Effect Of Rhubarb Free Anthraquinone On Weight Loss And Its Preliminary Mechanism

Objective: To explore the therapeutic effect of rhubarb free anthraquinone on obesity model rats,and to preliminarily analyze the possible mechanism of rhubarb free anthraquinone’s intervention in obesity,so as to provide a theoretical basis for the development of weight loss health products with rhubarb free anthraquinone.Methods: The rhubarb rhizome powder was extracted with 70% ethanol under reflux and the extract was fractionated with dichloromethane to obtain the total rhubarb free anthraquinone extract.The components of rhubarb free anthraquinone extract were identified by liquid chromatography-mass spectrometry（HPLC-MS）and the contents of five monomers of rhubarb free anthraquinones were determined by high performance liquid chromatography（HPLC）.The rhubarb free anthraquinone extract was prepared into suspension-type granules by wet granulation method.A obesity rat model was established by high-fat diet feeding,and the intervention effect of rhubarb free anthraquinone granules on obesity was studied.The degree of fatty lesions and liver and kidney toxicity were analyzed by pathological tissue sections（H＆E staining）and serum biochemical indexes.The toxicity of rhubarb free anthraquinone was evaluated by mouse acute toxicity test.The core target proteins and possible action pathways of rhubarb free anthraquinone against obesity were screened by network pharmacology,and the binding activity of the active ingredients to the core target proteins was verified by molecular docking.The expression changes of the core target proteins of rhubarb free anthraquinone intervention in obesity at the mRNA level were analyzed by qPCR,and the corresponding protein expression changes of the core target proteins were analyzed by Western blot.Results: The content of 5 monomers of rhubarb free anthraquinones（emodin,rhein,aloe emodin,physcion and chrysophanol）in the rhubarb free anthraquinone extract reached 93.46%;Rhubarb free anthraquinone can significantly reduce the body weight,Lee’s index,and fat body ratio of the model rats（P < 0.05）;the fat droplets in the liver of the rats in the treatment groups were significantly reduced and the fat cells were also decreased.After glucose injected,the blood glucose concentration of the rats in the model control group was significantly higher than that in the normal control group（P<0.05）,while the blood glucose concentration in the treatment group was lower than that in the model control group.After administration,the low-density lipoprotein cholesterol（LDL-C）of the treatment rats significantly decreased compared with that of the model control（P<0.05）,while the other three items had no statistical significance.The rhubarb free anthraquinone had low hepatic and renal toxicity.MAPK8,MAPK14 and CASP3 are the core target proteins of rhubarb free anthraquinone in the intervention of obesity.Obesity may be inhibited by these proteins through regulation of endocrine resistance pathway,cancer pathway,fluid shear stress and atherosclerosis pathway,AGE-RAGE signaling pathway in diabetes complications,GnRH signaling pathway and hepatitis B route.The docking scores of three core target proteins with five free anthraquinone monomers were less than-5.After administration,the expression of MAPK8 and CASP3 which were originally down regulated due to obesity were up-regulated,while the expression of MAPK14 which was originally up-regulated was still up-regulated.Conclusion: Rhubarb free anthraquinone can significantly improve obesity,regulate blood lipid and improve glucose metabolism,and has less toxic and side effects.Rhubarb free anthraquinone can change the expression of MAPK8 and CASP3 at gene and protein levels from down-regulation to up-regulation.The proteins may interfere with obesity by regulating endocrine resistance pathway,cancer pathway,fluid shear stress and atherosclerosis pathway,AGE-RAGE signaling pathway in diabetes complications,GnRH signaling pathway,and hepatitis B route.