Interaction Effect of Polyherbal Formulations with Antioxidant Activity

Abstract

Plant extracts individually contain a complex mixture of bioactive compound and various combinations of plant extracts might give interaction effect on antioxidant activity. Possible interactions among antioxidant component can be synergistic, antagonistic, additive and indifferent which is importance on determining the effectiveness of plant extract combinations on this activity. Therefore, in this study, the interaction effect towards antioxidant activity of total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and lipid peroxidation inhibition (LPI) presence in aqueous extract of leaves of Nephrodiuminophyllum (pakismerah), Polygonum minus (kesum), Annona squamosal L.(nona fruit) and Stevia rebudiana has been evaluated. The in-vitro antioxidant activity of the extracts and their different combinations were conducted by TPC, TFC, DPPH and LPI assays. Meanwhile, the interaction effect was assessed by comparing the experimental antioxidant activity of the mixtures with calculated theoretical values and the interactions of the compounds were determined. The results suggest that P. minus individually has highest phenolic content and percentage inhibition of DPPH while N. inophyllum has highest flavonoid compound and lipid peroxidation inhibition. Indifferent effect was exhibited in the majority of all combinations on all assays but only one antagonistic interaction between P. minus and A. squamosal L on DPPH assay. However, there were only four synergistic effects evaluated on all assays with the highest one was shown on DPPH assay for combination of N. inophyllum and A. squamosal L. In conclusion, this present study justifies these polyherbal formulations have influenced antioxidant properties by validating their interaction effects.