The Potential of Vouacapanes from Pterodon emarginatus Vogel Against COVID-19 Cytokine Storm

 The emergence of the COVID-19 pandemic has led to the search for potential therapeutic responses for various aspects of this disease. Fruits of Pterodon emarginatus Vogel (Fabaceae), sucupira, have been used in Brazilian traditional medicine because of their anti-inflammatory properties, which have been proven in vivo, in vitro, and in silico. Therefore, the aim of this work is to evaluate P. emarginatus oleoresin and isolated diterpenes by in vitro anti-inflammatory models.

 In this study, the mechanisms underlying the anti-inflammatory activity of P. emarginatus oleoresin and vouacapanes 6α,19β-diacetoxy-7β,14β-dihydroxyvouacapan (V1), 6α-acetoxy-7β,14β-dihydroxyvouacapan (V2), and methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate (V3) were investigated in HaCaT cells.

 Oleoresin, V2, and V3 inhibited phospholipase A2 (30.78%, 24.96%, and 77.64%, respectively). Both vouacapanes also inhibited the expression of COX-2 (28.3% and 33.17%, respectively). The production of interleukin 6 (IL-6) was inhibited by oleoresin by 35.47%. However, oleoresin did not interfere with Nrf-2 expression or IL-8 production.

 The results support the ethnomedicinal use of P. emarginatus oleoresin as an anti-inflammatory herbal medicine, and also highlight P. emarginatus oleoresin and isolated vouacapanes as an attractive therapeutic approach for COVID-19 through the reduction or chronological control of the inflammatory mediators IL-6, cyclooxygenase-2 (COX-2), phospholipase A2, and INF-y (indirectly) during the SARS-CoV-2 infection process.