One of the main mechanisms to increase star formation activity is through galaxy interactions. Tidal induced inflows of metal-poor material are responsible of this enhancement, which in turns are thought to be the driver of metallicity dilution observed in central regions of interacting galaxies. Thanks to the spatially resolved data from 103 galaxies included in the CALIFA survey, we are able to probe the star formation and ionized gas oxygen abundance at different galactic scales and at different interaction stages. These results are compared homogeneously with a control sample of 80 isolated galaxies from the same survey. We find that star formation is moderately enhanced in central regions of interacting galaxies compared with control galaxies (~factor of 2). Even more, interacting and control galaxies share similar metallicities. Our results suggest that although inflows play the main role in the enhancement of the central star formation in interacting galaxies, other processes such as stellar feedback could induce a chemical enrichment leading to central metallicities similar as those observed in isolated galaxies.