2.1. OS Scavenging Ability of TwM
TwM is an antioxidant formulation containing 15 ingredients; the antioxidant capacity of the TwM solution (60 mg/ml) and the vitamin C (VC) solution, one of the ingredients in TwM, was measured using the OXY adsorption test.
The TwM solution was found to have 5.4 times higher antioxidant capacity than the solution with the same concentration of VC contained in TwM (20.5 mg/ml). Furthermore, the TwM solution had approximately twice as much antioxidant capacity than the VC solution at the same concentration (60 mg/ml) (
Figure 1). These findings suggest that TwM possesses significantly greater antioxidant capacity than VC. Moreover, the results indicate that the combination of multiple beneficial components yields a higher capacity than a single-component antioxidant.
Reactive oxygen species (ROS) is a generic term for oxygen derivatives of free radicals (such as superoxide (O
2-) and hydroxyl radical (
•OH)) and non-radicals (such as peroxides (hydrogen peroxide/H
2O
2) and oxygen ions/O
2) [
22]. All of them are highly reactive, and when they come into contact with any cellular biomolecule, they readily capture electrons from the molecule (oxidation), setting off a chain reaction that ultimately leads to damage to the cell structure. Of these,
•OH is the most reactive and is known to directly attack the DNA backbone, causing DNA damage [
23,
24]. The body's ROS concentration is closely related to the maintenance of homeostatic functions. While ROS are a necessary metabolic byproduct in physiological functions, high levels are toxic. Levels of these OS factors increase through lifestyle and aging, leading to mitochondrial dysfunction and damage to all parts of the body [
25,
26]. The elevation of OS is related to the risk of aging and disease development due to the accumulation of oxidation products in the body. Therefore, we consider it desirable for antioxidants to be able to scavenge both radicals and non-radicals, and additionally to increase the antioxidant capacity of the body. In addition to its ability to scavenge non-radicals, TwM has been shown to scavenge the radicals
•CH
3,
•OH, and O
2- at low concentrations [
27]. Ascorbic-acid-containing formulations, including TwM, have been reported to produce ascorbyl radicals through high concentrations of VC [
28,
29], but the formation of ascorbyl radicals is suppressed in TwM [
27], indicating that it is not adversely affected by VC. In addition to this, the base TwX has high ROS scavenging capacity and SOD-enhancing properties. TwM has shown to have higher OXY measurements than TwX [
17]. This indicates that TwM has higher antioxidant capacity than TwX. In addition, TwM has been proven to be a safe antioxidant with significantly higher antioxidant capacity than the single component.
2.2. Effects of TwM on Various Symptoms in CFS
To investigate the impact of TwM on various symptoms of CFS, questionnaire participants were recruited (Eyez, Inc.). Participants were those who had been diagnosed with CFS by a physician at a hospital. The participants were informed of the purpose of the study and the dosage instructions on the website, and completed a pre-questionnaire to self-assess the impact of CFS on their daily lives and the extent of each symptom (fatigue, joint pain, muscle pain, sleep disturbance, headache, decrease in memory and concentration). The symptom severity was rated on a six-point scale ranging from none or low (0 points: 0P) to severe or high (5 points: 5P). Participants were considered to have agreed to participate by completing the pre-assessment questionnaire. TwM (13.51 mg/kg/day) was taken once daily for 2 months.
A total of 23 participants took part, including 5 males and 18 females diagnosed with CFS by a physician (
Figure 2A). Before taking the medication, the responses regarding the impact of participants' CFS on their daily lives were 5P (severely impacted): 34.8% and 4P (very much impacted): 30.4%, which together accounted for more than half of the responses. No participants answered 0P (not affected) or 1P (slightly affected) (
Figure 2B; Before). The results revealed that CSF has a severe impact on daily life, regardless of the degree of symptoms. In contrast, 2 months of TwM increased the number of participants who reported 0P-2P (0P: 9%, 1P: 9%, 2P: 13%), indicating being relatively unaffected by SSC, to 31%. Furthermore, the number of participants who reported 4P-5P (4P: 30%, 5P: 4%) decreased to a combined 34% (
Figure 2B; After), significantly improving the extent to which TwM affects the daily life of individuals with CFS (p<0.001).
A diagnosis of CFS is only determined after fatigue from other etiologies has been ruled out, and only for medical conditions with a history of at least 6 months [
30]. In many cases, CFS causes severe functional limitations in daily life and affects women more than men [
31,
32]. The reasons for this are unknown, but besides hormonal, viral, and immune causes [
33], genetic and epigenetic origins have been suggested as possible explanations [
34]. In the present study, female participants were also more common. Since TwM treatment showed a significant improvement trend in terms of the impact CFS on 23 patients’ daily lives, we considered the possibility that OS may play a major role in triggering the main symptoms of CFS.
