Tokishakuyakusan alleviates ultraviolet-induced skin pigmentation by decreasing the expression of melanogenesis-related enzymes.

ETHNOPHARMACOLOGICAL RELEVANCE: Tokishakuyakusan (TSS), a traditional Kampo medicine, can effectively alleviate symptoms unique to women, such as menstrual pain and menopausal symptoms, and this effect is believed to be related to its ability to increase the secretion of female hormones. TSS is also believed to be effective against skin pigmentation. However, no studies have examined the effect of TSS on pigmentation. AIM OF THE STUDY: In this study, we conducted basic research to determine the effects of TSS on pigmentation. MATERIALS AND METHODS: Female HRM-2 mice were given free access to a normal diet or a TSS-containing diet for 7 weeks. For 3 weeks starting from the 4th week of treatment, the back of the skin was irradiated with ultraviolet (UV) light, and the melanin level was measured. The expression levels of melanogenesis-related genes and inflammatory markers in the skin were analyzed. RESULTS: The melanin level in the skin of the mice exposed to UV radiation was approximately three times greater than that in the skin of the mice in the non-UV-irradiated group, confirming pigmentation due to UV irradiation. The protein expression levels of tyrosinase (Tyr), tyrosinase-related protein-1 (Tyrp1), and dopachrome tautomerase (Dct), which are important for melanin production, were significantly greater in the UV irradiation group than in the non-UV irradiation group. In contrast, the amount of skin melanin in the mice treated with TSS was significantly lower than that in the UV-irradiated group, and the expression levels of melanogenesis-related enzymes were also lower. Furthermore, TSS significantly decreased the expression of microphthalmia transcription factor (Mitf), a transcription factor for melanogenesis-related enzymes, and the inflammatory cytokines interleukin-1ß and interleukin-6. CONCLUSIONS: TSS inhibits melanin production in melanocytes by suppressing the increase in the expression of melanogenesis-related enzymes caused by UV irradiation. These findings suggested that this effect of TSS is exerted through the combined regulation of MITF expression and anti-inflammatory responses.

Effect of the gut microbiota on the expression of genes that are important for maintaining skin function: Analysis using aged mice.

The gut microbiota changes greatly at the onset of disease, and the importance of intestinal bacteria has been highlighted. The gut microbiota also changes greatly with aging. Aging causes skin dryness, but it is not known how changes in the gut microbiota with aging affects the expression of genes that are important for maintaining skin function. In this study, we investigated how age-related changes in gut microbiota affect the expression of genes that regulate skin function. The gut microbiotas from young mice and aged mice were transplanted into germ-free mice (fecal microbiota transplantation [FMT]). These recipient mice were designated FMT-young mice and FMT-old mice respectively, and the expression levels of genes important for maintaining skin function were analyzed. The dermal water content was significantly lower in old mice than that in young mice, indicating dry skin. The gut microbiota significantly differed between old mice and young mice. The water channel aquaporin-3 (Aqp3) expression level in the skin of FMT-old mice was significantly higher than that in FMT-young mice. In addition, among the genes that play an important role in maintaining skin function, the expression levels of those encoding ceramide-degrading enzyme, ceramide synthase, hyaluronic acid-degrading enzyme, and Type I collagen were also significantly higher in FMT-old mice than in FMT-young mice. It was revealed that the gut microbiota, which changes with age, regulates the expression levels of genes related to skin function, including AQP3.

Expression analysis of genes important for maintaining skin function in a senescence-accelerated mouse prone model.

AIM: Senescence-accelerated mouse prone (SAMP) mice can reproduce the same conditions as normal aging mice in a short period. Although SAMP mice have been widely used in aging research, research on skin function in SAMP mice is lacking. In this study, to investigate the skin function of SAMP mice, we analyzed the expression of genes important for maintaining skin function. METHODS: Eight-month-old SAMP mice and senescence-accelerated mouse resistant (SAMR) mice with normal aging were used. The expression levels of various functional genes in the skin were analyzed. RESULTS: The dermal water content of SAMP mice was significantly lower than that of SAMR mice, indicating dry skin. The mRNA expression levels of elastin (Ela), filaggrin (Flg), loricrin (Lor), collagen type I alpha 1 chain (Col1a1) and Col1a2 in the skin of SAMP mice were all significantly decreased compared with those of SAMR mice. Hyaluronan-degrading enzyme (Hyal1) expression levels in SAMP mice were similar to those in SAMR mice, but hyaluronan synthase (Has2) levels were significantly decreased. In addition, the expression level of aquaporin-3 in the skin of SAMP mice was significantly decreased at both the mRNA and protein levels. CONCLUSIONS: In the skin of SAMP mice, the expression levels of various skin function-regulating genes were decreased, and this phenomenon might cause skin dryness. The SAMP mouse could be a tool for analyzing skin aging. Geriatr Gerontol Int 2023; 23: 951-957.

