Investigating the effect of extraction procedure on the anti-inflammatory metabolites of olibanum resin from different Boswellia species through LC–MS/MS-based metabolomics

Olibanum is a resinous extract extracted from several species of Boswellia trees. This works aims to contribute to the research on the chemistry and anti-inflammatory activity of raw, acidic and neutral fractions of different olibanum species to determine the effects of different extraction procedures on the composition of anti-inflammatory constituents. Chemical profiling of different fractions of Boswellia species was attempted using UPLC/MS/MS coupled to chemometric analysis. The anti-inflammatory activity of the tested extracts was assessed on LPS-stimulated WBCs through four pro-inflammatory cytokines (TNF-α, IL-6, IL-1β and IFN-γ) in addition to reveal the efficacy-directed markers using multivariate analysis. UPLC/MS/MS analysis led to the annotation of 77 compounds belonging to several chemical classes. Chemometric models indicated that samples segregation was based on the geographical source of the oleo-gum-resin rather than extraction procedure. Acidic and neutral extracts of B. carterii and B. sacra alcoholic extract were strongly correlated to inhibition of the pro-inflammatory markers IL-1β and TNF-α while there was a strong correlation between the raw extract of B. frereana and the alcoholic extract of B. serrata activity to IFN-γ inhibition. Meanwhile, the most active extracts against IL-6 were the acidic and raw extracts of B. serrata and B. frereana.