Oleic acid is (OA) an unsaturated fatty acid that occurs naturally in animal and vegetable oils. Its structures are shown below and contain 18 carbon atoms, with the carbon of the unsaturated site alkene functional group located in a rounded rectangle. Oleic acid has only one double bond and is a monounsaturated fatty acid. This also illustrates the omega labelling system, with the blue numbers indicating the number from omega-1 (the carbon furthest from the carboxylic acid group) to the first carbon in the double bond. Since the first carbon in the double bond is carbon 9, oleic acid is an omega-9 fatty acid.

Oleic acid has a variety of pharmacological effects, including antihypertensive, cholesterol-lowering, anti-inflammatory, anti-bacterial, anti-infective, wound-healing promoting, and heart disease prevention. It is also beneficial for cancer, autoimmune and inflammatory diseases. Although the role of OA in the immune response remains controversial, by interfering with many components of the system, such as macrophages, lymphocytes, and neutrophils, consuming a diet containing olive oil may improve the immune response associated with more successful elimination of pathogens such as bacteria and fungi.

References:

[1] YAPRAK E, DURAN N. Activity of Oleic Acid on Biofilm Formation of S. aureus[J]. Proceedings of the 9th International Conference on Advanced Materials and Systems, 2022. DOI:10.24264/icams-2022.iii.21.

[2] HELIOSWILTON SALES-CAMPOS. An overview of the modulatory effects of oleic acid in health and disease.[J]. Mini reviews in medicinal chemistry, 2013, 29 1: 201-210. DOI:10.2174/1389557511313020003.