The present invention relates generally to an aqueous extract composition for synergistic anti-plaque activity. Accordingly, the aqueous extract composition includes combination of 0.25mg/ml green tea (Gt) aqueous extract and 7.82mg/ml Salvadora persica L. (Sp) aqueous extract, that is equivalent to 1/4 and 1/2 of MIC values of Gt and Sp aqueous extracts respectively, wherein the combination of Gt and Sp aqueous extracts enables to significant synergistic anti-bacterial and anti-adherence efficacy. It should be noted that by rinsing 15ml of the combination of the Gt and Sp aqueous extracts for 30 seconds twice/day is capable to significantly reduce plaque accumulation after 24 hours re-growth, where anti-plaque effect of the said combination is significantly better than non-alcoholic 0.12% Chlorhexidine (CHX).