Synergistic Antioxidant Activities Of Three Traditional Chinese Herbs

Recent studies suggested that a variety of diseases of human was related to free radical oxidative damage. Traditional Chinese herbs were an important source of antioxidant agents, and many studies indicated that the pharmacological effects of herbs were relevant to their antioxidant components. China had abundant resources of herbs, 201 kinds of herbs among which had been applied directly to health care products or food for its definite safety. Traditional herbal functional foods often presented in the form of formula, in which the herb pair was the basic unit. Therefore, it was important in theoretical and practical to develop herbal health protection food by investigating the antioxidant activity of substances and pharmacological of herb pairs.According to literature records, Astragalus membranaceus, Glycyrrhiza uralensis and Paeonia lactifora all had strong antioxidant activities. In this study, antioxidant synergies on different solvent extracts of the three herbs and herb pairs were discussed. The antioxidant activity changes and the physiological mechanisms on protecting cells from oxidative injury and of AG extracts were analyzed. And the pilot study on the basis of antioxidant substances was identified. The major results were as follows:1. In the study on antioxidant activity of different organic solvent extracts of Astragalus membranaceus, Glycyrrhiza uralensis and Paeonia lactifora,we found that the increase of DPPH free radical scavenging capacity was not only in the amount after combining the herbs. And DPPH free radical scavenging capacity was influenced by the polarity of solvents. More polar solvent extraction of herbs presented stronger capacity. There was a good linear relationship between the free radical scavenging capacity and total phenol content of extracts in PG or AG. It indicated that total phenolic substances had played an important role in the study on antioxidant activity of herbs.2. According to the study on antioxidant activity of different polar extractions of AME, GU and herb pair,we found that total phenol, flavonoid content and antioxidant capacity were different in various polar extractions. It had the highest total phenol, flavonoid content and antioxidant capacity in ethyl acetate extraction of AG, indicating that the content of total active ingredients were higher in ethyl acetate extraction. The extracts of herb pair showed a better antioxidant activity compared with their respective theoretical sum. The synergy of AG was related to the total phenolic/flavonoid increments, especially that of total phenolics. From the study, we could obtain that EA-AG had the strongest antioxidant capacity and the best synergy efficiency after combining.3. EA-AG could have a protective effect on H2O2 induced oxidative damage in MRC-5 cells. EA-AG could significantly improve the SOD and GSH-Px activity, and reduce the accumulation of MDA induced by H2O2. It indicated that EA-AG might also reduce oxidative stress damage of H2O2 by inducing the activity of intracellular antioxidant enzymes. Preliminary study found that EA-AG in the concentration range of 5 mg / L ~ 160 mg / L could inhibit the multiplication of HepG2 cells, and it also showed a clearly concentration-dependent manner. This indicated that EA-AG had a certain inhibition of the multiplication of cancer cell.4. According to changes of HPLC-DPPH analysis before and after antioxidant of AG, we selected 9 kinds of potential antioxidant substances from EA-AG , which proved to be phenols and flavonoids through HPLC-DAD and HPLLC-MS/MS structural identification analysis.In short, the different polar solvent-extracted method of AME and GU combination could obtain a higher antioxidant capacity. These data provided some useful information for the Chinese health protection food cooked with medicinal herbs, and also offered a theoretical basis for further development and potential application of new, natural antioxidant-containing food materials in functional foods.