The leukotoxin-neutralizing compounds of Guava are present in leaves and twigs, but not in the fruit. (A) LDH-release from human leukocytes exposed to A. actinomycetemcomitans leukotoxin (0, 80, or 240 ng/ml) for 60 min in the presence of Guava extracts (0.1%) from twigs, leafs or fruits. Representative results of relative LDH release are shown. (B) Leukotoxin neutralizing capacity in different concentrations of Guava extracts (twigs, leafs, fruits) based on LDH-release from macrophages exposed to leukotoxin (80 ng/ml) for 60 min. Mean ± SD of 3 observations is shown.