Redox status of plasma coenzyme Q10 indicates elevated systemic oxidative stress in Parkinson's disease

Neuroprotective effect of Coenzyme Q10 on ischemic hemisphere in aged mice with mutations in the amyloid precursor protein

This study was designed to test whether Coenzyme Q10 (CoQ10) supplementation has neuroprotective effect in aged, double-transgenic amyloid precursor protein (APP)/presenilin 1 (PS1), single transgenic APP and PS1 mice exposed to ischemic injury of the brain. Forty-eight mice (12 each of APP/PS1, APP, PS1 and wild-type) were studied. Half of each genotype groups (n=6 per group) was treated with CoQ10 (1200 mg/kg/day) after ischemic injury and the other half with placebo. Magnetic resonance (MR) images were used to measure the volume of induced infarction (IFV), as well as the volume of the hemispheres and hippocampi. Significantly greater volumes of infarction and lesser volumes of hemisphere/hippocampus on the ischemic side were observed in APP/PS1 and APP mice than in PS1 and wild-type mice. This is consistent with amplification of the effect of ischemia in APP carriers. After 28 days of CoQ10 treatment, APP/PS1 or APP mutations have smaller infarct volumes, while the volumes of hemisphere and hippocampus on the infarcted side were larger than those treated with placebo. No differences between CoQ10- and placebo-treated groups in volumes of infarct, hemisphere and hippocampus were observed in PS1 and wild-type mice. We conclude that CoQ10 has a protective effect on the brain from infarction and atrophy induced by ischemic injury in aged and susceptible transgenic mice.

Antioxidants, supplements, and Parkinson's disease

OBJECTIVE

To review the use of antioxidants and other supplements for the prevention and treatment of Parkinson's disease (PD).

DATA SOURCES

Biomedical literature was accessed through MEDLINE (1996-June 2005); key search terms included Parkinson's disease, coenzyme Q10 (CoQ10), antioxidants, supplements, and glutathione. Pertinent references cited in those articles were also evaluated for inclusion in this review.

DATA SYNTHESIS

Three main antioxidants or supplements have been studied for use in the prevention or treatment of PD: tocopherol, CoQ10, and glutathione. These agents have been studied because of their potential to alter the course of 2 common theories of PD pathogenesis: free radical generation and mitochondrial complex-1 deficiency. The literature search revealed 3 large clinical studies of tocopherol (2 observational, 1 prospective randomized), 4 trials of CoQ10, and 1 study of glutathione. With the exception of the large observational studies with tocopherol and one study of CoQ10 that enrolled 80 patients, each of the other studies retrieved included fewer than 30 patients and were conducted for 3 months or less. Antioxidant supplementation, in particular tocopherol, did not appear to alter the course of PD. However, in 2 of the studies of CoQ10 and in the study of glutathione, a small but statistically significant improvement in PD symptoms was observed.

CONCLUSIONS

At present, antioxidants and supplements appear to have a limited role in the prevention or treatment of PD. Of those reviewed here, CoQ10 appears to provide some minor treatment benefits. More study is necessary to determine whether CoQ10 has a significant role as primary or adjunctive therapy in PD.

Increased oxidative stress in patients with chronic obstructive pulmonary disease (COPD) as measured by redox status of plasma coenzyme Q10

STUDY OBJECTIVES

The percentage of oxidized coenzyme Q10 in total coenzyme Q10 (%CoQ-10) has been shown to indicate the degree of systemic oxidative stress. Chronic obstructive pulmonary disease (COPD) is regarded as a systemic disease that is linked to oxidative stress in its pathogenesis. In this study, the plasma %CoQ-10 levels in COPD patients were determined and assessed. In addition, the effect of oxygen supplementation on plasma %CoQ-10 was also evaluated.

MATERIAL AND METHODS

Thirteen COPD patients who had not received oxygen supplementation (COPD-Pt), five COPD patients who had received oxygen supplementation (COPD + O2) and 20 age-matched control subjects (CONTROL) were enrolled. We have also enrolled 83 young healthy non/slight smokers (smoking index <20 pack-year) and 24 young healthy smokers (smoking index > or = 20 pack-year) in order to assess the effect of smoking history on %CoQ-10 level. Their plasma was collected and plasma %CoQ-10 levels were determined and compared.

RESULTS AND CONCLUSION

The plasma %CoQ-10 of COPD-Pt was 6.3 +/- 2.3, significantly higher than that of CONTROL, 4.7 +/- 1.6 (p < 0.05), indicating an increased oxidative stress in the patients. In contrast, no significant difference in %CoQ-10 was observed between young healthy non/slight smokers (%CoQ-10 = 3.2 +/- 0.9) and young healthy smokers (%CoQ-10 = 3.7 +/- 1.3). Our observation of five COPD patients who received an oxygen supplementation revealed that their %CoQ-10 values (4.0 +/- 1.5) were significantly lower than those in COPD-Pt subjects (p < 0.05), suggesting that oxygen supplementation ameliorates the oxidative stress. In contrast, our study showed that no significant difference was observed among the three groups in plasma levels of Vitamin C or E. In conclusion, plasma %CoQ-10 levels are increased in COPD patients and oxygen supplementation attenuates this increasing effect by COPD. This implies that %CoQ-10 might be used practically to assess the COPD patients systemically.

