Protective effect of Spirulina extract against apoptotic cell death induced by a) DPPH and b) ABTS. The 3T3 cells were incubated in medium containing Spirulina extract or vitamin C for 1 h before being added with 20 μM DPPH or 50 μM ABTS and incubated for another 24 h before the determination of apoptotic cell death. The positive control contained cells incubated with vitamin C while the negative control contained medium alone. Data presented as mean ± standard deviation (n = 3). *Denotes significant difference (p < 0.05) from "cells + medium + DPPH/ABTS".