Topical anti-inflammatory activities of Vitis rotundifolia (muscadine grape) extracts in the tetradecanoylphorbol acetate model of ear inflammation

The ability of muscadine grape skin, seed, or combined skin and seed extracts to inhibit mouse ear inflammation, edema, and polymorphonuclear leukocyte infiltration was tested following topical application of 12-O-tetrade-canoylphorbol 13-acetate (TPA). Ethanolic extracts of skins, seeds, or a combination of these from purple (Ison) cultivars were applied to both ears of female Swiss mice 30 minutes after TPA (2 mu g per ear) administration. Control mice were treated with indomethacin or 50% ethanol vehicle 30 minutes after TPA. Ear thickness was measured before TPA and at 4 and 24 hours post-TPA administration to assess ear edema. Ear punch biopsies were collected at 24 hours and weighed as a second marker of edema. Myeloperoxidase (MPO) (EC 1.11.1.7) activity was measured in each ear punch biopsy as an index of neutrophil infiltration. Extracts of muscadine skin, seed, and combination treatments significantly reduced ear edema, ear biopsy weight, and MPO activity compared to TPA vehicle control. There was no significant difference in anti-inflammatory activity of the skin and seed extracts. However, an additive effect was observed with the combination treatment that was statistically similar to the anti-inflammatory activity of indomethacin treatment. It can be concluded that muscadine skin, seed, and combination skin/seed extracts exhibit significant topical anti-inflammatory properties.