Anti-Influenza Effect and Mechanisms of Lentinan in an ICR Mouse Model

Abstract

Influenza virus is a serious threat to global human health and public health security. There is an urgent need to develop new anti-influenza drugs. Lentinan (LNT) has attracted increasing attention in recent years. As potential protective agent, LNT has been shown to have anti-tumor, anti-inflammatory, and antiviral properties. However, there has been no further research into the anti-influenza action of lentinan in vivo, and the mechanism is still not fully understood. In this study, the anti-influenza effect and mechanism of Lentinan were studied in the Institute of Cancer Research (ICR) mouse model. The results showed that Lentinan had a high degree of protection in mice against infection with influenza A virus, delayed the emergence of clinical manifestations, improved the survival rate of mice, significantly prolonged the middle survival days, attenuated the weight loss, and reduced the lung coefficient of mice. It alleviated the pathological damage of mice infected with the influenza virus and improved blood indices. Lentinan treatment considerably inhibited inflammatory cytokine (TNF-α, IL-1β, IL-4, IL-5, IL-6) levels in the serum and lung and improved IFN-γ cytokine levels, which reduced cytokine storms caused by influenza virus infection. The underlying mechanisms of action involved Lentinan inhibiting the inflammatory response by regulating the TLR4/MyD88 signaling pathway. This study provides a foundation for the clinical application of Lentinan, and provides new insight into the development of novel immunomodulators.

Lentinan progress in inflammatory diseases and tumor diseases

“…LNT can reduce oxidative stress-induced apoptosis, and also reduce the expression of pro-inflammatory factors such as TNF-α, IL-8, IL-2, IL-6, IL-22, thereby reducing NF-kB activation, which proves its great potential in the treatment of COVID-19 [31]. Similarly, another study found that LNT can inhibit the overexpression of cytokine storms of TNF-α, IL-1β, IL-4, IL-5, and IL-6 in influenza A viral by modulating the TLR4/MyD88 signaling pathway [32] More interestingly, a randomized controlled human experiment showed that LNT combined with budesonide reduced endogenous anti-inflammatory factor adiponectin IL-17, D-dimer acute severe chronic obstructive pulmonary in patients [33]. Moreover, an animal experiment found that LNT could inhibit oxidative stress in bovine mammary epithelial cells and also reduce the expression of inflammatory factor protein by inhibiting NF-kB and mitogen-activated protein kinase (MAPK), suggesting its great potential in the treatment of mastitis [34].…”

Beta-(1,3/1,6)-D-glucan from Pleurotus ostreatus in the prevention of recurrent respiratory tract infections: An international, multicentre, open-label, prospective study

“…A recent animal experiment with β-glucan extract from Lentinus edodes (Lentinan) confirmed the cytoprotective effect on pulmonary cells and anti-inflammatory activity expressed by the changes in the cytokine spectrum. Furthermore, lentinan showed a high degree of protection against infection with the influenza A virus in mice ( 27 ). It alleviated the pathological changes of infected mice and inhibited inflammatory cytokine levels in the serum and lungs via regulation of the TLR4/MyD88 signalling pathway.…”