Oleanolic Acid-Enriched Olive Oil Alleviates the Interleukin-6 Overproduction Induced by Postprandial Triglyceride-Rich Lipoproteins in THP-1 Macrophages

Abstract

Oleanolic acid (OA), a triterpene that is highly present in olive leaves, has been proposed as a component of functional foods for the prevention of metabolic syndrome, due to its anti-inflammatory activity. We analyzed the effects of OA on inflammatory parameters and signaling proteins in LPS-stimulated THP-1 macrophages. Thus, THP-1 macrophages were incubated with LPS for 48 h after pretreatment with OA at different concentrations. Pretreatment with OA was significantly effective in attenuating IL-6 and TNF-α overproduction induced by LPS in macrophages, and also improved the levels of AMPK-α. We also evaluated the effects of human triglyceride-rich lipoproteins (TRLs) derived from individuals consuming an OA-enriched functional olive oil. For this purpose, TRLs were isolated from healthy adolescents before, 2 and 5 h postprandially after the intake of a meal containing the functional olive oil or common olive oil, and were incubated with THP-1 macrophages. THP-1 macrophages incubated with TRLs isolated at 2 h after the consumption of the OA-enriched olive oil showed significant lower levels of IL-6 compared to the TRLs derived from olive oil. Our results suggest that OA might have potential to be used as a lipid-based formulation in functional olive oils to prevent inflammatory processes underlying metabolic syndrome in adolescents.

Bioavailability and systemic transport of oleanolic acid in humans, formulated as a functional olive oil

“…10 We also demonstrated that administering these artificial lipoproteins to THP-1 macrophages and BV-2 microglial cells, OA can exert its pharmacological potential (specifically antioxidant and anti-inflammatory activities). 10,39 In the present investigation, we report, for the first time to the best of our knowledge, that physiological TRL assembled after ingestion of functional olive oil incorporate the administered OA. From Fig.…”

“…10 We also demonstrated that administering these artificial lipoproteins to THP-1 macrophages and BV-2 microglial cells, OA can exert its pharmacological potential (specifically antioxidant and anti-inflammatory activities). 10,39…”

Lipidomics of triglyceride‐rich lipoproteins derived from hyperlipidemic patients on inflammation

“…12,32 These effects vary depending on the fatty acid composition of the TRL, as those derived from olive oil-rich diets being less inflammatory than diets high in saturated fats. 33,34 Thus, in our study, particles triggered a molecular response that could be explained by different TRL components. The time-differential expression patterns we observed remain to be studied considering the physiological roles of the fatty acids, lipids and other components present in the TRL.…”

Bioactive compounds in pomace olive oil modulate the inflammatory response elicited by postprandial triglyceride-rich lipoproteins in BV-2 cells

“…In a previous work, 32 we demonstrated that OA, a natural component of POO, modulated the inflammatory response in LPS-activated BV-2 cells, reducing in a dose-dependent manner the IL-1β, IL-6 and TNF-α production. Additionally, in other earlier research studies, 52 we treated THP-1 macrophages with human postprandial TRLs obtained after the intake of an OA-enriched olive oil, and found that the treatment reduced the IL-6 production. More recently, we also observed a moderate reduction in the expression and release of IL-6 in BV-2 cells treated with lab-made OA-containing TRLs.…”