An L-theanine derivative targets against SARS-CoV-2 and its Delta and Omicron variants

[cedric]

l-theanine lowers cortisol

Heliyon
. 2022 Jun;8(6):e09660. doi: 10.1016/j.heliyon.2022.e09660. Epub 2022 Jun 9.
An L-theanine derivative targets against SARS-CoV-2 and its Delta and Omicron variants
Jing Lu 1, Ying Zhang 1 2 3, Dan Qi 4, Chunyan Yan 1 5, Benhao Wu 2, Jason H Huang 4 6, Jianwen Yao 1, Erxi Wu 4 6 7 8, Guoying Zhang 1

PMID: 35706933 PMCID: PMC9181633 DOI: 10.1016/j.heliyon.2022.e09660
Abstract
Recent research efforts have shown that tea has activities against SARS-CoV-2. However, the active compounds and the action mechanisms are largely unknown. Here we study the inhibitory potential of L-theanine from tea and its semi-synthesized derivative, a small-molecule fluorescent compound, ethyl 6-bromocoumarin-3-carboxylyl L-theanine (TBrC) against infection and replication of SARS-CoV-2 and the underlying mechanisms of action. We reveal that TBrC has potential activities against SARS-CoV-2 in addition to its activity against lung cancer. TBrC showed extracellular inhibition of SARS-CoV-2 Mpro/3CL and the host cell receptor ACE2 while interacting with the viral spike glycoproteins (wild-type, Delta, and Omicron mutants). Moreover, TBrC and L-theanine significantly suppressed growth and TNFα-induced nuclear transcriptional activation of NF-κB in human lung cancer cells without affecting the viability of normal lung cells, suggesting a potential protection of TBrC and L-theanine from pulmonary damages in SARS-CoV-2 infected patients, especially for lung cancer patients with SARS-CoV-2 infection.