Hirseins inhibit melanogenesis by regulating the gene expressions of Mitf and melanogenesis enzymes

Please cite this paper as: Hirseins inhibit melanogenesis by regulating the gene expressions of Mitf and melanogenesis enzymes. Experimental Dermatology 2009; 19: 450–457. Abstract: Previously, we reported that Thymelaea hirsuta extract has antimelanogenesis effect on B16 murine melanoma cells. The extract was subjected to fractionation, and hirsein A (HA) and hirsein B (HB) were discovered and tested for their ability to regulate melanogenesis in B16 cells. Western blot (WB) analysis was carried out to determine the expression of tyrosinase. Moreover, to elucidate the possible mechanism behind melanogenesis regulation, real‐time PCR using primers for Mitf, Tyr, Trp1 and Dct genes, and protein kinase C (PKC) activity assay were carried out. Results clearly show that 0.1 μm HA and HB significantly reduced the melanin content. This reduction in melanin content was accompanied by reduced tyrosinase expression as detected by WB analysis. There was also a significant decrease in the expression level of Mitf gene in HA‐ and HB‐treated cells. HA down‐regulated the expressions of Tyr, Trp1 and Dct, whereas HB down‐regulated only those of Trp1 and Dct. Interestingly, HB‐treated cells had lower kinase activity than HA‐treated cells indicating a possible difference in the activities of the compounds but with the same mechanism of melanogenesis regulation. We report for the first time that HA and HB can down‐regulate melanogenesis by down‐regulating Mitf gene expression, leading to reduced expressions of Tyr, Trp1 and Dct. The hirseins were also able to reduce the kinase activity, suggesting the possible involvement of PKC in the overall ability of the hirseins to down‐regulate melanogenesis.     

Infantile generalized pustular psoriasis: Successful disease control with intermittent etretinate

Infantile generalized pustular psoriasis is a rare form of psoriasis and the best treatment is controversial. We experienced a 2‐year‐old female with erythema on her neck and axilla starting at 3 months of age. She presented with recurrent annular and geographic scaly erythema with a few pustules on the neck, precordium and axilla, but no fever. The histopathology revealed subcorneal neutrophilic infiltration and microabscesses without Kogoj's spongiform pustules. The initial diagnosis was subcorneal pustular dermatosis. However, she developed widespread geographic erythema and numerous pustules over her entire body with a fever when she got a cold. A second skin biopsy revealed monolocular pustules and Kogoj's spongiform pustules in the subcorneal layer. Etretinate was administrated after a diagnosis of pustular psoriasis was made and her condition improved gradually. The choice of treatment depends on patient age, general condition and the disease severity.     

Successful treatment with 308‐nm monochromatic excimer light and subsequent tacrolimus 0.03% ointment in refractory plasma cell cheilitis

Plasma cell cheilitis is a chronic inflammatory disease that presents with erythema, erosions, ulcers and occasional nodules within the mucosa, including the lips. It is histopathologically characterized by dense plasma cell infiltration in the lamina propria of the mucous membranes. Several treatments for plasma cell cheilitis have been reported, including topical steroids, topical antibiotics or topical tacrolimus. However, 308‐nm monochromatic excimer light (MEL) has never been reported as a treatment option, while it was reported to be very effective in treating erosive oral lichen planus. We report a 62‐year‐old man who had chronic plasma cell cheilitis on the lower lip, which was refractory to topical and systemic corticosteroid. The lesion and severe pain were significantly improved by the treatment with nine sessions of 308‐nm MEL twice per week with a total dose of 1120 mJ/cm². However, the lesion gradually worsened after treatment frequency was reduced to once per month. Subsequent tacrolimus 0.03% ointment cleared the lesion completely in a month and no recurrence was observed a year later. Refractory plasma cell cheilitis and concomitant severe pain quickly responded to 308‐nm MEL when administrated twice per week. Because the long interval between each MEL treatment seemed ineffective to improve the lesion, appropriate frequency and adequate total dose of MEL treatment may be necessary for a successful treatment.     

