Physical characteristics
Centella asiatica is a small herbaceous annual plant of the family Mackinlayaceae, and is native to Sri Lanka, northern Australia, Indonesia, Iran Malaysia, Melanesia, New Guinea, and other parts of Asia. Common names include Gotu Kola, Asiatic Pennywort, and Luei Gong Gen, Takip-kohol, Antanan, Pegagan, Pegaga, vallaarai Kula kud and Brahmi (although this last name is shared with Bacopa monnieri and other herbs). Botanical synonyms include Hydrocotyle asiatica L. and Trisanthus cochinchinensis (Lour.) In Sinhalese (Sri Lanka) Gotu = conical shape and Kola= leaf
Small-sized leaves usually hug the ground and have a short petiole stem; however, large leaves can have a petiole up to 20cm long. When plants are grown in the shade, they tend to have large leaves and very long petioles. This petiole stem can have a pink/purple tinge. Pink flowers 5mm across, usually set 2 to 4, side by side, as an umbel, developing from the stem nodes. Flowers are so small (and often hidden underneath leaves) that, generally, the flower is not noticed at all. It is only under a microscope that the flower’s beauty is seen. Although Centella belongs to the umbel family of plants, now classified as Apiaceae, there is very little resemblance to other umbel plants: like parsley, dill, fennel and coriander. Seeds, of Centella, form in flat, oval capsules, usually containing two tiny, brown, kidney-shaped seeds.
Sometimes, Centella is mistaken for Swamp Pennywort (Centella cordifolia); as its name suggests, it does like to grow in damp places. The leaves of this species can be slightly longer than broad, with sinuate or faintly crenate margins and minute, purple flowers.
There are numerous other ‘look alike’ plants, such as Kidney Weed (Dichondra repens), a herb with creeping roots, petiolled kidney-shaped leaves with scalloped margins; a traditional Chinese herb for fevers, dysentery, jaundice and to remove excess fluid from the body. Native Violet (Viola hederacea) similar size and shaped leaf, to Centella, with scallops, but both ends of the leaf tend to overlap, near the stem, and it bears lavender and white non-fragrant violets. Coast Pennywort (Hydrocotyle bonariensis) which has a creeping root; the leaf-stem is attached to the centre of the leaf with broad, scalloped margins.
It is believed to have been introduced into Australia, from South America, where it has had traditional use for urinary disorders and as an anti-inflammatory. Alehoof (Glecoma hederacea) a hardy, creeping, ground cover, with dainty, kidney-shaped leaves and crenate margins: these can be used as salad greens, medicinally for colds and as a liver tonic (see p 23). Other plants that have a visual resemblance to Centella are several Ranunculus species, which have similar leaf formation; and other Hydrocotyle species. Before using Centella, it is important to make sure that it is the correct plant. I remember, several years ago, when a lady told me she had been using the native violet for some time, thinking it was Centella. She said "No wonder I was not getting rid of my arthritic pain".
The crop matures in three months and the whole plant, including the roots, is harvested manually.
Composition
Volatile oil containing vallerin, camphor, cineole, n-dodecane, terpene acetate, tran-B farnesene, germacrene-D, B-caryophyllene, p-cymol, a-pinene, methanol, allyl mustard oil; flavonoids, kaempferol, resin, alkaloid hydrocotyline; asiatic, betulic, brahmic, centellinic, isobrahmic, and madecassic acid; quercetin, tannin, sugar, asiaticoside, oxyasiaticoside, brahmoside, braminoside, centelloside, madecassoside, thunkuniside, bitters, sterols, pectin, B-sitosterol.
Active principles are pentacyclic tirterpenes, with healing potential were isolated, namely, terminolic acid, asiaticoside-B while sceffoleoside A and saponins (centellasaponins B,C and D) with four ursane- and oleanane-type triterpene oligoglycosides were isolated from Centella asiatica grown in Sri Lanka. The essential oil from Centella asiatica grown in South Africa contains 11 monoterpenoid hydrocarbons (20.2%), 9 oxygenated monoterpenoids (5.46%), 14 sesquiterpenoid hydrocarbons (68.8%), 5 oxygenated sesquiterpenoid (3.9%) and 1 sulphide sesquiterpenoid (0.76%). The predominant constitutes were b-caryophyllene (19.08%), bicyclogermacrene (11.22%), germacrene B (6.29%) and myrcene (6.55%). Other reports included trans-b-farnesene and germacrene D as prominent constituents of the essential oil.
