Greek Mountain Tea (Sideritis L.): Functional Components and Biological Activity



The Brunswick Labs Beat Ingredient Corner spotlight today is on Sideritis, or Greek Mountain Tea. Heard of it? It’s an important beverage in some parts of the world – well, such as Greece. Here’s a great Brunswick Labs look at what it is and how it works. Enjoy!
The dried inflorescences of several Sideritis L. (Lamiaceae) species, especially Sideritis scardica Griseb. and Sideritis raeseri Boiss. Et Heldr., are used in Greece and the other Balkan countries to prepare a traditional beverage, an herbal infusion most commonly known as Greek Mountain Tea.1 The common name for Sideritis plants in the US is ironwort. Depending on the country of origin and the mountain where the plants grow, Greek Mountain Tea is also known as Shepherds Tea or Olympus Tea (Greece), Malotira (Crete), Pirin tea or Mursalski tea (Bulgaria), or Sharplaninski chaj (Macedonia).



“Greek Mountain Tea (Sideritis) grows wild throughout Greece typically at elevations of 3000 feet or more above sea level and is also cultivated in small plots within the high elevations of the mountain regions” according to Steve Raftopoulos, the founder of Klio Tea – a major US based importer of Greek herbal teas. Greek Mountain Tea has a profound effect on Greek culture and tradition; the Greeks refer to it as the Tea of Gods or the Tea of the Titans. In Greek mythology, the Titans were powerful deities who lived on Mount Othrys and ruled the world before the Olympians. In reality, the consumption of Greek Mountain Tea dates back to ancient civilization in Greece. “Herbs play a significant role in the Greek/Mediterranean diet, both in culinary form and as herbal teas” says Raftopoulos. ”The unique growing environment of Greece’s mountains uniquely favors herbs and results in herbs of distinctive quality”, he adds.



The Sideritis genus consists of 150 species which are widespread in the Mediterranean region.2 S. scardica is endemic to the Balkan peninsula and was originally discovered on the Shara Mountain in Macedonia. Today, its growth is largely restricted to the Central Balkan Peninsula: throughout mainland Greece and many Greek islands, southwestern Albania, southern Bulgaria, and northern Turkey.1 Both S. scardica and S. raeseri are perennial herbaceous plants with a woody base and a well-developed root system. They grow in crevices of limestone rocks, on eroded soil and in dry, exposed, high-altitude locations. The plants grow between 15 and 40 cm high and are characterized by flowers clustered in a dense spike.

Photo - Farm Bioma


Functional components. The presence of many functional components has been confirmed in the extracts and essential oils prepared from Sideritis species; including terpenoids, phenolic compounds (flavonoids and phenolic acids) and their derivatives. S. scardica essential oils are especially rich in monoterpenes, sesquiterpenes and diterpens, and their composition depends on ecological conditions, as well as the source of plant material – wild growing versus cultivated plants.1

The total phenol (TP) analysis performed recently at Brunswick Labs resulted in the TP content of 13.60 mg/oz for S. raeseri tea brewed in water. Interestingly, its total bioflavonoid (TBF) content (6.51 mg/oz) was determined to be more than two times greater than the TBF content of chamomile tea (2.55 mg/oz), and comparable to the TBF content of sea buckthorn leaf tea (5.94 mg/oz). In a more detailed analysis of individual phenolic acid and flavonoid constituents, the following compounds were detected in S. raeseri tea in appreciable quantities: apigenin, quercetin, kaempherol, and caffeic and chlorogenic acids.

Biological activity. A range of biological effects has been attributed to Sideritis extracts and preparations in multiple research studies, such as antioxidant,3 oxidative stress reduction,4 antimicrobial,5,6 anti-inflammatory,6,7 and gastroprotective activities.7 In ethnobotanical practices, Greek mountain tea has been used to alleviate gastrointestinal problems, inflammation, as well as common cold and cough symptoms.1 S. scardica has also been identified as an active constituent of dietary supplements used in prevention of anemia.8 A recent study shows that S. scardica tea is as potent as Camellia sinenesis tea at inducing cellular antioxidant defense and preventing oxidative stress.4 The antioxidant and oxidative stress reduction activities of Sideritis species correlate well with the content of phenolic compounds, especially flavonoids and their derivatives.3 Brunswick Labs recently determined the ORAC 5.0 assay score for S. raeseri to be 739 µmol TE/oz dw, or 21.6 µmol/ml of brewed tea. When expressed per serving, the ORAC 5.0 values for brewed tea ranged from 6900-7400 µmol TE/per serving.



