Peptides with antimicrobial and anti-inflammatory activities that have therapeutic potential for treatment of acne vulgaris

The pathogenesis of acne vulgaris is multifactorial involving infection of the pilosebaceous unit with Propionibacterium acnes and a cytokine-mediated inflammatory response. Five frog skin-derived antimicrobial peptides ([D4k]ascaphin-8, [G4K]XT-7, [T5k]temporin-DRa, brevinin-2GU, and B2RP-ERa), chosen for their low hemolytic activity against human erythrocytes, were assessed for their effects on the growth of clinical isolates of P. acnes and on the release of pro-inflammatory and anti-inflammatory cytokines from peripheral blood mononuclear (PBM) cells. All peptides inhibited the growth of P. acnes with the highest potency exhibited by [D4k]ascaphin-8 (minimum inhibitory concentration, MIC = 3-12.5 mu M). Release of TNF-alpha from concanavalin A (ConA)-stimulated PBM cells was significantly reduced by [D4k]ascaphin-8, [G4K]XT-7, brevinin-2GU, and B2RP-ERa (1 and 20 mu g/ml) and by [T5k]temporin-DRa (20 mu g/ml). Release of IFN-gamma from unstimulated PBM cells was significantly reduced by [D4k]ascaphin-8 and brevinin-2GU (1 and 20 mu g/ml). No peptide showed significant effects on II-17 release. Release of the anti-inflammatory cytokines TGF-beta, IL-4, and IL-10 from both unstimulated and ConA-treated PBM cells was significantly increased by[T5k]temporin-DRa and B2RP-ERa (1 and 20 mu g/ml). The potent activities of [D4k]ascaphin-8 and[T5k]temporin-DRa in inhibiting the growth of P. acnes and the release of pro-inflammatory cytokines, and in stimulating the release of anti-inflammatory cytokines suggest a possible therapeutic role in the treatment of acne vulgaris. (C) 2012 Elsevier Inc. All rights reserved.