Tuesday, August 17, 2021

How Beta-Glucans of Shiitake kills tumor cells: An image

 

 pdf link

Fascinating stuff to be sure!!

 beta-glucan, a water-soluble polysaccharide, activates immune cells and proteins and macrophages, T cells, natural killer cells, and cytokines that attack tumor cells [10].
Mushroom cell walls contain two important compounds, chitin and β-glucans. Of these two, β-glucans β(1→3), β(1→4), and β(1→6) make mushroom of significance in health and treatment of various diseases [18–20]. In addition to these compounds, there are other important components in mushrooms. They include polysaccharides, polysaccharide-protein complexes, agaritine, ergosterol, selenium, polyphenols, and terpenoids.

The receptors of β-glucans, Dectin-1, are expressed on dendritic cells, macrophages, neutrophils, and monocytes [57, 58]. Binding of Dectin-1 and β-glucans leads to signal transduction which in turn activates T cells, mitogen activated protein kinases (MAPK), and nuclear factor kappa B (NF-kB), resulting in cytokine production [59, 60].

 Probable immunomodulation mechanism of action of mushroom glucans. 

They utilize Dectin-1, CR3, and TLR-2 leading to activation and signal transduction of T lymphocytes, MAPK, and NF-kB, in turn leading to chemokine production and activation and stimulation of lymphocytes, macrophages, and NK cells, which results in inhibition of cancer proliferation through either direct toxicity, apoptosis, and cancer cell cycle arrest or hindering angiogenesis and metastasis of cancer cells. 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5937616/ 

Following an oral uptake of mushrooms/mushroom compounds, intestinal immune factors are activated, that is, dendritic cells and macrophages that secrete cytokines that initiate local or systemic immunity. Intestinal epithelial cells are also stimulated to secrete IL-7, an important cytokine in cancer immunotherapy [73, 74]."

 "Specific receptors of beta-glucans are the Toll-like (TLR) and
the C-type lectin-like receptors: within the latter, dectin-1 is the best characterized one
and is predominantly expressed on the surface of monocyte/macrophages, neutrophils,
and dendritic and natural killer (NK) cells [11,12]. An intracellular signal transduction
follows the receptor recognition step and results in activation of the nuclear factor k-lightchain-
enhancer of activated B cells (NF-kB), transcription of inflammatory-immune genes,
production of cytokines, nitric oxide (NO), and reactive oxygen species (ROS) [2,13,14].
Other pattern recognition receptors (PRR) are implicated in beta-glucan recognition and may
act in cooperation with dectin-1/TLR [15], or even directly [16]. During injury, beta-glucan
receptors may be blocked, but a strong immunomodulatory response, independent of
these receptors, can be stimulated, for instance, by beta-glucans from a fungal pathogen, with
expression of high levels of the interleukin-1 receptor antagonist (IL-1RA) [16]. Lentinan
has been shown to upregulate cytokines in mouse macrophages and to attenuate IL-1
secretion resulting from Listeria activation of the absent in melanoma 2 (AIM2) inflammasome. Importantly, lentinan was able to reduce endotoxin lethality in mice despite
the up-regulation of cytokine expression, most probably via inhibition of non-canonical
inflammasome activation [17]."


Edible Mushrooms and Beta-Glucans: Impact on Human Health


Chiara Cerletti 1,* , Simona Esposito 1 and Licia Iacoviello
Impressive Lentinan action!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No comments:

Post a Comment