Resveratrol, a natural antioxidant, anti-inflammatory plant extract, was found to have a protective effect in poultry subjected to heat stress. In this study, we strove to characterize resveratrol on intestinal of duck exposed to acute heat stress and investigate the underlying mechanism. A total of 120 Shan-ma ducks (60 days old) were randomly divided into 2 groups. The control group was fed a basal diet, and the resveratrol group was fed a basal diet supplemented with 400 mg/kg resveratrol. Animals in 2 groups were kept at a temperature of 24°C ± 2°C for 15 d. Then, animals of both groups were placed in an artificial climate room at 39°C. Twelve ducks of each group were sacrificed for sampling at 0, 30, and 60 min, respectively. Results indicated that resveratrol increased the ratio of villus height to crypt depth, increased the number of goblet cells, and reduced the histopathological damage of jejunum caused by acute heat stress. Furthermore, the gene expression of heat shock proteins ( HSP60, HSP70 , and HSP90 ) and tight junction proteins ( CLDN1 and OCLN ) was significantly increased in the resveratrol group compared to that in the control groups. Simultaneously, resveratrol significantly activated the SIRT1-NRF1/NRF2 signaling pathways, improved ATP level of jejunum, and increased SOD and CAT antioxidant enzymes activities. In addition, we found that the NF-κB / NLRP3 inflammasome signaling pathways were repressed under acute heat stress. Meanwhile, supplement resveratrol further inhibited the NLRP3 inflammasome pathway, decreased protein level of NLRP3 and caspase1 p20, reduced the secretion of IL-1β. Taken together, our results indicate that resveratrol against the oxidative damage and inflammation injury in duck jejunum induced by heat stress via active SIRT1 signaling pathways.

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Estrogen receptor–α (ERα) expressed by neurons in the ventrolateral subdivision of the ventromedial hypothalamic nucleus (ERα vlVMH ) regulates body weight in females, but the downstream neural circuits mediating this biology remain largely unknown. Here we identified a neural circuit mediating the metabolic effects of ERα vlVMH neurons. We found that selective activation of ERα vlVMH neurons stimulated brown adipose tissue (BAT) thermogenesis, physical activity, and core temperature and that ERα vlVMH neurons provide monosynaptic glutamatergic inputs to 5-hydroxytryptamine (5-HT) neurons in the dorsal raphe nucleus (DRN). Notably, the ERα vlVMH → DRN circuit responds to changes in ambient temperature and nutritional states. We further showed that 5-HT DRN neurons mediate the stimulatory effects of ERα vlVMH neurons on BAT thermogenesis and physical activity and that ERα expressed by DRN-projecting ERα vlVMH neurons is required for the maintenance of energy balance. Together, these findings support a model that ERα vlVMH neurons activate BAT thermogenesis and physical activity through stimulating 5-HT DRN neurons.

Introduction Ginseng polysaccharide (GPS, same as Panax polysaccharide) is a kind of polysaccharide extracted from ginseng. It has been reported that GPS has the ability to activate innate immunity, regulates blood sugar balance, and improves antioxidant capacity, but the effect on feeding behavior and its mechanism remains unclear. Method To investigate the possible effect of GPS on feeding behavior of animals, mice were supplied with GPS in water, and food intake, hedonic feeding behavior, anxiety‐like behavior, expression of appetite‐regulation peptides in the central nervous system and glucose‐related hormone levels in the serum of mice were measured. Results Ginseng polysaccharide significantly increased the average daily food intake in mice and promoted hedonic eating behavior. Meanwhile, the levels of serum glucose and glucagon were significantly reduced by GPS, and GPS promoted hypothalamic neuropeptide Y expression, inhibited proopiomelanocortin (POMC) expression, and reduced dopamine D1 receptor (DRD1) levels in the midbrain. We also found that the anxiety level of mice was significantly lower after GPS intake. In conclusion, oral supplementation with GPS promoted food intake in mice, most likely through the regulation of circulating glucose levels.