Platinum-based anticancer drugs-induced downregulation of myosin heavy chain isoforms in skeletal muscle of mouse.

Cisplatin, a platinum-based anticancer drug used frequently in cancer treatment, causes skeletal muscle atrophy. It was predicted that the proteolytic pathway is enhanced as the mechanism of this atrophy. Therefore, we investigated whether a platinum-based anticancer drug affects the expression of the major proteins of skeletal muscle, myosin heavy chain (MyHC). Mice were injected with cisplatin or oxaliplatin for four consecutive days. C2C12 myotubes were treated using cisplatin and oxaliplatin. Administration of platinum-based anticancer drug reduced quadriceps mass and muscle strength compared to the control group. Protein levels of all MyHC isoforms were reduced in the platinum-based anticancer drug groups. However, only Myh2 (MyHC-IIa) gene expression in skeletal muscle of mice treated with platinum-based anticancer drugs was found to be reduced. Treatment of C2C12 myotubes with platinum-based anticancer drugs reduced the protein levels of all MyHCs, and treatment with the proteasome inhibitor MG-132 restored this reduction. The expression of Mef2c, which was predicted to act upstream of Myh2, was reduced in the skeletal muscle of mice treated systemically with platinum-based anticancer drug. Degradation of skeletal muscle MyHCs by proteasomes may be a factor that plays an important role in muscle mass loss in platinum-based anticancer drug-induced muscle atrophy.

Green tea extract prevents CPT-11-induced diarrhea by regulating the gut microbiota.

Irinotecan (CPT-11) is an anticancer drug with indications for use in treating various cancers, but severe diarrhea develops as a side effect. We investigated the effects of green tea extract (GTE) on CPT-11-induced diarrhea, focusing on ß-glucuronidase and intestinal UGT1A1. When CPT-11 was administered to rats alone, the fecal water content was approximately 3.5-fold higher in this group than in the control group, and diarrhea developed. The fecal water content in the GTE-treated group was significantly higher than that in the control group, but the difference was smaller than that between the group treated with CPT-11 alone and the control group, and diarrhea improved. When CPT-11 was administered alone, the abundances of Bacteroides fragilis and Escherichia coli, which are ß-glucuronidase-producing bacteria, increased and interleukin-6 and interleukin-1ß mRNA levels in the colon increased, but GTE suppressed these increases. CPT-11 decreased colon UGT1A1 and short-chain fatty acid levels; however, this decrease was suppressed in the GTE-treated group. The findings that GTE decreases the abundance of ß-glucuronidase-producing bacteria and increases colon UGT1A1 levels, thereby decreasing the production of the active metabolite SN-38 in the intestinal tract, indicate that GTE ameliorates CPT-11-induced diarrhea.

Effectiveness of Displaying Traffic Light Food Labels on the Front of Food Packages in Japanese University Students: A Randomized Controlled Trial.

Nutrition labeling on the front of food packages has been implemented worldwide to help improve public health awareness. In this randomized double-blind controlled trial, we used a Google Forms questionnaire to evaluate the effectiveness of nutrition labeling on food packages in university students. The questionnaire, ultimately completed by 247 students, included 15 dietary images from which they were asked to choose what they wanted to eat for breakfast, lunch, and dinner the following day. For the interventional (traffic light food [TLF]) group only, TLF labels were displayed on dietary images. This group had a significantly higher proportion of people conscious of healthy eating during all meals than the control group, and the effect of TLF labeling on choosing meals was the highest for lunch. In addition to the indicated nutritional components, the TLF group had a significantly higher proportion of people who were conscious of the ones of protein and dietary fiber that were not indicated on the label. The use of TLF labels resulted in an increase in the proportion of people choosing a healthy diet as well as being conscious of their nutritional components. Therefore, the use of TLF labels may help promote healthy dietary choices in Japan.

