Ursolic acid (sometimes referred to as urson, prunol, malol, or 3β-hydroxyurs-12-en-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.

Natural occurrence

Ursolic acid is frequently found in the human diet because of its widespread availability in many plants. Ursolic acid is distributed in plants by forming aglycone with free acid or triterpenoid saponins.Malus pumila (apple), Ocimum basilicum (basil), Vaccimum spp. (blueberries), Vaccinium macrocarpon (cranberry), Ola europaea (olive), Origanum vulgare, Rosmarinus officinalis, Salvia, and Thyme (thyme) are the main plants that contain ursolic acid.

Uses

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.

Ursolic acid is a lipophilic pentacyclic triterpenoid, especially abundant in apple peel, with anti-inflammatory and antihyperlipidemic properties. Recently, ursolic acid has been identified as a possible remedy for muscle atrophy in a screen for small-molecule inhibitors of skeletal muscle wasting in mice. Interestingly, supplementation with ursolic acid to mice on a high-fat diet increased muscle mass and strength, improved glucose tolerance, promoted brown adipose tissue deposition, and decreased white adipose tissue mass and the severity of hepatic steatosis.

Effects

Ursolic acid (0.001–10 mg/kg, per oral) have shown antidepressant-like effects in male Swiss rats. The antidepressant effects of the compound were similar to those of classical antidepressants, such as fluoxetine, imipramine, and bupropion.

Many studies in the cosmetic industry have shown that ursolic acid stimulated collagen production in fibroblasts and increased the formation of ceramide in human skin and epidermal keratinocytes.

It is reported that ursolic acid had protective effects on the nervous system. Ursolic acid (10 mg/kg), showed preventive effects against brain neurotoxicity caused by d-galactose by reducing lipid peroxidation and increasing antioxidant enzyme activities.