In vitro compatibility of tazarotene with other topical treatments of psoriasis

Tazarotene is the first receptor-selective retinoid indicated for the topical treatment of plaque psoriasis. It is being used clinically in combination with other topical antipsoriatic treatments, although its stability in the presence of these products has not been examined extensively. This study examines the compatibility of tazarotene 0.05% gel with 17 other topical products used in the treatment of psoriasis, assessed over a 2-week period. Tazarotene showed minimal degradation (<10%) at 0, 8, 24, and 48 hours after compounding with each of the 17 products. In addition, after 1 and 2 weeks, degradation of tazarotene remained less than 10% for 15 of the 17 products tested. Tazarotene appeared to have minimal impact on the stability of the other products. These results suggest that tazarotene gel can be successfully coprescribed with a range of commonly used topical psoriasis treatments without adversely affecting the chemical stability of either agent.

Effects of administration of a single dose of a humanized monoclonal antibody to CD11a on the immunobiology and clinical activity of psoriasis

BACKGROUND

CD11a/CD18 comprise subunits of leukocyte function associated antigen (LFA-1), a T-cell surface molecule important in T-cell activation, T-cell emigration into skin, and cytotoxic T-cell function.

OBJECTIVE

We explored the immunobiologic and clinical effects of treating moderate to severe psoriasis vulgaris with a single dose of humanized monoclonal antibody against CD11a (hu1124).

METHODS

This was an open label study with a single dose of hu1124 at doses of 0.03 to 10 mg/kg. Clinical (Psoriasis Area and Severity Index [PASI]) and immunohistologic parameters (epidermal thickness, epidermal and dermal T-cell numbers, and keratinocyte intercellular adhesion molecule 1 [ICAM-1] expression) were followed.

RESULTS

Treatment with hu1124, at doses higher than 1.0 mg/kg (group III), completely blocks CD11a staining for at least 14 days in both blood and psoriatic plaques. At 0.3 to 1.0 mg/kg, T-cell CD11a staining was completely blocked; however, blockade lasted less than 2 weeks (group II). Only partial saturation of either blood or plaque cellular CD11a was observed at doses of hu1124 between 0.01 and 0.1 mg/kg (group I). This pharmacodynamic response was accompanied by decreased numbers of epidermal and dermal CD3(+) T cells, decreased keratinocyte and blood vessel expression of ICAM-1, and epidermal thinning. Statistically significant drops in PASI compared with baseline were observed in group II patients at weeks 3 and 4 and in group III patients at weeks 2 through 10. No significant drop in PASI score was observed in group 1. Adverse events were mild at doses of 0.3 mg/kg or less and included mild chills, abdominal discomfort, headache, and fever. At a single dose of 0.6 mg/kg or higher, headache was the most common dose-limiting toxicity observed.

CONCLUSION

Targeting CD11a may improve psoriasis by inhibiting T-cell activation, T-cell emigration into the skin, and cytotoxic T-cell function.

Advances in psoriasis therapy

New uses of older drugs, new combinations of treatments, and new phototherapeutic modalities are enabling clinicians to offer patients safer and more effective treatments. New vehicles for topical delivery of older treatments have created more cosmetically elegant preparations that are better accepted by patients. This article discusses new developments in topical therapy, phototherapy, oral therapy, and injectable therapy for psoriasis.

Elastin gene deletions in Williams syndrome patients result in altered deposition of elastic fibers in skin and a subclinical dermal phenotype

Williams syndrome (WS) is a complex developmental disorder with multisystem involvement known to be the result of a microdeletion in the q11.23 region of chromosome 7. This deletion involves several genes, including the elastin gene. Although elastic fibers are important constituents of skin, little is known about the skin phenotype in WS patients. We have therefore studied the skin of four WS patients in which we've shown the deletion of one copy of the elastin gene. Physical examination and indirect immunofluorescent microscopy of elastin did not detect any major phenotypic or morphologic changes in the skin. We were able, however, to show subtle textural changes in skin and, by electron microscopy, that the amorphous component of elastic fibers in WS patients was consistently reduced when compared to normal controls. These findings indicate that deletion of one copy of the elastin gene results in reduced deposition of elastin in dermal elastic fibers, an altered elastic fiber ultrastructure, and a subclinical dermal phenotype in the children and young adult patients analyzed in this study.

Interactions between tazarotene and ultraviolet light

Tazarotene in combination with phototherapy is being used clinically for the treatment of plaque psoriasis. This study investigates the dose of UVB light required to induce minimal erythema and the dose of UVA light required to induce immediate pigment darkening, with and without pretreatment with tazarotene 0.1% gel. The photostability of tazarotene is also assessed. Pretreatment with tazarotene 0.1% gel 3 times per week for 2 weeks before phototherapy significantly reduced the mean minimal erythema dose (MED) for UVB from 56.25 to 42.50 mJ/cm(2) (P <.01), and significantly reduced the mean UVA exposure required to induce immediate pigment darkening from 20.18 to 18.50 J/cm(2) (P <.05). A thin application of tazarotene gel immediately before phototherapy had no significant effect on the mean MED for UVB, whereas a thick application of the gel increased the MED slightly, from 56.25 to 62.50 mJ/cm(2) (P =.1). Tazarotene remained chemically stable when used in conjunction with UVB or UVA phototherapy. To reduce the patient's potential to burn or tan, we recommend initiating UVB phototherapy at 50% to 75% of the MED when it is used in combination with tazarotene. We also recommend initiating PUVA therapy at slightly lower doses than usual. Lower total doses of UVA or UVB may be needed when patients with psoriasis are treated concomitantly with tazarotene.