Effect of partially hydrolyzed guar gum on the expression of aquaporin-3 in the colon.

In recent years, the development of functional foods targeting gastrointestinal disorders has been in progress. Partially hydrolyzed guar gum (PHGG), which is a water-soluble dietary fiber, is known to have a constipation-improving effect. However, many aspects of the mechanism remain unclear. In this study, we investigated the role of aquaporin-3 (AQP3), which regulates the water content of feces in ameliorative effect of PHGG on constipation. Rats were allowed to freely consume a normal diet or a diet containing 5% PHGG for 14 days, and defecation parameters were measured. We also analyzed the expression levels of genes involved in water transport in the colon. The defecation frequency and volume of rats treated with PHGG were not different from those from the control group, but the fecal water content was significantly increased, and soft stools were observed. The expressions of claudin-1, tight junction protein-1, and cadherin-1, which are involved in tight junctions or adherens junctions, were almost the same in the PHGG-treated group and the control group. The expression level of AQP3 in the colon was significantly decreased in the PHGG-treated group. In this study, PHGG decreased the colonic AQP3 expression, thereby suppressing water transport from the luminal side to the vascular side and improving constipation.

Downregulation of Sparc-like protein 1 during cisplatin-induced inhibition of myogenic differentiation of C2C12 myoblasts.

Patients with cancer often experience muscle atrophy, which worsens their prognosis. Decreased muscle regenerative capacity plays an important role in the complex processes involved in muscle atrophy. Administration of cisplatin, a cancer chemotherapeutic agent, has been implicated as a cause of muscle atrophy. In this study, we examined whether cisplatin affects the differentiation of myoblasts into myotubes. We treated C2C12 myoblasts with a differentiation medium containing cisplatin and its vehicle during for 8 days and observed the changes in the expression of myosin heavy chain (MyHC) and myogenin in the myoblasts. Cisplatin was injected in mice for 4 consecutive days; on Day 5, the mice quadriceps muscles were sampled and examined. The expression of MyHCs increased and that of myogenin decreased after cisplatin treatment. The secretion of acidic cysteine-rich proteins (e.g., Sparc proteins) reportedly promotes C2C12 myoblast differentiation. Therefore, we investigated the Sparc family gene expression during myogenesis in C2C12 myoblasts after cisplatin treatment. Of all the genes investigated, Sparc-like protein 1 (Sparcl1) expression was significantly suppressed by cisplatin on Days 4-8. Simultaneous treatment with recombinant mouse Sparcl1 almost inhibited the cisplatin-induced suppression of total MyHC and myogenin protein levels. Moreover, Sparcl1 expression decreased in the skeletal muscles of mice, leading to cisplatin-induced muscle atrophy. Our results suggest that cisplatin-induced myogenesis suppression causes muscle atrophy and inhibits the expression of Sparcl1, which promotes C2C12 cell differentiation during myogenesis.

Effect of Chimpi, dried citrus peel, on aquaporin-3 expression in HaCaT human epidermal keratinocytes.

BACKGROUND: Chimpi, the dried peel of Citrus unshiu or Citrus reticulata, has various pharmacological effects. Chimpi extract was recently shown to affect the skin, including its inhibitory effect against atopic dermatitis. In this study, we analyzed the effects of Chimpi extract on the functional molecule aquaporin-3 (AQP3), which is involved in water transport and cell migration in the skin. METHODS AND RESULTS: Chimpi extract was added to HaCaT human skin keratinocytes, and the AQP3 expression level was analyzed. A wound healing assay was performed to evaluate the effect of Chimpi extract on cell migration. The components of Chimpi extract and fractions obtained by liquid-liquid distribution studies were added to HaCaT cells, and AQP3 expression was analyzed. Chimpi extract significantly increased AQP3 expression in HaCaT cells at both the mRNA and protein levels. Immunocytochemical staining revealed that Chimpi extract also promoted the transfer of AQP3 to the cell membrane. Furthermore, Chimpi extract enhanced cell migration. Hesperidin, narirutin, and nobiletin did not increase AQP3 levels. Although the components contained in the fractions obtained from the chloroform, butanol, and water layer increased AQP3, the active components could not be identified. CONCLUSIONS: These results reveal that Chimpi extract may increase AQP3 levels in keratinocytes and increase the dermal water content. Therefore, Chimpi extract may be effective for the management of dry skin.

