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 of Gotu Kola
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.
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.
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 with Gotu Kola
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.
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.
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.