| There are lots of diseases are caused by the excess of free radicals according to thetheory of free radical medicine. It has opened up a new road for people to understandthe mechanism of pathogenesis and disease witch is difficult to cure till now. It is ofgreat significance in researching antioxidant with high activity investigating drugs tocure disease caused by free radical imbalance. The traditional method we used toevaluate drugs is to measure how much one or one kind of effective components do theyhave. But for traditional Chinese medicine and it’s dosages, this method is poor toreflect their actual therapeutic effects accurately. The reason lies both in the unstrictlinear correlation between antioxidant effect and the effective composition content andin the complex interaction between each components.In this paper, a new view is proposed to evaluation the efficacy of drugs from theside of antioxidation based on the theory of free radical medicine and drug evaluationstudy. The target object of the view is only limited to drugs witch treat oxidativedamage disease and antioxidant activity determination method is referenced. This paperis divided into two parts. Part one is methodology researching, in which, there are threekinds of antioxidant evaluation system based on radical scavenging capacity wereestablished, and the various experimental parameters were optimized. The second part ismethod application study, in which, the three kinds of method were applied toevaluation eight kinds of salvia miltiorrhiza drugs and two kinds of extracts of Chinesedrug.Three methods are as followes, The DPPH method with UV detection, thehydroxyl free radical (·OH) method with flow injection luminol chemiluminescencedetection. The hydroxyl free radical is produced by fenton reaction system (H2O2-Fe2+).And the superoxide anion is produced by luminol react with pyrogallol in alkalinesolution. Experimental parameters were optimized by single factor variable method.Many parameters were investigated respectively for each system, such as theconcentrations of DPPH, luminol, hydrogen peroxide and ferrous ion, the reaction time,the pH value of the reaction as well as the measure wavelength, flow road, pumprotation speed and negative high voltage of the instrument. Stability and precision of themethod are investigated to prove that they have good stability and high precision,andcan be applied to evaluate the antioxidant of drugs. The IC50value as a indicator to evaluate the ability of antioxidant to scavenging free radicals.The IC50value can beworked out by the dose-response relationship between free radical scavenging ratio andconcentration of antioxidant.It is showed that free radicals play a vital role in the development of cardiovasculardisease. The ability of salvia miltiorrhiza drugs to scavenge free radicals have a directeffect of the treatment of such diseases. There are little researches on the antioxidantablility of salvia miltiorrhiza medicines, so we choose8kinds of Salvia Miltiorrhizamedicines to evaluate the antioxidant efficacy. Results show so large a difference in thethree methods that we can’t make a comparison. It is difficult for a single method toevaluate the antioxidant capacity of a drug accurately. Because one determinationresults can only represent it’s own radical scavenging ability, but not others’,and it isvery necessery and emergency to establish a standardized assessment system to evaluatethe ability of antioxidant comprehensivelyWith Mori Cortex as the research object, the polysaccharide is extracted by waterand precipitated by alcohol. The extraction process was optimized by L9(34) orthogonalexperimental design method. Four factors and three levels are selected in thisdesignation.The extraction rate of Mori Cortex polysaccharide is choosed as index toevaluated results. It is showed that the best conditions for polysaccharide extraction isof20times of water adding,30min of ultrasonicing, temperature at50℃,2times ofextraction. To verify whether it is optimization, we extract200g samples and get12.59g polysaccharide, the extraction rate get rich to6.30%. Total sugar content isdeterminated by phenol sulfuric acid method, reducing sugar content is by DNS（3,5-2nitro salicylic acid）colorimetric method, the minus between these two is polysaccharidecontent. The scavenging activity on DPPH· and·OH of Mori Cortex polysaccharides isconcentration-depend. The polysaccharides have good scavenging on DPPH· and·OHfree radicals with Vc as a positive control, Especially, sensitizing effect of thepolysaccharides is found in luminol chemiluminescence system which caused bysuperoxide anion produced by the autoxidation of pyrogallol. Further research on thephenomenon found that the sensitizing effect of polysaccharide is linear correlation withthe concentration. Polysaccharides of Mori Cortex have some oxidation resistance butnot as better as Vc. It has specificity that sensitizing effect of the polysaccharides inluminol chemiluminescence system which caused by superoxide anion produced by theautoxidation of pyrogallol.The result has potential application value.95%ethanol is used to extract the total flavonoids from Miro Cortex and AB-8 macroporous adsorption resin to enrich and purify flavonoids extracts. Ultravioletspectrophotometric method was used to determinate the content. With Vc as the positivecontrol, the antioxidant activity was investigated by determining these three freeradicals capture abilities. The results showed that the content of Miro Cortex flavonoidswhich processed by macroporous adsorption resin can reach more to51%. In addition,the free radicals capture abilitie was related to the concentration dose. By Comparingthe IC50value of Vc with flavonoids’s we learned that Miro Cortex flavonoids havevery good antioxidant activity, especially for·OH and·O2-, the scavenging capacities ofthese two are even greater than these of Vc. As natural antioxidant, Miro Cortexflavonoids have great development value and potential in research fields of antioxidant,antiaging and health care. |
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