Snake venom-derived bradykinin-potentiating peptides: A promising therapy for COVID-19?

The severe acute respiratory syndrome coronavirus-2 (SARS-COV-2), a novel coronavirus responsible for the recent infectious pandemic, is known to downregulate angiotensin-converting enzyme-2 (ACE2). Most current investigations focused on SARS-COV-2-related effects on the renin-angiotensin system and especially the resultant increase in angiotensin II, neglecting its effects on the kinin-kallikrein system. SARS-COV-2-induced ACE2 inhibition leads to the augmentation of bradykinin 1-receptor effects, as ACE2 inactivates des-Arg9-bradykinin, a bradykinin metabolite. SARS-COV-2 also decreases bradykinin 2-receptor effects as it affects bradykinin synthesis by inhibiting cathepsin L, a kininogenase present at the site of infection and involved in bradykinin production. The physiologies of both the renin-angiotensin and kinin-kallikrein system are functionally related suggesting that any intervention aiming to treat SARS-COV-2-infected patients by triggering one system but ignoring the other may not be adequately effective. Interestingly, the snake-derived bradykinin-potentiating peptide (BPP-10c) acts on both systems. BPP-10c strongly decreases angiotensin II by inhibiting ACE, increasing bradykinin-related effects on the bradykinin 2-receptor and increasing nitric oxide-mediated effects. Based on a narrative review of the literature, we suggest that BPP-10c could be an optimally effective option to consider when aiming at developing an anti-SARS-COV-2 drug.