Haruko Mizoguchi

Epidermal changes associated with symptomatic resolution of dandruff: biomarkers of scalp health

Background  Dandruff is a common scalp condition characterized by flakes, pruritus and sometimes mild erythema. These symptoms reflect underlying histopathologic and biochemical events that must be reversed if treatment is to be effective.

The effects of a daily facial lotion containing vitamins B3 and E and provitamin B5 on the facial skin of Indian women: A randomized, double-blind trial

BACKGROUND The B vitamins niacinamide and panthenol have been shown to reduce many signs of skin aging, including hyperpigmentation and redness. AIMS To measure the facial skin effects in Indian women of the daily use of a lotion containing niacinamide, panthenol, and tocopherol acetate using quantitative image analysis. METHODS Adult women 30-60 years of age with epidermal hyperpigmentation were recruited in Mumbai and randomly assigned to apply a test or control lotion to the face daily for 10 weeks. Effects on skin tone were measured using an image capturing system and associated software. Skin texture was assessed by expert graders. Barrier function was evaluated by transepithelial water loss measurements. Subjects and evaluators were blinded to the product assignment. RESULTS Of 246 women randomized to treatment, 207 (84%) completed the study. Women who used the test lotion experienced significantly reduced appearance of hyperpigmentation, improved skin tone evenness, appearance of lightening of skin, and positive effects on skin texture. Improvements versus control were seen as early as 6 weeks. The test lotion was well tolerated. The most common adverse event was a transient, mild burning sensation. CONCLUSIONS Daily use of a facial lotion containing niacinamide, panthenol, and tocopheryl acetate improved skin tone and texture and was well tolerated in Indian women with facial signs of aging.

Inhibition of Rhinovirus Replication In Vitro and In Vivo by Acid-Buffered Saline

Abstract Human rhinoviruses (HRVs) are quite sensitive to low pH. To determine whether this characteristic might be a therapeutic target, we evaluated the sensitivity of HRV to low-pH buffers in vitro and in vivo. Our findings confirm that low pH inhibited replication of most HRVs and reduced the replication of influenza virus. Preliminary experiments verified that the surface pH of the human nasopharynx could be transiently lowered to pH ∼4.0 by topical administration of citrate/phosphate (CP) buffers, which was well tolerated. In a pilot experimental colds study, intranasal administration of CP buffer, compared with normal saline, reduced viral shedding by 1 log unit (103 vs. 104 50%tissue culture infective dose/mL; P < .01), although respiratory symptoms were not significantly reduced. These findings demonstrate that low-pH buffers have antiviral activity in vivo and suggest that a larger clinical trial is warranted to determine whether this approach could reduce rates of viral transmission.

Effects of Neurokinins on Ion Transport and Sulfated Macromolecule Release in the Isolated Ferret Trachea

The secretory actions of substance P (SP) were studied by examining its effects on ion transport and sulfated macromolecule release in the isolated ferret trachea. Responses to serosally administered SP were unmasked by thiorphan, suggesting that SP administered by this route was degraded by neutral endopeptidase. Therefore, the serosal actions of neurokinins and neurokinin analogues were studied in tissues pretreated with thiorphan. In thiorphan-treated tissues, SP dose-dependently increased the short-circuit current (Isc) with a maximum increase of 0.50 +/- 0.07 mueq/cm2.h above baseline. The SP-induced increase in Isc was inhibited by bumetanide but not by amiloride, suggesting the involvement of electrogenic Cl- secretion. The direct measurement of ion fluxes, however, failed to detect a significant unilateral movement of Cl- from the serosa to mucosa, probably due to a relatively small and transient increase in Isc produced by SP. Instead, SP (10(-6) M) induced large, electroneutral secretion of Na+ and Cl-. In addition, SP stimulated sulfated macromolecule output. The rank order of potency in increasing both Isc and sulfated macromolecule release among neurokinins and their analogues was SP = SP-methyl ester greater than neurokinin A greater than neurokinin B greater than senktide. These findings indicate that the secretory responses to SP are probably mediated by NK-1 receptors.

