Low Concentration of Dehydroleucodine promote cellular proliferation and activate antimicrobial peptides expression in a human keratinocytes cell line

LOPEZ ME, ZOPPINO FCM, INNOCENTI C, DE ROSAS JC, GIORDANO OS, KURINA MB, DEL RIO M, LARCHER F, HOLGUIN A, CARRETERO M

Buenos Aires Argentina

Congreso; 21st World Congress of Dermatology; 2007

International league of Dermatological Societies

Background: Vegetable secondary metabolites constitute a great variety of low molecular weight chemical compounds and are plant defense system part against harmful microorganisms. Dehydroleucodine (DhL) is a secondary metabolite from the sesquiterpene lactone group, isolated from Artemisia douglasiana Besser, known as “matico” which aerial parts are used in popular medicine as infusion to cure peptic ulcers and by topical administration for skin wounds repair. It has been shown that DhL possess cytostatic activity in vegetables stem cells and on animal vascular wall smooth muscle cells. Also DhL have gastroduodenal mucosal anti-inflammatory action and antiparasitic activities. Others sesquiterpene lactones have antimicrobial and antitumoral properties. Skin provides to the organism a protective barrier against water loss and infection. The healing of a skin wound is a complex process requiring the collaborative efforts of many different tissues and cell lineages during the phases of proliferation, migration, matrix synthesis, and contraction. Infections are the most important cause of wound repair failure and the continuous appearance of multidrug-resistant microbes limits the effectiveness of antibiotic treatment. Antimicrobial peptides are gene-encoded “natural antibiotics” that form part of the innate mechanism of defense and are expressed in human skin under inflammatory conditions and their function is not only limited to microbial killing but also influences tissue repair and adaptative immunity. Objectives: Due to skin infections interfere in the wound healing process and some of the sesquiterpene lactones have antimicrobial activity we determine the possible rol of DhL in skin wounds repair by assessing proliferation and expression of antimicrobial peptides in HaCaT cells, a long-lived spontaneously immortalized human keratinocyte line. Methods: To evaluate cellular proliferation under DhL different concentrations we used the reduction of tetrazolium salt (XXT) and Bromodeoxyuridine incorporation. RT-PCR semiquantitative was used to evaluate the antimicrobial peptides expression in HaCaT cells treated with DhL. Results: Concentrations between 200 and 50 ìM of DhL provoke cell death, with 50 to 25 ìM of DhL cell proliferation is reduced, with 10 ìM of DhL cell proliferation is the same as control, meanwhile between 1 ìM and 100 nM cell proliferation is promoted. Besides 1 ìM concentrations of DhL induce antimicrobial peptides expression in HaCaT cells. Conclusions: Keratinocytes proliferation is promoted by low concentrations and inhibited by high concentrations of DhL, showing a dual effect characteristic of some vegetable sign molecules. Given that 1 ìM concentrations of DhL promote cell proliferation and activate antimicrobial peptides expression, it is possible that DhL would contribute activating the skin wound healing process.