Peter Lyte

Anti-inflammatory and anti-itch activity of sertaconazole nitrate

Cutaneous fungal infections are frequently associated with an inflammatory component including irritated skin, itching and stinging/burning. Therapeutic anti-fungal agents that have anti-inflammatory activity have the potential to provide clinical benefit beyond fungus eradication. Recently, certain anti-fungal agents have been shown to have intrinsic anti-inflammatory activity, therefore we sought to determine the extent of the anti-inflammatory activity of these compounds. The anti-inflammatory activities of eight anti-fungal agents (butoconazole, ciclopirox olamine, fluconazole, miconazole nitrate, sertaconazole nitrate, terconazole, tioconazole and ketoconazole) were compared in a number of preclinical models of dermal inflammation and pruritus. While butoconazole, ciclopirox olamine, fluconazole, and miconazole nitrate were all found to have anti-inflammatory activity, only sertaconazole nitrate reduced the release of cytokines from activated lymphocytes and mitigated inflammation in animal models of irritant contact dermatitis and neurogenic inflammation. In addition, sertaconazole nitrate inhibited contact hypersensitivity and scratching responses in a murine model of pruritus. Furthermore, the in vitro and in vivo anti-inflammatory activity of sertaconazole nitrate was found to be greater than other topical anti-fungal agents examined. These studies demonstrate that topical administration of clinically relevant concentrations of sertaconazole nitrate resulted in an efficacious anti-inflammatory activity against a broad spectrum of dermal inflammation models and itch. The anti-inflammatory properties of sertaconazole may contribute to the efficacy of the drug in the treatment of cutaneous fungal conditions and provide greater anti-inflammatory activity compared with other anti-fungal agents.

Heat-killed Propionibacterium acnes is capable of inducing inflammatory responses in skin.

Abstract:  The etiology of acne is a complex process, and acne is one of the most common skin disorders affecting millions of people. The pathogenesis of acne is closely associated with the bacterium, Propionibacterium acnes which was previously known as Corynebacterium parvum. Both viable and non‐viable P. acnes/C. parvum have been shown to induce an immunostimulatory effect in vivo, suggesting that even dead bacteria continue to activate an inflammatory response. Acne treatments with lasers or devices, induce a bactericidal effect through heat generation which may not address the immunogenic activity of P. acnes and the resulting acne inflammation. Therefore, we sought to determine whether killed P. acnes is capable of inducing an inflammatory response and therefore could be a contributing factor in acne. Direct heat treatment of P. acnes cultures with temperatures ranging from 50°C to 80°C reduced P. acnes viability. Both viable and heat‐killed P. acnes activated the p38 MAP kinase and its downstream substrate Hsp27. Stimulating keratinocytes with normal and heat‐inactivated P. acnes resulted in an induction of proinflammatory nitric oxide and IL‐8 production. Thus killed P. acnes is capable of inducing inflammation in skin suggesting that therapies that have both bactericidal and anti‐inflammatory effects may result in a more effective treatment of patients with acne than treatments that are bactericidal alone.

Anti-Inflammatory Activity of Parthenolide-Depleted Feverfew (Tanacetum parthenium)

Abstract.Extracts of Tanacetum parthenium (L.) Sch. Bip., a plant known under the common name “Feverfew”, contains the sesquiterpene lactone parthenolide, a potent skin sensitizer. To eliminate the risk of skin sensitization from Feverfew, we developed a parthenolide-depleted extract of Feverfew (PD-Feverfew) and determined its effectiveness as an anti-inflammatory agent. We confirmed that PD-Feverfew was sufficiently depleted of parthenolide since PD-Feverfew did not inhibit TNF-α induced-NF-κB activity unlike parthenolide containing whole Feverfew. PD-Feverfew directly inhibited the activity of pro-inflammatory enzymes 5-lipoxygenase, phosphodiesterase-3 and phosphodiesterase-4. PD-Feverfew inhibited the release of pro-inflammatory mediators nitric oxide, PGE2 and TNF-α from macrophages and TNF-α, IL-2, IFN-γ and IL-4 from human peripheral blood mononuclear cells. Additionally, PD-Feverfew inhibited TPA-induced release of PGE2 from human skin equivalents. In vivo, PD-Feverfew inhibited oxazolone-induced dermatitis, and was more potent than whole Feverfew in reducing TPA-induced dermatitis. Finally the efficacy of PD-Feverfew was confirmed clinically by a reduction in erythema in a methyl nicotinate-induced vasodilation model. In conclusion, our results indicate that PD-Feverfew extracts have potent anti-inflammatory activity suggesting that this botanical would be efficacious in relieving inflammation without inducing immune sensitization.

