Study finds different gastroprotective potential for reishi components based on molecular weight
The new study was published in the journal Nutrients. It was the work of researchers associated with Zhejiang University of Technology in Huzhou, China and an employee of Longevity Valley Botanical Co., Ltd., in Hangzhou, a 113-year-old company devoted to the development of health products based on fungi. The research was funded by public and industry sources.
The researchers used acute gastric injury induced by ethanol in lab rats as a model to test the effects of various polysaccharides derived from Ganoderma lucidum, colloquially known as reishi mushroom.
Reishi is one of the longtime mainstays of Traditional Chinese Medicine (TCM). The 2011 text Herbal Medicine: Bimolecular and Clinical Aspects published by Taylor and Francis has this to say about the fungus:
“In Chinese, the name lingzhi (as rendered as reishi) represents a combination of spiritual potency and essence of immortality, and is regarded as the ‘herb of spiritual potency,’ symbolizing success, well-being, divine power, and longevity. Among cultivated mushrooms, G. lucidum is unique in that its pharmaceutical rather than nutritional value is paramount. A variety of commercial G. lucidum products are available in various forms, such as powders, dietary supplements, and tea. These are produced from different parts of the mushroom, including mycelia, spores, and fruit body. The specific applications and attributed health benefits of lingzhi include control of blood glucose levels, modulation of the immune system, hepatoprotection, bacteriostasis, and more.”
Separation by weight to determine activity
An issue with the effects of many TCM preparations from a Western scientific point of view has been that these are multicomponent formulas with many active constituents. That makes parsing out precise modes of action difficult. The same is true for reishi.
To drill down deeper into reishi’s effects the authors of the present study decided to focus on the polysaccharide fractions of the mushroom. After extracting the polysaccharide fractions of the fruiting body, the researchers used progressively finer filtration membranes of 100 kDa, 10 kDa ad 1 kDa to divide the polysaccharides into three groups by molecular weight that averaged 322.0 kDa, 18.8 kDa, and 6.4 kDa, respectively (kDa=kilodaltons).
Direct tissue injury, blood markers measured
The test rats were divided into several groups, with the experiment groups having had gastric injury induced by ethanol administration. Ethanol is what the researchers called “an acute gastric mucosal injury model. Ethanol can act directly on the gastric mucosa, leading to erosion, bleeding, perforation, and other injuries.”
Direct examination of the texture and integrity of the mucosal walls of the rats’ guts was one of the primary outcomes of the study. Other outcomes included measurement of antioxidant molecules in the serum, such as superoxide dismutase (SOD) and glutathione peroxidase-1 (GPx-1).
The researchers found that the higher the molecular weight of the polysaccharide, the greater the effect in lessening the gastrointestinal injury caused by ethanol.
“GLP100 has a greater improvement effect on acute gastric greater improvement effect on
injury than GLP10, and GLP10 has a better effect than GLP1,” the researchers wrote.
“There are still many contents that are worth further study. For instance, further separation and purification of GLPs are needed to determine efficacy. For instance, further separation and purification of GLPs are needed to determine efficacy. The synergistic effect of the components of each GLP fraction on gastrointestinal protection, and which proportion of GLP components are more effective when mixed in proportion are worthy of further study, so as to make the research results viable to application,” the authors concluded.
2022, 14(7), 1476; https://doi.org/10.3390/nu14071476
Gastroprotective Effects of Ganoderma lucidum Polysaccharides with Different Molecular Weights on Ethanol-Induced Acute Gastric Injury in Rats
Authors: Tian B, et al.