Dietary oregano aqueous extract improves growth performance and intestinal health of broilers through modulating gut microbial compositions

Background Intestinal health plays a pivotal role in broiler chicken growth.Oregano aqueous extract(OAE)effec-tively exerts anti-inflammatory and antibacterial effects.However,the protective effects of OAE on intestinal health in broilers and the underlying mechanism remain unclear.This study aimed to investigate the potential effects of OAE on growth performance,the gut microbiota and intestinal health.A total of 8401-d-old male and female broilers(Arbor Acres)were randomly allocated into 6 groups as follows:basal diet(Con),Con+antibiotics(Anti,colistin sulfate 7 g/kg,roxarsone 35 g/kg),Con+400,500,600 and 700 mg/kg OAE(OAE400,OAE500,OAE600 and OAE700).Subse-quently,fermentation in vitro together with oral administration trials were carried out to further assess the function of OAE on intestinal health of broilers.Results Dietary 700 mg/kg OAE supplementation resulted in an increase(P<0.05)in body weight and a decrease(P<0.05)in feed conversion ratio when compared with the control during d 22 to 42 of the trial.OAE addition resulted in lower(P<0.05)jejunal crypt depth and mRNA expression of IL-4 and IL-10 at d 42.In addition,dietary OAE addition increased the abundance of Firmicutes(P=0.087)and Lactobacillus(P<0.05)in the cecum,and increased(P<0.05)the content of acetic acid and butyric acid.In the in vitro fermentation test,OAE significantly increased(P<0.05)the abundance of Lactobacillus,decreased(P<0.05)the abundance of unspecified_Enterobacteriaceae,and increased the content of acetic acid(P<0.05).In the oral administration trial,higher(P<0.05)IL-4 expression was found in broilers when oral inoculation with oregano fermentation microorganisms at d 42.And SIgA content in the ileum was significantly increased(P=0.073)when giving OAE fermentation supernatant.Conclusions Dietary OAE addition could maintain intestinal health and improve growth performance through enhancing intestinal mucosal immunity and barrier function mediated by gut microbiota changes.

抗氧化治疗在放射性肺损伤中的研究进展

放射性肺损伤(radiation induced lung injury, RILI)是临床上胸部肿瘤患者放疗后发生的严重并发症,主要表现为气短、低热、咳嗽等,严重影响患者生存,如何更好地防治RILI是亟待探索的问题。RILI的发生机制主要包括靶细胞学说、细胞因子学说、自由基学说、血管内皮细胞损伤学说。其中放疗产生的活性氧(reactive oxygen species, ROS)对组织的损伤贯穿整个RILI病程,对放射性肺炎和放射性肺纤维化均具有直接促进作用。包括巯基化合物、抗氧化酶、植物抗氧化剂等在内的治疗手段已被用于防治RILI,本文即就抗氧化治疗在RILI中的研究与应用作一综述。

Dietary folic acid addition reduces abdominal fat deposition mediated by alterations in gut microbiota and SCFA production in broilers

Intensive selective breeding for high growth rate and body weight cause excess abdominal fat in broilers.Gut microbiota and folic acid were reported to regulate lipid metabolism.A total of 210 one-day-old broilers were divided into the control(folic acid at 1.3 mg/kg)and folic acid groups(folic acid at 13 mg/kg)to illustrate the effects of folic acid on growth performance,abdominal fat deposition,and gut microbiota,and the experiment lasted 28 d.Results revealed that dietary folic acid addition decreased abdominal fat percentage(P<0.05)and down-regulated genes expression related to cell proliferation and differentiation in abdominal fat including IGF1,EGF,C/EBPα,PPARγ,PLIN1,FABP4 and PCNA(P<0.05).Folic acid addition decreased caecal Firmicutes-to-Bacteroidetes ratio(P<0.01)and increased the proportions of Alistipes,Oscillospira,Ruminococcus,Clostridium,Dehalobacterium and Parabacteroides(P<0.05).Caecal acetic acid,and propionic acid contents were found to be higher under folic acid treatment(P<0.05),which were negatively related to genes expression associated with adipocyte proliferation and differentiation(P<0.05).Ruminococcus was positively correlated with caecal acetic acid content,and the same phenomenon was detected between propionic acid and Oscillospira and Ruminococcus(P<0.05).Acetic acid and Oscillospira were identified to be negatively associated with abdominal fat percentage(P<0.05).In conclusion,our data demonstrated that dietary supplementation of folic acid reduced fat deposition in broilers by inhibiting abdominal adipocyte proliferation and differentiation,which might be mediated by changes in gut microbiota and short chain fatty acid production.

De novo nucleotide biosynthetic pathway and cancer

De novo nucleotide biosynthetic pathway is a highly conserved and essential biochemical pathway in almost all organisms.Both purine nucleotides and pyrimidine nucleotides are necessary for cell metabolism and proliferation.Thus,the dysregulation of the de novo nucleotide biosynthetic pathway contributes to the development of many human diseases,such as cancer.It has been shown that many enzymes in this pathway are overactivated in different cancers.In this review,we summarize and update the current knowledge on the de novo nucleotide biosynthetic pathway,regulatory mechanisms,its role in tumorigenesis,and potential targeting opportunities.

Grazing alters environmental control mechanisms of evapotranspiration in an alpine meadow of the tibetan Plateau

Aims Evapotranspiration(Et)is an important component of the terrestrial water cycle and is easily affected by external disturbances,such as climate change and grazing.Identifying Et responses to grazing is instructive for determining grazing activity and informative for understanding the water cycle.Methods this study utilized 2 years(2014 and 2017)of eddy covariance data to test how grazing regulated Et for an alpine meadow ecosystem on the tibetan Plateau(tP)by path analysis.Important Findings Radiation dominated Et with a decision coefficient of 64-74%.the soil water content(SWc)worked as the limiting factor in the fenced site.However,in the grazing site,the limiting factor was the vapor pressure deficit(VPD).Grazing had large effects on Et because it greatly affected the water conditions.the SWc and VPD were enhanced by 14.63%and 4.36%in the grazing site,respectively.therefore,sufficient water was supplied to Et,especially during drought,and strengthened the transpiration pull.As a result,a favorable micrometeorological environment was created for Et.Grazing shifted the limiting factor of Et from the SWc to VPD,which weakened the limiting effect of the water conditions on Et and advanced the Et peak time.In addition,grazing altered the compositions of Et by changing the community structure,which directly resulted in an increased Et.In summary,grazing enhanced Et through altering the community structure and micrometeorological environments.the findings of this study further improve our understanding of the driving mechanisms of grazing on Et and will improve our predictions for the global water cycle.