Differences in Biological Response Modifier-like Activities According to the Strain and Maturity of Bananas

We have studied the neutrophil-increasing effects of fruits and vegetables and their priming effects on cytokine induction. Among fruits, bananas exhibited the most marked priming effects. Therefore, we evaluated possible differences in the biological response modifier (BRM)-like activities of bananas (such as the effects on neutrophil accumulation and macrophage morphology, and the priming effects on cytokine induction), according to their strain and maturity, using a conventional strain and a strain for highland cultivation. As a result, the total intraperitoneal leukocyte count and % neutrophils increased in parallel with the concentration and maturity of banana extracts. These effects were more marked in the highland strain. After the addition of banana extracts, marked macrophage spreading was observed, and morphological changes differed according to the strain and maturity of bananas. The priming effects on TNF-α or IL-12 induction also differed according to the maturity and strain of bananas, and could also be confirmed after oral administration. These results suggest that banana intake is associated with various BRM-like activities, and these effects differ according to the maturity level of the bananas.