Anti-inflammatory effects of naringenin 8-sulphonate from Parinari excelsa Sabine stem bark and its semi-synthetic derivatives

•P. excelsa extract strongly inhibited the activation of NF-κB in THP-1 cells.•Naringenin-8-sulphonate was described for the first time in the Parinari genus.•Naringenin-8-sulphonate affected NF-κB activity acting on p65 nuclear translocation.•Semi-synthetic naringenin metabolites were less active than naringenin-8-sulphonate.