Phytoconstituents from Adenanthera pavonina L. as antioxidants and inhibitors of inducible TNF-α production in BV2 cells

Abstract

Adenanthera pavonina L. has been used traditionally to relieve inflammation. This study aimed to expand the phytochemical knowledge of A. pavonina and evaluate its constituents for their antioxidant and anti-inflammatory potentials as tumor necrosis factor alpha (TNF-α) inhibitors. The antioxidant activity was evaluated using the DPPH radical scavenging assay, and the inhibition of TNF-α was assessed through ELISA and qRT-PCR techniques. Interestingly, five previously undescribed metabolites, including a pentadienoic acid derivative, a triterpenoid glycoside, and three tamarixetin glycosides, were identified alongside seven known compounds. Most compounds evaluated had higher DPPH radical scavenging capabilities than the standard, trolox. Tamarixetin 3-O-(α-ʟ-rhamnopyranosyl)-(1→2)-β-ᴅ-galactopyranoside (11), a previously undescribed compound, was the most effective at suppressing TNF-α protein and m-RNA levels. Other flavonoid glycosides, quercetin 3-O-(α-ʟ-rhamnopyranosyl-(1→2)-β-ᴅ-xylopyranoside (4), isovitixin (5), and quercetin-3-O-[α-ʟ-rhamnopyranosyl-(1→2)]-[α-ʟ-rhamnopyranosyl-(1→6)]-β-ᴅ-galactopyranoside (9), also significantly lowered TNF-α production.