Gotu Kola
Herb Library
This Asian species is reputed to bring long life to the user. According to the Sinhalese proverb: "Two leaves a day will keep old age away."
As the story goes, people in Sri Lanka noticed that elephants, animals known for their longevity, included Centella leaves in their diet. Extrapolation suggested that this creeping herb of Southeast Asian swamps might be good for almost anything that could ail a human, as well.
In Sri Lanka it is eaten as a salad, and in Vietnam it is considered an edible weed. It has been part of Ayurvedic medicine for a long time.
C. asiatica also grows in Madagascar, parts of southern Africa, and some parts of China. In Chinese medicine, it is known as luo de da or ji xue cao and is used to lower fever, promote urination, and "detoxify" the body.
The leaves and other aboveground parts of the plant are used.
Active Ingredients
C. asiatica contains several saponins, including brahmoside and brahminoside, and a number of alkaloids.
Madecassoside and asiaticoside appear to contribute to the plant's medicinal activity. It also contains flavonols, amino acids, fatty acids, sterols, saccharides, and some mineral salts.
Uses
Gotu kola is traditionally used for high blood pressure and to treat nervous disorders.
Chinese research suggests that it slows heart rate as well as lowers blood pressure. It also has some antibacterial activity.
Gotu kola extract (as titrated extract of C. asiatica, or TECA) has been studied for its effect on varicose veins as well as on poor venous circulation in the legs.
The results suggest that the extract can stimulate the synthesis of collagen in the walls of the veins and help them hold their tone and function better.
Other traditional uses of C. asiatica include skin problems, rheumatism, jaundice, and fever. Tests of TECA in animals showed that topical application helped experimental wounds heal faster. Asiaticoside may be responsible.
TECA has also been observed in clinical settings, where it appears to speed healing of surgical incisions and skin ulcers. In one trial it was administered to patients with parasitic infections that damage the bladder. Three-fourths of these patients recovered well, with little or no bladder scarring.
Tantalizing test tube research suggests that a Centella extract can destroy cultured cancer cells. It is far too soon, however, to determine whether it will be useful as an anticancer agent. Animal and eventually clinical studies will be needed.
Madecassoside has anti-inflammatory properties. In a small French study, a few patients with chronic liver disease had measurable improvement while using TECA. The majority of the patients in this group did not benefit, however.
High doses of the extract have a sedative effect on small animals.
Animal research also indicates that some gotu kola constituents can reduce fertility. Although the plant has a reputation as an aphrodisiac, no research supports this use.
Dose
Beyond the proverbial two fresh leaves a day, dosage information is limited.
The usual dose is 0.5 to 1 g three times a day.
The tea is made by pouring 1 cup of boiling water over teaspoon of dried leaves and steeping for ten minutes.
Standardized extract: 60 to 120 mg per day.
Fluid extract (1:1): 2 to 4 ml daily.
C. asiatica should not be used for more than six weeks consecutively.
Special Precautions
Pregnant women should avoid using this plant.
This herb is not appropriate for people with epilepsy.
Because of the possibility of photosensitivity, fair-skinned people and those who have reacted badly to sunlight while taking other medications should avoid sunshine, tanning lamps, and other sources of ultraviolet light while taking gotu kola.
Adverse Effects
Few side effects have been reported.
Contact dermatitis (skin rash) has occurred in some people using TECA topically.
Others, receiving the extract as a subcutaneous injection, developed pain and discoloration at the injection site. At least one person ingesting gotu kola experienced rash over the entire body.
This plant may make susceptible people more sensitive to sunburn and sun damage.
One component of C. asiatica, asiaticoside, may be a skin carcinogen.
Repeated topical application of the extract is not recommended.
Possible Interactions
At high doses, C. asiatica may interfere with oral diabetes medicines.
Gotu kola may raise cholesterol levels and should not be combined with cholesterol-lowering medications such as Lipitor, Lopid, Mevacor, niacin, or Zocor.
It is not known if the sedative effects of gotu kola are synergistic with those of other agents that promote sleep or reduce anxiety. It would be best not to mix C. asiatica with alcohol or drugs such as Ativan, Valium, or Xanax until this is determined.
