Flavonoids and saponins from Passiflora edulis f. edulis leaves (purple passion fruit) and its potential anti-inflammatory activity

Objectives The objective of this work was to evaluate the anti-inflammatory activity of the aqueous extract, fractions and major compounds, which are isolated and identified from Passiflora edulis f. edulis (purple passion fruit) leaves extract. Methods For the isolation of the major compounds, reversed-phase chromatography and normal phase countercurrent chromatography were used.The separation was followed by thin layer chromatography and HPLC-DAD-ELSD. One-dimensional and two-dimensional NMR and ESI-TOF-MS/MS were used for structural elucidation.The anti-inflammatory activity was evaluated on aTPA multiple dose model of skin chronic inflammation in mice. Additionally, myeloperoxidase (MPO) and nitric oxide synthase (NOS) activity assays were performed as possible mechanisms of action studies. Key findings and conclusions The study of the butanolic fraction mainly showed the presence of saponins and flavonoids. Three minor flavonoids were detected; and three known saponins, cyclopassiflosides IX, XI and III were isolated and identified. This is the first unequivocal report of the presence of these compounds in P. edulis f. edulis leaves. The most favourable results of anti-inflammatory activity were obtained for the flavonoid-rich fraction. All the fractions and isolated compounds evaluated, presented high percentages of inhibition of nitric oxide synthase activity.