The six main symptoms of CFS defined in this questionnaire were fatigue, muscle pain, joint pain, sleep disturbance, decrease in memory and concentration, and headache. After taking TwM for 2 months, the participants completed a similar questionnaire about the extent of their CFS symptoms. The responses to the pretreatment questionnaire were not revealed to prevent bias. The responses were made on a six-point scale: no symptoms (0 points: 0P), a low degree of symptoms (1 point: 1P), a slightly low degree of symptoms (2 points: 2P), a moderate degree of symptoms (3 points: 3P), a slightly high degree of symptoms (4 points: 4P), and a high degree of symptoms (5 points: 5P). In terms of fatigue, 80% of the participants reported a relatively high degree of symptoms at 3P-5P (3P: 22%, 4P: 30%, 5P: 30%) before taking TwM, and no participants reported having no symptoms. However, after the TwM treatment, the number of respondents reporting 5P, which indicated the highest degree of symptoms, decreased substantially (8.7%), and the percentage of those reporting 3P-5P decreased to 56.5%. In addition to the participants who reported 0P (8.7%), nearly half reported a lower degree of symptoms (
Figure 3; Fatigue). For muscle pain, 52% of the participants reported 3P-5P (3P: 30%, 4P: 9%, 5P: 13%) with a high degree of muscle pain before taking TwM; after the treatment, no participants reported 5P and almost half reported 0P (
Figure 3; Muscle pain). For joint pain, more than half of the participants (73.8%) reported 3P-5P (3P: 21.7%, 4P: 47.8%, 5P: 4.3%) before taking TwM. After treatment, about half of the participants reported 0P, similar to the results for muscle pain, and the scores were reversed before and after taking TwM (
Figure 3; Joint pain). In terms of the degree of sleep disturbance experienced before taking TwM, all participants selected 3P-5P (3P: 26.1%, 4P: 30.4%, 5P: 43.5%). This result suggests that the severity of this symptom was greater than for other symptoms and that sleep disturbance may have the highest impact on the daily life of individuals with CFS. In contrast, after taking TwM, 17% of the participants reported 0P, and nearly half reported 0P-1P (0P: 17%, 1P: 30%), indicating a lower level of symptoms. The proportion of participants who reported 5P, which accounted for nearly half of the participants, decreased to 9%, a significant improvement (
Figure 3; Sleep disorders). Memory and concentration difficulties before taking TwM were one of the symptoms affecting daily life, with 86.9% of participants responding with 5P-3P (3P: 39.1%, 4P: 26.1%, 5P: 21.7%). After taking TwM, however, no participants reported 5P, and 65% of participants reported the lower 0P-2P (0P: 13%, 1P: 30%, 2P: 22%) (
Figure 3; Decrease in memory and concentration). For headache, 74% of participants reported 3P-5P (3P: 35%, 4P: 26%, 5P: 13%) before taking TwM, while 78% of participants reported 0P-2P (0P: 39%, 1P: 26%, 2P: 13%) after taking TwM, indicating a reversal in the severity scores before and after TwM treatment (
Figure 3; Headache). A comparison of the mean scores for each symptom before and after taking TwM showed a significant decrease in all items and a trend toward improvement after TwM treatment (p<0.005).
CFS is a multifaceted chronic neuroinflammatory disease, and various research data accumulated to date indicate that CFS is associated with redox imbalance, mitochondrial dysfunction, and inflammatory status. Increased OS and the chronic activation of the innate immune system have been reported in many CFS patients. Chronic activated immune-inflammatory responses and OS induce brain damage, including decreased cerebral perfusion/metabolism, neuroinflammation, DNA damage, mitochondrial dysfunction, secondary autoimmune responses to damaged protein and lipid membrane components, and the dysfunction of intracellular signaling pathways. In the frontal, cingulate, temporal, and occipital cortices, the basal ganglia, and the hippocampus of patients with CFS, hypoperfusion and the decreased biosynthesis of neurotransmitters such as glutamate, aspartate, and γ-aminobutyric acid via acetylcarnitine have been reported [
35]. In addition, the serotonin transporter density in the rostral sector of the anterior cingulate cortex is decreased and negatively correlated with pain scores in patients with CFS [
36]. Voxel-based morphometry studies have shown decreased volume in the bilateral prefrontal cortex in patients with CFS, and the level of this reduction is associated with the severity of fatigue [
37]. Concentrations of inflammatory cytokines, which may be indicators of neuroinflammation, in peripheral blood and cerebrospinal fluid have been reported to be higher than in healthy controls, and neuroinflammation is likely to be related to the pathophysiology of CFS [
38,
39,
40]. Furthermore, widespread brain inflammation (inflammation in the amygdala, thalamus, and midbrain: cognitive function and severe fatigue; inflammation in the cingulate cortex and amygdala: decreased pain suppression; inflammation in the hippocampus: depressive symptoms) is closely related to the severity of neuropsychological symptoms such as fatigue, cognitive impairment, pain, and depression [
8]. The mechanism of neuroinflammation in CFS is unknown, but researchers have speculated that the many exertions required to compensate for the functional decline associated with CFS increase neuronal activation, and that this hyperactivity leads to elevated inflammatory cytokines [
41].
