Study On The Relationship Between Maillard Reaction And Mechanism For Processing Radix Rehmanniae

Rehmanniae Radix is widely used in different forms such as Rehmanniae Recens Radix, Rehmanniae Exsiccata Radix (RER), Radix Rehmanniae Preparata (RPR) and Radix Rehmanniae Carbonisata (RCR). They are different in flavor, nature, property and action. It is a typical representative for the same plant being used as different herbs by processing in traditional Chinese medicines. RPR and RCR are the main processed products. The efficacious material basis must be changed through processing. Until now, there has been little information about the processing.Verbascoside has been used in the quality control of RPR in Pharmacopoeia of People’s Republic of China of2010edition, its content regulations is the same to RER. It is obvious that this criterion couldn’t reflect the purpose of processing. Traditional end points for the processing of RPR are "black as pitch" and "sweet as maltose". This sensory evaluation makes the quality of RPR irregular. Previous investigations indicate that5-HMF generated and amino acids mostly decomposed during the processing. Due to high temperature applied in the processing of RPR and RCR, we hypothesized that Maillard reaction (MR) occurred during the processing, and the changes induced by MR and/or the MR products may be the material basis of new acquired actions. Therefore, the processing was investigated from the perspective of MR in this dissertation. In additioin, RPR is mainly used to nourish Yin and supplement blood. Inflammatory anemia (IA) is one of the most common anemia in clinic, so the effect of RPR on rat model of IA was also observed. The main results are as follows: 1. RER slices were steamed for different times (0-60h). The absorbance at420nm of a sample of the aqueous extract increased gradually, the change was exponential function of processing time. The total amino acid content fell from0.296%to0.087%during the first12h, and then remained at this low level in the first12h, and then increased and couldn t be detected after steaming for8,16,16and24h by the method of HPLC-ELSD; while fructose, glucoe (galactose), and mannotriose increased gradually, and reached the highest level at24h, then fructose and mannotriose changed with a downward tendency. During the processing of RPR, verbascoside was found decreased all the time, and only1/3remained after steamed for60h.2. With time increasing, it was found that the weights and the contents of water soluble extract and catalpol dropped consecutively. Slice volume, A420nm and HMF increased in the early stage and then decreased. The pH value, however, kept stable at about4.7in the early stage and increased for the last stage. When the properties of the material met the traditional criteria, black appearance with a yellowish-brown inside, HMF and A420nm were found at their highest level.3. Wistar rats were undergone once intracutaneous injection of Complete Freund’s Adjuvant at the tail base. Preventive treatment group were given low-, middle-, and high-dose RPR (0.54,1.08,2.16g/kg rat weight). The results showed that some indicators of anemia and oxidative damage ameliorated compared to the control rats receiving tap water, while the rats treated high-dose RRP deteriorated in many indexes, such as RBC, HGB, HCT, serum total iron binding capacity, tissue MDA, sulfhydryl and carbonyl concentration, the content of iron in serum, liver and spleen, serum transferrin saturation etc.4. Wistar rats were intracutaneously injected with Complete Freund’s Adjuvant at the tail base and sacrificed weekly. It was found that RBC and HGB was in the normal range for five weeks, but serum iron, serum total iron binding capacity and transferrin saturation have decreased significantly, the concentration of iron in liver and spleen significantly increased when compared with blank control group, these results indicated that the rats have fit the diagnosis index of IA. In conclusion:MR occurs during the preparation of RPR and RCR. The chemical changes boosted by MR and/or MR products may be responsible for the new obtained functions of RPR and RCR. The rat model of IA induced by once injection of CFA was not typical yet. High dose RPR seems to possess obvious side effect, should be carefully adopted in clinical application.