Influence of Chronic Coenzyme Q10 Supplementation on Cognitive Function, Learning, and Memory in Healthy and Diabetic Middle-Aged Rats

Oral administration of coenzyme Q10 ameliorates memory impairment induced by nicotine-ethanol abstinence through restoration of biochemical changes in male rat hippocampal tissues

Substance abuse among adolescents has become a growing issue throughout the world. The significance of research on this life period is based on the occurrence of neurobiological changes in adolescent brain which makes the individual more susceptible for risk-taking and impulsive behaviors. Alcohol and nicotine are among the most available drugs of abuse in adolescents. Prolonged consumption of nicotine and alcohol leads to drug dependence and withdrawal which induce various dysfunctions such as memory loss. Coenzyme Q10 (CoQ10) is known to improve learning and memory deficits induced by various pathological conditions such as Diabetes mellitus and Alzheimer's disease. In the present study we investigated whether CoQ10 treatment ameliorates memory loss following a nicotine-ethanol abstinence. Morris water maze and novel object recognition tests were done in male Wistar rats undergone nicotine-ethanol abstinence and the effect of CoQ10 was assessed on at behavioral and biochemical levels. Results indicated that nicotine-ethanol abstinence induces memory dysfunction which is associated with increased oxidative and inflammatory response, reduced cholinergic and neurotrophic function plus elevated Amyloid-B levels in hippocampi. CoQ10 treatment prevented memory deficits and biochemical alterations. Interestingly, this ameliorative effect of CoQ10 was found to be dose-dependent in most experiments and almost equipotential to that of bupropion and naloxone co-administration. CoQ10 treatment could effectively improve memory defects induced by nicotine-ethanol consumption through attenuation of oxidative damage, inflammation, amyloid-B level and enhancement of cholinergic and neurotrophic drive. Further studies are required to assess the unknown side effects and high dose tolerability of the drug in human subjects.

Empagliflozin alleviates diabetes-induced cognitive impairments by lowering nicotinamide adenine dinucleotide phosphate oxidase-4 expression and potentiating the antioxidant defense system in brain tissue of diabetic rats

BACKGROUND

Diabetes-induced cognitive impairment is a major challenge in patients with uncontrolled diabetes mellitus. It has a complicated pathophysiology, but the role of oxidative stress is central. Therefore, the use of antidiabetic drugs with extra-glycemic effects that reduce oxidative damage may be a promising treatment option.

METHODS

Male Wistar rats were randomly divided into four groups as normal, normal treated, diabetic and diabetic treated (n = 8 per group). Type 1 diabetes was induced by a single intraperitoneal dose of streptozotocin (STZ) (40 mg/kg). Two treatment groups received empagliflozin for 5 weeks (20 mg/kg/po). Cognitive ability was evaluated using open field, Elevated Plus Maze (EPM) and the Morris Water Maze (MWM) tests at study completion. Blood and brain tissue samples were collected - and analysis for malondialdehyde (MDA) and glutathione (GLT) content and catalase (CAT) and superoxide dismutase (SOD) enzyme activity were performed. Additionally, expression of nicotinamide adenine dinucleotide phosphate oxidase-4 (Nox-4) enzyme in brain tissue was analyzed using RT-PCR.

RESULTS

STZ increased blood glucose and induced diabetes with oxidative stress by lowering the antioxidant system potency and increasing Nox-4 expression after 5-weeks in brain tissue accompanied by reduction in cognitive performance. Also, diabetes induced anxiety-like behavior and impaired spatial memory in MWM, EPM and open field tests. However, empagliflozin reversed these changes, improving SOD and CAT activity, GLT content and reducing Nox-4 expression and MDA concentration in brain tissue while improving cognitive ability. It reduced anxiety and depression-related activities. It also improved spatial memory in MWM test.