Vitamins
A, B, C, D
Minerals
Calcium, chromium, cobalt, magnesium, manganese, phosphorus, sodium, potassium, selenium, silica, zinc.
Medicinal uses
Centella has been used as a wound-healing agent and a constituent of a brain tonic for the mentally challenged.
Centella is a mild adaptogen, is mildly antibacterial, anti-viral, anti-inflammatory, anti-ulcerogenic, anxiolytic, a cerebral tonic, a circulatory stimulant, a diuretic, nervine and vulnerary.
The isolated steroids from the plant have been used to treat leprosy. In addition, preliminary evidence suggests that it may have nootropic effects. Centella asiatica is used to re-vitalize the brain and nervous system, increase attention span and concentration and combat aging. Centella asiatica also has anti-oxidant properties. It works for venous insufficiency. It is used in Thailand for opium detoxification.
ADD, peptic ulcers, auto-immune, diseases, stress, gynaecological, disorders, asthma, low thyroid, function, neuritits, male tonic, menopausal, problems, eczema, scrofula, venereal diseases, cirrhosis, diarrhea, high blood pressure, laryngitis, stomach ache, muscular atrophy, fatigue, sore throat, schizophrenia, thrombosis, brain tonic, respiratory ailments, influenza, blood purifier, food poisoning, Vaginitis, diabetes, baldness, wounds, age spots, nervous break down, poor circulation, insomnia, retinal detachment, dysentery, liver problems, to increase energy, epilepsy, pleurisy, premenstrual pain, hair loss, blood disorders, mycosis fungoides, dementia, infections, periodontal disease, colds, coughing blood, vomiting blood, senility, hemorrhoids, prickly heat rash, measles, Poor appetite, atherosclerosis, depression, skin ulcers, urinary tract infection, candida, tuberculosis, mental retardation, sexual debility, elephantitis, fibrocystic breast disease, gastric, hypochondria, ankylosing spondylitis, skin ulcers, failing eyesight, abscesses, mouth ulcers, for impotence, stomach upsets, bruises, scleroderma, herpes, cramps, exam tonic, lupus, bowel disorders, fluid retention, hepatitis, swollen glands, intestinal worms, convulsions, surgical wounds, dermatitis, joint mobility, bowel disorders, anemia, hardening of, arteries, tingling in legs, to stimulate the liver,, bladder, kidneys, stimulate central, nervous system.
Many people have been able to correct high blood pressure, with consistent use of the herb. Research from the U.S. National Institute on Ageing, showed that high blood pressure can lead to atrophy and shrinkage of the brain. The study also showed, that: years of high blood pressure raises the amount of a liquid, known as cerebrospinal fluid, inside the skull, and lowers the amount of white matter. Who wants less white matter?
Centella’s constituents have a strong blood purifying action, and help to lower serum cholesterol levels; this could be mainly due to the action of Beta-sitosterol. The plant saponins help the function of the immune system, by assisting in breaking down the walls of diseased cells, making microbes easier to kill. It seems likely, that it is this same action that has been seen in research, which works to kill the leprosy bacteria by dissolving the waxy, protective substance around the bacteria.
Arthritis has been recognised as the single, largest and identified cause of disability and handicap in Australia, now affecting over 2.6 million people. It is an inflammatory condition of the joints (which can be of the fingers, wrists, elbows, shoulders, hips, knees, spine and toes) with symptoms of pain, swelling, stiffness and deformity. It may appear suddenly or come on gradually, with a toothache-like pain or sharp burning or grinding pain. There are many different forms arthritis can take. Osteoarthritis, a degenerative joint disease is related to the wear and tear of ageing, and involves the deterioration of the cartilage, at the end of the bones. The once-smooth cartilage becomes rough, resulting in friction; tendons, ligaments and muscles, holding the joints together, become weaker, and there is severe pain, stiffness and deformity.
