Yes, DEBASES is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, B 3, A 1, S 1, E 1, S 1.

Is it a valid word?

DEBASES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

corrupt morally or by intemperance or sensuality
lower in value by increasing the base-metal content
corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones

Not playable in Scrabble US: DEMORALISE.