Study On The Effect Of Steaming On The Content And Activity Of Main Components Of Rhubarb In Vitro

Rhubarb,a traditional Chinese medicine,has been widely used in clinics for the treatment of diarrhea.It has various functions such as purging and attacking accumulation,clearing away heat and fire,removing blood stasis and relieving menstruation.However,its purgative action is too strong to be used for the weak,elder and child patients.In fact,the purgative action could be reduced through the rhubarb being processed.There are four processed methods recorded in Chinese Pharmacopoeia.They are raw rhubarb,rhubarb steamed with wine,rhubarb stir-fired with wine and rhubarb charcoal in which rhubarb steamed with wine shows significant reduction on the purgative action.In this study,aiming to investigate the influence on the constituents and bioactivities from the wine-steaming,the rhubarb extract and rhubarb anthraquinonewere prepared and processed with steaming.By using HPLC analysis,they were investigated on chemical composition and in vitro metabolites.Furthermore,they were investigated on the anti-bacterial and antioxidant effects.The studies included:(1)High performance liquid chromatographic(HPLC)conditions were constructed to investigate the constituents of rhubarb extract and rhubarb anthraquinone.An orthogonal test method was performed to investigated the influence from the water,ethanol and wine added.(2)The metabolites were prepared by using the in vitro transformed system established,and analyzed with the differences on chemical constituents and HPLC fingerprint.(3)Their antibacterial and antioxidant activities were investigated on Staphylococcus aureus and Pseudomonas aeruginosa,and DPPH.The results showed as follows:(1)The significant influences were shown on the constituents of the wine-steamed samples in a long time.The process resulted in decreasing on the combined anthraquinone and increasing on the free anthraquinone.(2)In the in vitro biotransformed system,the combined anthraquinone in the samples were metabolized into free anthraquinone.The wine-steamed samples showed more content of the free anthraquinones with less content of the combined anthraquinone.(3)The samples with or without wine-steaming showed inhibitive effects on Staphylococcus aureus and Pseudomonas aeruginosa.But the effects were slightly decreased in the wine-steamed samples.With the antioxidant effects,all samples had similar DPPH scavenging ability.There were no differences among the samples and wine-steamed samples.In conclusion,the wine-steamed process could significant influence the content of main constituents involved in the rhubarb extract and rhubarb anthraquinone.The process resulted indecreasing on the content of combined anthraquinone,increasing on the content of free anthraquinone,reducing on the antibacterial activity and unchanged DPPH scavenging ability.