Ursolic acid (sometimes referred to as urson, prunol, malol, or 3-beta-3-hydroxy-urs-12-ene-28-oic-acid), is a pentacyclic triterpenoid identified in the epicuticular waxes of apples as early as 1920 and widely found in the peels of fruits, as well as in herbs and spices like rosemary and thyme.
A number of potential biochemical effects of ursolic acid have been investigated, but there has been no clinical study demonstrating benefits to human health. In vitro, ursolic acid inhibits the proliferation of various cancer cell types by inhibiting the STAT3 activation pathway, and may also decrease proliferation of cancer cells and induce apoptosis. Ursolic acid has also been shown to inhibit JNK expression and IL-2 activation of JURKAT leukemic T Cells leading to the reduction in proliferation and T cell activation. Ursolic acid is a weak aromataseinhibitor (IC50 = 32 μM), and has been shown to increase the amount of muscle and brown fat and decrease white fat obesity and associated conditions when added to diets fed to mice. Under physiological concentrations, ursolic acid also induces eryptosis (the apoptosis-like suicidal cell death in defective red blood cells). It has been found to reduce muscle atrophy and to stimulate muscular growth in mice, also shows a potential cardioprotection.
In mice, ursolic acid induces neural regeneration after sciatic nerve injury. Ursolic acid improves domoic acid-induced cognitive deficits in mice. Ursolic acid improves high fat diet-induced cognitive impairments by blocking endoplasmic reticulum stress and IκB kinase β/nuclear factor-κB-mediated inflammatory pathways in mice. Ursolic acid attenuates lipopolysaccharide-induced cognitive deficits in mouse brain through suppressing p38/NF-κB mediated inflammatory pathways. Ursolic acid ameliorates cognition deficits and attenuates oxidative damage in the brain of senescent mice induced by D-galactose. Ursolic acid enhances mouse liver regeneration after partial hepatectomy. Ursolic acid enhances the cellular immune system and pancreatic beta-cell function in streptozotocin-induced diabetic mice fed a high-fat diet. UA increased skeletal muscle mass, as well as grip strength and exercise capacity. Improved endurance, reduced the expression of the genes involved in the development of muscle atrophy, and decreased indicators of accumulated fatigue and exercise-induced stress.
In rats, ursolic acid ameliorated high-fat diet-induced hepatic steatosis and improved metabolic disorders in high-fat diet-induced non-alcoholic fatty liver disease.
Ursolic acid can be found in plants that are used for cosmetics additives. Ursolic acid can serve as a starting material for synthesis of more potent bioactive derivatives, such as experimental antitumor agents.
^Pathak AK, Bhutani M, Nair AS, et al. (2007). "Ursolic acid inhibits STAT3 activation pathway leading to suppression of proliferation and chemosensitization of human multiple myeloma cells". Mol. Cancer Res. 5 (9): 943–55. doi:10.1158/1541-7786.MCR-06-0348. PMID17855663.
^Wang X, Zhang F, Yang L, Mei Y, Long H, Zhang X, Zhang J, Qimuge-Suyila, Su X.,"Ursolic acid inhibits proliferation and induces apoptosis of cancer cells in vitro and in vivo", J Biomed Biotechnol. 2011;2011:419343 Full-text pdf
^Jilani K, Abed M, Zelenak C, Lang E, Qadri SM, Lang F (2011). "Triggering of erythrocyte cell membrane scrambling by ursolic acid". J Nat Prod. 74 (10): 2181–2186. doi:10.1021/np2005133. PMID21923134.