RESUMO
The objective of this study was to investigate the effect of verjuice on beef M. biceps femoris (BF). BF blocks were marinated with 30%, 70%, and 100% verjuice solutions containing 2% NaCl, for different marination times (12, 24, 48, and 72 h). Verjuice marination reduced the pH values of BF samples from 6.77 in control sample to 3.66 in 100% of verjuice for 72 h. The decreased values of water holding capacity (from 54.06% to 47.46%) with increasing verjuice concentration (from 30% to 100% for 72 h) confirmed the drop of proteins isoelectric point of the muscle due to salt presence preventing fibers swelling. Less cookout was observed with increasing acid concentration. Marination time had no significant effect on L* and a* coordinates of uncooked samples while acidification made the samples lighter and less red. Enzymatic proteolysis of myosin and troponin-T concomitant with increase in myofibrillar fragmentation index contributed to the decrease of shear force in a way dependent on verjuice concentration and marination time. Sensory panelists gave the highest score to cooked samples marinated with 70% verjuice solution.
RESUMO
BACKGROUND: Nanoselenium (Nan S) is a form of selenium element that acts with high absorption and low toxicity. However, few studies have examined the effects of Nan S on cognitive impairment. On the other hand, hypothyroidism is a common disease that causes cognitive disorders. Therefore, this study aimed to investigate the effect of Nan S on memory impairment in rats due to propylthiouracil (PTU) - induced hypothyroidism. The roles of brain-derived neurotrophic factor (BDNF), nitric oxide (NO), and oxidative stress were also challenged. MATERIALS AND METHODS: The animals were randomly divided into 4 groups: (1) Control group (normal saline), (2) hypothyroid (Hypo) group: where 0.05% PTU was added to drinking water, (3) and (4) Hypo-Nan S 50, Hypo-Nan S 100 in which 50 or 100 µg/ kg of Nan S were injected respectively. After 6 weeks, spatial and avoidance memory was measured by Morris water maze (MWM) and passive avoidance (PA) tests. The animals then underwent deep anesthesia and the serum samples and the hippocampus and cortex were collected to be used for thyroxin and biochemical measurements including malondialdehyde (MDA), NO, thiol, superoxide dismutase (SOD), catalase (CAT), and BDNF. RESULTS: The rats showed an increase in the escape latency and traveled path in MWM in the Hypo group compare with the Control group and these parameters were decreased in both Hypo-Nan S 50 and Hypo-Nan S 100 groups compared to the Hypo group. The rats of both Hypo-Nan S 50 and Hypo-Nan S 100 groups spent longer time and traveled longer distances in the target area during the probe trial of MWM than the Hypo group. In addition, the latency to enter the dark box in the PA test was lower in the Hypo group than in the Control group, which was significantly improved after Nan S treatment. Furthermore, the hippocampal and cortical lipid peroxide marker (MDA) levels and NO metabolites of the Hypo group were significantly increased and the antioxidant markers (total thiol, SOD, and CAT) were significantly inhibited compared to the Control group. Compared with the Hypo group, Nan S administration could significantly decrease the oxidant factors and increase the activities antioxidant system and concentration of BDNF. CONCLUSION: It is concluded that Nan S might be able to enhance endogenous antioxidant proteins due to its antioxidant activity, thereby improving BDNF and spatial and avoidance memory in the hypothyroidism-induced memory impairment model however, more studies are still necessary to elucidate the exact mechanism(s).
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Hipotireoidismo , Animais , Ratos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Óxido Nítrico/metabolismo , Antioxidantes/farmacologia , Ratos Wistar , Estresse Oxidativo , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/tratamento farmacológico , Hipocampo/metabolismo , Encéfalo/metabolismo , Superóxido Dismutase/metabolismo , Propiltiouracila/efeitos adversos , Propiltiouracila/metabolismo , Compostos de Sulfidrila/metabolismo , Aprendizagem em LabirintoRESUMO
BACKGROUND: Nano selenium (Nano Sel) has many therapeutic properties including antioxidant, anticancer, and anti-inflammatory actions. OBJECTIVE: Impacts of Nano Sel administration against cardiac fibrosis and heart and aorta tissue oxidative damage observed in hypothyroid rats were explored. METHODS: The animals were randomly grouped and treated as: 1) Control; 2) Propylthiouracil (PTU) in which PTU was added to the drinking water (0.05%) to induce hypothyroidism; 3-5) PTU-Nano Sel 50, PTU-Nano Sel 100, and PTU-Nano Sel 150 groups, which received daily PTU plus 50,100 or 150 µg/kg of Nano Sel for 6 weeks intraperitoneally. The heart and aorta tissues were removed under deep anesthesia and then biochemical parameters including malondialdehyde (MDA), total thiol groups, catalase (CAT), and superoxide dismutase (SOD), as well as cardiac fibrosis were assessed. RESULTS: Hypothyroidism induced by PTU was remarkably associated with myocardial hypertrophy and perivascular fibrosis in Masson's trichrome staining. Moreover, hypothyroidism increased MDA level, while it subtracted total thiol group content and activity of SOD and CAT. Treatment with Nano Sel recovered hypothyroidism-induced cardiac fibrosis in the histological assessment. Nano Sel also promoted CAT and SOD activity and thiol content, whereas alleviated MDA levels in the heart and aorta tissues. CONCLUSION: Results propose that administration of Nano Sel exerts a protective role in the cardio vascular system via preventing cardiac fibrosis and inhibiting oxidative stress.