Volume 37, Issue 12, Page 46 (December 2006)

LESLIE S. BAUMANN, M.D.

DR. BAUMANN is director of cosmetic dermatology at the University of Miami. To respond to this column, or to suggest topics for future columns, write to Dr. Baumann at our editorial offices via e-mail at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Centella asiatica, popularly known as gotu kola, is a perennial herb native to swampy areas of Sri Lanka, India, South Africa, and tropical regions. A member of the family Apiaceae or Umbelliferae, this slender plant has been in use for centuries in traditional Chinese medicine and Ayurveda (traditional Indian medicine).

The primary medical indications for the extract are reputedly dermatologic, including skin inflammation, burns, wounds, scars, ulcers, venous insufficiency, leprosy, infection, postsurgical recovery, and psoriasis. In modern medicine, C. asiatica extract is accepted as an effective wound healing agent (Indian J. Exp. Biol. 1996;34:1208–11; Ann. Plast. Surg. 1979;3:13–21; Eur. J. Dermatol. 1999;9:289–96; Proc. Soc. Exp. Biol. Med. 1967;125:279–80).

The extract also has been documented to be effective in the treatment of keloids, phlebitis, cellulitis, slow-healing wounds, and striae distensae (Contact Dermatitis 1993;29:175–9).

In recent years, extrapolating from the consumption of gotu kola by elephants (a mammal noted for its longevity), some in Sri Lanka have identified the herb as an antiaging agent. It also has gained a reputation as an aphrodisiac. These more fanciful claims have not been substantiated by scientific inquiry.

Mechanism of Action

Despite gotu kola's long history, an understanding of its mechanism of action is in its infancy.

Researchers using human skin fibroblast cultures found that the total triterpenoid fraction extracted from C. asiatica increased collagen and fibronectin synthesis during wound healing, and suggested that this effect was rooted in the basal endothelia (Ital. J. Biochem. 1988;37:69–77).

The stimulation of type I collagen production is believed to be one of the extract's primary mechanisms of action (Ann. Pharm. Fr. 1995;53:38–42). A study of the titrated extract of C. asiatica, a preparation long used in Europe to treat wound-healing defects, seems to bear this out: When the three triterpenes of C. asiatica were applied to a rat wound chamber model, they stimulated the synthesis of collagen and glycosaminoglycan (Eur. J. Dermatol. 1999;9:289–96). In other work, the C. asiatica derivative asiaticoside increased collagen formation and angiogenesis (Phytother. Res. 1999;13:50–4).

Wound Healing in Laboratory Animals

In one study, oral and topical administration of an alcohol extract of C. asiatica to wounds in rats accelerated cellular proliferation and collagen synthesis at the wound site, as suggested by increases in the DNA, protein, and collagen content of granulation tissues. Investigators observed faster and better maturation and crosslinking of collagen in the extract-treated rats, whose wounds epithelialized and contracted more rapidly than control wounds (Indian J. Exp. Biol. 1996;34:1208–11).

Several animal studies have shown that topical application of C. asiatica to sutured wounds enhances the breaking strength of the wounds (Altern. Med. Rev. 2003;8:359–77; Proc. Soc. Exp. Biol. Med. 1967;125:279–80; Curr. Ther. Res. Clin. Exp. 1976;19:121–5).

In an evaluation of C. asiatica's wound-healing activity, researchers topically applied a 0.2% asiaticoside solution to punch wounds on guinea pigs. The treatment resulted in increases in hydroxyproline, tensile strength, and collagen content, as well as improved epithelialization (J. Ethnopharmacol. 1999;65:1–11).

In the same study, delayed wound healing was evaluated by using streptozotocin diabetic rats. Topical application of a 0.4% asiaticoside solution to punch wounds resulted in increased hydroxyproline content, tensile strength, collagen content, and epithelialization. In addition, administration of oral C. asiatica reduced the wound area and improved tensile strength (J. Ethnopharmacol. 1999;65:1–11).

In another study, researchers applied topical 0.2% asiaticoside to excision wounds in rats twice daily for 7 days, and observed increased enzymatic and nonenzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, vitamin E, and ascorbic acid) in newly formed tissues, as well as a decline in lipid peroxide levels (Phytother. Res. 1999;13:50–4).

Help for Stretch Marks, Psoriasis

C. asiatica extract also has been studied in humans. In one investigation, researchers searched (1) the Cochrane Pregnancy and Childbirth Group trials register to evaluate the effects of topical treatment on the prevention of striae gravidarum (stretch marks), and (2) the Cochrane Controlled Trials Register to identify randomized trials comparing active creams with placebo for treatment of striae gravidarum during pregnancy.

The researchers identified a study of 100 women in which those treated with Trofolastin, which is a cream combining C. asiatica extract, alpha-tocopherol, and collagen-elastin hydrolysates, developed fewer stretch marks than did the placebo group (Cochrane Database Syst. Rev. 2000;2:CD000066). The same study showed that pregnant women who had previously developed stretch marks in pregnancy benefited more from treatment with the cream than did those with no previous stretch marks. Trofolastin is not available in the United States.

In another study, researchers compared the reputed antipsoriatic activity of C. asiatica with that of the psoralen-containing seeds of Psoralea corylifolia. Both extracts inhibited keratinocyte replication, Centella more effectively, which the authors ascribed to the triterpenoid glycosides madecassoside and asiaticoside (Phytomedicine 2001;8:230–5).

Prevention of Scars

Alpha centella cream is a formulation used by some physicians to prevent and treat scars. The cream has two components: an extract of the plant Bulbine frutescens, which possesses hydrating and antibacterial properties; and the principal terpenoids extracted from C. asiatica, namely asiatic acid, madecassic acid, and asiaticoside, which are known to aid wound healing. Centella extract is believed to stimulate scar maturation via the production of type I collagen, with a resulting reduction in inflammation and myofibroblast production (Aesthetic Plast. Surg. 2000;24:227–34).

There are no known adverse effects from the topical application of C. asiatica extract. Contact sensitivity is considered unlikely, as the plant and its three primary triterpenic constituents have been found to be weak sensitizers (Contact Dermatitis 1993;29:175–9).

Conclusions

The potential cosmetic uses of this herb are varied, given its skin-tightening and regenerative capacity. It is included in some products for its antiwrinkling properties and for its ability to reduce acne-induced blemishes.

C. asiatica is similar to aloe vera insofar as it has a long history of wide-ranging medical applications. But it is used in the West primarily for its cutaneous anti-inflammatory activity.

The amassed record thus far on Centella is relatively small but impressive. Randomized, controlled trials are warranted in human subjects to evaluate the safety and efficacy of topical products containing C. asiatica for wound healing and other applications. The future is promising regarding the inclusion of this herbal ingredient in an increasing number of products.

PII: S0037-6337(06)71757-0

doi:10.1016/S0037-6337(06)71757-0

© 2006 Elsevier Inc. All rights reserved.