Chinese researchers have identified a glucose-like metabolite associated with diabetes in human blood with effective antiviral activity against SARS-CoV-2.

The findings, led by researchers from Tsinghua University, were published in the journal Nature Metabolism on Tuesday.

Previous studies show that the severity and mortality of COVID-19 are associated with pre-existing diseases such as diabetes. However, the underlying causes behind this have not yet been well established.

In this new study, researchers screened out more than 200 small-molecule metabolites and found that 1,5-anhydro-D-glucitol (1,5-AG), which is deficient in patients with diabetes, can inhibit cellular entry of SARS-CoV-2.

They found the level of SARS-CoV-2 replication is higher in the presence of serum from patients with diabetes than from healthy individuals, but this can be counteracted by 1,5-AG supplementation to the serum from patients.

According to molecular mechanism analysis, 1,5-AG presented an effective anti-SARS-CoV-2 activity by binding to the S2 subunit of the SARS-CoV-2 spike protein, thereby interrupting the process of virus-cell membrane fusion.

In experiments conducted on mice, researchers discovered that diabetic mice undergoing SARS-CoV-2 infection were accompanied by much higher viral loads and more severe respiratory tissue damage when compared to non-diabetic mice. Sustained 1,5-AG supplementation in diabetic mice reduced SARS-CoV-2 loads and disease severity to similar levels in non-diabetic mice.

The results suggest that 1,5-AG supplementation can help reduce such incidences and prevent severe COVID-19 in diabetics, according to the study.

Editor: Guo Lili