| Background:Inflammation is a common defense when our body response to the external stimulus.Inflammatory site will trun red and will be swollen.At the same time,people will feel hot and painful.Inflammatory skin diseases usually accompany with pruritus.Whatever pain and pruritus is very uncomfortable physical feelings,which affect the work and life seriously.However,non-steroidal anti-inflammatory drugs,including aspirin and acetaminophen.Which are commonly used in clinical,have more or less different side efecets.Thus,researchers have turn their attention to natural products,such as aloe,gentian and yam.They have a good therapeutic effect on acute and chronic inflammation,but the specific anti-inflammatory components and mechanisms have not been clear.And Chinese yam just happens to be a plant can be used as medicine and food.So we started to study the anti-inflammatory active ingredients in Chinese yam.This is the first time to explore the anti-inflammatory effect of aloe-emodin from the perspective of mast cells,which can provide new ideas for the treatment of ACD with aloe-emodin.Purpose:To isolate and purify the anti-inflammatory component from Chinese yam with column chromatography and medium pressure preparative chromatography.To explore the anti-inflammatory mechanism with animal behavior experiments and immunohistochemistry.Experimental methods:The hollow fiber ultrafiltration membrane was used to roughly divide the yam extract.Thus,they become two parts----small molecule part(<10KD)and large molecule part(>10KD).For small molecule part,silica gel column chromatography,gel column chromatography,C-18 column chromatography,reversed-phase medium pressure preparative chromatography,high-performance liquid chromatography,and ultra-high performance liquid chromatography were used for separation and purification.Then we used mass spectrometry,nuclear magnetic resonance and other techniques for structural identification.Ion purification chromatography was used for large molecules part,and the activity compound was tracked by calcium ion imaging technology.The 2%urushiol-induced ACD model was used to simulate allergic contact dermatitis Animal behavior experiments was used to study the anti-inflammatory and anti-pruritic effects of aloe-emodin.HE staining was used to observe the skin thickness and explore the anti-inflammatory effects of aloe-emodin.Toluamine blue staining was used to observe the effects of aloe-emodin on the number of mast cells and the degranulation ratio of mast cells in the inflammation model.Experimental results:1.Small molecules part of yam was isolated and purified,and the structure was identified We finally get six compounds----aloe-emodin,Batatasin I,methylnissolin,formononetin,2,7-dihydroxy-4,6-dimethoxyphenanthrene,2,2,7,7'-Tetrahydroxy-4,4',6,6'-tetramethoxy-1,1'-biphenanthrenes2.Three chromatographic peaks were obtained from large molecules part of yam by ion exchange chromatography,while peak 1 and peak 3 have cellular activity among them.3.Aloe-emodin relieves acute and chronic allergic contact dermatitis which induced by 2%urushiol,by inhibiting degranulation of mast cells.Aloe-emodin can inhibit scratching behavior,reduce skin thickness of mice in the model group,reduce mast cell infiltration,reduce the proportion of mast cell degranulation and improve inflammation.Experimental conclusion:At present,there are six anti-inflammatory active ingredients was isolated from yam.Among them,aloe-emodin can alleviate acute and chronic allergic contact dermatitis which induced by 2%urushiol,by inhibiting degranulation of mast cells. |
PDF Full Text Request