Oleuropeinic acid

Bioactivity-guided isolation of immunomodulatory compounds from the fruits of Ligustrum lucidum.[Pubmed:33798661]

J Ethnopharmacol. 2021 Jun 28;274:114079.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruits of Ligustrum lucidum (FLL) W.T. Aiton (Oleaceae) is included in the 2020 "Chinese Pharmacopoeia" and is widely used in traditional Chinese medicine as a tonic. In recent years, FLL has been reported to improve immune function, but the bioactive compounds and mechanisms of FLL remain poorly characterized. AIM OF THE STUDY: To identify FFL compounds with strong immune activity and explore their molecular mechanisms. MATERIALS AND METHODS: The phagocytic activity of RAW264.7 macrophages and proliferation activity of spleen lymphocytes were used to guide the isolation of bioactive compounds from FLL extracts. Lymphocyte subpopulations, Ca(2+) concentrations, and surface molecule expression were analyzed using flow cytometry. Cytokine secretion was examined using ELISA. FITC-OVA uptake was observed using fluorescence microscopy. NF-kappaB activation was analyzed using western blotting. RESULTS: The extraction and isolation produced ten compounds, namely Oleuropeinic acid, nuezhenide, isonuezhenide, salidroside, isoligustrosidic acid, ligulucidumosides A, 8(E)-nuezhenide, hydroxytyrosol, oleuropein, and p-hydroxyphenethyl 7-beta-D-glucosideelenolic acid ester were isolated and identified from FLL-Bu-30%. Immunoactivity experiments showed that hydroxytyrosol had the strongest macrophage phagocytotic and lymphocyte proliferation-promoting activities. Further studies showed that hydroxytyrosol could significantly enhance lymphocyte subsets CD3(+), CD4(+)/CD8(+), and CD3(+)CD4(-)CD8(-), promote IL-4, IFN-gamma, and TNF-alpha secretion, and increase intracellular Ca(2+) concentrations. In addition, the results from RAW264.7 macrophages showed that hydroxytyrosol increased FITC-OVA uptake, induced TNF-alpha and IL-1beta production, upregulated MHC-II, CD80, and CD86 expression, promoted cytoplasmic IkappaB-alpha degradation, and increased nuclear NF-kappaB p65 levels. CONCLUSION: Our study provides substantial evidence regarding the mechanism of the immunomodulatory effects of compounds from FLL.

Isolation and identification of phenolic glucosides from thermally treated olive oil byproducts.[Pubmed:23323788]

J Agric Food Chem. 2013 Feb 13;61(6):1235-48.

A liquid phase rich in bioactive compounds, such as phenols and sugars, is obtained from olive oil waste by novel thermal treatment. Two groups of fractions with common characteristics were obtained and studied after thermal treatment, acid hydrolysis, and separation by ultrafiltration, chromatography, and finally Superdex Peptide HR. In the first group, which eluted at the same time as oligosaccharides with a low DP (4-2), an oleosidic secoiridoid structure conjugated to a phenolic compound (hydroxytyrosol) was identified as Oleuropeinic acid, and three possible structures were detected. In the second group, glucosyl structures formed by hydroxytyrosol and one, two, or three units of glucose or by tyrosol and glucose have been proposed. Verbascoside, a heterosidic ester of caffeic acid, in which hydroxytyrosol is linked to rhamnose-glucose or one of its isomers was also identified. Neutral oligosaccharides bound to a phenol-containing compound could be antioxidant-soluble fibers with bioactive properties.