Inhibition of Spred/Sprouty Expression in the Skin of a Contact Dermatitis-Like Model.

We have previously reported that swellings caused by haptens, such as 2,4,6-trinitrochlorobenzene (TNCB), may be associated with the extracellular signal-regulated kinase (ERK)-induced proliferation pathway. However, the involvement of the Spred/Sprouty family as critical negative regulators of the Ras/Raf/ERK signaling pathway at disease sites is not well-established. Thus, in the present study, the effects of hapten-challenge on the expression levels of genes and proteins associated with the Spred/Sprouty family in the ear of mice were investigated. The activation of ERK and epidermal growth factor receptor (EGFR) tyrosine kinase was inhibited by their selective inhibitors, namely, U0126 and PD168393, respectively. Twenty-four hours after the final challenge by the haptens TNCB, 2,4-dinitrofluorobenzene, or oxazolone, ear thickness was augmented by challenge with all haptens and the gene expression levels of Spred1, Spred2, Sprouty1, and Sprouty2 in swelling induced by all haptens were significantly decreased. Furthermore, Spred2, Sprouty1, and Sprouty2 genes were decreased in the epidermis and dermis of the TNCB-challenged ear. In conclusion, it is possible that the mechanism of hapten-challenge-induced skin thickening involves not only the enhancement of cell proliferative functions via the activation of ERK by EGFR tyrosine kinase activation but also the decreases expression of Spred/Sprouty family members.

Survey of Pharmacists' Knowledge, Attitudes, and Practices (KAP) concerning COVID-19 Infection Control after Being Involved in Vaccine Preparation: A Cross-Sectional Study.

Vaccination is crucial for preventing the spread of COVID-19. Vaccination for COVID-19 was implemented in Japan in community units, and community pharmacists were engaged in vaccine preparation. Capturing the knowledge, attitudes, and practices (KAP) of pharmacists regarding COVID-19 infection control is important for developing future community health action strategies and plans. We conducted a cross-sectional study among 141 pharmacists who were members of a pharmacist association in the Shinagawa Ward of Tokyo (1-31 July 2021) using a Google online questionnaire. The questionnaire included demographic information and KAP questions regarding COVID-19. A correlation test was used for analyzing KAP scores. Significant correlations were found among all KAP scores. Stepwise logistic regression analysis showed "age" as a significant knowledge factor and "marriage", "pharmacist careers", "information source: official government website", and "information source: word of mouth from family and friends" as significant attitude factors. Good KAP scores were recorded in this study, indicating increased comprehension of infection control measures and increased knowledge scores, as pharmacy pharmacists were practically involved in COVID-19 infection control measures through vaccine preparation. Policymakers should understand the value of pharmacists as healthcare professionals and should enhance public health through the effective use of pharmacists.

Increased 20S Proteasome Expression and the Effect of Bortezomib during Cisplatin-Induced Muscle Atrophy.

Cisplatin is a chemotherapy drug used to treat a variety of cancers. Muscle loss in cancer patients is associated with increased cancer-related mortality. Previously, we suggested that cisplatin administration increases the atrophic gene expressions of ubiquitin E3 ligases, such as atrogin-1 and muscle RING finger-1 (MuRF1), which may lead to muscle atrophy. In this study, C57BL/6J mice were treated with cisplatin (3 mg/kg, intraperitoneally) or saline for 4 consecutive days. Twenty-four hours after the final injection of cisplatin, quadriceps muscles were removed from the mice. The gene expression of Psma and Psmb, which comprise the 20S proteasome, was upregulated by cisplatin administration in the quadriceps muscle of mouse. Systemic administration of cisplatin significantly reduced not only the quadriceps muscle mass but also the diameter of the myofibers. In addition, bortezomib (0.125 mg/kg, intraperitoneally) was administered 30 min before each cisplatin treatment. The co-administration of bortezomib, a proteasome inhibitor, significantly recovered the reductions in the mass of quadriceps and myofiber diameter, although it did not recover the decline in the forelimb and forepaw strength induced by cisplatin. Increased 20S proteasome abundance may play a significant role in the development of cisplatin-induced muscle atrophy. During cisplatin-induced skeletal muscle atrophy, different mechanisms may be involved between loss of muscle mass and strength. In addition, it is suggested that bortezomib has essentially no effect on cisplatin-induced muscle atrophy.

