摘要
Soluble and insoluble/bound phenolic compounds and an aqueous infusion of two mint species(Medina and Hasawi),were tested for their total phenolic content,2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonate(ABTS)and 1,1-diphenyl-2picrylhydrazyl(DPPH)radical scavenging activity,iron(Ⅲ)reduction,iron(Ⅱ)chelating and oxygen radical absorbance capacity(ORAC).Furthermore,the potency of the mint extracts in the inhibition of radical-induced DNA scission,human low-density lipoprotein(LDL)cholesterol oxidation,formation of thiobarbituric acid reactive substances(TBARS)in a cooked ground meat system and LPS(lipopolysaccharide)-stimulated cyclooxygenase-2(COX-2)expression in J774A.1 mouse macrophage cells were monitored.Results showed that the soluble phenolics had a higher phenolic content and antioxidant activity than the insoluble-bound extracts and aqueous infusions in most of the assays.Both varieties exhibited notable antioxidant activities and inhibition of LDL cholesterol oxidation,DNA scission and COX-2 gene expression at transcriptional level.However,Medina mint was a more potent antioxidant than the Hasawi mint.High performance liquid chromatography with online tandem electrospray ionization mass spectrometry(HPLC/ESI-MS/MS)analysis of the extracts revealed that rosmarinic acid was the major phenolic compound present in both mint samples.
基金
We are grateful to the Natural Sciences and Engineering Research Council(NSERC)of Canada for partial financial support of this project and to Dr.Al-Khalifa for providing the samples.
