Ursolic acid, a pentacyclic triterpene with a multitude of potential CNS indications Ursolic acid is found in a variety of plants including common cooking herbs such as rosemary. Preclinical evidence suggests it may have merits for CNS conditions including neurodegenerative and psychiatric illnesses [1], in part through it's neuroprotective activity [2] (via anti-oxidant, anti-excitotoxic and anti-inflammatory mechanisms) and the added monoaminergic and other CNS activities may impart mood effects in neuropsychiatric disorders. It's low toxicity and ability to reach the CNS after oral administration adds to therapeutic merits and makes it a potential candidate for therapeutic use. That said, it seems to have poor oral bioavailability, being poorly absorbed from the GI tract There is preclinical suggestion that it may be of merit in Alzheimer's and Parkinsons, where it is neuroprotective and has effects on beta-amyloid models of neurodegeneration, also exerting relatively potent AChE inhibition [3] and in neurotoxin models of Parkinson's [4,5] Antidepressant effects of low doses seem to be noted in animal models, with the dopaminergic system [6] , other monoamines like 5-HT and NE [7] and and protein kinases implicated [8] along with anti-stress effects [9], which seem to be also related to it's activity on cortisol. It seems to extent lifespan in animal models via a dopaminergic mechanism, particularly involving D1 receptors [10]. One area of growing research seems to be it's use for immunomodulation and remyelination where it seems to exert beneficial effects, leading to potential efficacy for treating MS [11, 12]. References: [1] https://doi.org/10.1007/s40263-017-0474-4 [2] https://doi.org/10.1155/2019/8512048 [3] https://doi.org/10.1016/j.phymed.2021.153490 [4] https://doi.org/10.1007/s12640-019-00038-6 [5] https://doi.org/10.1016/j.brainresbull.2020.03.003 [6] https://doi.org/10.1016/j.pbb.2012.08.016 [7] https://doi.org/10.1016/j.pbb.2014.05.015 [8] https://doi.org/10.1016/j.pharep.2017.05.009 1 [9] https://doi.org/10.1007/s11011-020-00658-4 [10] https://doi.org/10.1016/j.phymed.2020.153439 [11] https://doi.org/10.1073/pnas.2000208117 [12] https://doi.org/10.1007/s12031-022-02059-x 2