Protective effects of black rice bran against chemically-induced inflammation of mouse skin

J Agric Food Chem. 2010 Sep 22;58(18):10007-15. doi: 10.1021/jf102224b.

Abstract

We investigated the inhibitory effects of black rice (cv. LK1-3-6-12-1-1) bran against 12-O-tetradecanolylphorbol-13-acetate (TPA)-induced skin edema and 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) in inflammatory mouse models. We also determined the effects of the bran extract on the following biomarkers: pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), eicosanoids leukotriene B4 (LTB4), and prostaglandin E2 (PGE2). Topical application of TPA to ears of CD-1 mice induced inflammation accompanied with substantial increase in TNF-α, IL-1β, IL-6, LTB4, and PGE2 levels and an elevation in intercellular adhesion molecule-1 (ICAM-1) gene expressions in ear skin tissues. Intraperitoneal injection of black rice bran extract prior to TPA application in mice significantly suppressed TPA-induced inflammation (edema) and induced a marked decrease in the production of TNF-α, IL-1β, IL-6, and LTB4. Feeding mice a standard diet with added 10% black rice bran also significantly suppressed DNFB-induced allergic contact dermatitis on the skin of the mice. By contrast, a nonpigmented brown rice bran extract did not inhibit the TPA-induced edema and failed to significantly suppress production of pro-inflammatory biomarkers (mediators). These in vivo findings further demonstrate the potential value of black rice bran as an anti-inflammatory and antiallergic food ingredient and possibly also as a therapeutic agent for the treatment and prevention of diseases associated with chronic inflammation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Dermatitis / drug therapy*
  • Dermatitis / metabolism
  • Dermatitis / pathology
  • Dermatitis, Allergic Contact / metabolism
  • Dermatitis, Allergic Contact / pathology
  • Dermatitis, Allergic Contact / prevention & control
  • Edema / metabolism
  • Edema / pathology
  • Edema / prevention & control
  • Female
  • Mice
  • Oryza / chemistry*
  • Phytotherapy*
  • Plant Extracts / therapeutic use*
  • Seeds / chemistry*
  • Skin / drug effects
  • Skin / metabolism
  • Skin / pathology

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Plant Extracts