Apoptosis and autophagy of muscle cell during pork postmortem aging.

OBJECTIVE: Pork is an important source of animal protein in many countries. Subtle physiochemical changes occur during pork postmortem aging. The changes of apoptosis and autophagy in pork at 6 h to 72 h after slaughter were studied to provide evidence for pork quality. METHODS: In this article, morphological changes of postmortem pork was observed through Hematoxylin-eosin staining, apoptotic nuclei were observed by TdT-mediated dUTP nick end labeling assay, protein related to apoptosis and autophagy expressions were tested by western blot and LC3 level were expressed according to immunofluorescence assay. RESULTS: In this study, we found the occurrence of apoptosis in postmortem pork, and the process was characterized by nucleus condensation and fragmentation, formation of apoptotic bodies, increase in apoptosis-related Bax/Bcl-2 levels, and activation of caspases. Autophagy reached its peak between 24 and 48 h after slaughter, accompanied by the formation of autophagosomes on the cell membrane and expression of autophagy-related proteins beclin-1, P62, LC3-I, LC3-II, and ATG5. CONCLUSION: Obvious apoptosis was observed at 12 h and autophagy reached its peak at 48 h. The present work provides the evidence for the occurrence of apoptosis and autophagy during postmortem aging of pork. In conclusion, the apoptosis and autophagy of muscle cells discovered in this study have important implications for pork in the meat industry.

Preparation, Characterization, and In Vitro Anticancer Activity Evaluation of Broccoli-Derived Extracellular Vesicle-Coated Astaxanthin Nanoparticles.

Astaxanthin (AST) is a type of ketone carotenoid having significant antioxidation and anticancer abilities. However, its application is limited due to its low stability and bioavailability. In our study, poly (lactic-co-glycolic acid) (PLGA)-encapsulated AST (AST@PLGA) nanoparticles were prepared by emulsion solvent evaporation method and then further processed by ultrasound with broccoli-derived extracellular vesicles (BEVs), thereby evolving as BEV-coated AST@PLGA nanoparticles (AST@PLGA@BEVs). The preparation process and methods were optimized by three factors and three levels of response surface method to increase drug loading (DL). After optimization, the DL was increased to 6.824%, and the size, polydispersity index, and zeta potential of AST@PLGA@BEVs reached 191.60 ± 2.23 nm, 0.166, and -15.85 ± 0.92 mV, respectively. Moreover, AST@PLGA@BEVs exhibited more notable anticancer activity than AST in vitro. Collectively, these results indicate that the method of loading AST in broccoli-derived EVs is feasible and has important significance for the further development and utilization of AST as a functional food.

[Effects of 16 week aerobic exercise on baPWV and ABI of middle-aged and elderly patients].

OBJECTIVES: To investigate the interventional effects of 16-week aerobic exercises on the elderly's arteriosclerosis and its mechanism. METHODS: Twenty-seven elderly people with the average age of 62. 70 ±3. 26 joined a 16-week square dance/taijiquan exercise program that conducted 60 minutes each time, six times per week. Arterial stiffness and its related indexes such as systolic pressure(SBP), diastolic pressure(DBP), left brachial-ankle pulse wave velocity (L-baPWV), right brachial-ankle pulse wave velocity(R-baPWV), left ankle brachial index (L-ABI), right ankle brachial index(R-ABI), serum triglyceride(TG), total cholesterol(TC), high density lipoprotein cholesterol(HDL-c), low density lipoprotein cholesterol(LDL-c), superoxide dismutase(SOD), malondialdehyde(MDA) and glutathione peroxidase (GSH-Px) were detected at 3 time points including before exercise program, by the end of exercise for 8 weeks and 16 weeks. RESULTS: ① Compared with pre-exercise, the R-baPWV and R-ABI of the elderly people were decreased at the end of the 8th week, and the L-baPWV, RbaPWV, R-ABI and L-ABI were decreased significantly at the end of the 16th week. ②Compared with pre-exercise, SBP and DBP were declined markedly (P<0.01, P<0.05) at the end of the 8th week, SBP, DBP and pulse pressure were decreased significantly (P<0.01, P<0.05) at the end of the 16th week. ③Compared with pre-exercise, TC and LDL-c were declined markedly (P<0.01) at the end of the 8th and the 16th week, and there was no difference of the level of TG and LDL-c between pre-exercise and post-exercise. ④There was no evident difference of serum level of SOD, GSH-Px, MDA between pre-exercise and post-exercise at the end of the 8th week. Compared with pre-exercise, the level of serum SOD, GSH-Px was increased evidently while the content of serum MDA was decreased significantly (P<0.01). CONCLUSIONS: Sixteen-week aerobic exercises could reduce baPWV and ABI levels, regulate blood pressure, blood lipids and lipid peroxides levels of the elderly evidently, thus improve the controlling quality of atherosclerosis.