Centella asiatica, also known as gotu kola, Indian pennywort, and sheep rot, is a perennial herb indigenous to India, northern Australia, and other tropical countries. It produces small, round flowers, green, smooth-textured, fan-shaped leaves, and slim green or red-green stems. It grows near ditches and other water sources. The herb has been used in cooking and medicinally for thousands of years.
This plant grows wild in many tropical areas, and in some areas it is considered a weed. It produces tiny, pinkish-red flowers of about 0.12 inches (3 mm) in size. At maturity, the flowers turn to a red fruit of about one half inch (1.27 cm) in diameter. The leaves can grow up to six inches (about 15.2 cm) long. Three months after planting the herb reaches maturity, at which time the entire plant, including the roots, is harvested by hand.
Centella asiatica is often used in Sri Lankan cooking. Its leaves are a popular side dish for rice, curry, and vegetarian foods. A porridge known as Kola Kenda, uses a blend of cooked red rice, coconut milk and the herb. The leaves are used in a sweet drink known as "pennywort drink."
The leaves and flowers of the plant have been used medicinally, both internally and externally, for thousands of years. This plant is often confused, however, with the caffeine-containing kola nut plant. Kola nut and Centella asiatica are unrelated. Centella asiatica contains no caffeine.
This herb is probably best known as an adaptogen, or overall health tonic, and brain stimulant. Research has shown that the herb may improve memory, recall, and understanding. In addition, some studies have shown that it can reduce the "startle response" in people with anxiety-related disorders, such as post-traumatic stress disorder and panic attacks. Many cultures use the herb as an afternoon energy booster.
Other research has shown that Centella asiatica can reduce scarring and assists wound healing when applied to lesions during the inflammatory period. Its anti-viral and anti-biotic properties help to prevent wound infections. Centella asiatica has also been used to treat leprosy, third degree burns, eczema and other skin conditions.
In addition, the herb is said to improve circulation, strengthen the walls of capillaries and veins, and thin the blood. Centella asiatica has been used used for circulation-related conditions including phlebitis, tingling of the arms and legs, hepatitis, high blood pressure, congestive heart failure, and leg cramps.
Centella asiatica may be taken as a tea, as a standardized extract, a tincture, or in capsule form. It can also be made into an oil and spread over the body as a treatment for nervous disorders. When taken internally, it is usually safe, and side effects are rarely reported. There have been reports of dermatitis when used externally. It should not be taken by women who are breastfeeding or pregnant, by people taking medication for blood pressure, high cholesterol, or diabetes; questions about the herb's interaction with medication may warrant checking with a doctor first.