Plasma lipid peroxidation in sporadic Parkinson's disease. Role of the l-dopa

Oxidative stress plays an important role in the pathogenesis of neurodegenerative diseases, such as Parkinson's disease (PD). There are several methods to measure oxidative stress, being lipid peroxidation (LPO) one of the most frequently used. Endogenous plasma LPO was determined by a spectrofluorimetric method in fifty two patients with sporadic PD and in forty controls. To know the maximum capacity of lipids to peroxidate, LPO was also measured after co-incubation with Fe2+/H2O2 (exogenous LPO). All PD patients were taken L-dopa and the effect of this treatment on LPO levels was additionally studied. Urine catecholamines and their main metabolites were also analyzed, and their possible correlation to LPO statistically studied. Endogenous plasma LPO levels were 33% higher in PD group than in control group (P<0.001). Exogenous plasma or oxidizability was also higher in PD patients compared to controls (20%, P<0.05). The intake of L-dopa was negatively dose-related to endogenous and exogenous plasma LPO. In conclusion, plasma of PD patients has elevated levels of LPO and also is more prone to peroxidation than that in the control group. The results also suggest an antioxidant effect of L-dopa.

Clinical aspects of coenzyme Q10: an update

PURPOSE OF REVIEW

Coenzyme Q10 is administered for an ever-widening range of disorders, therefore it is timely to illustrate the latest findings with special emphasis on areas in which this therapeutic approach is completely new. These findings also give further insight into the biochemical mechanisms underlying clinical involvement of coenzyme Q10.

RECENT FINDINGS

Cardiovascular properties of coenzyme Q10 have been further addressed, namely regarding myocardial protection during cardiac surgery, end-stage heart failure, pediatric cardiomyopathy and in cardiopulmonary resuscitation. The vascular aspects of coenzyme Q10 addressing the important field of endothelial function are briefly examined. The controversial issue of the statin/coenzyme Q10 relationship has been investigated in preliminary studies in which the two substances were administered simultaneously. Work on different neurological diseases, involving mitochondrial dysfunction and oxidative stress, highlights some of the neuroprotective mechanisms of coenzyme Q10. A 4-year follow-up on 10 Friedreich's Ataxia patients treated with coenzyme Q10 and vitamin E showed a substantial improvement in cardiac and skeletal muscle bioenergetics and heart function. Mitochondrial dysfunction likely plays a role in the pathophysiology of migraine as well as age-related macular degeneration and a therapy including coenzyme Q10 produced significant improvement. Finally, the effect of coenzyme Q10 was evaluated in the treatment of asthenozoospermia.

SUMMARY

The latest findings highlight the beneficial role of coenzyme Q10 as coadjuvant in the treatment of syndromes, characterized by impaired mitochondrial bioenergetics and increased oxidative stress, which have a high social impact. Besides their clinical significance, these data give further insight into the biochemical mechanisms of coenzyme Q10 activity.

α-Lipoic acid supplementation inhibits oxidative damage, accelerating chronic wound healing in patients undergoing hyperbaric oxygen therapy

Hyperbaric oxygen (HBO) therapy is successfully used for the treatment of a variety of conditions. However, prolonged exposure to high concentrations of oxygen induces production of reactive oxygen species, causing damage to the cells. Thus, antioxidant supplementation has been proposed as an adjuvant to attenuate such deleterious secondary effects. We evaluated the effects of alpha-lipoic acid (LA) in patients affected by chronic wounds undergoing HBO treatment. LA supplementation efficiently reduces both the lipid and DNA oxidation induced by oxygen exposure. LA exerted its antioxidant activity by directly interacting with free radicals or by recycling vitamin E. An inhibitory effect of LA on the pro-inflammatory cytokine interleukin-6 was observed. Taken together, we demonstrated an adjuvant effect of LA in HBO therapy used for impaired wound healing treatment. We propose that LA may be used to further promote the beneficial effects of HBO therapy.

Therapeutic role of coenzyme Q(10) in Parkinson's disease

Mitochondrial dysfunction has been well established to occur in Parkinson's disease (PD) and appears to play a role in the pathogenesis of the disorder. A key component of the mitochondrial electron transport chain (ETC) is coenzyme Q(10), which not only serves as the electron acceptor for complexes I and II of the ETC but is also an antioxidant. In addition to being crucial to the bioenergetics of the cell, mitochondria play a central role in apoptotic cell death through a number of mechanisms, and coenzyme Q(10) can affect certain of these processes. Levels of coenzyme Q(10) have been reported to be decreased in blood and platelet mitochondria from PD patients. A number of preclinical studies in in vitro and in vivo models of PD have demonstrated that coenzyme Q(10) can protect the nigrostriatal dopaminergic system. A phase II trial of coenzyme Q(10) in patients with early, untreated PD demonstrated a positive trend for coenzyme Q(10) to slow progressive disability that occurs in PD.

An increase of oxidized coenzyme Q-10 occurs in the plasma of sporadic ALS patients

We have compared plasma redox status of coenzyme Q-10 in 20 sporadic amyotrophic lateral sclerosis (sALS) patients with those in 20 healthy age/sex-matched controls. A significant increase in the oxidized form of coenzyme Q-10 (sALS=109.3+/-95.2 nM; controls=23.3+/-7.5 nM, P=0.0002) and in the ratio of oxidized form of coenzyme Q-10 to total coenzyme Q-10 (%CoQ-10) (sALS=12.0+/-9.3%; controls=3.2+/-0.9%, P<0.0001) were observed. Moreover, %CoQ-10 correlated significantly with the duration of illness (rho=0.494, P=0.0315). Our finding suggests systemic oxidative stress in the pathogenesis of sALS.