METHODS: PC-12 cells was pre-treated with HESAE for 48 h followed by 400 μM corticosterone for 24 h to induce oxidative stress. Cells in complete medium without any treatment or pre-treated with 3.125 μg/mL desipramine served as the negative and positive controls, respectively. The cell viability, lactate dehydrogenase (LDH) release, endogenous antioxidant enzyme activities, aconitase activity, mitochondrial membrane potentials (MMPs), intracellular reactive oxygen species (ROS) levels and number of apoptotic nuclei were quantified. In addition, HESAE ethanol extract was separated into fractions by chromatographic methods prior to spectroscopic analysis.
RESULTS: We observed that PC-12 cells treated with high-dose corticosterone at 400 μM had decreased cell viability, reduced endogenous antioxidant enzyme activities, disrupted mitochondrial function, and increased oxidative stress and apoptosis. However, pre-treatment with HESAE ranging from 0.25 to 1 mg/mL had increased cell viability, decreased LDH release, enhanced endogenous antioxidant enzyme activities, restored MMP, attenuated intracellular ROS and protected from ROS-mediated apoptosis. The neuroprotective effects could be attributed to significant amounts of adenosine and herierin III isolated from HESAE.
CONCLUSIONS: HESAE demonstrated neuroprotective effects against high-dose corticosterone-induced oxidative stress in an in vitro model mimicking depression. HESAE could be a potential dietary supplement to treat depression.
METHODS: A total of 120 male broiler chickens (Cobb 500) were assigned to a 2×3×2 factorial arrangement in a completely randomized design using two restraint methods (shackle and cone), three durations of restraint (10, 30, and 60 s), and two categories of live body weight (1.8±0.1 kg as lightweight and 2.8±0.1 kg as heavyweight).
RESULTS: Irrespective of the duration of restraint and body weight, the coned chickens were found to have lower plasma corticosterone (p<0.01), lactate (p<0.001), lower meat drip loss (p<0.01), cooking loss (p<0.05), and higher blood loss (p<0.05) compared with their shackled counterparts. The duration of restraint had significant effects on the meat initial pH (p<0.05), ultimate pH (p<0.05), and yellowness (p<0.01). The lightweight broilers exhibited higher (p< 0.001) blood loss and lower (p<0.05) cooking loss compared to the heavyweight broilers, regardless of the restraint method used and the duration of restraint. However, the interaction between the restraint method, duration of restraint, and body weight contributed to differences in pre-slaughter stress and meat quality. Therefore, the interaction between the restraint method and the duration of restraint affected the meat shear force, lightness (L*) and redness (a*).
CONCLUSION: The duration of restraint and body weight undoubtedly affect stress responses and meat quality of broiler chickens. Regardless of the duration of restraint and body weight, the cone restraint resulted in notably lower stress, lower meat water loss, and higher blood loss compared to shackling. Overall, the findings of this study showed that restraint method, duration of restraint, and body weight may affect the stress response and meat quality parameters in broilers and should be considered independently or interactively in future studies.