Rheumatoid arthritis, an auto-immune disease, is inflammation affecting the synovial membranes. Cartilage and tissue, surrounding the lubricating fluid in the joints, can be destroyed. The body replaces this damaged tissue with scar tissue, causing the spaces between the joints to become narrow, to develop folds and to fuse together. There is stiffness, swelling, anaemia, weight loss, and often crippling pain, with loss of mobility to carry out normal activity, which means the quality of life, becomes greatly reduced. Gout can be classed as another form of arthritis, which attacks the smaller joints of the feet and hands, depositing crystallised uric acid salts in the joints causing swelling, redness, a sensation of heat and extreme pain. People, who wished to be free of these painful, debilitating diseases, have taken the herb. After a period of weeks to months, they usually experience a lessening of pain and disability: some report a complete cure.
Actions
Antipyretic, diuretic, antibacterial, antifungal, anti-inflammatory, sedative, antispasmodic, antioxidant, adaptogen, tonic, digestive, vulnerary, alterative, antiviral, antibiotic, nervine, rejuvenate, blood purifier, adrenal strengthener.
Pre-clinical data
Pharmacology
Wound-healing activity
A formulation which contained Centella asiatica plant extract induced proliferation of granulation tissue and increased tensile strength when applied locally on wounds in rats and decreased the area of skin necrosis caused by burns . The plant purportedly reduced scarring and stimulated skin growth by acting on the production of collagen fibres by fibroblasts and resulted in a decrease in the inflammatory reaction and myofibroblast production. Asiaticoside, a major constituent of the herb, promoted wound-healing by reducing lipid peroxide levels in wounds while it increased enzymatic (superoxide dismutase, catalase, glutathione peroxidase) and non-enzymatic (vitamin E and ascorbic acid) antioxidant levels.
Antibacterial activity
The essential oil of centella showed a broad spectrum of antibacterial activities against Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Shigella sonnei) organisms. Activity against Gram-positive bacteria was greater than against Gram-negatives. Germacrene compounds in the essential oil are known to be strong antimicrobial and anti-tumour agents.
Anti-tumour activity
Methanolic extract of Centella asiatica (100 µg/mol) showed 100% cytotoxicity to two tumour cell lines (Dalton’s ascites tumour cells and Ehrlich ascites tumour cells) after a 3 hour incubation at 37oC . The acetone fraction of Centella asiatica extract, a partially purified fraction (3.5 & 8 µg/mL), inhibited the proliferation of mouse lung fibroblast cells after exposure for 6-7 days at 37oC. Both the crude extract and the acetone fraction of Centella asiatica significantly reduced the development of murine solid tumors when administered simultaneously with tumour transplantations or given 10 days prior to tumour transplantation. The latter finding suggested a mechanism which involves stimulation of the immune system. The crude extract also significantly reduced ascites tumour growth and increased the life span of tumour bearing mice. The mechanism may involve inhibition of DNA synthesis.
Neuropharmacology and antioxidant activity
The hydroalcoholic extract of Centella asiatica leaves possesses potential anticonvulsant, antioxidant and central nervous system (CNS) depressant actions. The extract (100 mg/kg) showed 50% protection while a higher dose (200 mg/kg) completely protected against pentylenetetrazol-induced convulsions in rats. The extract also protected against convulsions induced by an increase in current electroshock and by strychnine. Spontaneous motor activity was reduced while diazepam withdrawal-induced autonomic hyperactivity was potentiated as was the pentobarbitone sleeping time in mice. The extract (100-150 mg/kg) significantly reduced the normal body temperature of mice, while in brain homogenates it (1.3-40 mg/mL) reduced the formation of lipid peroxidation products.
