Hola Emanuel

Yes, here:

Antes que digas nada, yo no tuve la culpa.

Before you say anything, it wasn't my fault.

You could also say "Antes que digas algo"

However, it sounds better to use nada here. Although there is no negative element at the beginning of the sentence, in this case, the negative "nada" is reinforcing the negativity, as if we said: 

"No digas nada; yo no tuve la culpa." 

I hope this helps,

Saludos,

Inma