| The oxidation stress is being implicated in many diseases such as aging, cancer, and immunity deficiency etc, which can be prevented by xenobiolic antioxidant. Terminalia chebula Retz.was proven to be of the strongest antioxidant activity among 19 stuffs as food additives permitted by Ministry of Health of China for the manufacture of functional foods..The antioxidant activities of 19 stuffs were studied based on the FRAP values and the data of Reducing power. The results showed that the extract solution from Terminalia chebula Retz has highest antioxidant activity among 19 stuffs tested. The FRAP value and the percentage of scavenging DPPH radicals from it were (4422.33±123.56) mmol·g-1 and (90.123±1.388)%, respectively. The contents of total flavonoids and phenols were (211.23±8.24) mg·g-1 and (49.51±0.00) mg·g-1, respectively. The FRAP value of different stuffs has high correlation with the total phenols contents with the correlation coefficient up to 0.7779.The extracting technology of bioactive components of Terminalia chebula Retz. were studied. The optimal parameters of the extracting technology were that the concentration of ethanol was 50%, the ratio of sample to extracting solution was 1:20 (m·v-1), the extracting temperature was 60℃, the extracting times was 4 and the extracting time was 7 min. The recovery ratio of bioactive compounds of Terminalia chebula Retz. was (8958.07±145.05) mmol·g-1 by using this optimum technology.In order to further prove the strongest antioxidant activity of Terminalia chebula Retz., comparison tests of antioxidant activities were conducted taking Longjing tea and Ginkgo biloba leaf as references which are conventionally accepted as strong antioxidant. The results showed that the FRAP value of Terminalia chebula Retz. was 1.43 times more than that of Longjing tea, and 10.81 times more than that of Ginkgo biloba leaf. The percentage of scavenging DPPH radicals of Terminalia chebula Retz. was 1.27 times more than that of Longjing tea, and 1.99 times more than that of Ginkgo biloba leaf.The antioxidant activity of crude extracts from Terminalia chebula Retz.was proved to have strong antioxidant activity by using six evaluation indexs including the reducing power assay, the FRAP values, the DPPH radicals scavenging percentage, the total antioxidant activity, the inhibition of linoleic acid peroxidation and superoxide anion radicals scavenging percentage. It was found by the bioassay-guided method combing with multilateral method analysis system that the bioactive antioxidants of Terminalia chebula Retz. were mainly lay in the ethyl acetate fraction and the fraction was proved to has strongest antioxidant activities among all subfractions. As for the ethyl acetate fraction, the OD values at 700 nm (reducing power) of with the concentrations of 25 and 50μg·mL-1 were 1.16,1.30 times, and the FRAP values (OD593 nm) were 5.19,3.36 times, and the percentage of scavenging DPPH radicals were 1.45,1.19 times, more than that of BHT respectively. The total antioxidant activity at 695nm with concentrations of 100 and 200μg·mL-1 was a bit equivalent to that of BHT. Inhibition of linoleic peroxidation of the same fraction with concentration of 100μg·mL-1 was being increased up to (86.18±0.26)% during the culture of 120h, which was almost equal to that of BHT. The scavenging percentages for superoxide anion radical with concentration of 500μg·mL-1 was highest among all fractions, up to (89.52±1.27)%, which was 5.44 times more than that of Vc. The correlation of different subfractions between the active component contents and the various methods showed that the strong antioxidant activity mainly resultes from the high contents of the total phenols and total flavonoids.It comes to conclusion that Terminalia chebula Retz., with high antioxidant activity can be used as functional ingredient for prodution of functional foods with high added value.
|
PDF Full Text Request