CONCLUSION

Uncontrolled diabetes negatively impacts mental function and impairs learning and cognitive performance via oxidative stress induction, the Nox-4 enzyme playing a central role. Empagliflozin reverses these effects, improving cognitive ability via promoting the anti-oxidative system and damping Nox-4 free radical generator enzyme expression. Therefore, empagliflozin is a promising treatment, providing both antidiabetic and extra-glycemic benefits for improving brain function in the diabetic milieu.

The Protective Effects of High-Intensity Interval Training Combined with Q10 Supplementation on Learning and Memory Impairments in Male Rats with Amyloid-β-Induced Alzheimer's Disease

Background

Oxidative stress plays a major role in the progression of Alzheimer's disease (AD)-related cognitive deficits.

Objective

This study was done to determine the protective effects of coenzyme Q10 (CoQ10) and high-intensity interval training (HIIT) alone and in combination for eight continuous weeks, on oxidative status, cognitive functions, and histological changes in the hippocampus in amyloid-β (Aβ)-induced AD rats.

Methods

Ninety male Wistar rats were randomly assigned to the sham, control, Q10 (50 mg/kg of CoQ10; P.O.), HIIT (high intensity: 4 min running at 85-90% VO2max, low intensity: 3 min running at 50-60% VO2max), Q10 + HIIT, AD, AD+Q10, AD+HIIT, and AD+Q10 + HIIT groups.

Results

The results showed that Aβ injection reduced cognitive functions in the Morris water maze (MWM) test and recognition memory in the novel object recognition test (NORT), which was accompanied by a decrease in total thiol groups, catalase, and glutathione peroxidase activities, an increase in malondialdehyde levels, and neuronal loss in the hippocampus. Interestingly, pretreatment with CoQ10, HIIT, or both, could markedly improve the oxidative status and cognitive decline in the MWM and NOR tests, and hinder neuronal loss in the hippocampus of Aβ-induced AD rats.

Conclusion

Therefore, a combination of CoQ10 and HIIT can improve Aβ-related cognitive deficits, probably through an amelioration in hippocampal oxidative status and prevention of neuronal loss.

Effectiveness of coenzyme Q10 on learning and memory and synaptic plasticity impairment in an aged Aβ-induced rat model of Alzheimer's disease: a behavioral, biochemical, and electrophysiological study

RATIONALE

Aging is the major risk factor for Alzheimer's disease (AD), and cognitive and memory impairments are common among the elderly. Interestingly, coenzyme Q10 (Q10) levels decline in the brain of aging animals. Q10 is a substantial antioxidant substance, which has an important role in the mitochondria.

OBJECTIVE

We assessed the possible effects of Q10 on learning and memory and synaptic plasticity in aged β-amyloid (Aβ)-induced AD rats.

METHODS

In this study, 40 Wistar rats (24-36 months old; 360-450 g) were randomly assigned to four groups (n = 10 rats/group)-group I: control, group II: Aβ, group III: Q10; 50 mg/kg, and group IV: Q10+Aβ. Q10 was administered orally by gavage daily for 4 weeks before the Aβ injection. The cognitive function and learning and memory of the rats were measured by the novel object recognition (NOR), Morris water maze (MWM), and passive avoidance learning (PAL) tests. Finally, malondialdehyde (MDA), total antioxidant capacity (TAC), total thiol group (TTG), and total oxidant status (TOS) were measured.

RESULTS

Q10 improved the Aβ-related decrease in the discrimination index in the NOR test, spatial learning and memory in the MWM test, passive avoidance learning and memory in the PAL test, and long-term potentiation (LTP) impairment in the hippocampal PP-DG pathway in aged rats. In addition, Aβ injection significantly increased serum MDA and TOS levels. Q10, however, significantly reversed these parameters and also increased TAC and TTG levels in the Aβ+Q10 group.

CONCLUSIONS

Our experimental findings suggest that Q10 supplementation can suppress the progression of neurodegeneration that otherwise impairs learning and memory and reduces synaptic plasticity in our experimental animals. Therefore, similar supplemental Q10 treatment given to humans with AD could possibly provide them a better quality of life.

