Dietary salmon milt deoxyribonucleic acid prevents hepatosteatosis in mice

With the increased incidence of lifestyle-related diseases, prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing at an unprecedented rate, leading to rising interest in studying the role of functional foods in its prevention. This study demonstrated the efficacy of salmon milt deoxyribonucleic acid (SM DNA) in preventing liver dysfunction in a diet-induced obesity model. Seven-week-old male C57BL/6J mice were fed normal diet (ND), high-fat diet (HFD), and HFD supplemented with 3% SM DNA (HFD?+?SM DNA) for 12 weeks. Increased body weight, fat-to-body weight ratio, and fat accumulation in HFD-fed mice demonstrated successful establishment of an obesity model. The HFD group showed increased alanine aminotransferase (ALT) levels, a marker of liver function, and NAFLD activity score (NAS) based on histological observations showed steatosis and mild inflammation but no fibrosis, indicating NAFLD but no nonalcoholic steatohepatitis. In the HFD?+?SM DNA group, the improved superoxide dismutase activity and NAFLD activity score suggested that SM DNA prevented liver dysfunction while maintaining antioxidant capacity and suppressing intrahepatocyte fat droplet formation. SM DNA attenuated fat accumulation in the liver and improved hepatic function. This study explored the potential of SM DNA as a functional food to prevent NAFLD and other visceral obesity-related diseases.

     

Otolith development and daily increment formation in laboratory-reared larval and juvenile black-spot tuskfish <Emphasis Type="Italic">Choerodon schoenleinii</Emphasis>

Microstructures of lapilli were examined for reared larvae and juveniles of black-spot tuskfish Choerodon schoenleinii. Lapilli of larvae at 1 day after hatching have one diffuse and obscure ring with an otolith radius of 4.3 ± 0.50 μm (mean ± SD, N = 8). The slope and intercept of the regression between the number of days after hatching and increment counts did not differ significantly from one and zero, respectively, indicating that lapillus increments were formed on a daily basis after hatching. There was an ontogenetic shift in the relative values of somatic and otolith growth, which corresponded to the transition from pelagic larvae to settlement stage. Simultaneously, the daily increment width reached the maximum value. These findings suggest that age at maximum value of increment width can be used as an indicator of the planktonic larval duration while settlement mark is not found. Since ontogenetic shift in the relationship between otolith radius and body size was observed, back-calculation of somatic growth in black-spot tuskfish using the otolith radius during the early life stages should be analyzed with caution, and the method requires further validation.