Centella Asiatica (Jixuecao): Anticancer, Analgesic, Wound-Healing, and Cosmetic Effects
The Chinese medicine Jixuecao is the whole herb of Centella asiatica (L.) Urban of the Apiaceae family, also called Lianqiancao, Diqiancao, or Maticao, named for the shape of its leaves, which resemble copper coins or horse hooves.
Centella has a long medicinal history. The earliest TCM materia medica, the Shennong Bencao Jing (Divine Husbandman Classic of Materia Medica), records that it mainly treats great heat, evil sores, spreading ulcers and carbuncles, red fiery eruptions, red skin, and body fever. Clearly, ancient doctors already recognized it could treat swollen ulcerous lesions and skin disorders and reduce fever.
Traditional TCM holds that Centella is bitter and pungent in taste and cold in nature, entering the Lung, Spleen, Kidney, and Bladder meridians. It clears heat and drains dampness, invigorates blood and stops bleeding, and detoxifies and reduces swelling. It is mainly used for fever, cough and panting, sore throat, enteritis, dysentery, damp-heat jaundice, edema, lin syndrome, urinary blood, epistaxis, dysmenorrhea, metrorrhagia and metrostaxis, erysipelas, scrofula, furuncle and swelling toxins, herpes zoster, traumatic swelling and pain, external bleeding, and snake or insect bites.
Modern pharmacology has found that Centella has antitumor, anti-inflammatory and analgesic, antimicrobial effects, promotes wound healing, and has cosmetic uses.
The anticancer active components of Centella are mainly asiaticoside, total asiaticosides, and pentacyclic triterpenoids. Asiaticoside can induce tumor-cell apoptosis and has some synergistic effect with vincristine. Animal experiments show asiaticoside significantly inhibits the growth of cervical HeLa cells in a dose- and time-dependent manner. The mechanism may involve inhibiting survivin expression and promoting Caspase-3 expression to induce apoptosis in cervical cancer cells. Asiaticoside also prolongs survival in S180 sarcoma mice and markedly inhibits the mitotic growth of B16 cells, inducing apoptosis or death, suggesting asiaticoside inhibits melanoma cell growth. Pharmacological experiments also show total asiaticosides inhibit proliferation of human hepatoma cell lines SMMC-7721 and HepG-2, human myeloid leukemia cell line U937, and human gastric cancer cell line SGC-7901, and also enhance immunity in experimental mice. The pentacyclic triterpenoids in Centella inhibit RPMI8226 cells.
Centella has good anti-inflammatory and antibacterial effects and is often used to treat lung infections, infectious hepatitis, epidemic cerebrospinal meningitis, nasopharyngitis, chronic bronchitis, and asthma. Because it reduces fever and pain, it is more effective in patients with fever and pain from the above diseases.
Centella works well for hepatobiliary diseases and nephritis and has a strong diuretic effect. The Mindong Bencao records that fresh Centella, one liang, crushed and applied to the navel, treats difficult urination. Centella promotes diuresis and reduces swelling and can treat acute nephritic edema and has some effect on uremia. Centella alone, or combined with Jinhua (Lonicera), Yinchen (Artemisia), Zhizi (Gardenia), and Longdancao (Gentiana), treats acute infectious hepatitis. Centella can also treat cholecystitis; the Yuxi Chinese Herbal Medicine records that for acute cholecystitis, use 30-60g Matic leaf (i.e., Centella), 15g Materaline (Maweihuanglian), and 15g Longdancao (Gentiana), decocted in water.
Centella promotes wound healing. Tablets and ointments made from asiaticoside have been clinically tried on chronic, non-healing lower-limb ulcers due to venous insufficiency and traumatic cases, as well as on keloids after recovery from tendon adhesion caused by surgery or trauma and from burns; they show some efficacy. So Centella is also often used as a cosmetic medicine; it treats small wounds, hypertrophic scars, burns, psoriasis, and scleroderma.
Research shows Centella can repair aged skin; the mechanism may relate to its promotion of fibroblast proliferation and increased intracellular collagen and fibronectin. Centella also improves the tensile strength of newly formed skin and inhibits the inflammatory response of hypertrophic scars or keloids.
The usual dose of Centella is 15-30g; when fresh herb is used, the dose may be doubled. Centella may also be crushed into juice for external application to the navel or affected area. Centella has low toxicity and is tolerated by most patients.