Requirements for Translation in Clinical Trials of Aromatherapy: The Case of the Essential Oil of Bergamot (BEO) for Management of Agitation in Severe Dementia.

Due to the tight link between undertreated pain and agitation in dementia patients, aromatherapy can be a useful approach if an essential oil (EO) with powerful analgesic activity is used. The methodological difficulties of most aromatherapy trials have not allowed any definitive conclusion about the effectiveness of aromatherapy in dementia. The objective of the present perspective is to illustrate the long rigorous process leading from preclinical research to clinical translation of the EO of bergamot (BEO) for the management of agitation in dementia. A nanotechnology-based delivery system consisting of odorless alpha-tocopheryl stearate solid lipid nanoparticles (SLN) loaded with BEO (NanoBEO), has been proven active in acute and neuropathic pain models confirming the strong antinociceptive and anti-allodynic efficacy reported for BEO in preclinical studies. In particular, prolonged physicochemical stability of NanoBEO and titration in its main components are remarkable advantages allowing reproducible antinociceptive and anti-itch responses to be measured. Furthermore, the possibility to perform double-blind clinical trials made impossible so far because of the strong smell of essential oils used in aromatherapy. Demented patients receive limited treatment for chronic pain, particularly neuropathic. The BRAINAID (NCT04321889) trial will assess the effectiveness of NanoBEO on agitation and pain in severely demented patients to offer a safe tool able to provide relief to this fragile population. This double-blind clinical trial will be the first to assess the efficacy and safety of an engineered essential oil and will provide the rationale for the safer treatment of neuropsychiatric symptoms of dementia and pain in clinic.