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Greenselect^® Phytosome^®
Bioavailable standardised extract from Green Tea leaves

Tea is second only to water as the most popular beverage in the world; it is prepared by infusion of the leaves of Camellia sinensis L., originally grown in the South of China where it has been cultivated since the ancient times. According to the Chinese tradition, tea drinking was introduced in China in the third millenium BC, during the reign of the legendary emperor Shen Nong. At first tea was regarded as a medicine, and its stimulant and invigorating properties were much appreciated by the Buddist monks, who contributed to its diffusion throughout China and Japan by encouraging the habit of tea drinking as a remedy for intemperance.
The development of a flourishing trade led to the introduction of tea cultivations in Japan, and since the 19th century in India, Ceylon, Java, Sumathra, Georgia and Kenya.

Types of tea
There are three main groups of teas: black tea, oolong tea and green tea.
- Black tea is obtained from fermented (oxidized) leaves. During fermentation, extensive enzymatic oxidation of catechin derivatives takes place.
- Oolong (or Wulong) tea is obtained from partially fermented leaves; heating at a predetermined stage blocks the fermentation process when required.
- Green tea is produced by steaming or drying fresh leaves at elevated temperatures, inactivating oxidative enzymes and thus preserving catechins.
Green tea is widely used in China, Japan and other Eastern countries, while black tea is more diffuse in the Western countries. Nevertheless, green tea is growingly consumed also in North America and Europe. The average consumption of tea catechins in the Eastern countries rises to 700-900 mg of tea catechins (by HPLC), whereas one “Western” cup of tea* only provides 50 mg of tea catechins (by HPLC), a much lower quantity compared to the Asian average consumption. These data are highly hypothetic, since catechin degrade rapidly in commercial teas, and the extent of extraction critically depends on the temperature and length of infusion. 
Green tea infusions contain flavanols (catechin polyphenols), flavonols and phenolic acids⁽¹⁾.
Several flavanols have been isolated and identified from green tea, and two of these, (-)-epigallocatechin 3-O-gallate (EGCG) and (-)-epigallocatechin (EGC) exhibited a marked antioxidant activity.


*2 g dry leaves in 200 mL hot water, infused for 5 minutes

Clinical Use
The antioxidant activity of green tea has been extensively studied; however, the results obtained from dietary intervention studies are controversial probably due to the differences in the considered population and in the experimental protocols.
Consumption of green tea has been correlated with low incidence of chronic pathologies in which oxidative stress seems to be involved, such as cancer or cardiovascular diseases: a higher dietary intake of antioxidant compounds might be considered preventive in the onset of ROS (Reactive Oxygen Species)-related diseases in humans by increasing the antioxidant potential of subjects⁽²⁾.
The effectiveness of a moderate intake of Greenselect^® (green tea extract) on the antioxidative status, on lipid profile in plasma, the resistance to oxidative damage of lipids and DNA structures as well as the activity of antioxidant enzymes on lymphocytes have been investigated^(3,4). The importance of demonstrating the antioxidant effects of tea in human beings is emphasized by the observation that catechins are extensively metabolized in vivo and that the antioxidant and biological activities of their metabolites may differ from those of the original compounds.
Epidemiological data also indicate that green tea consumption may help weight management by improving energy expenditure.
The weight loss promotion appears to be sustained by the thermogenic effect exerted by galloyl catechin derivatives. Greenselect^® Phytosome^® has been tested on a multicentric trial in combination to a low caloric diet⁽⁵⁾ to assess its capability to promote weight loss.

Clinical studies on Greenselect^® Phytosome^®

Weight loss promotion of Greenselect^® Phytosome^® on obese and overweight patients⁽⁵⁾

One hundred patients affected by overweight and obesity have been treated with 150 mg of Greenselect® Phytosome® twice daily (300 mg/day). During the study, all patients (treated and placebo) followed a low caloric diet (1250-1350 Kcal for women and 1650-1750 Kcal for men) distributed in at least 4 meals per day. Parameters such as body weight, body mass index, waistline, total cholesterol, basal glycemia and total triglycerides were measured at the beginning, after 45 days and after 90 days (end of the study). The average weight loss was of 6 kg in the diet only group and 14 kg in the treated group. Accordingly, relevant results have been reported in terms of body mass index, waistline and blood parameters. Greenselect® Phytosome® may be a valid support in weight management.