Coenzyme Q10 supplementation improves the motor function of middle-aged mice by restoring the neuronal activity of the motor cortex

Physiological aging causes motor function decline and anatomical and biochemical changes in the motor cortex. We confirmed that middle-aged mice at 15-18 months old show motor function decline, which can be restored to the young adult level by supplementing with mitochondrial electron transporter coenzyme Q₁₀ (CoQ₁₀) as a water-soluble nanoformula by drinking water for 1 week. CoQ₁₀ supplementation concurrently improved brain mitochondrial respiration but not muscle strength. Notably, we identified an age-related decline in field excitatory postsynaptic potential (fEPSP) amplitude in the pathway from layers II/III to V of the primary motor area of middle-aged mice, which was restored to the young adult level by supplementing with CoQ₁₀ for 1 week but not by administering CoQ₁₀ acutely to brain slices. Interestingly, CoQ₁₀ with high-frequency stimulation induced NMDA receptor-dependent long-term potentiation (LTP) in layer V of the primary motor cortex of middle-aged mice. Importantly, the fEPSP amplitude showed a larger input‒output relationship after CoQ₁₀-dependent LTP expression. These data suggest that CoQ₁₀ restores the motor function of middle-aged mice by improving brain mitochondrial function and the basal fEPSP level of the motor cortex, potentially by enhancing synaptic plasticity efficacy. Thus, CoQ₁₀ supplementation may ameliorate the age-related decline in motor function in humans.

Study of Diet Habits and Cognitive Function in the Chinese Middle-Aged and Elderly Population: The Association between Folic Acid, B Vitamins, Vitamin D, Coenzyme Q10 Supplementation and Cognitive Ability

A growing body of evidence suggests that vitamin supplements play a role in the prevention of cognitive decline. The objective of the present cross-sectional study was to evaluate the relationship between cognitive ability and folic acid, B vitamins, vitamin D (VD) and Coenzyme Q10 (CoQ10) supplementation. The sample consisted of 892 adults aged above 50 who were assessed for their cognitive status in the Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (China) from July 2019 to January 2022. According to the degree of cognitive impairment, the subjects were divided into a normal control (NC) group, subjective cognitive decline (SCD) group, mild cognitive impairment (MCI) group and Alzheimer's disease (AD) group. The results indicated a lower risk of AD in the daily VD-supplemented subjects with MCI compared to those who were not supplemented; a lower risk of cognitive impairment in those with normal cognitive who consumed VD, folic acid or CoQ10 on a daily basis compared those who did not; and a lower risk of cognitive impairment in subjects with normal cognitive performance who consumed B vitamin supplements, either daily or occasionally, compared to those who did not. The correlation was independent of other factors that potentially affect cognition, such as education level, age, etc. In conclusion, our findings confirmed a lower prevalence of cognitive impairment in those who took vitamins (folic acid, B vitamins, VD, CoQ10) daily. Therefore, we would recommend daily supplementation of vitamins (folic acid, B vitamins, VD, CoQ10), especially group B vitamins, as a potential preventive measure to slow cognitive decline and neurodegeneration in the elderly. However, for the elderly who have already suffered from cognitive impairment, VD supplementation may also be beneficial for their brains.

Coenzyme Q10 Levels Associated With Cognitive Functioning and Executive Function in Older Adults

Brain deterioration with age is associated with inflammation and oxidative stress that result in structural and functional changes. Recent studies have indicated that coenzyme Q10 (CoQ10) is associated with neurological oxidative stress and cognitive impairment. Studies with older people have shown a relationship between neurodegenerative diseases and CoQ10 levels. However, no studies have analyzed the relationship between CoQ10 and cognitive functioning in older adults. The aim of this study was to analyze the association between CoQ10 and cognitive functioning in an older adult sample, controlling for other factors that may influence aging, such as the level of physical activity and nutritional status. The sample consisted of 64 older adults aged 65-99 years (76.67 ± 8.16 years), among whom 48 were women (75%). The participants were recruited among those who attended community centers to voluntarily participate in leisure activities. According to previous studies, physical activity and nutritional status are positively associated with cognitive functioning. However, the main finding of this study was that plasma CoQ10, controlling for other measures, was significantly associated with cognitive functioning and executive function. The current findings suggest that a decline in cognitive capacities may be related to reduced antioxidant defenses, as reflected by low CoQ10 levels in older adults.

