Evaluation of the Topical Anti-Inflammatory Activity of Ginger Dry Extracts from Solutions and Plasters

Abstract

In this study the skin permeation and the topical anti-inflammatory properties of ginger extracts were investigated. A commercial ginger dry extract (DE) and a gingerols-enriched dry extract (EDE) were evaluated for their in vivo topical anti-inflammatory activity by inhibition of Croton oil-induced ear oedema in mice. Furthermore, the feasibility of an anti-inflammatory plaster containing DE or EDE was evaluated. Since the in vivo activity was evaluated in mice, the ex vivo skin permeation study was performed by using mouse skin or human epidermis. The DE from the acetonic solution exerted a dose-dependent topical anti-inflammatory activity (ID₅₀ = 142 μg/cm²), not far from that of the potent reference substance indomethacin (ID₅₀ = 93 μg/cm²). Similarly, the EDE induced a dose-dependent oedema reduction though its potency (ID₅₀ = 181 μg/cm²) was slightly lower than that of DE. Increase of the 6-gingerol concentration in the extract did not improve the anti-inflammatory activity. The medicated plasters, containing 1 mg/cm² of the commercial DE or EDE, had good technological characteristics and exerted a significant antiphlogistic effect, too. By using the plaster containing EDE, the 6-gingerol amount that permeated through human epidermis was 6.9 μg/cm² while the amount that passed through mouse skin was 22.1 μg/cm². Nevertheless, the amounts of 6-gingerol permeated through human epidermis and mouse skin in the early period (8h) were comparable (p > 0.3). This preliminary result suggests that the anti-inflammatory effect observed in mice could also be exerted in humans.

Gingerols - Zingiber officinale - Zingiberaceae - topical anti-inflammatory activity - Croton oil-induced ear oedema - ex vivo skin permeation study - adhesive plaster

References

• 1 Grzanna R, Lindmark L, Frondoza C G. Ginger - an herbal medicinal product with broad anti-inflammatory actions.  J Med Food. 2005;  8 125-32.
• 2 Shen C -L, Hong K -J, Kim S W. Effect of ginger (Zingiber officinale Rosc.) on decreasing the production of inflammatory mediators in sow osteoarthritic cartilage explants.  J Med Food. 2003;  6 323-8.
• 3 Shen C -L, Hong K -J, Kim S W. Comparative effects of ginger root (Zingiber officinale Rosc.) on the production of inflammatory mediators in normal and osteoarthrotic sow chondrocytes.  J Med Food. 2005;  8 149-53.
• 4 Frondoza C G, Sohrabi A, Polotsky A, Phan P V, Hungerford D S, Lindmark L. An in vitro screening assay for inhibitors of proinflammatory mediators in herbal extracts using human synoviocyte cultures.  In Vitro Cell Dev Biol Anim. 2004;  40 95-101.
• 5 Penna S C, Medeiros M V, Aimbire F SC, Faria-Neto H CC, Sertié J AA, Lopes-Martins R AB. Anti-inflammatory effect of the hydroalcoholic extract of Zingiber officinale rhizomes on rat paw and skin oedema.  Phytomedicine. 2003;  10 381-5.
• 6 Park K -K, Chun K -S, Lee J -M, Lee S S, Surh Y -J. Inhibitory effects of [6]-gingerol, a major pungent principle of ginger, on phorbol ester-induced inflammation, epidermal ornithine decarboxylase and skin tumor promotion in ICR mice.  Cancer Lett. 1998;  129 139-44.
• 7 Tubaro A, Dri P, Delbello G, Zilli C, Della Loggia R. The croton oil ear test revisited.  Agents Actions. 1985;  17 347-9.
• 8 Casiraghi A, Ardovino P, Minghetti P, Botta C, Gattini A, Montanari L. Semisolid formulations containing dimethyl sulfoxide and α-tocopherol for the treatment of extravasation of antiblastic agents.  Arch Dermatol Res. 2007;  299 201-7.