Eicosapentaenoic acid suppresses cisplatin-induced muscle atrophy by attenuating the up-regulated gene expression of ubiquitin.

Previously it was shown that cisplatin causes muscle atrophy. Under this condition, cisplatin increased the expression of atorogenes, such as muscle ring finger 1 and atrogin-1 (also known as muscle atrophy F-box protein), in mouse skeletal muscle. It was reported recently that ubiquitin (Ub) and ubiquitinated protein levels in skeletal muscle were also up-regulated in cisplatin-induced muscle atrophy, and cisplatin-induced ubiquitinated proteins were degraded by the 26S proteasome pathway. Eicosapentaenoic acid (EPA) is effective against skeletal muscle atrophy in mice. However, it is unclear how EPA suppresses the Ub-proteasome pathway. In this study, the effect of EPA on cisplatin-induced muscle atrophy in mice was examined. Mice were intraperitoneally injected with cisplatin or vehicle control once daily for 4 d. EPA or its vehicle was orally administered 30 min before cisplatin administration. Cisplatin systemic administration induced decrease in muscle mass, myofiber diameter, and increase in Ub genes and ubiquitinated proteins in mouse skeletal muscle were recovered by co-treatment with EPA. However, weight loss and up-regulated atrogenes induced by cisplatin were not changed by co-treatment with EPA in skeletal muscle. In this study, EPA attenuated cisplatin-induced muscle atrophy via down-regulation of up-regulated Ub gene expression. Although further clinical studies are needed, EPA administration can be effective in the development of muscle atrophy in cisplatin-treated patients.

Cannabidiol Application Increases Cutaneous Aquaporin-3 and Exerts a Skin Moisturizing Effect.

Cannabidiol (CBD) is a major nonpsychotropic component of Cannabis sativa with various pharmacological activities. In this study, we investigated the skin moisturizing effect of CBD and its mechanism. A 1% CBD solution was applied daily to skin of HR-1 hairless (Seven-week-old, male) for 14 days. The dermal water content in CBD-treated mice was significantly increased compared to that in the control group. Furthermore, no inflammatory reaction in the skin and no obvious skin disorders were observed. The mRNA expression levels of loricrin, filaggrin, collagen, hyaluronic acid degrading enzyme, hyaluronic acid synthase, ceramide degrading enzyme, and ceramide synthase in the skin were not affected by the application of CBD. However, only aquaporin-3 (AQP3), a member of the aquaporin family, showed significantly higher levels in the CBD-treated group than in the control group at both the mRNA and protein levels. It was revealed that CBD has a moisturizing effect on the skin. In addition, it is possible that increased expression of AQP3, which plays an important role in skin water retention, is a contributor to the mechanism. CBD is expected to be developed in the future as a cosmetic material with a unique mechanism.

Wound-Healing and Skin-Moisturizing Effects of Sasa veitchii Extract.

Sasa veitchii (S. veitchii) is a traditional herb derived from the bamboo genus, which is collectively called Kumazasa. Although Kumazasa extract is believed to have various effects on the skin, there is little scientific evidence for these effects. In this study, we aimed to obtain scientific evidence regarding the wound-healing and skin-moisturizing effects of Kumazasa extract. Kumazasa extract was applied to the skin of a mouse wound model for 14 days, and the wound area and dermal water content were measured. Mice treated with Kumazasa extract had smaller wound areas than control mice. The dermal water content in the Kumazasa extract-treated group was significantly higher than that in the control group. The mRNA and protein expression levels of cutaneous aquaporin-3 (AQP3), which is involved in wound healing and increases in dermal water content, were significantly increased by treatment with Kumazasa extract. Kumazasa extract-treated HaCaT cells exhibited significantly higher AQP3 expression and p38 mitogen-activated protein kinase (MAPK) phosphorylation than control cells. With continuous application, Kumazasa extract increases AQP3 expression and exerts wound-healing and moisturizing effects. The increase in AQP3 expression elicited by Kumazasa extract may be due to enhancement of transcription via activation of p38 MAPK signaling.