Scavenging of hydrogen peroxide and inhibition of ultraviolet light-induced oxidative DNA damage by aqueous extracts from green and black teas

Aqueous extracts of green and black teas have been shown to inhibit a variety of experimentally induced animal tumors, particularly ultraviolet (UV) B light-induced skin carcinogenesis. In the present study, we compared the effects of different extractable fractions of green and black teas on scavenging hydrogen peroxide (H2O2), and UV irradiation-induced formation of 8-hydroxy 2'-deoxyguanosine (8-OHdG) in vitro. Green and black teas have been extracted by serial chloroform, ethyl acetate and n-butanol, and divided into four subfractions designated as GT1-4 for green tea and BT1-4 for black tea, respectively. The total extracts from green and black teas exhibited a potent scavenging capacity of exogenous H2O2 in a dose-dependent manner. It appeared that the total extracts from black tea scavenged H2O2 more potently than those from green tea. When tested individually, the potency of scavenging H2O2 by green tea subfractions was: GT2 > GT3 > GT1 > GT4, whereas the order of efficacy for black tea was: BT2 > BT3 > BT4 > BT1. In addition, we demonstrated that total fractions of green and black teas substantially inhibited the induction of 8-OHdG in calf thymus by all three portions of UV spectrum (UVA, B and C). Consistent with the capacity of scavenging H2O2, the subfractions from black tea showed a greater inhibition of UV-induced 8-OHdG than those from green tea. At low concentrations, the order of potency of quenching of 8-OHdG by green tea subfractions was: GT2 > GT3 > GT4 > GT1 and the efficacy of all subfractions became similar at high concentrations. All subfractions of the black tea except BT1 strongly inhibited UV-induced 8-OHdG and the order of potency was: BT2 > BT3 > BT4 > BT1. Addition of (-)-epigallocatechin gallate (EGCG), an ingredient of green tea extract, to low concentration of green and black tea extracts substantially enhanced the scavenging of H2O2 and quenching of 8-OHdG, suggesting the important role of EGCG in the antioxidant activities of tea extracts. The potent scavenging of oxygen species and blocking of UV-induced oxidative DNA damage may, at least in part, explain the mechanism(s) by which green/black teas inhibit photocarcinogenesis.

Acitretin in combination with UVB or PUVA

Combination therapy of psoriasis with acitretin and phototherapy (psoralen-ultraviolet A [PUVA] or ultraviolet B [UVB]) offers multiple advantages over use of either modality alone. As monotherapy, acitretin in doses of 50 mg/day is moderately effective, but is associated with numerous side effects. Single modality treatment with UVB or PUVA involves multiple visits over a period of months and is also associated with dose-limiting side effects. When used in combination, lower doses of both modalities can be used more effectively, helping to reduce side effects. In addition, clearing occurs much more quickly, reducing treatment time and number of phototherapy visits. Moreover, patients whose psoriasis does not clear with monotherapy will often achieve significant clearing with the combination of acitretin and phototherapy.

Duration of remission of psoriasis therapies

The armamentarium of therapies for psoriasis continues to expand with drugs such as tazarotene, calcipotriene, and acitretin approved in recent years. New forms of old treatments such as cyclosporine and anthralin have also been introduced. Frequently, inadequate attention is devoted to duration of remission. The purpose of this article is to examine the duration of remission reported with many therapies currently used for psoriasis. Studies examining duration of remission are included. Among our conclusions were the following: the definitions of remission/relapse used in various studies differ, duration of remission is influenced by the natural history of each patient's disease, among topical monotherapies anthralin and tazarotene appear to induce longer remissions than calcipotriene and corticosteroids, among systemic agents longer remissions occur with etretinate than cyclosporine or methotrexate but compared with the remission rate of phototherapeutic modalities, especially Goeckerman and PUVA therapy, the remission rates are much less.

PUVA (8-methoxy-psoralen plus ultraviolet A) induces the formation of 8-hydroxy-2'-deoxyguanosine and DNA fragmentation in calf thymus DNA and human epidermoid carcinoma cells

