The Pharmacokinetic Study Of Antioxidation Of Extracts Of Magnoliae Officinalis

Superoxide dismutase activity can reflect the organism's ability of scavenging superoxide anion radicals,so determining the activity accurately is often required in antiaging study.Kinones with hyperfluorescence can be produced from the autoxidation process of pyrogallol.The kinones can be decreased when the superoxide radicals formed in the process are scavenged by superoxide dismutase.A kinetic fluorescent spectrophotometry based on the principle has been developed to determine superoxide dismutase activity.The influence of buffer concentration,pH,pyrogallol concentration and temperation on the determination were discussed.The optimum result can be achieved with buffer(tris-acetic acid)concentration of 0.1mol/L,and pyrogallol concentration of 0.385mmol/L in pH 8.2,25℃.The linear response range of superoxide dismutase is 0.31～1.58mg/L,the RSD of serum sample determination is 1.12%(n=5),and the recoveries of spiked sample are between 94.3%and 103.49%.The result of this assay is identical with that of xanthine -xanthinoxidase assay.This assay can be applied to determine the superoxide dismutase activity in animal tissue sample.As one of Chinese traditional herbs,magnoliae officinalis not only have the traditional effects of broad-spectrum anti-bacteria,anti-agnail,anti-canker and anti-cruor, but also have those of antiotumour,protecting cardiac and cerebral vessels,antioxygen and anti-aging.It is important to understand the antioxidation pharmacokinetic processes and parameters of magnoliae officinalis extracts for exploiting their new officinal functions and guiding their clinical medicaation.The antioxidation pharmacokinetic processes and parameters in vivo of aceti ether extracts of magnoliae was studied with the advancing rates of the SOD,GSH-Px and CAT activity as pharmacodynamic index.If the magnoliae extracts are intragastrically administered to mice with the doses of 0.25g/kg,0.40g/kg,0.86 g/kg,and the advancing rates of SOD activity in blood serum are used as pharmacodynamic index,their pharmacokinetic process is identical with that of first order dynamics and two compartment model by T-E and T-D methods,and the time of T-D peak is the same as that of T-E peak(Tp=2h).Because elimination half life and AUC_{0→∞}are not proportional to doses,the no-linear character in vivo is shown when the mice are orally administered with the extracts of magnoliae officinalis.If magnoliae extracts are intragastrically administered with dose of 0.25g/kg and the advancing rate of GSH-Px activity in blood serum is used as pharmacodynamic index,its pharmacokinetic parameters can be obtained with T-E methods.The pharmacokinetic process of magnoliae extracts is identical with that of first order dynamics and one-compartment model,and the attenuated speed of pharmacologic action is faster than that of blood drug level.If magnoliae extracts are intragastrically administered with the dose of 0.86g/kg and the advancing rate of CAT activity in blood serum is used as pharmacodynamic index,its pharmacokinetic process is identical with that of first order dynamics and one compartment model by T-E method.For the three pharmacodynamic indexes,the absorption half lives of magnoliae extracts are all smaller than their elimination half lives(t_1/2ka＜t_1/2),which the elimination speed of drug is slower than its absorption speed.It can be concluded that the drug may stay in vivo for long time.