Tar content per cigarette of various brands, the dry weight of tar trapped on the Cambridge filter after combustion of one cigarette and the EC50 values of cCSEs for inhibition of MTS reduction activity.

aNicotine and tar content per cigarette is the value reported by its manufacturer and determined by puff smoking based on ISO regulation.bFor determination of dry tar weight per cigarette, smoke of one cigarette from either brand was continuously sucked through the Cambridge filter, and the increase in the dry weight of the filter was determined (represented as means ± SD of three experiments).cFor determination of the EC50 values, cCSEs at the original tar concentration of 10 mg/ml were prepared from cigarettes of various brands by continuous smoking, and subjected to MTS reduction assay in C6 glioma cells for construction of concentration-response curves from which the EC50 values (means ± SE of three experiments, each in triplicate) were determined.Tar content per cigarette of various brands, the dry weight of tar trapped on the Cambridge filter after combustion of one cigarette and the EC50 values of cCSEs for inhibition of MTS reduction activity.