Both anti-inflammatory and gastroprotective activities of S. scardica extracts were observed in vivo, in a study published in 2012 in Planta Medica.7 The observed anti-inflammatory effect of S. scardica ethyl ether extract was dose-dependent and confirmed in a rat model. In the same study, the n-butanol extract of S. scardica exhibited the most prominent gastroprotective activity against ethanol-induced acute stress ulcer in rats.

In a different study, the same group of authors evaluated anti-inflammatory and antimicrobial activity of S. scardica extracts and observed significant anti-inflammatory effects.6 The antimicrobial activity was evaluated using five strains of microorganisms, including Staphylococcus epidermidis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and yeast Candida albicans. The various fractions of the ethanolic S. scardica extract exhibited antimicrobial activity to a varying degree against all tested strains, with maximum activity observed against E. coli, S. epidermidis, M. luteus, and P. aeruginosa strains, and moderate activity against the K. pneumoniae strain.6

Even though some of the biological activities and ethnobotanical applications of Sideritis extracts have been investigated in in vitro experiments, further research of particular active constituents and their mechanisms of action is needed. Elucidating the mechanism of action of active constituents would have important implications on understanding the biological effects that Sideritis preparations might have in vivo. The scientific community still needs to confirm the efficacy of Greek Mountain Tea in clinical trials/studies. From the practical point of view, variability in the chemical and nutraceutical composition of this medicinal plant needs to be addressed and minimized in the scope of cultivation practices, in order to ensure consistency in the quality and potency of Sideritis plant material.

References
1.Todorova M, Trendafilova A. Sideritis scardica Griseb., an endemic species of Balkan peninsula: Traditional uses, cultivation, chemical composition, biological activity. J. Ethnopharmacol. 2014;152: 256-265.
2.Petreska J, Stefkov G, Kulevanova S, et al. Phenolic compounds of mountain tea from the Balkans: LC/DAD/ESI/MS Profile and Content. Nat. Prod. Commun. 2011;6(1): 21-30.
3.Gabrieli CN, Kefalas PG, Kokkalou EL. Antioxidant activity of flavonoids from Sideritis raeseri. J. Ethnopharmacol. 2005;96: 423-428.
4.Danesi F, Saha S, Kroon PA, et al. Bioactive-rich Sideritis scardica tea (mountain tea) is as potent as Camellia sinensis tea at inducing cellular antioxidant defences and preventing oxidative stress. J. Sci. Food Agric. 2013;93: 3558-3564.
5.Aligiannis N, Kalpoutzakis E, Chinou IB, et al. Composition and antimicrobial activity of the essential oils of five taxa of Sideritis from Greece. J. Agric. Food Chem. 2001;49(2): 811–815.
6.Tadić VM, Djordjević S, Arsić I, et al. Anti-inflammatory and antimicrobial activity of Sideritis scardica extracts. Planta Med. 2007;73(9): 98.
7.Tadić VM, Jeremić I, Dobrić S, et al. Anti-inflammatory, gastroprotective and cytotoxic effects of Sideritis scardica extracts. Planta Med. 2012;78: 415-427.
8.Đorđević S, Blagojević S, Sekulović D, et al. The analysis of mineral content in active components and the preparation of phytopreparations for anemia prevention. Arh. Farm. 1993;43: 225–231.

Jasenka Piljac Zegarac is a scientist and freelance writer. She holds a PhD in biology and a BS degree in biochemistry, and contributes on a regular basis to several health and science blogs. She may be contacted for assistance with a variety of science and medical writing projects. Find Jasenka on LinkedIn.

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