Mycobacterium vaccae Reduces Scratching Behavior but not the Rash in NC Mice with Eczema: A Randomized, Blinded, Placebo-Controlled Trial

The Effect of Gromwell (Lithospermum erythrorhizon) Extract on the Stratum Corneum Hydration and Ceramides Content in Atopic Dermatitis Patients

BACKGROUND

A disruption of the balance between the water content of the stratum corneum (SC) and skin surface lipids may lead to the clinical manifestation of dryness of skin in patients with atopic dermatitis (AD).

OBJECTIVE

To determine whether supplementation of gromwell (Lithospermum erythrorhizon), one of herbs used in East Asia in remedies for various abnormal skin conditions, may improve the SC level of hydration and ceramides, major lipid in SC in patients with AD.

METHODS

A total of 28 subjects with AD were randomly assigned into two groups: either gromwell group received dextrose contained capsules with 1.5 g of gromwell extracts or placebo group received only dextrose contained capsules for 10 weeks.

RESULTS

In contrast to no alteration of SC hydration and ceramides in placebo group, the SC hydration in gromwell group was significantly increased in parallel with an increase of SC ceramides. Furthermore, % increase of SC hydration in gromwell group bore a positive correlation with the clinical severity, which suggests that the increase of SC hydration in gromwell group was more effective as AD was more severe.

CONCLUSION

Supplementation of gromwell improves SC hydration in parallel with an increase of ceramides in part.

Dietary Pulverized Konjac Glucomannan Suppresses Scratching Behavior and Skin Inflammatory Immune Responses in NC/Nga Mice

BACKGROUND

Feeding with pulverized konjac glucomannan (PKGM) suppresses the development of eczema and hyper-IgE production in NC/Nga mice, a model of atopic dermatitis. This study aimed to examine the effects of PKGM on scratching behavior and skin inflammatory immune responses in NC/Nga mice.

METHODS

Four-week-old NC/Nga mice were maintained for 8 or 9 weeks on diet containing PKGM. Scratching behavior and clinical symptoms were evaluated every 2 weeks. Effects of PKGM on cutaneous inflammation were evaluated by histopathological analysis. Local expression levels of substance P and proinflammatory cytokines were measured by ELISA.

RESULTS

An increase in scratching behavior was evident from 6 weeks of age in control mice, but this symptom was dose-dependently inhibited in PKGM-fed mice. Continuous PKGM feeding then significantly inhibited eczematous skin lesions including hyperkeratosis, dermal mastocytosis and eosinophilia. Concomitantly, cutaneous overproductions of substance P, IL-10, IL-4, and TNF-alpha were all suppressed in PKGM-fed mice.

CONCLUSIONS

PKGM feeding markedly suppressed development of scratching behavior, substance P expression with mastocytosis, and skin inflammatory immune responses in NC/Nga mice.