1.)Saponins are the glycosides of 27 carbon atom steroids, or 30 carbon atom triterpenes in plants. They are found in various parts of the plant: leaves, stems, roots, bulbs, blossom, and fruit. They are characterized by their bitter taste, and their ability to hemolyze red blood cells. The botanical family Sapindaceae with its defining member, the genus Sapindus (soapberry) or (soapnut), includes 2000 species in 150 genera; and now including new family members, Aceraceae (maples) and Hippocastanaceae (horse chestnuts).
Toxicity
Saponins are highly toxic to cold-blooded animals, due to their ability to lower surface tension. Saponin as the sapogenin aglycone have also been identified in the animal kingdom in snake venom, starfish, and sea cucumber. Some saponins (including those produced by the soapberry) are poisonous if swallowed and can cause urticaria (skin rash) in many people. Any markedly toxic saponin is known as a sapotoxin. Digitalis-saponins have been used in high doses as arrow and spear poisons by African and South American natives. [13] Like all detergents, saponins are highly toxic if injected, because they cause hemolysis of blood cells. If eaten or swallowed, hydrolysis of the glycoside into its sugar moiety and aglycone or sapogenin reduces a saponin's toxicity. Ingested, the sapogenin is less toxic and not hemolytic. Native Americans eat Indian ice-cream made with Canada Buffaloberry, which contains saponins. Dog feeds often contain soybeans and beet pulp, which contain saponins that may be toxic to dogs.[5
Medicinal use
Soap nuts (sapindus), especially Sapindus mukorossi, are used medically as an expectorant, emetic, and for treatment of excessive salivation, epilepsy, chlorosis, and migraines. Soap nuts are among the list of herbs and minerals in Ayurveda. They are a popular ingredient in Ayurvedic shampoos and cleansers. They are used in Ayurvedic medicine as a treatment for eczema, psoriasis, and for removing freckles.
Saponins are believed to be useful in the human diet for controlling cholesterol. The Maasai eat soup laced with bitter bark and roots containing saponins. Heart disease is nearly nonexistent among the Maasai, and their cholesterol is one third lower than the average U.S. citizen. Urban Massai who don't eat the traditional soup, do develop heart disease.[6] [14] Bile cholesterol is secreted into the intestine. Much of it is later reabsorbed into the body. Saponins bind to bile acids and cholesterol, so much of it is not reabsorbed, and instead excreted from the body. [7] Digitalis-type saponins strengthens heart muscle contractions, causing the heart to pump more efficiently.[8]
Saponins inhibit some kinds of cancer cell tumor growth in animals, particularly lung and blood cancers, without killing normal cells. Cancer cells contain more cholesterol compounds than normal cells. Saponins bind to cholesterol, interfering with cell growth and division. In the colon, bacteria metabolize primary bile acids into secondary bile acids, which are a cause of colon cancer. Saponins bind to primary bile acids, preventing much of the secondary bile acids from forming.[9][10]
Saponins are the plants' immune system, acting as a natural antibiotic to protect the plant against microbes and fungus. Quillaja saponins stimulate the immune system and enhance both injected and oral vaccines. Saponin kills protozoa in the intestines by causing it's cell membrane to lyse.[11] Scientists are experimenting with saponin-based antibiotics, fungicides, yeast disinfectants, and vaccines against HIV.[12][13]
In laboratory studies saponins can be used at 0.04%-0.2% to permeabilize ("make holes in") the plasma membrane as well as the membranes of internal organelles such as ER and Golgi but does not penetrate the nuclear membrane. Therefore it is used in intracellular histochemistry staining to allow antibody access to intracellular proteins.
Because of its reversible nature on cells and its ability to permeabilize cells without destroying cell morphology, it is used in laboratory applications to treat live cells in order to facilitate peptide or reagents such as antibodies to enter cells instead of the harsher detergent triton X-100. It is also done on whole cell preparations such as cell smears and cytospins where the cell membrane is intact. It can also be done on frozen sections but is not used on fixed tissue sections. To preserve the permeabilizing effect, saponin has to be used in all processes involved in the staining steps or otherwise removed after reagent of interest has reached the cell.
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