Comparison between famciclovir and valacyclovir for acute pain in adult Japanese immunocompetent patients with herpes zoster

Famciclovir is a guanine analog antiviral drug used commonly for herpes zoster. Efficacy of famciclovir treatment has been reported to be comparable to valacyclovir treatment. Both of these medications reduce the time to complete cessation of zoster‐associated pain including post‐herpetic neuralgia, as compared to acyclovir. We conducted a multicenter, randomized, open clinical trial in order to evaluate the extent of pain relief afforded by these two antiviral drugs during the acute disease phase of herpes zoster. The study group comprised 86 immunocompetent adult patients suffering from herpes zoster, who were treated with either famciclovir or valacyclovir for 7 days. Of these, 55 patients enrolled in this study within 72 h of the onset of the rash and 31 patients after 72 h of the onset. There was a significant reduction in acute herpes zoster pain with famciclovir on day 7 and at 2–3 weeks in both of these patient groups, while with valacyclovir, there was not significant reduction in pain on day 7. Of patients aged 50 years or older, there was a significantly earlier reduction in pain with famciclovir than with valacyclovir. In addition, a significant reduction in the number of patients with pain was observed as early as days 3–4 with famciclovir treatment as compared with valacyclovir treatment. We conclude that famciclovir was superior to valacyclovir in the relief of acute pain of herpes zoster. Accordingly, famciclovir is recommended for herpes zoster patients with moderate symptoms and a visual analog scale score of under 50 mm.     

Two Japanese cases of dermatitis herpetiformis associated each with lung cancer and autoimmune pancreatitis but showing no intestinal symptom or circulating immunoglobulin A antibodies to any known antigens

Dermatitis herpetiformis (DH) is common in some Caucasian populations but extremely rare in Japanese, probably because of different immunogenetic backgrounds. We report two Japanese DH cases with typical clinical, histological and direct immunofluorescence features. However, no symptom of gluten‐sensitive enteropathy was shown. The diagnosis was confirmed by eliminating other autoimmune blistering diseases by indirect immunofluorescence, enzyme‐linked immunosorbent assays and immunoblotting. However, circulating immunoglobulin (Ig)A anti‐endomysium, reticulin and gliadin antibodies were not detected. IgA antibodies to tissue and epidermal transglutaminases were also negative. One case was associated with lung cancer and the other one with autoimmune pancreatitis. On review of 17 cases of DH reported in Japan over the previous 10 years, including our cases, one case was associated with gluten‐sensitive enteropathy, four with malignant neoplasms, two with autoimmune systemic disorders and one with psoriasis. Although our cases were typical of DH in clinical, histopathological and IgA deposit features, they showed different human leukocyte antigen haplotypes, no gluten‐sensitive enteropathy and no DH‐specific IgA antibodies, including those to epidermal and tissue transglutaminases. These results suggest that studies of unique characteristics in Japanese DH patients should facilitate further understanding of pathogenesis in DH.     

Case of toxic epidermal necrolysis occurring after bone marrow transplantation accompanied by engraftment failure

Toxic epidermal necrolysis (TEN) is a rare condition, causing life‐threatening adverse cutaneous reactions. TEN occurrence after bone marrow transplantation (BMT) is a well‐known phenomenon; however, to date, only a few cases have been reported in the published work. Here, we describe the case of a 53‐year‐old woman who experienced TEN after undergoing allogenic BMT for malignant lymphoma. Skin erosion spread across a maximum of 70% of the body surface area and severe mucosal lesions developed. Steroid pulse therapy, plasma apheresis and immunoglobulin therapy were administrated, which resulted in the complete resolution of TEN. However, she developed hemophagocytic lymphohistiocytosis and died 38 days after BMT, owing to rupture of the lower digestive tract complicated by multi‐organ failure. In our case, engraftment failure occurred, and the peripheral white blood cell count was less than 100/μL during the TEN course, suggesting that the presence of only a few immune cells could cause TEN. Our findings showed that high mortality rates and widespread skin erosion could be regarded as the most important characteristics of TEN occurring after BMT.