Corrigendum to “Naturally occurring sesquiterpene lactones and their semi-synthetic derivatives modulate PGE2 levels by decreasing COX2 activity and expression” [Heliyon 5 (3) (March 2019) e01366] (Heliyon (2019) 5(3), (S2405844018347509), (10.1016/j.heliyon.2019.e01366))