Selenium Status Affects Hypertrophic Growth of Skeletal Muscle in Growing Zebrafish by Mediating Protein Turnover.

BACKGROUND: Selenium (Se) status is closely related to skeletal muscle physiological status. However, its influence on skeletal muscle growth has not been well studied. OBJECTIVES: This study aimed to analyze the impacts of overall Se status (deficient, adequate, and high) on skeletal muscle growth using a growing zebrafish model. METHODS: Zebrafish (1.5-mo-old) were fed graded levels of Se (deficient: 0.10 mg Se/kg; marginally deficient: 0.22 mg Se/kg; adequate: 0.34 mg Se/kg; high: 0.44, 0.57, and 0.69 mg Se/kg) as Se-enriched yeast for 30 d. Zebrafish growth, and Se accumulation, selenoenzyme activity, selenotranscriptome profiles, and oxidative status in the whole body, and selenotranscriptome profiles, histological characteristics, biochemicals, and gene and protein expression profiles related to muscle growth in the skeletal muscle were analyzed by model fitting and/or 1-factor ANOVA. RESULTS: Se status biomarkers within the whole body and skeletal muscle indicated that 0.34 mg Se/kg was adequate for growing zebrafish. For biomarkers related to skeletal muscle growth, compared with 0.34 mg Se/kg, 0.10 mg Se/kg decreased the white muscle cross-sectional area (WMCSA) and the mean diameter of white muscle fibers (MDWMF) by 14.4%-15.1%, inhibited protein kinase B-target of rapamycin complex 1 signaling by 63.7%-68.5%, and stimulated the autophagy-lysosome pathway by 1.07 times and the ubiquitin-proteasome pathway (UPP) by 96.0% (P < 0.05), whereas 0.22 mg Se/kg only decreased the WMCSA by 7.8% (P < 0.05); furthermore, 0.44 mg Se/kg had no clear effects on skeletal muscle biomarkers, whereas 0.57-0.69 mg Se/kg decreased the WMCSA and MDWMF by 6.3%-25.9% and 5.1%-21.3%, respectively, and stimulated the UPP by 2.23 times (P < 0.05). CONCLUSIONS: A level of 0.34 mg Se/kg is adequate for the growth of zebrafish skeletal muscle, whereas ≤0.10 and ≥0.57 mg Se/kg are too low or too high, respectively, for maintaining efficient protein accretion and normal hypertrophic growth.

Anti-diabetic effects of polysaccharides from Talinum triangulare in streptozotocin (STZ)-induced type 2 diabetic male mice.

The present study evaluated the anti-diabetic effects of the polysaccharides obtained from Talinum triangulare (TTP). Two TTP doses (150 mg/kg and 300 mg/kg · bw/d) were administered orally to normal and streptozotocin (STZ)-induced type 2 diabetic male Kunming mice, respectively. The TTP hypoglycemic and hypolipidemic effects were evaluated by testing the fast blood glucose (FBG) level, fasting serum insulin (FINS), and serum lipids (TC, TG, HDL, LDL) as well as the body, hepar and kidney weights. After four weeks administration, the low-dose group 150 mg/kg · bw/d) and high-dose group (300 mg/kg · bw/d) showed a marked FBG fall rate of 29.85% and 41.18% (FBG fall rate% = ((Diabetic control--TTP group)/Diabetic control) × 100%). The results of FBG and serum lipids indicate that TTP possess significant hypoglycemic effect, but no significant hypolipidemic effect. These results suggest the potential use of TTP as a functional food for the treatment of type 2 diabetic mellitus (T2DM).

Antitumor efficacy in H22 tumor bearing mice and immunoregulatory activity on RAW 264.7 macrophages of polysaccharides from Talinum triangulare.

The aim of this paper was to study the antitumor and immunoregulatory activities of a polysaccharide (TTP) from Talinum triangulare. The molecular weight of TTP-IV was 49.9 kDa. The monosaccharide composition analysis of TTP-IV revealed that it was a heteropolysaccharide consisting of rhamnose, arabinose, mannose and galactose with a molar ratio of 1.22 : 1.00 : 1.05 : 1.51. The results of the in vivo study showed that TTP (200 mg per kg bw) significantly inhibited the growth of tumor by 49.07% in H22-bearing Kunming mice. In vitro, the growth of primary murine macrophages was promoted by TTP in a dose- and time-dependent manner significantly. Besides, RAW 264.7 cells were activated by TTP to produce NO and the toxicity of RAW 264.7 supernatant was markedly enhanced in vitro. The levels of iNOS, TLR2, TLR4 and IL-1ß were obviously increased by TTP. Therefore, it is suggested that TTP can be utilized as a potent antitumor and immunoenhancing material in functional food.