The text below is composed of entire paragraphs from research papers cited in the reference section of this site.
There is a renewed interest in non-nutritive bioactive compounds of foods and beverages as ‘lifespan nutrients’ in the risk reduction of non-communicable diseases. Herbal beverages, consumed as part of a balanced diet, may improve the antioxidant status and enhance the overall health status. Herbal teas/beverages are rich sources of natural bioactive compounds such as carotenoids, phenolic acids, flavonoids, coumarins, alkaloids, polyacetylenes, saponins and terpenoids, among others. A wealth of available scientific evidence demonstrates that natural bioactive compounds render a number of diversified biological effects, such as antioxidant, antibacterial, antiviral, antiinflammatory, antiallergic, antithrombotic and vasodilatory actions, as well as antimutagenicity, anticarcinogenicity and antiaging effects. A number of herbal beverages are consumed globally and some beverages have gained more popularity than others depending on their geographical origin. However, in the era of globalization, ethnic barriers have gradually been removed and such commodities although from different areas, are now universally available as international health-pro products (105).
Herbal beverages, commonly known as teas, have gained popularity among health conscious consumers. They have penetrated into an emerging niche market along with other popular beverages such as tea, coffee and cocoa which are also prepared using plant materials. In addition, a rapidly growing segment of the population uses herbal beverages for slimming, weight loss and a number of other cosmetic purposes. In general, herbal beverages are prepared from natural ingredients of different morphological plant parts, namely leaves, stems, roots, fruits, buds and flowers. Herbal teas/beverages are rich sources of natural bioactive compounds such as carotenoids, phenolic acids, flavonoids, coumarins, alkaloids, polyacetylenes, saponins and terpenoids, among others. Scientific evidence shows that these bioactive compounds render a myriad of biological effects, such as antioxidant, antibacterial, antiviral, antiinflammatory, antiallergic, antithrombotic and vasodilatory action, as well as antimutagenicity, anticarcinogenicity and antiaging effects, among others (105).
These plants are very popular in Macedonia, Albania, Bulgaria, and Greece, as well as throughout the Eastern Mediterranean as herbal tea refreshment. These herbs are often used for preparing teas to cure common cold, to alleviate sinus congestion, aches, pains and viruses, including flu. Their use as a remedy is based on antiinflammatory and antioxidant properties, antimicrobial effects, and possible immune-stimulant activity (14).
Regarding the important place that tea and herbal infusions have as a popular beverages in the Mediterranean region and the increased interest in recent years for food and beverages enriched in beneficial health constituents, it may be suggested that tea and herbal infusions can be major sources of polyphenols that exhibit important antioxidant behavior (19).
In recent years, a substantial body of evidence has indicated a key role for free radicals as major contributors to aging and to degenerative diseases of aging, such as cancer, cardiovascular disease, cataracts, immune system decline, and brain dysfunction (20, 21, 22). When the availability of antioxidants is limited, this damage can become cumulative and debilitating oxidative stress results (23). Antioxidants are capable of stabilizing, or deactivating free radicals before the latter attack cells and biological targets. They are therefore critical for maintaining optimal cellular and systemic health and well-being (21). Many research groups are examining the chemical nature and activity of natural antioxidants in fruits, vegetables, grains, herbs and other foods (24,25). Most antioxidants isolated from higher plants are polyphenols, which show biological activity as antibacterial, anti-carcinogenic, anti-inflammatory, antiviral, anti-allergic, estrogenic, and immune stimulating effects (24). The antioxidant effect of plant phenolics has been studied in relation to the prevention of coronary diseases and cancer, as well as age-related degenerative brain disorders (26). Tea and herbal infusions contribute to the major source of phenolic compounds in our diet (25).
Polyphenols are major constituents of tea and coffee beverages and are considered responsible not only for their flavor characteristics, but also for their beneficial properties. Due to the polyphenol antioxidant activity, the interest all over the world in consuming beverages that contain polyphenols is growing. Although tea and coffee are the most widely consumed beverages in the world, there is a great interest in herbal extracts with medicinal properties, such as Sideritis, a herb also known as ‘‘mountain tea’’, which has been credited with providing a wide variety of health benefits (27). The aerial parts of plants from this genus are famous in the Mediterranean region for their antioxidant, anti-ulcer, and anti-inflammatory effect. These properties have been attributed to the polyphenolic content of the plant (28, 29).
