The antioxidant activity of methanol extracts from Passiflora edulis and Passiflora alata pulp, and P. edulis
rinds, healthy or infected with the passion fruit woodiness virus (PWV), was investigated using the oxidant
activities of the neutrophil and the neutrophil granule enzyme myeloperoxidase (MPO), both playing
key roles in inflammation. The reactive oxygen species produced by stimulated neutrophils were
evaluated by lucigenin-enhanced chemiluminescence (CL) and the activity of purified MPO was measured
by SIEFED (Specific Immunological Extraction Followed by Enzymatic Detection), a technique for
studying the direct interaction of a compound with the enzyme. The rind extracts of P. edulis possessed
higher and dose-dependent inhibitory effects on CL response and on the peroxidase activity of MPO than
total pulp extracts from both passion fruit species. The quantification of isoorientin in the extracts
showed a correlation with their antioxidant activity, suggesting the potential of P. edulis rinds as functional
food or as a possible source of natural flavonoids