Monday, August 24, 2009

Gotu Kola

Gotu kola (Centella asiatica) is a creeping vine-like plant native to India and Southeast Asia. In India and Indonesia, gotu kola has a long history of use to promote wound healing and treat skin diseases. In Europe, extracts of Centella asiatica are used as drugs for the treatment of wound healing defects. Gotu kola should not be confused with Kola nut – which is completely unrelated and is often used in dietary supplements as a “natural” source of caffeine. Modern dietary supplements of gotu kola are generally marketed to help prevent varicose veins and hemorrhoids, heal scars/burns/wounds, reduce skin inflammation and smooth skin wrinkles (smoother skin). In addition to the benefits of gotu kola on connective tissue, there also appear to be some central nervous system benefits with potential improvements in energy levels, memory, anxiety, and sleep patterns.

The primary benefits of gotu kola appear to be an enhancement of wound healing and an improvement in overall vein function (especially for varicose veins and hemorrhoids). Anti-anxiety effects are also interesting and warrant additional study. Based on traditional usage patterns and more recent clinical findings, gotu kola represents a good value for people who suffer from varicose veins or swollen ankles as well as for anybody recovering from a connective tissue injury such as a muscle or tendon strain, ligament sprain, or skin abrasion.

Scientific Support
Gotu kola contains a blend of compounds including at least 3 triterpenes (asiatic acid, madecassic acid and asiaticoside) that appear to have antioxidant benefits and an ability to stimulate collagen synthesis for tissue regeneration (Tenni et al. 1988). Perhaps the best data for gotu kola is shown by its ability to improve symptoms of varicose veins, particularly overall discomfort, tiredness, and swelling (Cataldi et al. 2001). In human studies, gotu kola extract (30-180mg/day/4 weeks) leads to improvements in various measurements of vein function (foot swelling, ankle edema, and fluid leakage from the veins) compared to placebo (Cesarone et al. 1994). Gotu kola appears to have a generally beneficial effect on connective tissues, where it may improve the structure and function of the connective tissue in the body, keeping veins stronger and also possibly reducing the symptoms of other connective-tissue diseases. In one animal study, asiatic acid and asiaticoside were the most active of the 3 triterpenes – but all 3 were effective in stimulating collagen synthesis and glycosaminoglycan synthesis (Masquart et al. 1999). Radiation injury to the skin of laboratory rats can be reduced by treatment with madecassol (one of the triterpene compounds in gotu kola) – suggesting a skin regeneration and anti-inflammatory activity (Suguna et al. 1996).

The activity of asiaticoside has been studied in normal as well as delayed-type wound healing. In one study, administration of asiaticoside produced significant increases in hydroxyproline content tensile strength and collagen content of wounds. In addition, other studies have indicated an antioxidant effect of asiaticoside and triterpense contained in gotu kola (Shukla et al. 1999) – with significant increases in both enzymatic and non-enzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase, vitamin E, and ascorbic acid in newly formed tissues as well as a several-fold decrease in free radical damage and lipid peroxide levels. This enhancement of antioxidant levels at the initial stage of healing may be an important contributory factor in the healing properties of gotu kola.

Orally, gotu kola appears to be nontoxic and it seldom causes any side effects other than the occasional allergic skin rash. There are some concerns that gotu kola may be carcinogenic if applied topically to the skin – though this has only been reported in one laboratory study and has not appeared as a major concern in human studies or in animal models of wound healing. Typical dosage recommendations are in the range of 60-180mg/day, usually consumed in divided doses of 20-60mg, 3 times daily for at least 4 weeks. It is important to look for an extract standardized to contain triterpene compounds – typically 30-40% and including asiaticoside, asiatic acid, madecassic acid, and madecassoside (which typically occur at only 1-4% in the whole herb).

1.Bradwejn J, Zhou Y, Koszycki D, Shlik J. A double-blind, placebo-controlled study on the effects of Gotu Kola (Centella asiatica) on acoustic startle response in healthy subjects. J Clin Psychopharmacol. 2000 Dec;20(6):680-4.
2.Cataldi A, Gasbarro V, Viaggi R, Soverini R, Gresta E, Mascoli F. Effectiveness of the combination of alpha tocopherol, rutin, melilotus, and centella asiatica in the treatment of patients with chronic venous insufficiency. Minerva Cardioangiol. 2001 Apr;49(2):159-63.
3.Cesarone MR, Laurora G, De Sanctis MT, Incandela L, Grimaldi R, Marelli C, Belcaro G. The microcirculatory activity of Centella asiatica in venous insufficiency. A double-blind study. Minerva Cardioangiol. 1994 Jun;42(6):299-304.
4.Maquart FX, Chastang F, Simeon A, Birembaut P, Gillery P, Wegrowski Y. Triterpenes from Centella asiatica stimulate extracellular matrix accumulation in rat experimental wounds. Eur J Dermatol. 1999 Jun;9(4):289-96. Phytother Res 1999 Feb;13(1):50-4.
5.Sastravaha G, Yotnuengnit P, Booncong P, Sangtherapitikul P. Adjunctive periodontal treatment with Centella asiatica and Punica granatum extracts. A preliminary study. J Int Acad Periodontol. 2003 Oct;5(4):106-15.
6.Shukla A; Rasik AM; Dhawan BN Asiaticoside-induced elevation of antioxidant levels in healing wounds.
7.Shukla A; Rasik AM; Jain GK; Shankar R; Kulshrestha DK; Dhawan BN. In vitro and in vivo wound healing activity of asiaticoside isolated from Centella asiatica. J Ethnopharmacol 1999 Apr;65(1):1-11.
8.Suguna L, Sivakumar P, Chandrakasan G. Effects of Centella asiatica extract on dermal wound healing in rats. Indian J Exp Biol. 1996 Dec;34(12):1208-11.
9.Tenni R, Zanaboni G, De Agostini MP, Rossi A, Bendotti C, Cetta G. Effect of the triterpenoid fraction of Centella asiatica on macromolecules of the connective matrix in human skin fibroblast cultures. Ital J Biochem. 1988 Mar-Apr;37(2):69-77.

EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS

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