Resveratrol inhibits oxidative damage in lungs of heat-stressed broilers by activating Nrf2 signaling pathway and autophagy.

The purpose of this study was to investigate the effects of resveratrol on heat stress-induced lung injury in broilers and the mechanism underlying this process. Sixty two-week-old SPF BWEL broilers were randomly divided into the heat stress group (HS), resveratrol group (heat stress + 400 mg/kg resveratrol), and the control group after one week of feeding, with 20 chickens in each group. Broilers in the control group were reared at 23 ± 2 â„ƒ. Those in the HS and resveratrol group were reared under heat stress (35 â„ƒ ± 2 â„ƒ) for 8 h/day for seven days. Broilers in the resveratrol group were fed a diet supplemented with 400 mg/kg resveratrol two days before the start of the experiment. The feeding was continued for nine days. The results showed that HS decreased body weight (BW), average daily feed intake (ADFI), average daily gain (ADG), and lung weight. It, however, increased the lung index, induced lung congestion, and promoted infiltration of inflammatory cells to the lung. Resveratrol improved growth performance and inhibited heat stress-induced lung damage. Compared with broilers in the control group, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), Beclin-1, LC3 Ⅰ, and LC3 Ⅱ genes in the lung of heat-stressed broilers was significantly lower. The levels of kelch-like ECH-associated protein 1 (Keap1), NQO1, and HO-1 showed a similar trend with gene expressions. Immunofluorescence indicated that HS inhibited the expression of Nrf2 and LC3B proteins. Finally, the ratio of LC3 Ⅱ/LC3 Ⅰ was also significantly lower in the HS group. Further analyses revealed that resveratrol supplements in feeds enhanced antioxidation in the lung by activating the Nrf2 signaling pathway and autophagy. In conclusion, HS causes oxidative damage and inhibits autophagy in broilers. However, resveratrol protects against lung injury by alleviating oxidative stress and enhancing autophagy.

Acetaminophen-induced hepatotoxicity predominantly via inhibiting Nrf2 antioxidative pathway and activating TLR4-NF-κB-MAPK inflammatory response in mice.

To explore the action time and molecular mechanism underlying the effect of acetaminophen (APAP) on liver injury. APAP was used to establish drug-induced liver injury (DILI) model in mice. Mice in the model group were intraperitoneally injected 300 mg/kg APAP for 6, 12, and 24 h respectively, and control group mice were given the same volume of normal saline. The mice were anesthetized through intravenous injection of sodium pentobarbital at 6, 12, and 24 h after APAP poisoning. Analysis of ALT, AST and ALP in serum, liver histopathological observation, oxidative damage and western blot were performed. The livers in APAP exposed mice were pale, smaller, with a rough texture, and poorly arranged cells. Lesions, large areas of hyperemia, inflammation, swelling, poorly cell arrangement, necrosis, and apoptosis of liver cells were obvious in the liver tissue sections. Serum ALT, AST and ALP levels were significantly enhanced at 12 h of APAP adminstration mice than that of in control group mice (P＜0.05). The histopathological alterations and proinflammatory cytokines (IL-1ß, TNF-α and IL-6) levels were most severe at 12 h of APAP-induced hepatotoxicity. APAP treatment induced oxidative stress by decreasing hepatic activities of superoxide dismutase (SOD) and glutathione (GSH) (P＜0.05), and enhancing malondialdehyde (MDA) content (P＜0.05). Moreover, APAP inhibited erythroid 2-related factor 2 (Nrf2) antioxidative pathway with decreased of Nrf2 and HO-1 proteins levels. Furthermore, APAP aggravated the activation of NLRP3 inflammasome by increasing of NLRP3, caspase-1, ASC, IL-1ß and IL-18 proteins levels. Finally, APAP further significantly activated the toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) signaling pathways. This study demonstrated that APAP-induced hepatotoxicity by inhibiting of Nrf2 antioxidative pathway and promoting TLR4-NF-κB-MAPK inflammatory response and NLRP3 inflammasome activation.

