Anti-central fatigue effects of myelophil in 5-HTergic hyperactivity mice model

Abstract:

Background: Myelophil is a standardized ethanol extract of Astragali Radix and Salviae Miltiorrhizae Radix, which has been developed based on clinical experience in traditional Korean medicine practices for patients with unexplained chronic fatigue, including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Our previous studies demonstrated Myelophil’s clinical efficacy in ME/CFS, as well as its brain-related activities in animal models. However, the underlying pharmacological mechanisms remain unclear. Recently, we identified serotonergic hyperactivity as a key pathophysiological factor in central fatigue, such as ME/CFS. Therefore, in the present study, we aimed to investigate the mechanisms by which Myelophil exerts its effects, particularly in the context of a 5-HTergic hyperactivity model.

Method: To verify the action mechanisms of Myelophil on serotonergic hyperactivity condition, we herein assessed its anti-central fatigue properties using a fluoxetine-treated mice model. Male C57BL/6 N mice (9 weeks old) were subjected to periodic intraperitoneal (IP) injections of fluoxetine for 4 weeks and the mice were simultaneously oral administered Myelophil (0, 50, or 100 mg/kg) or ascorbic acid (100 mg/kg).

Result: Four-week injection of fluoxetine notably increased serotonin (5-hydroxytryptamine, 5-HT) activity, as evidenced by immunofluorescence staining and Western blot assays in the raphe nuclei (RN), and induced central fatigue-like behaviors in the nest building test, wheel running test, rota-rod test, plantar test, and open field test. Meanwhile, Myelophil (100 mg/kg) administration significantly ameliorated those fatigue-related behaviors including pain sensitivity. Furthermore, the anti-fatigue effects of Myelophil were corroborated by changes in serotonin-related parameters (serotonin transporter; 5-HTT and vesicular monoamine transporter 2; VMAT2), as well as neurotrophic markers including c-Fos and brain-derived neurotrophic factor (BDNF) in the RN.

Conclusion: These results provide experimental evidence suggesting the potential mechanisms by which Myelophil may alleviate central fatigue associated with hyper-5-HTergic activity.

Source: Kang JY, Baek DC, Lee JS, Son CG. Anti-central fatigue effects of myelophil in 5-HTergic hyperactivity mice model. BMC Complement Med Ther. 2025 Apr 23;25(1):153. doi: 10.1186/s12906-025-04882-2. PMID: 40269903; PMCID: PMC12020330. https://pmc.ncbi.nlm.nih.gov/articles/PMC12020330/ (Full text)

Astragalus polysaccharide ameliorated complex factor-induced chronic fatigue syndrome by modulating the gut microbiota and metabolites in mice

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating disease with no symptomatic treatment. Astragalus polysaccharide (APS), a component derived from the traditional Chinese medicine A. membranaceus, has significant anti-fatigue activity. However, the mechanisms underlying the potential beneficial effects of APS on CFS remain poorly understood.

A CFS model of 6-week-old C57BL/6 male mice was established using the multiple-factor method. These mice underwent examinations for behavior, oxidative stress and inflammatory indicators in brain and intestinal tissues, and ileum histomorphology. 16 S rDNA sequencing analysis indicated that APS regulated the abundance of gut microbiota and increased production of short chain fatty acids (SCFAs) and anti-inflammatory bacteria.

In addition, APS reversed the abnormal expression of Nrf2, NF-κB, and their downstream factors in the brain-gut axis and alleviated the reduction in SCFAs in the cecal content caused by CFS. Further, APS modulated the changes in serum metabolic pathways induced by CFS.

Finally, it was verified that butyrate exerted antioxidant and anti-inflammatory effects in neuronal cells. In conclusion, APS could increase the SCFAs content by regulating the gut microbiota, and SCFAs (especially butyrate) can further regulate the oxidative stress and inflammation in the brain, thus alleviating CFS.

This study explored the efficacy and mechanism of APS for CFS from the perspective of gut-brain axis and provides a reference to further explore the efficacy of APS and the role of SCFAs in the central nervous system.

Source: Wei X, Xin J, Chen W, Wang J, Lv Y, Wei Y, Li Z, Ding Q, Shen Y, Xu X, Zhang X, Zhang W, Zu X. Astragalus polysaccharide ameliorated complex factor-induced chronic fatigue syndrome by modulating the gut microbiota and metabolites in mice. Biomed Pharmacother. 2023 May 9;163:114862. doi: 10.1016/j.biopha.2023.114862. Epub ahead of print. PMID: 37167729. https://www.sciencedirect.com/science/article/pii/S0753332223006522?via%3Dihub (Full study)

Brain atrophy in a murine model of chronic fatigue syndrome and beneficial effect of Hochu-ekki-to (TJ-41)

Abstract:

Brain-derived neurotrophic factor (BDNF) is associated with the main symptoms of chronic fatigue syndrome (CFS) and neuron apoptosis. Nevertheless, no study has been performed directly to explore the relationship between CFS, BDNF and neuron apoptosis.

We induced a CFS model by six injections of killed Brucella abortus antigen in BALB/c mice and treated them with Hochu-ekki-to (TJ-41). Daily running activity, body weight (BW), ratio of cerebral weight to BW (CW/BW) and expression levels of BDNF and Bcl-2 mRNA in the hippocampus were determined. The daily activity and CW/BW decreased significantly in the CFS model. BDNF and Bcl-2 mRNA expression levels in the hippocampus were suppressed in the CFS model and TJ-41 treated mice, while no significant difference was found between them.

We improved a murine model to investigate the relationship between CFS and brain dysfunction. In this model, reduced daily activity might have been associated with decreased hippocampal BDNF mRNA expression, hippocampal apoptosis and brain atrophy. TJ-41 increased the daily running activity of the model, which was independent of brain recovery.

 

Source: Chen R, Moriya J, Yamakawa J, Takahashi T, Li Q, Morimoto S, Iwai K, Sumino H, Yamaguchi N, Kanda T. Brain atrophy in a murine model of chronic fatigue syndrome and beneficial effect of Hochu-ekki-to (TJ-41). Neurochem Res. 2008 Sep;33(9):1759-67. doi: 10.1007/s11064-008-9620-1. Epub 2008 Mar 4. https://www.ncbi.nlm.nih.gov/pubmed/18317925