Diabetes mellitus associated neurovascular lesions in the retina and brain: A review

Diabetes mellitus (DM) is now recognized as a system-wide, autoimmune, inflammatory, microvascular disorder, which, in the retina and brain results in severe multifocal injury now recognized as a leading cause, world-wide, of progressive vision loss and dementia. To address this problem, resulting primarily from variations in glycemia in the prediabetic and overt diabetic states, it must be realized that, although some of the injury processes associated with diabetes may be system wide, there are varying responses, effector, and repair mechanisms that differ from organ to organ or within varying cell structures. Specifically, within the retina, and similarly within the brain cortex, lesions occur of the "neurovascular unit", comprised of focal microvascular occlusions, inflammatory endothelial and pericyte injury, with small vessel leakage resulting in injury to astrocytes, Müller cells, and microglia, all of which occur with progressive neuronal apoptosis. Such lesions are now recognized to occur before the first microaneurysms are visible to imaging by fundus cameras or before they result in detectable symptoms or signs recognizable to the patient or clinician. Treatments, therefore, which currently are not initiated within the retina until edema develops or there is progression of vascular lesions that define the current staging of retinopathy, and in the brain only after severe signs of cognitive failure. Treatments, therefore are applied relatively late with some reduction in progressive cellular injury but with resultant minimal vision or cognitive improvement. This review article will summarize the multiple inflammatory and remediation processes currently understood to occur in patients with diabetes as well as pre-diabetes and summarize as well the current limitations of methods for assessing the structural and functional alterations within the retina and brain. The goal is to attempt to define future screening, monitoring, and treatment directions that hopefully will prevent progressive injury as well as enable improved repair and attendant function.

Coenzyme Q10 ameliorates aging-induced memory deficits via modulation of apoptosis, oxidative stress, and mitophagy in aged rats

The behavioral effects and molecular signaling mechanisms of Coenzyme Q₁₀ (Q₁₀) in age-related memory impairment are poorly understood. This study aimed to investigate the effects of Q₁₀ on memory impairment, oxidative stress, apoptosis, and mitophagy in aged rats. 40 aged (24 months old) and 10 young (3 months old) male Wistar rats were randomly divided into the following groups (n = 10/group): young + vehicle, aged + vehicle, and aged + Q₁₀ (at 100, 200, 300 mg/kg/day doses). Treatments were administrated orally by gavage for 2 weeks. The novel object recognition test was used to assess episodic memory. Oxidative stress, apoptosis, and mitophagy-related protein expressions were measured in the hippocampus. We found that Q10 reversed aging-induced memory impairment at the dose of 300 mg/kg. Moreover, aging was associated with a reduction in ATP production, decrease in mitophagy-related proteins (PINK, Parkin, and P62 levels and LC3II/I ratio), excessive generation of reactive oxygen species and lipid peroxidation, and apoptosis in the hippocampus, which were partially reversed following oral administration of Q₁₀. These findings indicate the therapeutic potential of Q₁₀ in aging-induced memory decline.

Neuroprotective effect of hesperidin and its combination with coenzyme Q10 on an animal model of ketamine-induced psychosis: behavioral changes, mitochondrial dysfunctions, and oxidative stress

Background

Psychosis is a complex mental illness divided by positive symptoms, negative symptoms, and cognitive decline. Clinically available medicines are associated with some serious side effects which limit their use. Treatment with flavonoids has been associated with delayed onset and development, decreased risk, or increased improvement of various neuropsychiatric disorders including psychosis with negligible side effects. Therefore, the present study was aimed to investigate the protective effects of hesperidin (flavonoid) alone or its combination with coenzyme Q10 against ketamine-induced psychotic symptoms in mice.