Aqueous extract of Centella asiatica (100-300 mg/kg) was able to prevent cognitive deficits in intracerebroventricular streptozotocin-induced cognitive impairment in rats after 14 and 21 days indicating improved acquisition and retention of memory. These doses of Centella asiatica did not affect spontaneous locomotor activity in these rats thus excluding the possibility that the CNS depressant/stimulant activity of the herb had contributed to the changes in the passive avoidance and elevated plus maze tests. After 21 days of treatment in the same groups of rats, the extract (200 & 300 mg/kg) significantly reduced brain malondialdehyde levels and increased brain glutathione levels without affecting brain superoxide dismutase activity while brain catalase levels were increased by the highest dose of the extract (300 mg/kg).
Centella asiatica extract (0.3%) and powder (5%) reduced oxidative stress when given to H2O2-exposed rats for 25 weeks. There was a reduction in erythrocyte malondialdehyde levels as well as a decrease in the superoxide dismutase activity of these rats given Centella asiatica although the catalase activities were higher than in the H2O2-fed rats.
Other effects
Asiatic acid and its derivatives protected cultured neurons from glutamate-induced excitotoxicity.
Oral administration of Centella asiatica water extract and asiaticoside reduced the size of acetic acid-induced gastric ulcers in rats at 3 and 7 days in a dose-dependent manner with concomitant attenuation of myeloperoxidase activity in the ulcer tissues. Cell proliferation and angiogenesis were promoted, the expression of basic fibroblast growth factor in ulcer tissues in rats treated with extract or compound were upregulated. The aqueous extract of Centella asiatica (0.05g, 0.25 and 0.50 g/kg) significantly inhibited ethanol-induced gastric lesions and decreased mucosal myeloperoxidase in a dose dependent manner when the extract was given before ethanol administration. These results suggest that Centella asiatica protected the gastric mucosa by improving the integrity of the mucosal lining while reduction of myeloperoxidase and gastric lesions could be due to a decrease in the recruitment of neutrophils by Centella asiatica or to its free radical scavenging activity.
Toxicities
Aqueous extract of Centella asiatica (5 mg/plate)lack cytotoxicity and mutagenicity on Salmonella typhimurium TA98 or TA100 with or without S9 mixture. Acetone fraction of Centella asiatica extract did not induce cytotoxicity in normal human lymphocytes at a 50 µg/mL. Oral administration the crude extract and the acetone fraction of Centella asiatica to normal and tumour bearing mice at maximal concentrations of 500 mg/mouse did not produce any toxic symptoms while the body weights of the mice were increased. Asiaticoside, a major triterpenic acid in Centella asiatica was thought to be allergenic although in guinea pigs; centella raw extract and its triterpenic constitutents’ asiaticoside, asiatic acid and madecassic acid were considered to be weak sensitizers.
Other Uses
It is used as a medicinal herb in Ayurvedic medicine and traditional Chinese medicine.
In India it is popularly known by a variety of names: Bemgsag, Brahma manduki, Brahmanduki, Brahmi (North India, West India), Centella, Khulakhudi, Mandukparni, Mandookaparni, Mandukaparni (South India), or Thankuni depending on region. It is often confused with Bacopa monnieri which is the more famous "Brahmi", both have some common therapeutic properties in Vedic texts and both are used for improving memory. However, current research has clearly established the difference in pharmacological activities of these two herbs. Centella acts as a powerful "brain food", and is known for its ability to enhance mental ability. It supports and improves comprehension, memory and recollection . It coordinates these three aspects of mind power to develop a more effective level of performance. It has a "Vayasthapana effect", meaning that it helps retard the aging process. It is excellent for both internal and topical application. Centella nourishes the mind-body connection and enhances the psychoneuro immune (PNI) response. It supports the formation of quality blood , as well as the bone marrow and nerves.
Centella is used as a leafy green in Sri Lankan cuisine. It is most often prepared as mallung; a traditional accompaniment to rice and curry, and goes especially well with vegetarian dishes such as parippu' (dhal), and jackfruit or pumpkin curry. It is considered quite nutritious. In addition to finely chopped Centella, mallung almost always contains grated coconut and may also contain chillies, lime (or lemon) juice, dried fish, curry leaves, and spices such as fried mustard seeds. Centella leaves are also used in the sweet "pennywort drink."
