Gaultheria procumbens L. (American wintergreen, Ericaceae) is an evergreen shrub native to North America and commonly used in traditional medicine as anti-inflammatory, analgesic and antipyretic drug [1]. The active wintergreen components are salicylates, but also other polyphenols, i.e. flavonoids, proanthocyanidins and monocaffeoylquinic acids [2,3]. The plant parts used for medicinal purposes are leaves, stems and fruits, among which stems are the least characterized both in terms of chemical composition and biological activity. Therefore, the present study was conducted for thorough phytochemical profiling of G. procumbens stem extracts and measuring their anti-inflammatory and antioxidant effects in model of human neutrophils.
The dry extracts were prepared by direct extraction of the plant material with the use of five solvents of different polarity. The first stage was the UHPLC-PDA-ESI-MS3 qualitative analysis, that led to the full or tentative structural identification of over forty phenolic constituents. The quantitative standardization was conducted by HPLC-PDA-fingerprinting and by spectrophotometric determination of total polyphenolic (183.7-347.8 mg GAE/g dw) and total proanthocyanidin (51.6-241.6 mg CyE/g dw) contents. In the next stage, the influence of the extract richest in polyphenols on pro-inflammatory and pro-oxidant functions of neutrophils stimulated with LPS and f-MLP was examined in the release tests of elastase, matrix metalloproteinase and pro-inflammatory cytokines, i.e. interleukins IL-8, IL-1β, TNF-α, as well as in the model of oxidative burst. The results showed that the G. procumbens stem extracts are rich source of structurally divers polyphenols, especially proanthocyanidins and gaultherin, and exhibit significant anti-inflammatory and antioxidant activity in in vitro cellular models.
Acknowledgements : This work was financially supported by National Science Centre, Poland (Grant Project: 2015/19/N/NZ7/00959).
References:
[1] Liu W.R. et al.: Molecules 2013, 18, 12071-12108.
[2] Michel P. et al.: Molecules 2014, 19, 20498-20520.
[3] Michel P. et al.: Phytochem. Lett. 2017, 20, 356-364.