Dietary Burden of Phenolics per Serving of “Mountain Tea” (Sideritis) from Macedonia and Correlation to Antioxidant Activity

Abstract

This work was afforded from 2 points of view, phytochemical evaluation and relation to antioxidant activity and dietary burden of phenolics of a cup of “Mountain tea”, a drink obtained by domestic infusion of Sideritis. Phytochemically, two extraction protocols using water and methanol as solvent were used for comparison. Methanol and boiling water extracts (by domestic infusion procedure) showed that extracts were rich in bound forms of phenolics such as hydroxycinnamic acids, phenylethanoid glycosides and flavonoid glycosides. The total phenolic content for Sideritis species ranged around 190 mg per serving (2 g infusion bag) for methanol extracts and around 72 mg per serving in water extracts. Among the two different Macedonian Sideritis species, Sideritis raeseri (wild growing) showed the highest phenolics content in both extracts (212 mg and 89 mg per serving, respectively). Concerning the phenolic content in the different aerial parts, leaf was the richest plant organ in phenolics followed by flower and stem with the lowest amount. The methanol extract from Sideritis raeseri (wild growing) showed the highest antioxidant capacity as shown by DPPH, ABTS and FRAP assays. The antioxidant capacity was linearly correlated with phenolic content. Nutritionally, the dietary burden of phenolics of a “Mountain tea” bag for domestic infusion (serving size) was established at 89 mg for an homogeneous and equal distribution of the different aerial parts (leaf, flower and stem). However, and according to our results a rate of 60% leaf and 40% flower would increase the content of bioavailable phenolics and also the total phenolics content of a serving bag of “Mountain tea”.

Characterization of urinary bioactive phenolic metabolites excreted after consumption of a cup of mountain tea (Sideritis scardica) using liquid chromatography – tandem mass spectrometry

“…In our previous study, chemical characterization of Sideritis scardica and Sideritis raeseri decoction has been successfully performed using HPLC/DAD/ESI/MS n and 35 major polyphenolic constituents were identified [6,7,11,12]. In the present study, identification of these compounds and their conjugated forms in human urine after ingestion of S. scardica decoction was carried out.…”

Traditional uses, chemical composition and biological activities ofSideritis raeseriBoiss. & Heldr.

“…The most important compounds with significant antioxidant activity are flavonoids, which have been identified as 5‐ and 8‐disubstituted‐flavones, glucosidic flavonoids, polyhydroxyflavones and similar phenylpropanol‐compounds . In addition, the total phenolic content in the species of the genus Sideritis ranges between 30–400 mg gallic acid equivalents g extract −1 . The main phenolic components that characterise the genus Sideritis are chlorogenic acid, myricetin, isocoutellarein, catechin, apigenin, vanillic acid and the gallate ester of epicatechin .…”

“…The aerial parts of the plant can act on intestinal smooth muscle, justifying its use in gastrointestinal disorders . Nutritionally, even though there are no studies on the bioavailability of S. raeseri , it was estimated that an infusion bag of S. raeseri from Macedonia contains 89 mg of bioactive phenolic content . Such an amount of phytochemicals may be effective in the management of medical conditions associated with oxidative stress.…”

“…14,28,36 In addition, the total phenolic content in the species of the genus Sideritis ranges between 30-400 mg gallic acid ----equivalents g extract −1 . 11,37 The main phenolic components that characterise the genus Sideritis are chlorogenic acid, myricetin, isocoutellarein, catechin, apigenin, vanillic acid and the gallate ester of epicatechin. 36 Among the compounds isolated from S. raeseri, three of them (16, 17 and 19) showed strong antioxidant activity.…”

Evaluation of the ion trap MS performance for quantification of flavonoids and comparison to UV detection

“…In the studied Sideritis samples, three structurally different groups of compounds have already been identified in our laboratory: flavonoid-7-O-diglycosides, flavonoid acetylglycosides and acylglucosides. [30][31][32][33] The 8-hydroxyflavone 7-allosyl(1 ! 2)glucosides occur as non-acetylated, monoacetylated and diacetylated derivatives.…”