Study On The Differences Of Polysaccharide Components And Antioxidant Activities In Fresh And Dry Dendrobium Officinale Kimura Et Migo

Objective:Fresh herb is one of the characteristic of traditional medication in Chinese traditional medicine,which has a long historical standing.Dendrobium is conxentional fresh herb,when it was used in traditional Chinese medicine,which was accustomed to pay great attention to its fresh form and believed to possess exellent feature of fresh form.Modern studies have reported that fresh Dendrobium has more significant pharmacological activity than in dried Dendrobium.Therefore,the 2015 edition of Chinese pharmacopoeia introduces respectively fresh and dried forms on Dendrobium processing.At present,the research of Dendrobium on chemical components and pharmacological properties has focused on dried forms.However,there is lack of systematical and in-depth study of fresh and dried Dendrobium difference on chemical compositions and efficacy,which limit the market application and product delopment of fresh Dendrobium.This article adopts systematical research of fresh Dendrobium officinale?FDO?and dried Dendrobium officinale?DDO?on antioxidant capacities in vitro and in vivo,activities of polysaccharide,polysaccharide content and polysaccharide structure to confirm the reason of difference on polysaccharide gradient and antioxidant activity between FDO and DDO.Which preliminarily illuminated the material foundation of antioxidant property in D.officinale,verified scientific connotation in “fresh is great” of Dendrobium,and provided therotical foundation for the development of fresh D.officinale.Methods:Firstly,the diference of in vitro antioxidant ability of FDO and DDO was investigated and analyzed by regarding DPPH·,ABTS⁺· and ·OH free radical as indicators.Based on these,through constructing CCl₄-induced toxic mice model,which is to study the effects on antioxidant parameters including T-AOC,GSH,CAT,SOD and MDA in the liver and serum of CCl₄ –treated mice,and investigate the difference of antioxidant capacity in vivo of FDO and DDO.Meanwhile,preparing the polysaccharide of fresh D.officinale?FDOP?and polysaccharide of dried D.officinale?DDOP?,the activity difference of FDOP and DDOP was explored.To clarify the reason of activity difference,the difference of polysaccharide in FDO and DDO was furtherly research,which incudes measuring the polysaccharide content,the content of derivative product mannose and analyzing molecular weight distribution by high performance liquid gel permeation chromatography?HPLC-GPC?and monosaccharide composition by gas liquid chromatography-mass spectrometry?GC-MS?.Results:1.FDO and FDOP have much stronger antioxidant capacity in vitro,compared to DDO.The results prove that FDO and DDO all have strong abilities of scavenging DPPH·,ABTS⁺· and ·OH free radical.The maximum scavenging rate of FDOP for each free radical was respectively 52.56%,61.24%,28.71%,DDO was respectively41.34%,48.01%,15.84%.The scavenging ability of FDO is obviously strong than DDO.Thus,in vitro antioxidant capacity of FDO is superior to DDO?p < 0.05?.In addition,the polysaccharide which is from FDO and DDO by extraction and separation,the maximum scavenging rate of FDOP were respectively 45.7%,42.4%,28.71%,DDOP were respectively 40.09%,35.13%,21.98%.The capacity of scavenging free radical of FDOP is better than DDOP,indicating that FDOP is good than DDOP in antioxidant activity in vitro?p < 0.05?.2.FDO and FDOP are superior to its dried forms on antioxidant capacity in vivo.By constructing CCl₄-induced toxic mice model,which is to study the effects on antioxidant parameters including T-AOC,GSH,CAT,SOD and MDA in the liver and serum of mice,and investigate the difference of antioxidant capacity in vivo of FDO and DDO.Results show that both of FDO and DDO can enhance the level of T-AOC,GSH,CAT,SOD and decrease MDA level in the liver and serum of CCl₄ –treated mice,and FDO is markedly strong than DDO,and FDO is observably excellent in antioxidant effect than DDO?p < 0.05?.Besides,the antioxidant effect in vivo of DDOP is weaker than FDOP?p < 0.05?.3.The content of polysaccharide and mannose in FDO are higher than in DDO,and the monosaccharide eompositions of FDOP is significantly different from FDOPTo find the reason of difference in activity,the contents of polysaccharide and mannose in FDO and DDO were determined.On the aspect of polysaccharide and mannose,the content of both in FDO(512 mg·g^-1 and 489.5 mg·g^-1)are significantly higher than in DDO(348.7 mg·g^-1 and 291.3 mg·g^-1).Result of HPLC-GPC shows that the molecular weight in FDOP is 1572 KDa and distributes uniformly.But DDOP was decomposed into three various molecular weight segments,which are including 1572KDa?583 KDa and 8 KDa.The result of GC-MS indicates that both of FDOP and DDOP have the same monosaccharide compositions,but the propotion of relative content of monosaccharide is distinctly different.The relative content of glucose,mannose and rhamnose in FDO are repectively 1,0.830 and 0.008,whereas,three of them in DDOP are repectively 0.810,1.120 and 0.001.Conclusion:This study suggests that FDO is dramatically superior to DDO on antioxidant effect in vivo and vitro.There are two mainly reasons to illustrate the difference: one is that the content of polysaccharide in FDO is higher than DDO,the other one is that polysaccharide structure is changed in process of D.officinale,which caused the decrease in activity.