RESUMO
The aim of the current study was to evaluate interactions among polyphenols from different plants and their effect on antioxidant potential. Different mixtures of plant extracts of Crataegus oxyacantha [C], Elettaria cardamomum [Cr], Terminalia arjuna [T] and Rauvolfia serpentina [R] were prepared and evaluated for total phenolics, flavonoid contents, and antioxidant activity. A correlation was also established between total phenolics, flavonoids and antioxidant activity. Comparative evaluation revealed that phenolics, flavonoids and antioxidant activity were found high in plant extracts mixtures than individual plants. Highest phenolics [580+/-1.12mg GAE/g], flavonoids [67.10+/-0.11mg CE/g] and antioxidant activity [IC[50] 0.109mg/ml] was observed with ratio 1:1:1:2 of plant mixture C, Cr, T, R. A weak linear positive correlation was found between antioxidant activity, total phenolic and flavonoid contents. A negative correlation was observed among IC[50] value, total phenolics and flavonoid contents. Investigation through RP-HPLC revealed the presence of different potent phenolics in plants understudy. More antioxidant potential of extracts in combinations as compared to that of individual plants was clear corroboration of synergism. The ratio [1:1:1:2] of the studied plants in combination, that showed the highest free radical potential, was another expected better pharmacological prospect. This formulation can bring maximum relief against free radical-associated diseases