I don't think, well, at least they shouldn't age normally as we do.
I believe a great deal of time has passed by, we are infact talking about DMC4 being in the sequence after DMC1, so in between DMC3 and 4 I would have to say a larger amount of time has elapsed. If it were upto me I would place DMC4 at least 20 years after the events of DMC1, thus giving Dante a slightly more aged look but not in line with the ageing of mere mortals, keeping in mind he is of Sparda progeny, so his ageing would be considerably slower than ours.