Results

Ketamine (50 mg/kg, i.p.) was given for 21 days to induce psychosis in Laca mice of either sex. Locomotor activity and stereotypic behaviors, immobility duration (forced swim test), and increased transfer latency (elevated plus maze) were performed to test the effect of hesperidin (50 mg/kg, 100 mg/kg, 200 mg/kg, p.o.) and coenzyme Q10 (20 mg/kg, 40 mg/kg, p.o.) and combination of hesperidin + coenzyme Q10 followed by biochemical and mitochondrial complexes assays. For 21 days, ketamine (50 mg/kg, i.p.) administration significantly produced increased locomotor activity and stereotypic behaviors (positive symptoms), increased immobility duration (negative symptoms) and cognitive deficits (increases transfer latency) weakens oxidative defense and mitochondrial function. Further, 21 days’ administration of hesperidin and coenzyme Q10 significantly reversed the ketamine-induced psychotic behavioral changes and biochemical alterations and mitochondrial dysfunction in the discrete areas (prefrontal cortex and hippocampus) of mice brains. The potential effect of these drugs was comparable to olanzapine treatment. Moreover, the combination of hesperidin with coenzyme Q10 and or a combination of hesperidin + coenzyme Q10 + olanzapine treatment did not produce a significant effect compared to their per se effect in ketamine-treated animals.

Conclusions

The study revealed that hesperidin alone or in combination with coenzyme Q10 could reduce psychotic symptoms and improve mitochondrial functions and antioxidant systems in mice, suggesting neuroprotective effects against psychosis.

Diosgenin Attenuates Cognitive Impairment in Streptozotocin-Induced Diabetic Rats: Underlying Mechanisms

OBJECTIVE

Prolonged diabetes mellitus causes impairments of cognition and attentional dysfunctions. Diosgenin belongs to a group of steroidal saponins with reported anti-diabetic and numerous protective properties. This research aimed to assess the effect of diosgenin on beneficially ameliorating learning and memory decline in a rat model of type 1 diabetes caused by streptozotocin (STZ) and to explore its modes of action including involvement in oxidative stress and inflammation.

METHODS

Rats were assigned to one of four experimental groups, comprising control, control under treatment with diosgenin, diabetic, and diabetic under treatment with diosgenin. Diosgenin was given daily p.o. (40 mg/kg) for 5 weeks.

RESULTS

The administration of diosgenin to the diabetic group reduced the deficits of functional performance in behavioral tests, consisting of Y-maze, passive avoidance, radial arm maze, and novel object discrimination tasks (recognitive). Furthermore, diosgenin treatment attenuated hippocampal acetylcholinesterase activity and malon-dialdehyde, along with improvement of antioxidants such as superoxide dismutase and glutathione. Meanwhile, the hippocampal levels of inflammatory indicators, namely interleukin 6, nuclear factor-κB, toll-like receptor 4, tumor necrosis factor α, and astrocyte-specific biomarker glial fibrillary acidic protein, were lower and, on the other hand, tissue levels of nuclear factor (erythroid-derived 2)-related factor 2 were elevated upon diosgenin administration. Besides, the mushroom-like spines of the pyramidal neurons of the hippocampal CA1 area decreased in the diabetic group, and this was alleviated following diosgenin medication.

CONCLUSIONS

Taken together, diosgenin is capable of ameliorating cognitive deficits in STZ-diabetic animals, partly due to its amelioration of oxidative stress, inflammation, astrogliosis, and possibly improvement of cholinergic function in addition to its neuroprotective potential.

Coenzyme Q10 nullified khat-induced hepatotoxicity, nephrotoxicity and inflammation in a mouse model

Ethnopharmacological relevance

The consumption of khat (Catha Edulis, Forsk) is on the rise despite the much publicized associated deleterious health effects. How chemicals present in khat, affect various physiological and biochemical processes requires further scrutiny. A clear understanding of these processes will provide an avenue for countering khat-driven negative effects using appropriate pharmacological and/or nutritional interventions.

