Anti-allergic triterpenes isolated from olive milled waste

Abstract

The degranulation of basophils stimulated by antigen is one of the allergic mechanisms of immediate hypersensitivity reactions. In a previous study, the β-hexosaminidase release of rat basophilic leukemia (RBL-2H3) cells stimulated by IgE cross-linking was specifically inhibited by ethanol extract of olive milled waste (OMW). OMW is a potential source of triterpenes, which show several biological activities. However, little is known about the effect of triterpenes in OMW on β-hexosaminidase release. Here we investigated anti-allergic triterpenes from the ethanol extract of OMW, and we discuss the structure-activity relationship. We subjected ethanol extract of OMW to activity-guided fractionation; this led to the isolation of five known triterpenes, i.e., maslinic acid (1), oleanolic acid (2), punicanolic acid (3), 2-O-acetylmaslinic acid (4), and epimaslinic acid (5) as well as one new triterpene, 11-oxo-maslinic acid (6). An anti-allergic assay revealed that 2-O-acetylmaslinic acid (4) and 11-oxo-maslinic acid (6) showed anti-allergic activity. Considering the structure-activity relationship of these triterpenes, it appears that the existence of a ketone group at C-11 or an acetyl group at C-2 would influence the anti-allergic activity.

Plant Secondary Metabolites: An Opportunity for Circular Economy

“…During the production process, assuming a maximum content up to 3.1% of oleanolic acid in the leaves of O. europaea , a large amount of this high-value compound can potentially be extracted, contributing to the integrated valorization of the olive oil production chain [ 153 ]. In this context, the terpenes contained in the ethanol extract of olive milled residue showed anti-allergic activity on the cell line of rat basophilic leukemia, supporting the potential valorization of this other olive by-product [ 154 ].…”

Related Pentacyclic Triterpenes Have Immunomodulatory Activity in Chronic Experimental Visceral Leishmaniasis

“…Betulin (Be), lupeol (Lu), and ursolic acid (UA) are pentacyclic triterpenoids widely distributed in nature and exhibit important pharmacological effects such as antioxidant, antiallergic, antipruritic, antiangiogenic, and antimicrobial agents [16][17][18]. Additionally, these pentacyclic triterpenes have immunomodulatory activity and depending on the dose employed and route of administration Th1-associated cytokines as well as specific mediators of inflammation can be produced by innate or acquired immune cells [19].…”

Effect of the Tibetan Medicine Zuotai on Degranulation and Inflammatory Mediator Release in RBL-2H3 Cells

“…RBL-2H3 cells were cultured with Zuotai, β-HgS of different concentrations (1, l0, 50, 100, 500 µg/mL, The release of Hg from Zuotai samples was very low in simulated gastric juice and much lower in simulated intestinal juice. 14) So Zuotai or β-HgS was sonicated 60 min to get slight disperse in Eagle's Minimum Essential Medium), Compound 48/80 of different concentrations (10, 20, 50, 100, 200 µg/mL, Compound 48/80 was sonicated 60 min in Eagle's Minimum Essential Medium) at 37°C for 24 h respectively. As the literature reported 15) each of the values of CC 50 and CC 10 (CC 50 , half-minimum cytotoxic concentration and CC 10 , 10%-minimum cytotoxic concentration) was calculated from the concentrations of two data points interposing cytotoxicity of 50% or 10%, respectively.…”