Tentar non nuoce.
"To try doesn't harm." I.e., "There's no harm in trying."
This proverb is a great reminder of how to make negative statements in Italian. Nuoce = it harms. Non nuoce = it doesn't harm. (Nuoce comes from the verb nuocere - to harm).
"Tentar" is just a more literary way of saying "tentare" - to try or attempt.