Infusion of aerial parts of a number of Sideritis species are used as tonics, carminatives, as anti-inflammatory agents, antispasmodics, diuretics and digestives, and in the treatment of colds (31; 32; 33; 34). The genus Sideritis (Lamiaceae) comprises more than 150 perennial and annual vegetal species widely distributed in the Mediterranean area, together with Canary and Madeira islands (3). It is a controversial botanic genus, with a complex taxonomical classification due to the high number of hybridizations that occur between species; their study requires a deep research experience (3). Sideritis species have been traditionally used as teas for feeding, flavoring agents and in folk medicine as antiinflammatory, antiulcerative, antimicrobial, vulnerary, antioxidant, antispasmodic, anticonvulsant, analgesic and carminative agents. The chemical components found in Sideritis genus include terpenes, flavonoids, essential oil, iridoids, coumarins, lignanes and sterols, among others. Diterpenes, flavonoids and essential oil occur in almost every species and are the main compounds responsible for the observed in vivo and in vitro pharmacological activities (3).
The genus Sideritis belongs to the Labiateae Family, tribe Lamieae. This genus comprises more than 150 species which are distributed in temperate and tropical regions of the Northern hemisphere, from Bahamas to Western China and from Germany to Morocco. Most species are mainly found in the Mediterranean area, from Canary Islands and Madeira to Caucasus; Spain and Turkey possess the highest number of different species. In Spain, most of them are established in the Southeast of Iberian Peninsula and Canary Islands whereas Marmara and Aegean regions predominate in Turkey (35, 36 ; 37).
The genus name Sideritis L., derives from the Greek word “sideros” (iron) in reference to the use given for these plants since ancient times to heal wounds caused by weapons made with this metal (38). The extensive and important use of Sideritis spp. in Mediterranean traditional medicine has been reported in many ethnopharmacological papers (3). Font Quer pointed out in his book “El
Dioscórides renovado” a notable widespread use for Sideritis angustifolia (cua de gat) as mainly vulnerary in veterinary medicine in Catalu˜na in the first half of the XX century: “All catalan herbalistˇıs shop have “cua de gat”, at least in the capital” (38). Alongside its traditional use extensive mentioned, the importance of this genus lies in the type of disorders for which preparations of its aerial parts are used: gastritis, gastric ulcer, mucous membrane inflammation, burns and wounds, among others. For these purposes, infusions and decoctions are prepared from aerial parts and administered both orally and topically as compresses or baths (3).
Dried leaves and spikes or heads of Sideritis species are served as tea, instantly prepared by dipping one or two spikes and leaving them in a cup of hot water for half a minute or so, to extract
the pleasant aroma (98).
In recent decades a deep researchs on this genus, mainly based on their botanical, phytochemical and pharmacological aspects have taken place (3). Sideritis species grow as herbs or small shrubs, both annual or perennial and aromatic. Leaves are often narrow, opposite, entire or crenate–dentate, sessile to petiolate (3). Sideritis species grow optimally in full sun and are well suited to rought conditions. They are found on rocky slopes and pastures, from a few meters above the sea level to more than 3000 m, and require moderately nutrient-rich soils and slightly alkaline (40,41). This genus is characterized by a strong tendency to hybridize between species (3).
The therapeutic use of Sideritis species was first mentioned by Dioscorides in his book “De Materia Medica” written in the 1stcentury (38). Sideritis species have been traditionally used as teas, flavoring agents or for therapeutical purposes. Most of the medicinal uses of Sideritis spp. are limited to folk medicine, although it is worth noting the more and more frequent presence of Sideritis spp. in herbal remedies market and the increasing number of prescriptions that contain the specie Sideritis tragoriganum (42). The decoction or the infusion of aerial parts, orally or topically administered, are used in folk medicine as anti-inflammatory, antiulcerative, antimicrobial, vulnerary, antispasmodic, anticonvulsant, analgesic and carminative agents (3). The infusion of aerial parts from Spanish Sideritis spp. has been used for its gastroprotective properties, whereas the decoction of the leaves has been employed as anti-inflammatory and anti-rheumatic preparation (39). Moreover, water extract of the stalks has been employed externally for disinfecting and healing wounds and burns (43). Greece, the aerial parts of these plants are widely used to prepare herbal remedies and traditional teas. This tea, which is often served with honey and lemon, is well known for its pleasant aroma, special taste and yellowish colour. Sideritis tea is widespread used against gastrointestinal disorders such as stomache ache, indigestion and flatulence, to alleviate the symptoms of common colds including fever, flu, sore throat, and bronchitis as well as a tonic and diuretic remedy (3).