Therapeutic efficacy of anti‐dandruff shampoos: A randomized clinical trial comparing products based on potentiated zinc pyrithione and zinc pyrithione/climbazole

Dandruff is a chronic, relapsing scalp condition that negatively impacts the quality of life of sufferers. Regular use of anti‐fungal shampoos represents a proven therapeutic strategy to improve the most common symptoms of flakes and itch. Two recent approaches for enhancing the efficacy of anti‐fungal shampoos are maximizing bio‐availability of the active material or the addition of a second active material. Our aim is to compare the therapeutic efficacy of these two approaches – maximization of bio‐availability of the zinc pyrithione (ZPT) active material or the combination of ZPT with a secondary active material.

Assessing therapeutic effectiveness of scalp treatments for dandruff and seborrheic dermatitis, part 1: a reliable and relevant method based on the adherent scalp flaking score (ASFS)

Background: Dandruff and seborrheic dermatitis (D/SD) are common and troublesome scalp conditions with the primary signs and symptoms being presence of skin flakes, pruritus, a tight feeling, and sometimes erythema. Aim: To demonstrate the reliability and relevance of a clinical model for the assessment of therapeutic efficacy of a treatment using the Adherent Scalp Flaking Score (ASFS) method to quantitate the flaking severity. Methods: Six randomized, double-blind, parallel design studies were conducted in either North America or Asia with subjects suffering from dandruff using the ASFS grading method before and after a 3-week test product treatment period. Results: Treatment with a commercial potentiated 1% zinc pyrithione (ZPT) shampoo resulted in statistically significant (p < 0.0001) improvements in total ASFS compared with the placebo cosmetic shampoo. Results were consistent across all studies, geographies, and product usage protocols (controlled on-site versus home use conditions), and were associated with statistically significant improvements in self-perception of scalp condition. Conclusion: The ASFS-based clinical model was demonstrated to be a reliable and proven methodology to assess the effectiveness of widely used anti-dandruff treatments. The results are consistent with patient self-assessments, establishing this methodology as relevant to patient perception of product benefits.

The role of oxidative damage in poor scalp health: ramifications to causality and associated hair growth

The oxidative stress element of unhealthy scalp leads to compromised pre‐emergent hair formation and poorly formed hair as it grows. Only cosmetic solutions can minimize the impact of unhealthy hair and to achieve healthy looking and feeling hair, the scalp health must be normalized first. The objectives of this research were to both investigate whether oxidative stress was a relevant aetiological element in scalp dandruff and seborrhoeic dermatitis and whether scalp condition affects the quality of hair that grows from it. Further, this research was designed to determine whether an effective anti‐dandruff shampoo would repair and protect the scalp and pre‐emergent hair from oxidative stress. This study demonstrated that oxidative stress is an aetiological element relevant to the dandruff condition and that a potentiated ZPT shampoo effectively improves scalp condition, including a reduction in oxidative stress. The compromised hair condition associated with dandruff is concomitantly improved when the scalp condition is improved. It appears that there is a direct link between hair quality and scalp health.

Assessing therapeutic effectiveness of scalp treatments for dandruff and seborrheic dermatitis, part 2: the impact of gender and ethnicity on efficacy

Background: Dandruff and seborrheic dermatitis (D/SD) are common and troublesome scalp conditions that affect individuals independent of gender or ethnicity. Aim: To evaluate whether population gender or ethnic origins impact the magnitude of anti-dandruff therapeutic benefit obtained from use of a potentiated zinc pyrithione shampoo treatment. Methods: A retrospective evaluation of anti-dandruff clinical data covering a single-product technology was conducted to assess whether statistically meaningful differences were observed for gender or ethnic sub-populations. An analysis of covariance was performed on the pooled subject-level data. Results: Meta-analysis of clinical data involving 1114 subjects from seven trials demonstrated the lack of statistically significant impact of gender on flaking or selected biomarker measures. Similarly, a smaller population chosen to assess ethnicity demonstrated the lack of differences between Asian and Caucasian clinical sub-population responses (flaking severity). Conclusion: Through the use of both expert symptom grading and objective biomarker assessments, therapeutic efficacy of a potentiated zinc pyrithione shampoo was found to be independent of gender and ethnicity, being consistent with the lack of functional differences in skin from these populations.