Galvanic zinc–copper microparticles produce electrical stimulation that reduces the inflammatory and immune responses in skin

The human body has its own innate electrical system that regulates the body’s functions via communications among organs through the well-known neural system. While the effect of low-level electrical stimulation on wound repair has been reported, few studies have examined the effect of electric potential on non-wounded, intact skin. A galvanic couple comprised of elemental zinc and copper was used to determine the effects of low-level electrical stimulation on intact skin physiology using a Dermacorder device. Zn–Cu induced the electrical potential recorded on intact skin, enhanced H2O2 production and activated p38 MAPK and Hsp27 in primary keratinocytes. Treatment with Zn–Cu was also found to reduce pro-inflammatory cytokines, such as IL-1α, IL-2, NO and TNF-α in multiple cell types after stimulation with PHA or Propionibacterium acnes bacteria. The Zn–Cu complex led to a dose-dependent inhibition of TNF-α-induced NF-κB levels in keratinocytes as measured by a dual-luciferase promoter assay, and prevented p65 translocation to the nucleus observed via immunofluorescence. Suppression of NF-κB activity via crosstalk with p38 MAPK might be one of the potential pathways by which Zn–Cu exerted its inflammatory effects. Topical application of Zn–Cu successfully mitigated TPA-induced dermatitis and oxazolone-induced hypersensitivity in mice models of ear edema. Anti-inflammatory activity induced by the Zn–Cu galvanic couple appears to be mediated, at least in part, by production of low level of hydrogen peroxide since this activity is reversed by the addition of Catalase enzyme. Collectively, these results show that a galvanic couple containing Zn–Cu strongly reduces the inflammatory and immune responses in intact skin, providing evidence for the role of electric stimulation in non-wounded skin.

p38 MAP Kinase Inhibition Reduces Propionibacterium acnes-Induced Inflammation in Vitro

IntroductionPropionibacterium acnes, a ubiquitous skin bacterium, stimulates keratinocytes to produce a number of proinflammatory cytokines and may contribute to inflammatory acne. The aim of the study was to investigate whether P. acnes-induced proinflammatory cytokine release is mediated by P. acnes-induced activation of p38 mitogen-activated protein kinase (p38 MAPK or p38) in human keratinocytes.MethodsImmunohistochemistry was used to evaluate p38 phosphorylation in human skin samples with or without acne. Primary human keratinocytes and epidermal skin equivalents were exposed to viable P. acnes. Phosphorylation of MAPKs without or with p38 inhibitors was examined by Western blot and cytokine secretion was detected by Enzyme-Linked Immunosorbent Assay (ELISA).ResultsIncreased levels of phospho-p38 were observed in human acne lesions, predominantly in follicular and perifollicular keratinocytes. Exposure of cultured human keratinocytes to viable P. acnes resulted in phosphorylation of multiple members of the MAPK family, including rapid and transient activation of p38 and extracellular signal-related kinase (ERK1/2) and relatively slow but sustained activation of c-Jun N-terminal kinases (JNK1/2). Viable P. acnes induced the secretion of interleukin-1α (IL-1α), tumor necrosis factor-α (TNF-α), and IL-8 from human keratinocytes. The phosphorylation of p38 (phospho-p38) and the secretion of cytokines induced by P. acnes in cultured keratinocytes were inhibited by SB203580, a p38α/β inhibitor. Furthermore, SCIO-469, a selective inhibitor of p38α, showed similar effects in cultured keratinocytes. Topical treatment of SCIO-469 inhibited the P. acnes-induced phospho-p38 and cytokine secretion in human epidermal equivalents.ConclusionThe data demonstrate that P. acnes induces p38-dependent inflammatory responses in keratinocytes, and suggest that p38 may play an important role in the pathogenesis of inflammatory acne.FundingJohnson & Johnson.