5-Acetylsalicylic acid (5-acetyl-2-hydroxybenzoic acid) has anti-inflammatory effects and can be used to treat inflammatory bowel disease, including ulcerative colitis, inflamed anus or rectum, and to maintain remission in Crohn's disease.

Methyl salicylate (Gaultheria oil) is an organic ester naturally produced by many species of plants, particularly wintergreens. For acute joint and muscular pain, methyl salicylate is used as a rubefacient and analgesic in deep heating liniments.

Salicylic acid (2-Hydroxybenzoic acid), a natural compound extracted from Willow bark, is an anti-inflammatory inhibitor of activity cyclooxygenase.

Salicin (Salicine), a phenol β-glycoside produced from willow bark, shows anti-inflammatory functions.

Physostigmine, a parasympathomimetic alkaloid, is a reversible cholinesterase inhibitor. It extracts from the Calabar bean.