Resveratrol relieves chronic heat stress-induced liver oxidative damage in broilers by activating the Nrf2-Keap1 signaling pathway.

Heat stress (HS) affects poultry production and welfare, causing enormous damage to poultry. Resveratrol, an antioxidant and anti-inflammatory natural plant polyphenol, is widely used in agriculture for the prevention of oxidative stress-related diseases. This study aimed to explore the effects and potential mechanism of resveratrol on liver oxidative damage in heat-stressed broilers. Sixty SPF chickens were randomly divided into control, heat stress (HS) and HS+ resveratrol (resveratrol) groups. Broilers were exposed to 35 ± 2 â„ƒ (8 h/d) for 7 consecutive days to induce HS, and the other 16 h/d were kept at 23 ± 2 â„ƒ, similar to the control group. Broilers received 400 mg/kg resveratrol in the basic diet 2 days before exposure to HS and for the following 7 days. The results showed that resveratrol improved growth performance by increasing the average daily gain (ADG) and reducing the feed conversion ratio (FCR), compared with the HS group. Heat stress reduced liver weight and index, increased inflammatory cell infiltration in the liver, enhanced serum AST levels, and decreased TP and ALB II levels, which resulted in liver injury in broilers, and resveratrol effectively alleviated liver injury. Moreover, supplementation with resveratrol enhanced the activities of liver antioxidant enzymes resulting in higher GPX and SOD levels than those in the heat-stressed broilers, and decreased MDA levels. Furthermore, resveratrol alleviated liver oxidative stress by activating the gene and protein levels of Nrf2 and HO-1, enhancing NQO1 and SOD1 gene levels, and decreasing protein levels of HSP70, p62, and Keap1, and thereby alleviated the liver injury of heat-stressed broilers. Compared with the HS group, Nrf2 immunofluorescence was significantly up-regulated in the livers of resveratrol group. These results suggest that resveratrol can enhance the liver antioxidant function by activating the Nrf2-Keap1 signaling pathway to promote growth performance in broilers under HS.

Heat stress in broilers of liver injury effects of heat stress on oxidative stress and autophagy in liver of broilers.

This study aimed to investigate the effect of chronic heat stress on oxidative stress in liver of broilers. In our study, chickens were randomly allocated to control 1 group (control 7 d), heat stress 1 group (HS1, 7 d), control 2 group (control 14 d) and heat stress 2 group (HS2, 14 d), with 30 replicates in each group. Broilers in heat stress groups exposed 8 h/day heat stress (35 ± 2°C) for 7 or 14 consecutive days, and the rest of time per day were kept at 23 ± 2℃ the same as control group broilers. Growth performance and the liver tissues were collected for histological observation and detection of organ index and liver redox status. The serum indicators (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) related to liver injury were determined. Moreover, Nrf2-related genes and protein expression levels in liver were measured. The results showed that in heat stress group broilers the body weight gain, feed conversion ratio, liver weight, and liver index were decreased, inflammatory cells infiltration in liver, and serum AST level was enhanced, compared with control group broilers. Moreover, the hepatic malondialdehyde (MDA) and superoxide dismutase (SOD) level were increased after 1 wk of heat stress. Nrf2, Sqstm1/p62, HO-1, and NQO1 mRNA expressions in the liver of broilers were decreased by heat stress. P62 and p-p62 protein expressions were significantly up-regulated, but Nrf2 and keap1 protein level was decreased in heat stress group broilers as compared to control group. The mRNA expression levels of Beclin1, LC3-I, LC3-II were down-regulated significantly with heat stress for 1 wk. The mRNA expression level of mTOR up-regulated after 2 wk of heat stress. In conclusion, heat stress induced liver injury of broilers by down-regulating Nrf2-keap1 signaling pathway and autophagy.

Yinhuang oral liquid protects acetaminophen-induced acute liver injury by regulating the activation of autophagy and Nrf2 signaling.

