Research On Immunomodulatory Activity Of Konjac Glucomannan

Konjac Glucomannan (KGM) powder

Konjac Glucomannan (KGM) powder is the main component of the natural plant konjac, accounting for approximately 60% of its corm content. It is a high molecular weight non-ionic polysaccharide with an average relative molecular weight ranging from 200,000 to 2,000,000. KGM consists of β-D-glucose and β-D-mannose in a molar ratio of 1:1.6, linked by β-1,4-glycosidic bonds. It exhibits excellent immunomodulatory activity, impacting immune organs, mononuclear macrophages, T and B lymphocytes, cytokines, and intestinal mucosal immunity.

1. Immune Organs

Immune organs are the tissue structures responsible for executing the body's immune functions. KGM's influence on immune organ development is mainly manifested in its effects on the thymus and spleen, including weight and cell proliferation. Animal experiments with the overall administration of konjac extract revealed that the spleen index and thymus index of mice in the konjac extract group were significantly higher compared to the control group (NS). The impact of konjac extract on the spleen index was most prominent at a dose of 300 mg/kg·d, while doses of 100 mg/kg·d and 300 mg/kg·d had highly significant effects on the thymus index.

2. Mononuclear Macrophage System Function

Macrophages play a crucial role in eliminating pathogenic microorganisms, phagocytizing damaged, and promoting immune function restoration. Konjac Glucomannan powder can activate macrophages and monocytes, stimulating them to secrete vascular growth factors and heparin. Studies have also shown that KGM enhances the ability of murine peritoneal macrophages to phagocytize chicken red blood cells in a dose-dependent manner.

The polysaccharides on the surface of macrophages mainly contain mannose. Mannose receptors on macrophages are closely related to phagocytic activity and are crucial for phagocytosing fungi and bacteria. Mannose in polysaccharides binds to the sugar recognition domain on mannose receptors, activating macrophages, and enhancing their immune functions. Research indicates that KGM has a strong affinity for mannose receptors on macrophages, followed by (rhubarb polysaccharides), while D-mannose has the weakest affinity. This suggests that KGM may regulate the cytokine balance in macrophages of rats with ulcerative colitis through interaction with mannose receptors.

3. Oligosaccharides and Derivatives

Existing research has found that adding KGM oligosaccharide sulfate and &beta;-glucan to the feed of South American white shrimp significantly enhances the shrimp's lysozyme activity, phenoloxidase activity, and superoxide dismutase activity, thereby strengthening its disease resistance. Additionally, in mouse experiments, different components of konjac oligosaccharides also showed significant effects. For instance, compared to the model group, konjac oligosaccharide components significantly increased the thymus index of mice (P<0.01) and increased the secretion of cytokines IFN-y, IL-4, and IL-2. It also synergistically promoted the proliferation of spleen lymphocytes in immunosuppressed mice. Furthermore, konjac oligosaccharide component 1 effectively stimulated the proliferation of RAW 264.7 macrophages. These findings indicate the positive impact of konjac oligosaccharides and their derivatives on immunomodulatory activity. They provide important research evidence for the application of konjac oligosaccharides and derivatives in the field of immunology, but further exploration is still required.

4. Immunological Applications of Konjac

The complex preparation of KGM and water hyacinth sugar plays a crucial role in intestinal lubrication and laxation, offering valuable insights into the research of konjac products in intestinal immunity. Improved konjac glucomannan overcomes issues of low solubility and susceptibility to hydrolysis and is widely used in the food industry as a food thickener, edible film, and biodegradable green packaging material.

Experiments have shown that konjac mannan oligosaccharides enhance the cellular immune function and mononuclear macrophage phagocytic function in ICR mice, providing animal experimental evidence for the use of konjac as a health food. Researchers found that adding 4 g/kg of mannan oligosaccharide significantly increased the thymus index (P<0.05) and serum lysozyme activity (P<0.05) in mice. It increased the number of cecal lactobacilli and reduced the number of Salmonella (P<0.05), making it a potential replacement for lincomycin in 'three yellow chickens' farming.

Conclusion

Konjac glucomannan powder found in konjac exhibits significant physiological activity, playing an indispensable role in enhancing immunity. Unlike other polysaccharides with singular mechanisms of action, it exerts a multifaceted immunomodulatory effect by influencing immune organs, immune cells, immune molecules, and intestinal immunity. This leads to an improvement in overall immune function and increased resistance. Furthermore, the application of konjac in immunology has progressed to include modified glucomannan powder and konjac oligosaccharides, both of which require further in-depth exploration in future research.

E-mail: sales@sxytorganic.com

Phone: +8617795611310

Telephone: +86-029-86478251

Address: No. 10, Jinye 1st Road, Yanta District, Xi'an, Shaanxi,China