I guess I worded that badly, I meant should I have an equivalent transistor set up to control a different circuit which has a 25V supply would the Arduino be protected from the 25V, but as you say they should be PNPs anyway I guess the question is invalid.
In a circuit running from 25V with PNPs rather than NPNs would the Arduino be protected?
Also 120R is way too low to have as a base resistor.
Is that in the general case, as it is wired at the moment? what would be a more appropriate value?