Severe acute respiratory distress syndrome (ARDS) is a major COVID-19 morbidity . COVID-19 instigates chronic inflammation resulting in a “cytokine storm” that causes most ARDS mediated deaths [, , ]. COVID-19 also causes multisystem inflammatory syndrome (MIS) in children and adolescents. This hyper-inflammation leads to multiple organ failure and shock . Treatments for these inflammatory syndromes include parenteral immunoglobulin and steroids with limited efficacy . The IL-6 antibody blocker tocilizumab was found an effective treatment for CAR-T cell induced cytokine storm, and has been adopted as a treatment for COVID-19 inflammation [, , ].
The spike and ACE2 proteins are highly glycosylated with sialic acid modifications that direct viral-host interactions and infection. Maackia amurensis seed lectin (MASL) has a strong affinity for sialic acid modified proteins and can be used as an antiviral agent. Here, we report that MASL targets the ACE2 receptor, decreases ACE2 expression and glycosylation, suppresses binding of the SARS-CoV-2 spike protein, and decreases expression of inflammatory mediators by oral epithelial cells that cause ARDS in COVID-19 patients. In addition, we report that MASL also inhibits SARS-CoV-2 infection of kidney epithelial cells in culture.
Unlike antibodies, lectins can be taken orally to treat diseases [, , ] including cancer  and viral infections . MASL targets sialic acid modified receptors to inhibit cancer progression and inflammation [18,19,21]. Results from this study indicate that MASL inhibits ACE2 expression, SARS-CoV-2 spike binding, and major components of the IL6 amplifier including STAT3, IL6, and NFκB as illustrated in Fig. 4d. In addition to viral lung inflammation, IL6 signaling also triggers contact dermatitis and psoriasis in keratinocytes , as well as arthritic inflammation in chondrocytes . COVID-19 inflammation shares inflammatory mechanisms with arthritis . Indeed, COVID-19 infection causes arthralgia and myalgia in 15% and 44% of patients, respectively [68,69]. It should therefore be noted that MASL has been found to attenuate inflammatory NFκB signaling and inflammation in chondrocyte cell culture, and can be administered orally to alleviate arthritis progression in mice . In addition, MASL has also been reported to suppress interleukin induced psoriatic inflammation in reconstituted epidermis . Taken together, data suggest that MASL has the potential to be used alone or in combination with other antiviral and anti-inflammatory agents for COVID-19 treatment.
Хорошо бы проверить и "in vivo"..