Exogenous insulin-like growth factor 1 attenuates cisplatin-induced muscle atrophy in mice.

BACKGROUND: A reduction in the skeletal muscle mass worsens the prognosis of patients with various cancers. Our previous studies indicated that cisplatin administration to mice caused muscle atrophy. This is a concern for human patients receiving cisplatin. The insulin-like growth factor 1 (IGF-1)/phosphoinositide 3-kinase (PI3K)/Akt pathway stimulates the rate of protein synthesis in skeletal muscle. Thus, IGF-I can be a central therapeutic target for preventing the loss of skeletal muscle mass in muscle atrophy, although it remains unclear whether pharmacological activation of the IGF-1/PI3K/Akt pathway attenuates muscle atrophy induced by cisplatin. In this study, we examined whether exogenous recombinant human IGF-1 attenuated cisplatin-induced muscle atrophy. METHODS: Male C57BL/6J mice (8-9 weeks old) were injected with cisplatin or saline for four consecutive days. On Day 5, quadriceps muscles were isolated. Mecasermin (recombinant human IGF-1) or the vehicle control was subcutaneously administered 30 min prior to cisplatin administration. A dietary restriction group achieving weight loss equivalent to that caused by cisplatin administration was used as a second control. C2C12 myotubes were treated with cisplatin with/without recombinant mouse IGF-1. The skeletal muscle protein synthesis/degradation pathway was analysed by histological and biochemical methods. RESULTS: Cisplatin reduced protein level of IGF-1 by about 85% compared with the vehicle group and also reduced IGF-1/PI3K/Akt signalling in skeletal muscle. Under this condition, the protein levels of muscle ring finger protein 1 (MuRF1) and atrophy gene 1 (atrogin-1) were increased in quadriceps muscles (MuRF1; 3.0 ± 0.1 folds, atrogin-1; 3.0 ± 0.3 folds, P < 0.001, respectively). The administration of a combination of cisplatin and IGF-1 significantly suppressed the cisplatin-induced downregulation of IGF-1/PI3K/Akt signalling and upregulation of MuRF1 and atrogin-1 (up to 1.6 ± 0.3 and 1.5 ± 0.4 folds, P < 0.001, respectively), resulting in diminished muscular atrophy. IGF-1 showed similar effects in cisplatin-treated C2C12 myotubes, as well as the quadriceps muscle in mice. CONCLUSIONS: The downregulation of IGF-1 expression in skeletal muscle might be one of the factors playing an important role in the development of cisplatin-induced muscular atrophy. Compensating for this downregulation with exogenous IGF-1 suggests that it could be a therapeutic target for limiting the loss of skeletal muscle mass in cisplatin-induced muscle atrophy.

Role of Cutaneous Aquaporins in the Development of Xeroderma in Type 2 Diabetes.

Xeroderma is induced by diabetes, reducing patients' quality of life. We aimed to clarify the roles of cutaneous water channel aquaporin-3 (AQP3) in diabetic xeroderma using type 2 diabetes model db/db mice. Blood glucose levels were unchanged in 5-week-old db/db mice compared to db/+ mice (control mice), but the pathophysiology of type 2 diabetes was confirmed in 12-week-old db/db mice. The dermal water content and AQP3 expression in 5-week-old db/db mice were almost the same as those in the control mice. On the other hand, in 12-week-old db/db mice, the dermal water content and AQP3 expression were significantly decreased. The addition of glucose to HaCaT cells had no effect on AQP3, but tumor necrosis factor-α (TNF-α) decreased the AQP3 expression level. Blood TNF-α levels or skin inflammation markers in the 12-week-old db/db mice were significantly higher than those in control mice. AQP3 levels in the skin were decreased in type 2 diabetes, and this decrease in AQP3 may be one of the causes of xeroderma. Therefore, a substance that increases AQP3 may be useful for improving xeroderma. Additionally, a decrease in skin AQP3 may be triggered by inflammation. Therefore, anti-inflammatory drugs may be effective as new therapeutic agents for diabetic xerosis.

Effect of Astaxanthin on the Expression and Activity of Aquaporin-3 in Skin in an In-Vitro Study.

