Protective effect of hochuekkito, a Kampo prescription, against ultraviolet B irradiation‐induced skin damage in hairless mice

Abstract

A Kampo prescriptions, hochuekkito (HET) has been utilized for treating functional conditions such as general fatigue, compromised state and gastrointestinal motility disorder. Recently, HET has attracted the attention of dermatologists because of its clinically positive effects in atopic dermatitis (AD) treatment. To explain this positive effect of HET, we examined its protective ability against oxidative skin stress using a murine model. The dorsal region of 8-week-old male HR-1 hairless mice, which were raised on a HET (0%, 2% and 10%) mixed diet, was irradiated once with 70 mJ/cm(2) of ultraviolet (UV)-B light. After 4 days, transepidermal water loss (TEWL) and stratum corneum water content (SCWC), were determined as a measure of degree of skin dysfunction. To estimate the amount of active oxygen generated, the stratum corneum catalase activity (SCCA) and stratum corneum carbonylated protein (SCCP) content in the tape-stripped stratum corneum samples were measured. We also measured the H(2) O(2) scavenging ability of HET, and analyzed the changes in the expression levels of several inflammation and oxidative stress-related genes in the skin of HET-fed mice. In control mice, exposure to UV-B led to significant increases in TEWL and SCCP and significant decreases in SCWC and SCCA. These UV-B-induced changes were reduced in mice administrated HET, and the reduction was HET dose-dependent. Our results suggested that HET offered a protective effect against UV-B-induced skin damage. We also found that HET had relatively low ability to scavenge H(2) O(2) , and expression level of cyclooxygenase-2 mRNA decreased in HET-fed mouse.

Is Lack of Sleep Capable of Inducing DNA Damage in Aged Skin?

“…However, the consequences of sleep loss, acute or chronic, in the elderly and on skin integrity remain unknown in animal models. Thus, the purpose of this study was to verify whether the lack of sleep can induce DNA damage in the skin of female hairless mice, which is a strain often used for studies related to the skin [21,22,23], at an advanced age.…”

A Topical Mitochondria-Targeted Redox-Cycling Nitroxide Mitigates Oxidative Stress-Induced Skin Damage

“…4c,g). Further, while irradiation resulted in substantial oxidative stress induced protein carbonylation (Azzam et al, 2012; Doctrow et al, 2013; Yanagihara et al, 2013) in untreated and formulation treated skin, JP4-039 protected proteins in the skin from oxidative damage as evidenced by the absence of carbonylated proteins which remained at negligible un-irradiated baseline levels (Fig. 4h).…”

Ameliorative Effect of Hochu-ekki-to on Natural Skin Aging

“…Generally, hochu-ekki-to has an effect of ameliorating functions of the stomach and intestines by recovering physical strength [19]. In the past, hochu-ekki-to has been reported to improve atopic dermatitis [11,13], and it has also been reported to improve skin inflammation caused by ultraviolet rays [20]. As a results, hochu-ekki-to is expected to have a good effect on the skin, and we used hochu-ekki-to in our experiment for natural aging skin at this time.…”