It has also been used traditionally and in Ayurvedic medicine for central nervous system ailments including failing memory, insomnia, depression, stress and epilepsy.
In South Africa it was used to treat leprosy, wounds, cancer, fever and syphilis, while in Europe, the extract has been used for many years to treat wounds. The plant is also used to treat acne and allergies and as a psycho-physical regenerator and blood purifier.
In China, Centella asiatica has been used for a long time to treat dermal wounds and leprosy patients. Other folk medicine uses are for abscesses, headache, asthma, bronchitis, catarrh, convulsions, dysentery, eczema, gonorrhea, hypertension, jaundice, pleuritis, rheumatism, spasms, tuberculosis, ulcers, urethritis and as a diuretic. In Kenya, the leaves were applied to the skull amongst the Kisii tribe to improve healing. When eaten raw as a salad leaf, Pegaga is thought to help maintain youthfulness. In Thailand cups with Centella leaves are used as an afternoon pick me up. A decoction of juice from the leaves is thought to relieve hypertension. This juice is also used as a general tonic for good health. A poultice of the leaves is also used to treat open sores. Interestingly, chewing on the plant for several hours induces entheogenic meditation, similar to the effects of salvia divinorum, although this practice is widely considered dangerous, as it can cause temporomandibular joint pains.
Richard Lucas claimed in a book published in 1979 that a subspecies "Hydrocotyle asiatica minor" allegedly from Sri Lanka also called "Fo ti tieng", contained a longevity factor called 'youth Vitamin X' said to be 'a tonic for the brain and endocrine glands' and maintained that extracts of the plant help circulation and skin problems. However according to master herbalist Michael Moore, it appears that there is no such subspecies and no Vitamin X is known to exist. Nonetheless some of the cerebral circulatory and dermatological actions claimed from Centella (as hydrocotyle) have a solid basis.
Several scientific reports have documented Centella asiatica's ability to aid wound healing, which is responsible for its traditional use in leprosy. Upon treatment with Centella asiatica, maturation of the scar is stimulated by the production of type I collagen. The treatment also results in a marked decrease in inflammatory reaction and myofibroblast production.
In Sinhalese culture, they valued the herb to strengthen and revitalize worn out bodies and brains; eating 2-3 leaves a day to bring about a gradual return to health and strength, provided that the body is exposed to the sun, for a time, each day. Many herbalists have called Centella: the finest of all herb tonics. It appears, they say, to have no equal in the treatment of general debility and decline. Digestion is strengthened (no doubt aided by the bitter properties) and food better utilized, with the process of overall metabolism, increased. Centella has been called ‘a pharmacy in one herb’, offering impressive benefits. In India, Centella is a traditional remedy for skin conditions, wounds and bruises. With controlled tests, in which an extract of Centella was applied, to 20 people, suffering with slow healing wounds: 64% of the wounds healed completely and 16% improved considerably. At Sydney University, research on wound healing is being carried out, following invitro studies on the herb. It is one of the most important, rejuvenating herbs in Ayurvedic medicine, particularly valued for: revitalising nerve and brain cells, promoting calmness and clarity, helping poor memory and lack of concentration, increasing meditation ability and to help balance the left and right hemispheres of the brain. Valued as a brain food, for improving intelligence and reflexes, it has been a herb students have used for: renewing mental alertness, clarity, and energy levels, without the ‘jitteriness’ some people may experience with coffee. It can be used throughout life. Centella contains neither caffeine, nor theobromine.
As one of its common names implies, ‘Indian Ginseng’, it is similar to ginseng in its actions. In fact, some herbalists regard Centella as highly as ginseng, and more affordable: besides, it is easy to grow. Note, Centella is not Withania somnifera, which also has the common name of Indian ginseng.
A popular folklore tale from Sri Lanka speaks of a prominent king from the 10th century AD named Aruna who claimed that Centella provided him with energy and stamina to satisfy his 50-woman harem.
BACK TO TOP
