The Anti-inflammation And Anti-hyperlipidemia Effects And The Potential Molecular Mechanism Of Oat-beta-glucan

Oat(Avena sativa)is gramineous avena annual herbaceous plants,as an old cereal plant,it was planted for 2 thousand years and used as food or feed for livestock.The oats was divided into skinned oats and naked oats,the latter one was planted in China for years.The old medical book Bencaogangmu mentioned that the oat is good for the human heart and decrease sweat.Beside that,it is a valuable food.Another medical book Jiuhuangbencao mentioned that the oat can treat too much sweat or phthisis.It can be boiled or added into flour.The modern medical researcher found that the oat can increase gastrointestinal peristalsis,well for stool.It is also a low energy food,as a result,it can lowering the glycemic index.There is little research articles about the oats,however,there are more and more papers about the oats’function,including lowering the cholesterol and glucose,stimulate the immune system and decrease the risk of colon cancer.It is also revealed that the most important component of oat is oat β-glucan(βG),which is mainly exist in the oat cell walls of endosperm and the aleurone layer.It was composed by many of monosaccharide by β-(1,3)and β-(1,4)glucosidic bond and can not be digested by mammals.This special chemical structure gives the oat β-glucan special salubrity.The FDA suggests people eat 3g oat β-glucan food and clear identified on food.1.The effect of oat β-glucan on DSS-induced colitisAfter drinking 3%DSS for 7 days,and the colitis model was built.500mg/kg.bw and 1000mg/kg.bw of oat β-glucan were given to mice by intragastric administration 3 days before DSS was adding to drinking water and last to the end of the experiment.There is no difference between groups in the first 2 days,however,the DSS group mice was weak,anorexia,diarrhea and hair messy,as well as hematochezia,However,the β-glucan groups got lower DAI score.The colon and spleen tissue were collected after the mice were scarified.The length of colon in DSS group was significantly shorted,swelled and enlarged,and it has not shaped stool in the colon.However,the βG can ameliorate these and prevented the shorting of the colon.The high βG group colon is close to the control group.This revealed that the PG can ameliorate the swelling of the colitis.The size and weight of DSS group spleen were larger than control group.Though the βG group spleen were enlarged,it significantly smaller than the DSS group.The high βG group spleen is obviously different with the DSS group.The colons were embedded,sliced and dyed by H&E method.The control group colon showed integrated structure,uniformity intestinal wall,clear intestinal villus and fossae.While the DSS group colon showed seriously inflammatory effect,such as increasing of intestinal wall,erosion of colonic epithelium mucosal,destroying of the structure of fossae,swelling of epithelium,infiltration of lymphocytes and neutrophils,hyperplasia of colon inner wall.The βG group colon showed inflammatory condition,however,the thickness of colon wall is significantly smaller than DSS group,and the colon structure is integrant.The myeloperoxidase(MPO),malondialdehyde(MDA)and nitric oxide(NO)in colon were detected,and these indexes of DSS group were obviously higher than the control group.These indexes in βG group were much lower than DSS group.The total RNA was isolated from colon and the real-time PCR was performed to detect the mRNA difference.Total protein was also extracted and the western blot was performed.The inflammatory cytokines such as tumor necrosis factor α(TNF-α),interleukin β(IL-β)and 6,induced nitric oxide synthase(iNOS)all showed a sharp increase in DSS group.While these were lower in PG group,besides,they were concentration dependence.Immunohisto chemistry(IHC)results showed the similar conclusions;the inflammatory cytokines were high in DSS group and much less in prevention group.2.The effect of oat p-glucan on LPS-induced inflammation in macrophage RAW264.7 cellsThe macrophages were added lipopolysaccharide(LPS)and the inflammatory model was established.Then the β-glucan was added to inhibit it.LPS can activate the immune system and cause septic shock;it can activate the immune system in a low concentration(lower than Inmol/L).20 μg/mL and 40 μg/mL oat p-glucan will not affect the vitality of macrophage.Compared with control group,the inflammatory cytokines such as TNFa,IL-6,IL-β,iNOS and IFN-γ were higher in LPS group and the oat β-glucan group cytokines were lower than LPS group.3.The oat β-glucan ameliorates hyperlipidemia and the molecular mechanismsThe mice hyperlipidemia model was established by giving mice with high fat feed.500mg/kg.bw and 1000mg/kg.bw of oat β-glucan were used to prevent this disease.The weight of high fat group is increased,however,the βG groups were lower than the high fat group.The livers of control group were in dark red and the size is smaller.While the high fat group got heavier and larger liver,besides,they color is white or yellow,seems oily and got some embossment.The livers in low βG group were smaller,much darker than the high fat group and less embossment.The high βG group liver looks even closer to the control group.The spleens of high fat group were much heavier than the control group,while the prevention group were smaller.Serum were also collected to test the blood fat including total triglyceride(TG),total cholesterol(TC),low density lipoprotein cholesterol(LDL-C)and high density lipoprotein cholesterol(HDL-C).The high fat group’s TG,TC and LDL-C were much higher than the control group,but the HDL-C was lower.The βG can obviously decrease the TG,TC and LDL-C.And increase the HDL-C,although the difference is not so obvious.The H&E staining of liver showed that the control group liver cells were in order and the cell nucleus was large and round,no fat babbles.While the high fat group liver cells were loosely arranged and swelling,many fat babbles can be seem,and the cell nucleus were on side,which means lots of fat exist in the liver.While the βG group was much better than high fat group,the liver cells were smaller and well arranged.The H&E staining of abdominal fat pad also different,the control cells were small and tight,while the high fat cells were much larger than control,the length of high fat cells diameter was nearly twice of control group.The βG group cells’diameter was much lower than high fat group.To determine the variation of fat metabolism associate genes,the RNA of mouse liver was isolated and real-time PCR was performed.The fat metabolism associate genes such as peroxisome proliferator-activated receptor(PPARa)in high fat group was much more lower than control group,the βG group mice showed a much higher expression of PPARα.PPARγ,Fatty acid synthesis(FAS)and Sterol-regulatory element binding protein 1C(SREBP-1C)in high fat group were sharply increased,while these were much lower in βG group.The PCR data showed that TNF-α,IL-6 and inducible nitric oxide synthesis(iNOS)were increased in high fat group but downregulated expression in PG group.βG can ameliorate HFD-induced inflammation in mice.