Clinical studies on Greenselect^®

Effectiveness of Greenselect^® on improvement of antioxidant defenses in plasma⁽⁴⁾

Greenselect® was administered at a dosage of 160 mg/b.i.d. (320 mg/day) to 24 healthy female volunteers held on a controlled diet, for six weeks' treatment. At the end of the treatment, the subjects treated with Greenselect® had a significantly lower LDL cholesterol level, while the Total Antioxidant Activity (TAA) was significantly increased compared to control subjects. It is noticeable that blood samples were obtained 12 hours after the last consumption, indicating that the effect on the antioxidative status of plasma persists at least for that period of time. When tea consumption is regular, in fact, the mean plasma concentration of catechins reaches a steady state significantly higher than the baseline levels, and remains for at least 12 hours after the last ingestion. The results of this study suggest that a moderate intake of Greenselect® in healthy subjects improves antioxidant defenses in plasma and protects lymphocytes from DNA oxidative damage.

Effect of Greenselect® on peroxide level measured by Carr Units Effect of Greenselect® on total antioxidant activity in plasma

Pharmacokinetics

Bioavailability of flavonoids, both in aglyconic or glycosidic form, is reported to be low and erratic due to limited absorption, elevated presistemic metabolism and rapid elimination. Flavonoid aglycons and glycosides, once ingested, reach the small intestine intact and then are metabolized to the methylated, glucuronidated or sulfated metabolites. Flavonoids or flavonoids metabolites that reach the colon are usually further metabolized by local enzymes and then absorbed. This figure is at the base of a non-linear pharmacokinetics and has to be taken into account when evaluating the relationship among in vitro biochemical effects, oral dosages and plasma levels⁽⁶⁾.

Previous experiences indicate that the complexation of polyphenolic compounds with phospholipids improves the bioavailability of the natural molecules and stabilize them at intestinal pH values. In order to increase the bioavailability of green tea polyphenols Greenselect^® Phytosome^® was produced by complexing Greenselect^® (a standardized caffeine-free green tea extract) with soy phospholipids in a 1:2 ratio.

Improvement of radical antioxidant parameter (TRAP) with Greenselect^® Phytosome^®(7)

Twelve healthy male volunteers were randomly divided in two groups. One received a single dose of Greenselect®  (containing 240 mg of tea catechins by HPLC). The second group received 1,200 mg of Greenselect® Phytosome® (containing 240 mg of tea catechins by HPLC).  The antioxidant parameter TRAP, mesured as Trolox equivalents, has been evaluated, in the two groups. A 20% increase of the antioxidative capacity was observed in the volunteers treated with Greenselect® Phytosome® compared to the ones treated with Greenselect® (Chart 5).

TRAP modification with Greenselect® and Greenselect® Phytosome®

1. Gutman R. L., Ryu B. H., Herbalgram 37, Special Supplement, 34 (1996).
2. Weisburger J. H., Chung F. L., “Mechanisms of chronic disease causation by nutritional factors and tobacco products and their prevention by tea polyphenols”, Food Chem. Toxicol. 40, 1145-1154 (2002).
3. Pietta P. G., Simonetti P.,Mauri P., “Antioxidant activity of selected medicinal plants”, J. Agric. Food Chem. 46, 4487-4490, (1998).
4. Erba D., Riso P., Bordoni A., Foti P., Biagi P.L., Testolin G., “Effectiveness of moderate green tea consumption on antioxidative status and plasma lipid profile in humans”, J. Nutrit. Biochem. 16, 144-149 (2005).
5. Di Pierro F, Menghi AB, Barreca A, Lucarelli M, Calandrelli A. “Greenselect Phytosome as an adjunct to a low-calorie diet for treatment of obesity: a clinical trial “, Altern Med Rev. Jun;14(2):154-60. (2009).
6. Manach C., Williamson G., Morand C., Scalbert A., Remesy C., “Bioavailability and bioefficacy of polyphenols in humans”, Am. J. Clin. Nutr. 81 (1 Suppl), 230S-242S (2005).
7. Pietta P., Simonetti P., Gardana C., Brusamolino A., Morazzoni P., Bombardelli E., “Relationship between rate and extent of catechin absorption and plasma antioxidant status” , Biochemistry and Molecular Biology International 46 (5), 895-903 (1998).