Anti-inflammatory and vasoconstrictive properties of Potentilla erecta - A traditional medicinal plant from the northern hemisphere.

ETHNOPHARMACOLOGICAL RELEVANCE: Potentilla erecta (L.) Raeusch is a medicinal plant of the Northern hemisphere belonging to the plant family of roses (Rosaceae). It has traditionally been used to treat inflammatory disorders of the skin and mucous membranes as well as chronic diarrhea.

AIM OF THE STUDY: In the present study we analyzed the anti-inflammatory and vasoconstrictive effect of a Potentilla erecta extract (PE) and questioned if PE is similar effective as mild corticosteroids. Then we analyzed if PE acts in the skin via a similar mode of action as corticosteroids.

MATERIAL AND METHODS: The anti-inflammatory effect of PE was analyzed in irradiated HaCaT keratinocytes by measuring the formation of IL-6 and PGE2 . Additionally the effect of PE on TNF-α induced NF-κB activation was determined. As the anti-inflammatory effect of corticosteroids correlates with their vasoconstrictive properties we tested if PE displays also vasoconstriction. Therefore we performed an occlusive patch test and a collagen contraction assay. Furthermore the binding of PE to the glucocorticoid receptor was determined with stainings and reporter assays. The interaction of PE on the nitric oxide (NO) content was examined with radical scavenging and endothelial NO synthase (eNOS) reporter assays.

RESULTS: In irradiated or TNF-α stimulated HaCaT cells the formation of IL-6 and PGE2 or NF-κB activation was strongly reduced by PE. Furthermore PE showed a blanching effect comparable to hydrocortisone. However, in contrast to glucocorticoids, PE did not cause nuclear translocation of the glucocorticoid receptor in HaCaT cells. The blanching effect of PE was at least partly attributable to a scavenging effect of NO and inhibition of eNOS.

CONCLUSIONS: PE displays anti-inflammatory and vasoconstrictive effects and might therefore be beneficial for the topical treatment of inflammatory skin disorders.