Sideritis teas are named in different ways; they are commonly known as “mountain tea”, the reason is that some species grow in the high mountain areas. Because of the mountainwherethey grow, they are also named “Olympus tea”, “Parnassos tea” or “Pirin tea”. Moreover, the beverage derived from this plant is also known as Shepherd’s Tea (the Madonie Mountains shepherds used to keep some leaves of Sideritis in their pockets just in case they were needed) (44, 45). a study about plants known as té in Spain (46) showed this diversity in the following names: Sideritis hyssopifolia is called “té amarillo” (yellow tea), té de monte” (mountain tea) or “té borriquero” and is very popular in the Picos de Europa mountain range and the Pyrenees as digestive and for the treatment of gastric ulcers. The most frequently recorded medical uses of Sideritis spp. are related to their digestive, anti-inflammatory and vulnerary properties. Based on these properties, infusions and decoctions made from aerial parts have been employed for the treatment of gastrointestinal, respiratory and urogenital disorders as well as wound healing. Differences in uses have been observed among Sideritis spp. and the region where they grow (3). The uses in everywhere are based on plant properties. In Taurus Mountains of Turkey, a poultice prepared with boiled leaves of Sideritis psidica, barley flour, grated onion and pine tar and applied on the abdomen as a plaster is used to treat abdominal pain (47).
Many chemical constituents have been identified in Sideritis genus such as terpenes, flavonoids, essential oil, iridoids, coumarins, lignanes, and sterols. Diterpenes, flavonoids and essential oil occur in almost every species; in fact they are the main responsible for the pharmacological activity (3).
Since 1990s, most papers reported the pharmacological activity of Sideritis species. These studies have been performed with different extracts from aerial parts, essential oil and isolated compounds such as diterpenoids, flavonoids or phenylpropanoid glycosides. These investigations make possible to justify the traditional uses for these plants and to find new pharmacological actions. It has only been studied the pharmacological activity of a small percentage of species in this genus, so much remains to be elucidated (3).
Sideritis scardica has become very popular and widely advertised herb in Europe. Although some of ethnobotanical uses have been proved through in vitro experiments,further studies of the individual compounds or chemical class of compounds responsible for the pharmacological effects and the mechanisms of action are necessary. In addition, the toxicity and the side effects from the use of Sideritis scardica as well as clinical trails need attention. The variability in the chemical composition of this medicinal plant depending on the origin requires development of a protocol for its standardization (81).
Sideritis scardica Griseb. (genus Sideritis, family Lamiaceae)isan endemic plant of alpine zone of the Balkan Peninsula (82). It is known as Mountain tea, Ironwort, Shepard’s tea, and is usually named after the mountain in which it is distributed: “Pirin tea,” “Mursalski tea,” or “Alibotushkitea” in Bulgaria; “Sharplaninsi chaj” in Former Yugoslav Republic of Macedonia (FYROM);or “Greek Mountain tea” and “Olympus tea” in Greece. Widely used for the treatment of inflammation, gastrointestinal disorders, and coughs, Sideritis scardica is also in traditional medicine as a loosening agent to combat bronchitis, bronchialasthma, the common cold, lung emphysema and as an active constituent of dietary supplements for the prevention of anemia (83).
During the last decade, Sideritis scardica from Bulgaria,FYROM, and Greece have been extensively investigated for the content of phenolic compounds, terpenoids, hydrocarbons and related compounds, and essential oil composition. It has been suggested that phenolic and/or polyphenolic components are responsible for the antioxidant activity of the alcohol extracts, while terpene components from the essential oil and diterpenoids are responsible for the anti-inflammatory,analgesic, antiulcer, antibacterial, antifungal, cytotoxic, and antitumoractivities (83). The species occurs in open, dry, stony places: on limestone and on shallow and eroded soil. It grows in the subalpine and alpine vegetation belts accompanied by high-mountain,mostly hasmophytic, plants (83).
