Curcumin herbal therapy found to ease disease severity in MG mice
Traditional Asian medicine has positive effects on gut, immune system: Study
Curcumin therapy — treatment with the traditional Asian medicine, which is the main ingredient in the spice turmeric — was found to ease disease severity in a mouse model of myasthenia gravis (MG).
Use of curcumin, a bright yellow chemical produced by plants, also was shown to normalize microbial and metabolic changes in the gut, and inflammatory activity in the bloodstream, among the mice, a new study on the research reported.
“This study provides novel insights into curcumin’s clinical value in MG therapy,” the researchers wrote, noting that clinicians “urgently need new drugs with fewer side effects and better efficacy” for treating the neuromuscular disease.
“Traditional Chinese herbal medicine has shown good results in this area recently,” the team added.
The study, “Curcumin protects mice with myasthenia gravis by regulating the gut microbiota, short-chain fatty acids, and the Th17/Treg balance,” was published in the journal Heliyon.
Investigating the use of curcumin therapy in MG
The gut microbiome — the collection of microbes that populate the intestinal tract — plays an important role in modulating the immune system, research has shown. Also important in these processes are short-chain fatty acids (SCFAs), which are metabolic byproducts that come from certain types of bacteria.
Increasingly, studies on such research have described a role for the gut microbiome in contributing to inflammatory and autoimmune diseases throughout the body.
Alterations in the gut microbiome and disrupted SCFA production have been observed in MG patients, according to researchers from institutions in China. Thus, “effective interventions targeting gut microbiota may be part of the most promising strategies to alleviate MG,” the team wrote.
Curcumin is the main active ingredient in the spice turmeric. It has long been used in traditional Chinese medicine for its anti-inflammatory, antioxidant, and neuroprotective properties. According to the researchers, curcumin has been used to treat neurodegenerative conditions, including both Huntington’s disease and Alzheimer’s disease.
More recently, studies in neurological diseases have found that curcumin may in part be therapeutic by helping to restore a healthier gut microbiome.
While a previous study found that curcumin eased disease severity in a rat model of MG, where it modulated certain immune cells, whether curcumin might also have beneficial effects in the gut has not been widely explored in the context of MG.
Now, in this study, researchers aimed to examine the effects of curcumin on clinical disease symptoms, immune cell signaling, and gut microbe composition in a mouse model of the autoimmune disease.
A month of treatment with curcumin was found to significantly ease overall disease severity, increase body weight, and boost locomotor activity relative to untreated mice.
Greater disease severity in the MG model was associated with higher circulating levels of IL-17A, an inflammatory signaling molecule, and lower levels of IL-10, an anti-inflammatory signaling molecule. Moreover, greater disease severity scores were linked to a lower abundance of Oscillospira bacteria in the gut.
In mice, treatment seen to help gut microbiome
Compared with healthy mice, MG mice had significantly reduced overall diversity of gut microbes, altered levels of certain types of gut bacteria, and diminished production of known anti-inflammatory SCFAs.
These changes tended to be reversed with curcumin. Specifically, the treatment led to reductions in inflammation-associated bacteria, increases in SCFA-producing bacteria, and elevations in acetate and butyrate — SCFAs with immune-modulating abilities.
The intestines contain a cellular lining that helps control the passage of materials within the gut out into the bloodstream. A leaky, or more permeable, barrier can allow inflammatory molecules in the gut to travel to the rest of the body, contributing to autoimmune diseases.
Signs of increased intestinal permeability were observed in the MG mouse model, but were “dramatically reduced” with curcumin treatment, according to the researchers.
Curcumin may protect mice against MG. … Further research is needed to investigate the signaling pathways and targets that curcumin uses to improve gut barrier function and alter the gut microbiota.
The MG disease state also was associated with immune cell alterations, including an increase in inflammatory T-helper 17 cells (Th17) and a decrease in regulatory T cells, which normally help to control inflammation by regulating the activity of other immune cells. Again, curcumin treatment helped to reverse these changes.
Likewise, curcumin-treated mice exhibited significantly diminished circulating levels of pro-inflammatory molecules and an increase in anti-inflammatory molecules compared with untreated mice.
Altogether, these findings suggest that “curcumin may protect mice against MG by modulating both gut microbiota and SCFAs levels, improving gut permeability, and regulating Th17/Treg balance,” the researchers wrote.
“Further research is needed to investigate the signaling pathways and targets that curcumin uses to improve gut barrier function and alter the gut microbiota and its metabolites,” the team noted.
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