBMED Abstract]
- Ernster L, Forsmark-Andrée P: Ubiquinol: an endogenous antioxidant in aerobic organisms. Clin Investig 71 (8 Suppl): S60-5, 1993. [PUBMED Abstract]
- Folkers K: The potential of coenzyme Q 10 (NSC-140865) in cancer treatment. Cancer Chemother Rep 2 4 (4): 19-22, 1974. [PUBMED Abstract]
- 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]
- Jolliet P, Simon N, Barré J, et al.: Plasma coenzyme Q10 concentrations in breast cancer: prognosis and therapeutic consequences. Int J Clin Pharmacol Ther 36 (9): 506-9, 1998. [PUBMED Abstract]
- Baggio E, Gandini R, Plancher AC, et al.: Italian multicenter study on the safety and efficacy of coenzyme Q10 as adjunctive therapy in heart failure. CoQ10 Drug Surveillance Investigators. Mol Aspects Med 15 (Suppl): s287-94, 1994. [PUBMED Abstract]
- Cortes EP, Gupta M, Chou C, et al.: Adriamycin cardiotoxicity: early detection by systolic time interval and possible prevention by coenzyme Q10. Cancer Treat Rep 62 (6): 887-91, 1978. [PUBMED Abstract]
- 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]
- Iarussi D, Auricchio U, Agretto A, et al.: Protective effect of coenzyme Q10 on anthracyclines cardiotoxicity: control study in children with acute lymphoblastic leukemia and non-Hodgkin lymphoma. Mol Aspects Med 15 (Suppl): s207-12, 1994. [PUBMED Abstract]
- Folkers K, Shizukuishi S, Takemura K, et al.: Increase in levels of IgG in serum of patients treated with coenzyme Q10. Res Commun Chem Pathol Pharmacol 38 (2): 335-8, 1982. [PUBMED Abstract]
- Complementary treatments highlighted at recent meeting. Oncology (Huntingt) 13 (2): 166, 1999. [PUBMED Abstract]
- Bliznakov E, Casey A, Premuzic E: Coenzymes Q: stimulants of the phagocytic activity in rats and immune response in mice. Experientia 26 (9): 953-4, 1970. [PUBMED Abstract]
- Folkers K, Hanioka T, Xia LJ, et al.: Coenzyme Q10 increases T4/T8 ratios of lymphocytes in ordinary subjects and relevance to patients having the AIDS related complex. Biochem Biophys Res Commun 176 (2): 786-91, 1991. [PUBMED Abstract]
- Kawase I, Niitani H, Saijo N, et al.: Enhancing effect of coenzyme, Q10 on immunorestoration with Mycobacterium bovis BCG in tumor-bearing mice. Gann 69 (4): 493-7, 1978. [PUBMED Abstract]
- 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]
- Bliznakov EG, Adler AD: Nonlinear response of the reticuloendothelial system upon stimulation. Pathol Microbiol (Basel) 38 (6): 393-410, 1972. [PUBMED Abstract]
- 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.
- Barbieri B, Lund B, Lundström B, et al.: Coenzyme Q10 administration increases antibody titer in hepatitis B vaccinated volunteers--a single blind placebo-controlled and randomized clinical study. Biofactors 9 (2-4): 351-7, 1999. [PUBMED Abstract]
- Lockwood K, Moesgaard S, Hanioka T, et al.: Apparent partial remission of breast cancer in 'high risk' patients supplemented with nutritional antioxidants, essential fatty acids and coenzyme Q10. Mol Aspects Med 15 (Suppl): s231-40, 1994. [PUBMED Abstract]
- Lockwood K, Moesgaard S, Folkers K: Partial and complete regression of breast cancer in patients in relation to dosage of coenzyme Q10. Biochem Biophys Res Commun 199 (3): 1504-8, 1994. [PUBMED Abstract]
- Lockwood K, Moesgaard S, Yamamoto T, et al.: Progress on therapy of breast cancer with vitamin Q10 and the regression of metastases. Biochem Biophys Res Commun 212 (1): 172-7, 1995. [PUBMED Abstract]
- Folkers K: Relevance of the biosynthesis of coenzyme Q10 and of the four bases of DNA as a rationale for the molecular causes of cancer and a therapy. Biochem Biophys Res Commun 224 (2): 358-61, 1996. [PUBMED Abstract]
- Ren S, Lien EJ: Natural products and their derivatives as cancer chemopreventive agents. Prog Drug Res 48: 147-71, 1997. [PUBMED Abstract]
- Hodges S, Hertz N, Lockwood K, et al.: CoQ10: could it have a role in cancer management? Biofactors 9 (2-4): 365-70, 1999. [PUBMED Abstract]
- 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]
Reference [for Parkinson's Disease]
- Shults CW, Oakes D, Kieburtz K, Beal F, Haas R, Plumb S, Juncos JL, Nutt J, Shoulson I, Carter J, Kompoliti K, Perlmutter JS, Reich S, Stern M, Watts RL, Kurlan R, Molho E, Harrison M, Lew M, and the Parkinson Study Group. "Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline." Archives of Neurology , October 2002, Vol. 59, No. 10, pp. 1541-1550.
Serving Size: 1 Softgel
Servings Per Container: 50
Vitamin E (d-alpha Tocopheryl Acetate) 30 IU
Coenzyme Q10 (CoQ10) 100 mg
Other Ingredients: Rice Bran Oil, Gelatin, Glycerin, Water, Annatto (natural color), Beeswax, Lecithin and Titanium Dixoide.
Suggested Use: As a dietary supplement, take 1-2 softgels daily with meals.