[Evaluation of antioxidant activity of Radix Linderae and other two Chinese drugs using TLC-bioautography].

AIM: To evaluate the antioxidant capacity and quality of traditional Chinese medicines using TLC-bioautography.

METHODS

Two chromatograms of each crude drug sample were obtained, after developing, by spraying with 1,1-diphenyl-2-picrylhydrazyl (DPPH) solution in ethanol and classical stained reagents, separately. The images sprayed with DPPH solution were captured under light after the plates were heated at 40 degrees C for 30 min, and scanned using video scan software to get peak areas of active compounds.

RESULTS

Total peak areas of the spots on TLC were calculated to evaluate the antioxidant capacity of the tested crude drugs from different habitats and sources. The results indicated that Radix Linderae cultivated in Tiantai (Zhejiang province), Cortex Magnoliae Officinalis cultivated in Liangshan (Sichuan province), and Fructus Perillae acquired in Shanghai have the highest scavenging properties towards DPPH in their respective TLC-autographic assays. Norisoboldine, magnolol and honokiol, luteolin, apigenin and an unknown compound "U" proved to be the major antioxidant components in the corresponding crude drugs as they contribute the dominating peak areas to the total ones.

CONCLUSION

TLC-bioautography can not only be used for screening of the components with antioxidant potency but also for the purpose of quality evaluation of traditional Chinese medicines at the same time, and the method proved to be selective, simple and reproducible.