Combinative effects of thanh hao miet giap thang (sweet wormwood and tortoise shell decoction) ingredients on antioxidative activity in vitro.

BACKGROUND Traditional formulae usually exhibit therapeutic effects through the combinations of different ingredients. The purpose of this study was to investigate in vitro anti-oxidative activity of Thanh Hao Miet Giap Thang (THMGT) (Sweet Wormwood and Tortoise Shell Decoction) formula and the interactions of its ingredients leading to the overall anti-oxidative effect. MATERIALS AND METHODS We prepared 31 combinations containing two to four of the five ingredients including Herba Artemisia apiacea L (HbA), Carapax Trionycis (Tryonix sinensis) (CT), Rhizoma Anemarrhenae (Anemarrhena asphodeloides) (RzA), Radix Rehmanniae (Rehmannia glutinosa Libosch) (RdR), Moutan Cortex (Paeonia suffruticosa) (MC). These combinations were tested for anti-oxidative activity using DCFH-DA and DPPH assays on Hep G2 cells. We also analyzed changes in expression of genes involved in antioxidant defense system including Nuclear Factor Erythroid-Derived 2-Like 2 (NFE2L2), catalase (CAT), heme oxygenase-1 (HO-1), glutathione peroxidase (GPx), cytoplasmic superoxide dismutase (SOD1), mitochondrial superoxide dismutase (SOD2). RESULTS The complete formula and all combinations containing Moutan Cortex showed high antioxidant activity in both radical solution-based chemical assay and cellular-based assay. On the contrary, Carapax Trionycis displayed inhibitory effect on the overall antioxidant activity when present in a combination, an effect clearly emphasized in cellular-based assay. Hep G2 cells treated with the formula showed increased gene expression of HO-1 and SOD2 while expression of CAT, SOD1, GPx was unchanged. CONCLUSION Our results suggested that THMGT had anti-oxidative activity essentially through intrinsic reducing capacities and the overall activity of the formula resulted from enhancing and inhibiting interactions of ingredients.