A new approach from Khosravani et al. (22) assessed the capacity of physostigmine (a plant-derived alkaloid acetylcholinesterase inhibitor) as a sialogogue drug in patients with xerostomia of unknown cause (patients not suffering any disease that would justify it like Sjögren , sarcoidosis, etc), or who had received radiation and who had not been labelled a priori as taking xerostomic drugs. Here, ACHE is linked to xerostomia.