Aim of the study

The current study investigated the effect of khat on vital physiological and biochemical processes such as oxidative stress, inflammation and immune responses and the role of Coenzyme-Q₁₀ (CoQ₁₀), a potent antioxidant and anti-inflammatory, in modulating any negative effects due to khat exposure.

Methodology

Three (3) weeks old forty (40) Swiss albino mice were randomly assigned into four treatment groups (n = 10). The first group was the control that was not administered with khat or CoQ₁₀. The second group received 200 mg/kg body weight (b/w) of CoQ₁₀, while the third group received 1500 mg/kg b/w of khat extract and finally the forth group was co-treated with 200 mg/kg b/w of CoQ₁₀ and 1500 mg/kg b/w of khat extract. The experiment was conducted for 90 days after which samples were collected for physiological and biochemical analyses.

Results

The effects of khat and CoQ₁₀ on the weights of brain, liver, kidney and spleen was determined. Administration of khat decreased the levels of RBCs and its subtypes (MCV, MCH, RDW-SD and RDW-CV), a clear indicator of khat-induced normochromic microcytic anemia. White blood cells (lymphocytes, monocytes, neutrophils and eosinophil) which are vital in responding to infections were markedly elevated by khat. Moreover, these results provide evidence for khat-induced liver and kidney injury as shown by increased biomarkers; AST, ALT, GGT and creatinine respectively. Standard histopathological analysis confirmed this finding for khat-driven liver and kidney injury. Further studies showed evidence for khat-induced inflammation and oxidative stress as depicted by increased levels of the pro-inflammatory cytokine TNF-alpha and elevation of GSH in the brain, liver and spleen. Remarkably, this is the first study to demonstrate the potential of CoQ₁₀ in ameliorating khat-induced negative effects as outlined. CoQ₁₀ supplementation restored the khat-induced reduction in RBC subtypes, and was protective against liver and kidney injury as shown by the appropriate biomarkers and standard histopathology analysis. The other significant finding was the CoQ₁₀-driven normalization of GSH and TNF-α levels, indicating a protective effect from khat-driven oxidative stress and inflammation respectively.

Conclusion

From this study, we conclude that CoQ₁₀ may be useful in nullifying khat-driven deleterious events among chronic khat users.

Combination of Omega 3 and Coenzyme Q10 Exerts Neuroprotective Potential Against Hypercholesterolemia-Induced Alzheimer's-Like Disease in Rats

Alzheimer's disease (AD) is the most common form of dementia that progressively disrupts neurocognitive function, which has neither cure nor effective treatment. Hypercholesterolemia might be involved in brain alterations that could evolve into AD. The present study aims to evaluate the potential of omega-3, Co-enzyme Q10 (Co-Q10), as well as their combination in ameliorating hypercholesterolemia-initiated AD-like disease. We adapted a hypercholesterolemic (HC) rat model, a model of oxidative stress-mediated neurodegeneration, to study AD-like pathology. Hypercholesterolemia resulted in increased lipid peroxidation coupled with declined nitric oxide production, reduced glutathione levels, and decreased antioxidant activities of glutathione-s-transferase (GST) and glutathione peroxidase (GSH-Px) in the brain. Moreover, hypercholesterolemia resulted in decreased acetylcholine (ACh) levels and increased acetylcholine-esterase (AChE) activity, along with an increment of tumor necrosis factor and amyloid-β 42. Behaviorally, HC-rats demonstrated depressive-like behavior and declined memory. Treatment of HC-rats with omega-3 and Co-Q10 (alone or in combination) alleviated the brain oxidative stress and inflammation, regulated cholinergic functioning, and enhanced the functional outcome. These findings were verified by the histopathological investigation of brain tissues. This neuroprotective potential of omega-3 and Co-Q10 was achieved through anti-oxidative, anti-inflammatory, anti-amyloidogenic, pro-cholinergic, and memory-enhancing activities against HC-induced AD-like disease; suggesting that they may be useful as prophylactic and therapeutic agents against the neurotoxic effects of hypercholesterolemia.

