Ultraviolet (UV) light induces skin photoaging, which is characterized by thickening, wrinkling, pigmentation, and dryness. Astaxanthin (AST), a ketocarotenoid isolated from Haematococcus pluvialis, has been extensively studied owing to its possible effects on skin health as well as UV protection. In addition, AST attenuates the increased generation of reactive oxygen species (ROS) and capillary regression of the skeletal muscle. In this study, we investigated whether AST could protect against UV-induced photoaging and reduce capillary regression in the skin of HR-1 hairless mice. UV light induces wrinkle formation, epidermal thickening, and capillary regression in the dermis of HR-1 hairless mice. The administration of AST reduced the UV-induced wrinkle formation and skin thickening, and increased collagen fibers in the skin. AST supplementation also inhibited the generation of ROS, decreased wrinkle formation, reduced epidermal thickening, and increased the density of capillaries in the skin. We also found an inverse correlation between wrinkle formation and the density of capillaries. An association between photoaging and capillary regression in the skin was also observed. These results suggest that AST can protect against photoaging caused by UV irradiation and the inhibitory effects of AST on photoaging may be associated with the reduction of capillary regression in the skin.

Immobilization induces skeletal muscle fibrosis characterized by increasing collagen synthesis in the perimysium and endomysium. Transforming growth factor-β1 (TGF-β1) is associated with this lesion via promoting differentiation of fibroblasts into myofibroblasts. In addition, reactive oxygen species (ROS) are shown to mediate TGF-β1-induced fibrosis in tissues. These reports suggest the importance of ROS reduction for attenuating skeletal muscle fibrosis. Astaxanthin, a powerful antioxidant, has been shown to reduce ROS production in disused muscle. Therefore, we investigated the effects of astaxanthin supplementation on muscle fibrosis under immobilization. In the present study, immobilization increased the collagen fiber area, the expression levels of TGF-β1, α-smooth muscle actin, and superoxide dismutase-1 protein and ROS production. However, these changes induced by immobilization were attenuated by astaxanthin supplementation. These results indicate the effectiveness of astaxanthin supplementation on skeletal muscle fibrosis induced by ankle joint immobilization.

New Findings: What is the central question of this study? We asked whether the combination of astaxanthin supplementation and intermittent loading would attenuate both the muscle atrophy and the capillary regression associated with chronic unloading. What is the main finding and its importance? Intermittent loading alone attenuated atrophy of the soleus, while astaxanthin treatment alone maintained the capillary network in the soleus. The combination of these two interventions ameliorated both the muscle atrophy and the capillary regression induced by chronic unloading. A chronic decrease in neuromuscular activity (activation and/or loading) results in muscle atrophy and capillary regression that are due, in part, to the overproduction of reactive oxygen species. We have reported that antioxidant treatment with astaxanthin attenuates the overexpression of reactive oxygen species in atrophied muscles that, in turn, ameliorates capillary regression in hindlimb‐unloaded rats. Astaxanthin supplementation, however, had little effect on muscle mass and fibre cross‐sectional area. In contrast, intermittent loading of the hindlimbs of hindlimb‐unloaded rats ameliorates muscle atrophy. Therefore, we hypothesized that the combination of astaxanthin supplementation and intermittent loading would attenuate both muscle atrophy and capillary regression during hindlimb unloading. As expected, 2 weeks of hindlimb unloading resulted in atrophy, a decrease in capillary volume and a shift towards smaller‐diameter capillaries in the soleus muscle. Intermittent loading alone (1 h of cage ambulation per day) attenuated atrophy of the soleus, while astaxanthin treatment alone maintained the capillary network to near control levels. The combination of intermittent loading and astaxanthin treatment, however, ameliorated atrophy of the soleus and maintained the capillary volume and luminal diameters and the superoxide dismutase‐1 protein levels near control values. These results indicate that intermittent loading combined with astaxanthin supplementation could be an effective therapy for both the muscle atrophy and the capillary regression associated with a chronic decrease in neuromuscular activity.

[Purpose] To clarify health-related quality of life (HR-QOL) in subjects with mild cognitive impairment (MCI), using EuroQOL (EQ-5D), and to investigate the relationship between HR-QOL and Tokyo Metropolitan Institute Gerontology Index of Competence (TMIG-IC) scores. [Subjects and Methods] The subjects included 25 women with MCI or frail constitutions. A variety of methods were used to assess mental states and activities of daily living (ADL). [Results] EQ-5D scores were significantly lower in the MCI group than in the normal cognitive (NC) group. Among the assessed subscales, the percentages of participants with "moderate problems" during self-care and "moderate and extreme problems" during usual activities were significantly higher in the MCI group. TMIG-IC scores were significantly lower in the MCI group than in the NC group. There was a positive correlation between TMIG-IC and EQ-5D scores in the MCI group. There were also significant positive correlations between instrumental activities of daily living and social roles between EQ-5D and TMIG-IC scores in the MCI group. [Conclusion] TMIG-IC scores may reflect cognitive disorders earlier than BI and FIM. The decline of TMIG-IC scores, especially for IADL and social roles, affects HR-QOL even in the early phases of cognitive impairment.

Malnutrition impaired mitochondrial metabolic capacity via downregulating SIRT1 induced by increased oxidative stress in both fast and slow muscles although no atrophy was observed in slow muscle. Th...