HS twitter announced the nerfed cards:
Wild Growth now costs 3 mana instead of 2
Nourish now costs 6 instead of 5
Saronite Chain Gang now summons another saronite instead of ( an exact copy )
Level Up! now costs 6 instead of 5
Leeching Poison now gives lifesteal this turn only and for 1 mana
source: https://playhearthstone.com/en-us/blog/22817529