The objective of this study is to investigate if 8-methoxy-psoralen (8-MOP) plus ultraviolet A (UVA) radiation (PUVA) induces oxidative DNA damage. When calf thymus DNA was incubated with 8-MOP and irradiated with UVA (335-400 nm), the level of 8-hydroxy-2'-deoxyguanosine (8-OHdG) was substantially increased by approximately 6-fold. Formation of 8-OHdG proportionally correlated with both UVA fluence and 8-MOP concentrations. Human epidermoid carcinoma cells were incubated with 10 microg 8-MOP per milliliter, followed by irradiation of 25 kJ/m2 UVA. The level of 8-OHdG increased by nearly 3-fold in PUVA-treated cells compared to 8-MOP and UVA controls. The formation of 8-OHdG correlated with DNA fragmentation as determined by spectrofluorometry. To investigate the reactive oxygen species (ROS) involved in PUVA-induced oxidative DNA damage, less or more specific ROS quenchers were added to DNA solution prior to PUVA treatment. The results showed that only sodium azide and genistein significantly quenched PUVA-induced 8-OHdG, whereas catalase, superoxide dismutase, and mannitol exhibited no effect. The quencher study with cultured cells indicated that N-acetyl-cysteine and genistein protected oxidative DNA damage as well as DNA fragmentation by PUVA treatment. Our studies show that PUVA treatment is able to induce the formation of 8-OHdG in purified DNA and cultured cells and suggest that singlet oxygen is the principle reactive oxygen species involved in oxidative DNA damage by PUVA treatment.

Finasteride in the treatment of men with frontal male pattern hair loss

BACKGROUND

Finasteride, a specific inhibitor of type II 5alpha-reductase, decreases serum and scalp dihydrotestosterone and has been shown to be effective in men with vertex male pattern hair loss.

OBJECTIVE

This study evaluated the efficacy of finasteride 1 mg/day in men with frontal (anterior/mid) scalp hair thinning.

METHODS

This was a 1-year, double-blind, placebo-controlled study followed by a 1-year open extension. Efficacy was assessed by hair counts (1 cm2 circular area), patient and investigator assessments, and global photographic review.

RESULTS

There was a significant increase in hair count in the frontal scalp of finasteride-treated patients (P < .001), as well as significant improvements in patient, investigator, and global photographic assessments. Efficacy was maintained or improved throughout the second year of the study. Finasteride was generally well tolerated.

CONCLUSION

In men with hair loss in the anterior/mid area of the scalp, finasteride 1 mg/day slowed hair loss and increased hair growth.

Scavenging of hydrogen peroxide and inhibition of ultraviolet light-induced oxidative DNA damage by aqueous extracts from green and black teas

Aqueous extracts of green and black teas have been shown to inhibit a variety of experimentally induced animal tumors, particularly ultraviolet (UV) B light-induced skin carcinogenesis. In the present study, we compared the effects of different extractable fractions of green and black teas on scavenging hydrogen peroxide (H2O2), and UV irradiation-induced formation of 8-hydroxy 2'-deoxyguanosine (8-OHdG) in vitro. Green and black teas have been extracted by serial chloroform, ethyl acetate and n-butanol, and divided into four subfractions designated as GT1-4 for green tea and BT1-4 for black tea, respectively. The total extracts from green and black teas exhibited a potent scavenging capacity of exogenous H2O2 in a dose-dependent manner. It appeared that the total extracts from black tea scavenged H2O2 more potently than those from green tea. When tested individually, the potency of scavenging H2O2 by green tea subfractions was: GT2 > GT3 > GT1 > GT4, whereas the order of efficacy for black tea was: BT2 > BT3 > BT4 > BT1. In addition, we demonstrated that total fractions of green and black teas substantially inhibited the induction of 8-OHdG in calf thymus by all three portions of UV spectrum (UVA, B and C). Consistent with the capacity of scavenging H2O2, the subfractions from black tea showed a greater inhibition of UV-induced 8-OHdG than those from green tea. At low concentrations, the order of potency of quenching of 8-OHdG by green tea subfractions was: GT2 > GT3 > GT4 > GT1 and the efficacy of all subfractions became similar at high concentrations. All subfractions of the black tea except BT1 strongly inhibited UV-induced 8-OHdG and the order of potency was: BT2 > BT3 > BT4 > BT1. Addition of (-)-epigallocatechin gallate (EGCG), an ingredient of green tea extract, to low concentration of green and black tea extracts substantially enhanced the scavenging of H2O2 and quenching of 8-OHdG, suggesting the important role of EGCG in the antioxidant activities of tea extracts. The potent scavenging of oxygen species and blocking of UV-induced oxidative DNA damage may, at least in part, explain the mechanism(s) by which green/black teas inhibit photocarcinogenesis.

Photoinduced dermal pigmentation in patients taking tricyclic antidepressants: histology, electron microscopy, and energy dispersive spectroscopy

Two patients had been taking long-term tricyclic antidepressant therapy. Each developed a blue to slate-gray hyperpigmentation in sun-exposed areas. On histologic examination there were refractile golden brown granules free in the dermis along collagen bundles. Similar pigment was present in macrophages and along the basement membrane zone. The granules stained for melanin, but not for iron, and were bleached by the permanganate method. Electron microscopy showed varying size and shaped electron-dense granules within lysosomes and free in the dermis, which, in unstained sections, showed a less dense peripheral halo. This peripheral halo was also evident on light microscopy. Energy dispersive spectroscopy showed these granules to be rich in copper and sulfur (elements present in tyrosinase and pheomelanin, respectively). We believe that this represents a drug-melanosome complex, which is most likely caused by chronic photoactivation.