Astaxanthin (3,3'-dihydroxy-ß,ß-carotene-4,4'-dione) is a red lipophilic pigment with strong antioxidant action. Oral or topical administration of astaxanthin has been reported to improve skin function, including increasing skin moisture. In this study, we examined the mechanism by which astaxanthin improves skin function by focusing on the water channel aquaporin-3 (AQP3), which plays important roles in maintaining skin moisture and function. When astaxanthin was added to PHK16-0b or HaCaT cells, the mRNA expression level of AQP3 increased significantly in a concentration-dependent manner in both cell lines. The AQP3 protein expression level was also confirmed to increase when astaxanthin was added to HaCaT cells. Similarly, when astaxanthin was added to 3D human epidermis model EpiSkin, AQP3 expression increased. Furthermore, when glycerol and astaxanthin were simultaneously added to EpiSkin, glycerol permeability increased significantly compared with that observed for the addition of glycerol alone. We demonstrated that astaxanthin increases AQP3 expression in the skin and enhances AQP3 activity. This result suggests that the increased AQP3 expression in the skin is associated with the increase in skin moisture by astaxanthin. Thus, we consider astaxanthin useful for treating dry skin caused by decreased AQP3 due to factors such as diabetes mellitus and aging.

Upregulation of ubiquitinated proteins and their degradation pathway in muscle atrophy induced by cisplatin in mice.

We previously demonstrated that cisplatin administration in mice induces muscle atrophy and an increase in the expression of two muscle-specific ubiquitin E3 ligase genes, muscle ring finger protein 1 (MuRF1), and atrophy gene-1 (atrogin-1), in skeletal muscle. Ubiquitination serves as a degradation signal in both the ubiquitin-proteasome and selective autophagy pathways. In the present study, we investigated changes in the expression of ubiquitin and ubiquitinated proteins and their degradation pathways. Ubiquitin and ubiquitinated protein levels were increased by cisplatin compared with those in the vehicle and dietary restriction (DR) groups. To quantify the levels of ubiquitin and ubiquitinated proteins, we conducted a dot blot assay using an anti-ubiquitin antibody. The expression of ubiquitin was also significantly increased by cisplatin compared with that in the vehicle and DR groups. Since the ubiquitin proteins were upregulated by cisplatin, we measured the mRNA levels of the ubiquitin genes: Ubb, Ubc, Rps27a, and Uba52. All these four genes were increased by cisplatin administration compared with those in both the vehicle-treated and DR groups in quadriceps muscle tissue. The anti-ubiquitin antibody-sensitive bands increased when C2C12 myotubes were treated with cisplatin. Furthermore, MG-132 (26 s proteasome inhibitor), but not bafilomycin A1 (autophagy inhibitor), caused a further increase in expression. In conclusion, ubiquitin and ubiquitinated proteins are upregulated in cisplatin-induced muscle atrophy. Cisplatin-induced ubiquitinated proteins are degraded by the 26 s proteasome pathway.

Lactobacillus helveticus-Fermented Milk Whey Suppresses Melanin Production by Inhibiting Tyrosinase through Decreasing MITF Expression.

Whey obtained from milk fermented by the Lactobacillus helveticus CM4 strain (LHMW) has been shown to improve skin barrier function and increase skin-moisturizing factors. In this study, we investigated the effects of LHMW on melanin production to explore the additional impacts of LHMW on the skin. We treated mouse B16 melanoma cells with α-melanocyte-stimulating hormone (α-MSH) alone or simultaneously with LHMW and measured the amount of melanin. The amount of melanin in B16 cells treated with α-MSH significantly increased by 2-fold compared with that in control cells, and tyrosinase activity was also elevated. Moreover, treatment with LHMW significantly suppressed the increase in melanin content and elevation of tyrosinase activity due to α-MSH. LHMW also suppressed the α-MSH-induced increased expression of tyrosinase, tyrosinase-related protein 1 (TRP1), and dopachrome tautomerase (DCT) at the protein and mRNA levels. Furthermore, the mRNA and protein microphthalmia-associated transcription factor (MITF) expression levels were significantly increased with treatment with α-MSH alone, which were also suppressed by LHMW addition. LHMW suppression of melanin production is suggested to involve inhibition of the expression of the tyrosinase gene family by lowering the MITF expression level. LHMW may have promise as a material for cosmetics with expected clinical application in humans.