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Botany
A herbaceous perennial growing up to 0.6
10 1 meter high, with leaves 2 to 3 cm long, flowering from January to March in the southern hemisphere.
General info
A South American plant
popular as a natural sweetening agent and dietary supplement. It was
discovered in Paraguay in 1887 and is native to Brazil, Venezuela, Columbia
and Paraguay where it has been used for over 1000 years to sweeten unpleasant
tasting medicinal drinks. It is a potential natural alternative to artificial
sweeteners (such as aspartame or sodium saccharin), but it has been
involved in a tug-o-war of controversy. In December 2008, the United
States FDA permitted Rebiana-based sweeterners as food additive. Widely
used in Japan, China, Korea, Israel and South American countries, It
is available in the U.S. as a dietary supplement.
Distribution
Recently introduced and
cultivated in the Benguet region for its sweet leaves.
Chemical constituents and properties
• The sweetness in stevia is mainly
attributed to two compounds viz stevioside (3-10% of dry leaf weight)
and rebaudioside A (1-3%) which can be up to 250 times sweeter than
sucrose.
• Stevioside, a natural plant glycoside, has been shown to have
blood lowering effects.
• Dry stevia leaf is up to 30 times sweeter than sucrose.
Parts
used
Leaves
Uses
Folkloric
In other countries, plant
has been used for diabetes, candidiasis, high blood pressure, skin abrasions.
In South America, used for diabetes, cavities, depression, hypertension, obesity, wound healing and as tonic and sweetener.
Common Use
Its crude leaf form is
used as sweetener in foods and beverages.
Preparations:
Fresh stevia
(1) Add several leaves to a cup of hot liquid. (About 3 tablespoons of chopped fresh leaves equal one cup of sugar or 1 tsp of processed Stevia extract powder.)
(2) Fresh whole leaf extract: Steep a tea ball packed with fresh stevia leaves in just-boiled water for 30 minutes. Add the liquid to foods where its green color is compatible.
Dried stevia
(1) Dry in a warm dark and dry area. (2) Grind the dry leaves to a fine powder. Store in an airtight container away from light. (3) One tablespoon of dried powder equals a cup of sugar or 1 tsp of processed Stevia extract powder.
In the News
!
• Truvia and PureVia,
purified forms of stevia, rebaudioside A, was recently approved by the
FDA for use sweetener in foods and beverages. Coca-cola and Pepsico
will soon be launching stevia-sweetened products.
• Some reported side effects: muscle pain and weakness, dizziness,
nausea and abdominal fulness which usually resolve after a week of use.
Studies
• Anti-inflammatory:
Of the 100 methanol extracts from spices studied, hop, stevia,
cinamon, tumeric, mate, mint, New Zealand spinach, watercress, tomato
and radish seedling showed marked inhibition of inflammatory activity
induced by TPA in mice. Two active compounds, humulone and lupeol 3-palmitate
were separated from hop and stevia,
respectively.
• Renal Effects on Chronic Administration:
Administration of crude extract of Stevia dried leaves for 40 to 60
days induced systemic and renal vasodilation causing hypotension, diuresis
and natriuresis.
• Anti-Hypertension:
(1) Using stevioside capsules (Nan Kai Chemical Factory, Tien Jing, China)
250 mg 3 times daily, the study found stevioside to be a safe and effective
compound or supplementary therapy for hypertension. (2) Study showed stevioside caused vasorelaxation through an inhibition of Ca influx into the blood vessels.
• Antioxidant: Study
of ethanolic and ethly acetate extracts of leaves indicate Stevia rebaudiana
may be a useful as a potential source of natural antioxidants.
• Stevioside / Anti-Diabetic: Study
on SXZ-induced diabetes in rats showed stevioside lowered blood glucose. It dose-dependently decreased the protein levels of phosphoenol pyruvate carboxykinase, reduced insulin resistance in diabetic animals. Study concludes stevioside regulates blood glucose by enhancing insulin secretion and insulin utilization in insulin-deficient rats.
• Powdered Form / Anti-Diabetic / Weight Reducing: Study
of powdered form of Stevia leaves on STZ-induced diabetic rats showed significant hypoglycemic effects and body weight reducing effects.
• Antimicrobial / Anti-Tumor Activities: Four solvent extracts showed effective antibacterial potential. The acetone extract showed no toxicity to normal cells and showed both anti-proliferative and anticancer activities. Study
confirms the antimicrobial and antitumor activities of various Stevia rebaudiana leaf extracts, suggesting a potential drug that warrants further studies and development.
• Glucose Tolerance Effect: Study on the effects of aqueous extrac ts of S rebaudiana leaves on glucose tolerace in normal volunteers showed an increase in glucose tolerance, with a significant decrease of plasma glucose during the test and after overnight fasting in all volunteers.
Availability
Wildcrafted leaf form.
Limited commercial availability in powder and liquid form.
Recently approved: Truvia and PureVia.
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