Oleanolic acid


Oleanolic acid or oleanic acid is a naturally occurring pentacyclic triterpenoid related to betulinic acid. It is widely distributed in food and plants where it exists as a free acid or as an aglycone of triterpenoid saponins.

Natural occurrence

Oleanolic acid can be found in olive oil, Phytolacca americana, and Syzygium spp, garlic, etc. It was first studied and isolated from several plants, including Olea europaea, Rosa woodsii, Prosopis glandulosa, Phoradendron juniperinum, Syzygium claviflorum, Hyptis capitata, Mirabilis jalapa and Ternstroemia gymnanthera. Other Syzygium species including java apple and rose apples contain it.

Pharmacological research

Oleanolic acid is relatively non-toxic, hepatoprotective, and exhibits antitumor and antiviral properties.
Oleanolic acid was found to exhibit weak anti-HIV and weak anti-HCV activities in vitro, but more potent synthetic analogs are being investigated as potential drugs.
An extremely potent synthetic triterpenoid analog of oleanolic acid was found in 2005, that is a powerful inhibitor of cellular inflammatory processes. They work by the induction by IFN-γ of inducible nitric oxide synthase and of cyclooxygenase 2 in mouse macrophages. They are extremely potent inducers of the phase 2 response, which is a major protector of cells against oxidative and electrophile stress.
A 2002 study in Wistar rats found that oleanolic acid reduced sperm quality and motility, causing infertility. After withdrawing exposure, male rats regained fertility and successfully impregnated female rats.