Elevated inflammatory cytokines lead to elevated ROS. Mitochondria play a pivotal role in maintaining cell stability through energy production, the regulation of Ca2+ levels, the maintenance of ROS levels, and the regulation of apoptosis, whereby ROS rapidly lose their function by inducing damage to mitochondrial membrane lipids [
42]. Therefore, elevated ROS levels lead to mitochondrial dysfunction. OS and energy metabolism have been elucidated as dysfunctional metabolic pathways in patients with CFS [
43], and furthermore, the response of CFS patients to accumulative exercise is associated with elevated OS as well as noticeable changes in myofascial dysfunction that induce the post-exercise fatigue and muscle soreness reported by CFS patients [
44,
45].
OS has also been reported to be relevant in sleep disorders. Processes such as cognition, immunity, and metabolism are all dependent on sleep, and inadequate sleep is believed to cause serious health problems. Studies have reported changes in antioxidant responses in the brain during sleep deprivation [
46,
47,
48]. When wild-type flies are treated with antioxidants to increase sleep, the overexpression of antioxidant genes reduces OS in fly neurons, resulting in decreased sleep and prolonged survival [
47]. In addition, sleep deprivation in flies causes ROS to accumulate in the gut, causing OS in this organ. However, ceasing sleep deprivation gradually eliminates ROS and OS markers [
48]. These results suggest that sleep plays an important role in protecting against OS [
49], and it is asserted that there is a reciprocal relationship between ROS and neurons in regulating sleep. We hypothesize that the accumulation of ROS in the gut during sleep deprivation also affects the gut microbiota (GM). Short-term (<4 years) CFS patients show abnormalities in GM, particularly reduced butyrate production [
50]. SCFAs have been studied as a byproduct of bacterial fermentation following soluble fiber intake, with acetate, propionate, and butyrate being the major bacterial products in the colon [
51].
SCFAs have been reported to be released into the bloodstream, potentially reaching the brain. In particular, butyrate has anti-inflammatory effects [
52], improves learning disabilities, and has been reported to improve dendritic spine density in hippocampal neurons in Tg2576 mice, a mouse model of AD [
53]. It has been posited that if GM abnormalities are left untreated, they may lead to microglial activation, BBB destruction, and subsequent systemic inflammation that determines the crossing of pathogens and immune cells [
54]. For all these reasons, the regulation of OS in CFS is important. TwM is an antioxidant combination drug based on TwX, which has been shown to reduce brain inflammation and blood OS, maintain neurogenic cells, prolong telomere, improve the balance of intestinal microflora, and increase butyrate-producing bacteria in addition to its mitochondrial protective effect based on previous basic experiments. TwM was suggested to show a tendency to improve various symptoms indicated in this questionnaire by reducing OS, maintaining ATP production through mitochondrial protection, and suppressing inflammation, including in the brain.
In addition to evaluating the degree of CFS symptoms, the survey included an open-ended question about subjective symptoms not covered by the items. Besides the muscle and joint pain included in the survey, the participants reported feeling less pain, including stiff shoulders and lower back pain, as well as feeling lighter and less mentally depressed and fatigued. They also reported feeling less susceptible to catching colds, which may be related to the immune system. Regarding sleep, the participants reported experiencing sound sleep and waking up refreshed (
Table 1).
Many patients with CFS have been reported to have both anxiety and depressive disorders [
55]. Depression is associated with altered brain function, neuronal plasticity, and decreased frontal cortical and hippocampal volume [
56]. Increased ROS generation and the depletion of antioxidant defenses have been reported to be responsible for changes in brain structure in depression [
57,
58,
59]. It is also associated with increased inflammatory cytokine levels and decreased nerve growth and subsequent neural progression. Mitochondrial dysfunction not only leads to cellular energy deficiency, but may also be involved in impaired neuronal communication and cellular resilience, which leads to mood and psychotic disorders [
60,
61]. Various types of stress have also been consistently observed to decrease hippocampal neurogenesis in adults, leading to depression. Increased mitochondrial genome and mitochondrial proteins are required for neuronal differentiation during neuronal development, and mitochondrial dysfunction plays an important role in impaired adult hippocampal neurogenesis in depression [
62,
63].
In addition, we speculate that the experience of fewer colds may have been due to a decrease in intestinal OS associated with improved sleep quality, which normalized GM and improved immune system function. Increased OS activates inflammatory signaling pathways, and increased inflammation also increases OS. Since OS and inflammation have a synergistic effect on each other, we speculate that a vicious cycle of OS and inflammation is established, which exacerbates and maintains the disease state. TwM could break the vicious cycle between OS and inflammation in CFS.