This study aimed to investigate the protective effect and potential mechanism of Yinhuang oral liquid (YOL) against acetaminophen (APAP) induced liver injury in mice. C57BL/6 mice were randomly divided into control group, model group (300 mg/kg APAP), NAC group and YOL group. Mice were treated intragastrical with YOL (8 g/kg) and N-Acetylcysteine (NAC, 300 mg/kg) 6 h before and 6 h after the APAP (300 mg/kg) intraperitoneal injection. 12 h after APAP exposure, blood and liver samples were collected for subsequent testing. The results showed that APAP decreased liver index, induced liver pathological injury with hepatocytes swelling, necrosis and apoptosis and inflammatory cell infiltration. APAP exposure significantly increased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels to 35 and 6 multiples than their original levels. YOL alleviated liver pathological damage, decreased the serum levels of ALT and AST in APAP exposure mice, and it worked better than NAC. Moreover, APAP promoted oxidative stress by increasing lipid peroxidation (MDA) and decreasing anti-oxidant enzyme activities of SOD and GSH, inhibited the mRNA levels of Nrf2, HO-1, Gclc and Gclm, and decreased the protein levels of Nrf2, HO-1 and Keap1, compared to control group. Furthermore, APAP exposure significantly down-regulated the mRNA and protein levels of autophagy related genes (Beclin-1, LC3-II, LC3-I, Atg4B, Atg5, Atg16L1 and Atg7). However, the gene levels of mTOR and p-mTOR increased, and p-ULK1 protein level decreased in liver of APAP treated mice. Additionally, YOL alleviated the oxidative injury by up-regulating Nrf2 pathway. The gene and protein levels of autophagy-related genes Beclin-1, LC3-II, LC3-I, Atg4B, Atg5, Atg16L1 and Atg7 reached the basal levels after YOL treatment. In conclusion, YOL had a protective and therapeutic role in APAP-induced liver injury in mice by activating Nrf2 signaling pathway and autophagy.

Chronic heat stress promotes liver inflammation in broilers via enhancing NF-κB and NLRP3 signaling pathway.

BACKGROUND: This study investigated the effects of chronic heat stress on liver inflammatory injury and its potential mechanisms in broilers. Chickens were randomly assigned to the 1-week control group (Control 1), 1-week heat stress group (HS1), 2-week control group (Control 2), and a 2-week heat stress group (HS2) with 15 replicates per group. Broilers in the heat stress groups were exposed to heat stress (35 ± 2 °C) for 8 h/d for 7 or 14 consecutive days, and the rest of 26 hours/day were kept at 23 ± 2 °C like control group broilers. Growth performance and liver inflammatory injury were examined for the analysis of liver injury. RESULTS: The results showed that heat stress for 2 weeks decreased the growth performance, reduced the liver weight (P < 0.05) and liver index (P < 0.05), induced obvious bleeding and necrosis points. Liver histological changes found that the heat stress induced the liver infiltration of neutrophils and lymphocytes in broilers. Serum levels of AST and SOD were enhanced in HS1 (P < 0.01, P < 0.05) and HS2 (P < 0.01, P < 0.05) group, compared with control 1 and 2 group broilers. The MDA content in HS1 group was higher than that of in control 1 group broilers (P < 0.05). Both the gene and protein expression levels of HSP70, TLR4 and NF-κB in the liver were significantly enhanced by heat stress. Furthermore, heat stress obviously enhanced the expression of IL-6, TNF-α, NF-κB P65, IκB and their phosphorylated proteins in the livers of broilers. In addition, heat stress promoted the activation of NLRP3 with increased NLRP3, caspase-1 and IL-1ß levels. CONCLUSIONS: These results suggested that heat stress can cause liver inflammation via activation of the TLR4-NF-κB and NLRP3 signaling pathways in broilers. With the extension of heat stress time, the effect of heat stress on the increase of NF-κB and NLRP3 signaling pathways tended to slow down.