In the folk medicine the tea is made from the aerial parts of the plant by infusion or decoction. Some examples for preparations and dosages are given below:
Infusion of 3–5 flowering stems with 1L of boiling water for 20–30 min,without continuous simmering. After filtering, the tea can be consumed hot or cold through out the day (84).
One table spoon of infusion obtained from 2 to 3 flowering stems and two cups of boiling water is taken every 2h as warm tea (85).
One wine glass tea prepared by boiling of the herb (three tablespoons) in water (1L) for 3min is drunk three times daily instead of water before meal (86).
Five grams of the herb soaked in 200g hot water and sweetened with sugar is taken as tea (87).
Infusion from “Pirin tea” (2–4 sprigs) and common balm (1–2 sprigs) has to be drunk in the morning and in the evening, warmed with a little bit of sugar, and during the day it can be taken instead of water (88; 89).
Sideritis scardica (Mountain Tea), an endemic plant of the Balkan Peninsula, is generally acknowledged as a very popular consumed beverage with multiple pharmacological properties including antioxidant activity. This study was designed to optimize the infusion conditions, aiming to maximize the phenolic compounds and antioxidant activity of the tea-infusion, made from different parts of Sideritis plants. The influence of different infusion temperatures (60, 80 and 93 °C) and steeping times (10, 20 and 30 min) either as aerial parts or as stems, flowers, leaves of Sideritis plants was determined using response surface methodology. The results showed good fit of data and the optimal infusion conditions were steeping time no more than 10 min and temperature water ranged between 87.5–99.8 °C for all infusions under investigation. The highest bioactive content and antioxidant activity was exhibited in leaves infusions followed by flower, aerial parts, and stems. Under this condition, chlorogenic acid was detected as the major phenolic acids in all Sideritis infusions. Moreover, the most abundant minerals were recorded in the order: K > P > Ca > Mg > Na > Fe. Stems tea-infusions contained the highest amount of minerals followed by those obtained from flowers, aerial parts and leaves, respectively (94).
Herbal infusions have been traditionally used in the folk medicine for the ailment of various disorders. Nowadays, their consumption has been very popular due to the vast variety of tea flavors marketed worldwide and their health benefits, attributed to their bioactive compounds. Besides polyphenols, which are mainly associated to the antioxidant activity and scavenging harmful free radicals, teas may contribute to the intake of a number of essential minerals (95).
Polyphenol rich foods may prevent degenerative diseases such as cardiovascular diseases, cancer and other degenerative disorders and their daily intake by different types of foods and beverages, is mainly in the form of hydroxycinnamates and flavonoids (estimated about 1/3 and 2/3 of the total intake respectively) (97).
Pharmacological properties of the plant Mountain tea could be explained by biologically active substances detected in the plant. For example, antimicrobial activity of the plant could be explained by the presence of etheric oil; antioxidant – with the presence of flavonoids; antiiflammatory – with the presence of tannins and etheric oil (100).
In written sources some of which have dated since the first decades of the last century was found information about the use of the plant Pirin tea (Sideritis scardica Grsb.) that is endemic for the
Balkan peninsula; moreover, its use in our country as herbal tea and in the traditional medicine mainly in respiratory tract diseases (100).
The plant Pirin tea (Sideritis scardica Grsb.) has been places in the List of medicinal plants (herbs index) that is regulated under the Medicinal Plants Act, published in State Gazette, No. 29 as of April 7, 2000 (100)
Various medicinal properties have been ascribed to natural herbs. Medicinal plants constitute the main source of new pharmaceuticals and healthcare products, including medications for ethnoveterinary medicine. A whole range of plant-derived dietary supplements, phytochemicals and pro-vitamins that assist in maintaining good health and combating disease are now being described as functional foods, nutriceuticals and nutraceuticals. Plant-derived products are also increasingly accepted and used in the cosmetic industry (101). The widespread use of traditional herbs and medicinal plants has been traced to the occurrence of natural products with medicinal properties. The roles of herbal tea in disease prevention and cure have been attributed, in part, to antioxidant properties of their constituents-liposoluble vitamins A and E, the water soluble vitamin C, and a wide range of amphipathic molecules, broadly termed phenolic compounds. The antioxidant activity of phenolics is mainly due to their redox properties, which allow them to act as reducing agents, hydrogen donators, singlet oxygen quenchers, and metal chelators (102, 103).
Sideritis species are likely not to exhibit drug interactions (106).