Progress and perspectives of brain-targeting lipid-based nanosystems via the nasal route in Alzheimer's disease

Since health care systems dedicate substantial resources to Alzheimer's disease (AD), it poses an increasing challenge to scientists and health care providers worldwide, especially that many decades of research in the medical field revealed no optimal effective treatment for this disease. The intranasal administration route seems to be a preferable route of anti-AD drug delivery over the oral one as it demonstrates an ability to overcome the related obstacles reflected in low bioavailability, limited brain exposure and undesired pharmacokinetics or side effects. This delivery route can bypass the systemic circulation through the intraneuronal and extraneuronal pathways, providing truly needleless and direct brain drug delivery of the therapeutics due to its large surface area, porous endothelial membrane, the avoidance of the first-pass metabolism, and ready accessibility. Among the different nano-carrier systems developed, lipid-based nanosystems have become increasingly popular and have proven to be effective in managing the common symptoms of AD when administered via the nose-to-brain delivery route, which provides an answer to circumventing the BBB. The design of such lipid-based nanocarriers could be challenging since many factors can contribute to the quality of the final product. Hence, according to the authors, it is recommended to follow the quality by design methodology from the early stage of development to ensure high product quality while saving efforts and costs. This review article aims to draw attention to the up-to-date findings in the field of lipid-based nanosystems and the potential role of developing such forms in the management of AD by means of the nose-to-brain delivery route, in addition to highlighting the significant role of applying QbD methodology in this development.

Miso Soup Consumption Enhances the Bioavailability of the Reduced Form of Supplemental Coenzyme Q10

Coenzyme Q₁₀ (CoQ₁₀) is an essential compound that is involved in energy production and is a lipid-soluble antioxidant. Although it has been proposed as an antiaging and a health-supporting supplement, its low bioavailability remains a significant issue. Concurrent food intake enhances the absorption of orally administered CoQ₁₀, but it has not been fully established whether specific food substances affect intestinal CoQ₁₀ absorption. Therefore, to determine whether the bioavailability of supplemental CoQ₁₀ is affected by diet, P30, a granulated and reduced form of CoQ₁₀, was dispersed in four different foods, clear soup, miso soup, milk soup, and raw egg sauce. Those foods which contained CoQ₁₀ were consumed on different occasions at intervals of 6–14 weeks by the same participants. Thirteen participants were recruited in the single-dose and repeated clinical study. When miso soup containing P30 was provided, the serum CoQ₁₀ concentration increased faster than when participants consumed other P30-containing soups or a P30-containing raw egg sauce. The area under the curve for serum CoQ₁₀ during the first 5 h after consumption of the P30-containing miso soup was approximately 1.5 times larger than those after the consumption of other P30-containing meals. These data imply that the absorption of CoQ₁₀ supplements can be enhanced by consuming them with food and in particular with specific food substances, such as miso soup.

The Paradox of Coenzyme Q10 in Aging

Coenzyme Q (CoQ) is an essential endogenously synthesized molecule that links different metabolic pathways to mitochondrial energy production thanks to its location in the mitochondrial inner membrane and its redox capacity, which also provide it with the capability to work as an antioxidant. Although defects in CoQ biosynthesis in human and mouse models cause CoQ deficiency syndrome, some animals models with particular defects in the CoQ biosynthetic pathway have shown an increase in life span, a fact that has been attributed to the concept of mitohormesis. Paradoxically, CoQ levels decline in some tissues in human and rodents during aging and coenzyme Q₁₀ (CoQ₁₀) supplementation has shown benefits as an anti-aging agent, especially under certain conditions associated with increased oxidative stress. Also, CoQ₁₀ has shown therapeutic benefits in aging-related disorders, particularly in cardiovascular and metabolic diseases. Thus, we discuss the paradox of health benefits due to a defect in the CoQ biosynthetic pathway or exogenous supplementation of CoQ₁₀.