Chai Hu oral liquid enhances the immune functions of both spleen and bursa of Fabricius in heat-stressed broilers through strengthening TLR4-TBK1 signaling pathway.

Heat stress can affect the poultry production and immune status of broilers. Heat stress disrupts intestinal integrity and increases intestinal inflammation, which is related with body immune dysfunction. Chai Hu oral liquid used as an antipyretic and anti-inflammatory drug is widely used in exogenous fever of poultry, but its resistance to heat stress and the mechanism is still unclear. In this study, a chronic heat stressed broilers model was established to explore the mechanisms of broilers' immune function changes and the effects of Chai Hu oral liquid. In this study, a total of 480 broilers were randomly divided into 6 groups with 80 replicates. Heat stress (HS) group broilers were stressed at 35 ± 2°C for 5 or 10 consecutive d with 6 h/d. Heat stressed (for 5 or 10 d) broilers were given with Jieshu KangreSan (Positive), Chai Hu oral liquid high, middle and low dosage (CH-High, CH-Mid, CH-Low) by oral administration. Birds in control group were treated with the same volume of PBS only in 25 ± 2°C. All birds were sacrificed at last heat stress challenged day. Changes in immune function were assessed by immune organs index, serum IFN-γ level, gene and protein expressions of immune factors in spleen and bursa of Fabricius. Results from this experiment showed that heat stress enhanced the immune organs' edema by directly increased the organs indexes of spleen and bursa of Fabricius in broilers. Heat stress for 10 d also increased bursa of Fabricius HSP70 protein level and significantly lowered the spleen and bursa of Fabricius proteins expressions of IFN-α, IFN-ß, and IFN-γ in broilers. The IFN-ß and IFN-γ protein levels in spleen and bursa of Fabricius also decreased in heat stressed broilers for 5 d. The gene and protein expressions of TLR4 and TBK1 markedly decreased in spleen and bursa of Fabricius of broilers treated with chronic heat stress. Chai Hu oral liquid reduced edema of immune organs and elevated TLR4-TBK1 signaling pathway to release immune factors. Above results indicated that chronic heat stress induced impaired immune function by inhibiting TLR4-TBK1 signaling pathway, and Chai Hu oral liquid had effective protection of body's immune ability by enhancing this signaling pathway.

Effect of peroxisome proliferator activated receptor γ agonist on angiotensin converting enzyme 2 mRNA expression in monocyte-derived macrophages of essential hypertensive patients.

OBJECTIVE: To study the effect of peroxisome proliferator activated receptor γ (PPAR-γ) agonist on the angiotensin converting enzyme 2 (ACE2) mRNA expression in monocyte-derived macrophages of essential hypertensive patients. METHODS: Totally 57 essential hypertensive patients were randomly divided into three groups: conventional treatment group (n=18), telmisartan group (n=19), and benazepril group (n=20); 20 patients with normal blood pressure were also selected as the control group. Monocyte-derived macrophages were isolated from blood samples of patients in all four groups. The expression of ACE2 mRNA in monocyte-derived macrophages was detected by RT-PCR before treatment and 4 and 12 weeks after treatment. RESULTS: Four and 12 weeks after treatment, the systolic pressure and diastolic pressure of telmisartan group and benazepril group were significantly lower than that of the conventional treatment group (all P<0.01), and the systolic pressure and diastolic pressure of telmisartan group were significantly lower than that of the benazepril group(both P<0.01) .The expression of ACE2 mRNA in monocyte-derived macrophages were significantly lower in essential hypertensive patients than that in control group (P<0.01). After having been treated for 4 weeks and 12 weeks, the expression of ACE2 mRNA in monocyte-derived macrophages of hypertensive patients in telmisartan and benazepril groups were significantly higher than that in conventional treatment group (all P<0.01), and the expression of ACE2 mRNA in telmisartan group was significantly higher than that in benazepril group (both P<0.01). CONCLUSION: PPAR-γ agonist could increase the ACE2 mRNA expression in monocyte-derived macrophages of essential hypertensive patients.