Polyphenolic Profile, Antioxidant and Anti-Inflammatory Activity of Eastern Teaberry (Gaultheria procumbens L.) Leaf Extracts

Piotr Michel, Anna Dobrowolska, Agnieszka Kicel, Aleksandra Owczarek, Agnieszka Bazylko, Sebastian Granica, Jakub Piwowarski, Monika Olszewska
2014 Molecules  
Dry leaf extracts of eastern teaberry (Gaultheria procumbens L.) were evaluated as a source of bioactive phytocompounds through systematic activity testing and phytochemical profiling. The antioxidant efficiency was tested using five complementary in vitro models (DPPH; FRAP; linoleic acid (LA) peroxidation assay; O2 •− and H2O2 scavenging tests) in parallel with standard antioxidants. The 75% methanol extract and its diethyl ether, ethyl acetate (EAF), n-butanol and water fractions exhibited
more » ... actions exhibited the dose-dependent responses in all assays, with the highest capacities found for EAF (DPPH EC50 = 2.9 μg/mL; FRAP = 12.8 mmol Fe 2+ /g; IC50 for LA-peroxidation = 123.9 μg/mL; O2 •− SC50 = 3.9 μg/mL; H2O2 SC50 = 7.2 μg/mL). The EAF had also the highest anti-inflammatory activity in the inhibition tests of lipoxygenase and hyaluronidase (60.14% and 21.83% effects, respectively, at the concentration of 100 μg/mL). Activity parameters of the extracts correlated strongly with the levels of total phenolics (72.4-270.7 mg GAE/g), procyanidins, and phenolic acids, whereas for flavonoids only moderate effects were OPEN ACCESS Molecules 2014, 19 20499 observed. Comprehensive UHPLC-PDA-ESI-MS 3 and HPLC-PDA studies led to the identification of 35 polyphenols with a procyanidin A-type trimer, quercetin 3-O-glucuronide, isomers of caffeoylquinic acids, and (-)-epicatechin being the dominant components. Significant activity levels, high phenolic contents and high extraction yields (39.4%-42.5% DW for defatted and crude methanol extracts, respectively) indicate the value of eastern teaberry leaves as bioactive products.
doi:10.3390/molecules191220498 pmid:25493634 fatcat:skk5pbh2nrczvozjtairgni6gu