Figure 5. Calcium is involved in shikonin-medaited glucose uptake.

(A) Insulin and A23187 stimulated glucose uptake in L6 myotubes. Data are mean ± SEM of three experiments (B) Measurement of intracellular calcium levels by the fluorescent ratiometric Ca²⁺ indicator indo-1 following acute treatment with shikonin (1 µM) or insulin (1 µM). ***p<0.001, *p<0.05, one way ANOVA . Graph show mean delta value ± SEM of 15 experiments performed. Asterisks represent statistical difference as analyzed by one way ANOVA between basal and treated cells (*p<0.05, *** P<0.001). (C) Effect of BAPTA-AM on glucose uptake mediated by shikonin in L6 mytoubes. Cell were stimulated with shikonin for 2 h in the absence or presence of 5 µM 1,2-Bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid tetrakis(acetoxymethyl ester), BAPTA (BA). Graph show mean ± SEM of 3 experiments performed. Asterisks represent statistical difference as analyzed by one way ANOVA (*p<0.05, **<0.01).