Oleocanthal – an essential compound of extra virgin olive oil with anti-cancer effect
1. What are the natural sources and chemical structure of oleocanthal?
(-)-Oleocanthal (CAS: 289030-99-5) is a deacetoxy-ligstroside aglycon that was first reported as a phenolic component in the olive tree’s fruit in 1993. Ten years later, it was determined as a compound of the extra virgin olive oil that cause throat irritation and initiate the pungency effect during consummation. Nowadays, oleocanthal or 2-(4-Hydroxyphenyl)ethyl (3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate (IUPAC), can be synthesized in the laboratory for further research use. It has a molecular formula C₁₇H₂₀O₅ (figure A) and appears as a colourless to light yellow thick oil that is not chemically stable in solution. Methanol and Chloroform are identified as possible solvents for oleocanthal. This natural olive oil compound is a subject of high scientific interest due to its antioxidative, anticancer, anti-inflammatory and antimicrobial activities.
2. What determines the anti-inflammatory properties of oleocanthal?
Many reports describe the throat irritant sensation caused by oleocanthal as similar to ibuprofen’s effect despite their different chemical structures. Oleocanthal is shown as an inhibitor of cyclooxygenase-1 and -2 (COX1 and COX2, figure B). Both enzymes are related to the synthesis of prostaglandins, which regulate inflammation. The potential anti-inflammatory properties of oleocanthal are observed with the inhibition of 5-lipoxygenase (5-LOX) activity, LPS-mediated upregulation of proinflammatory signalling molecules, including interleukin-1β, interleukin-6, macrophage inflammatory protein-1α, tumour necrosis factor-α, and granulocyte-macrophage-colony-stimulating factor. Scientists reported that oleocanthal injected in Wistar albino rats at certain concentration protects the brain cortexes from traumatic degenerative changes and neuronal loss as result of brain injuries.
3. How effective could be the oleocanthal against pathogens?
The relation between the concentration of oleocanthal and the antimicrobial activity of extra virgin olive oil is well described by many research groups. This chemical inhibits the growth of Escherichia coli, Salmonella enterica and Listeria monocytogenes. It can eliminate the growth of Helicobacter pylori strains for 1 hour of contact.
4. What shows the antimicrobial activity of oleocanthal?
The antioxidant activity of extra virgin olive oil is well-documented, but little is known about the specific role of oleocanthal. A certain study determines this compound as an inhibitor of nicotinamide adenine dinucleotide phosphate oxidase (NOX) activity, which may reduce the oxidative stress.
5. How oleocanthal can be effective against carcinogenesis?
Due to its anti-inflammatory effects, oleocanthal is a potential food compound that may serve as a suppressor of canrcinogenesis. It has showed a promising anti-cancer activity on several melanoma, breast cancer, prostate cancer, leukemia cell lines. Oleocanthal has been described as a selective chemical agent that has no cytotoxic effect on non-tumorigenic cell lines (HDFa cells, human liver LO2 cells, human fibroblast BJ cells, and primary human hepatocytes. The oleocanthal also inhibits cancer cell xenograft tumour growth and metastasis in mice models and does not show any toxicity.
Oleocanthal, along with the other compounds of extra virgin olive oil, has a significant positive effect on human health. Further assays in vivo will validate the physiological activities of the oleocanthal and the results may lead to industrial production of this chemical as a food additive for prevention from inflammatory processes and carcinogenesis.