Research Paper Volume 4, Issue 6 pp 436—447

Figure 3. AS101 treatment increases SIRT1 expression through a possible mechanism of serum IGF-1 reduction.

(A) Sera from AS101 treated rats contained significantly reduced IGF-1 levels. AS101 (0.5mg/kg) or PBS was injected daily i.p into healthy rats for 14 days and IGF-1 levels were measured by ELISA (*p<0.01 versus PBS). Error bars represent the ±SEM of all animals (AS101 n=5, PBS n-4). (B) SIRT1 expression increased in HEK293 cells incubated with AS101-treated rat serum. Supplementing with rIGF-1 back to normal levels (500 ng/ml) restored SIRT1 levels as in control mice. Cell extracts, were used for western blot analysis with anti- SIRT1 antibodies; Actin was used as a loading control. (C) Sera from AS101 treated rats contained significantly reduced insulin levels. AS101 (0.25-1mg/kg) and PBS were injected daily i.p to healthy rats for 14 days. Serum insulin levels were measured by ELISA kit after 4 hours starvation (*p<0.001 versus PBS) (n=3 in each group). (D-E) AS101 decreases PPARγ levels in tissue culture in vitro. AS101 and PBS were added to tissue cultures of HEK293 (D) and HL-60 (E) cells at the indicated concentrations for 48 hours. Western blots were probed with PPARγ antibody; actin was used as a loading control. (F) AS101 maintains normal insulin levels in HFD fed rats. AS101 (0.5-1mg/kg) and PBS was injected daily i.p into HFD/ND rats for 14 days. Serum insulin was measured by ELISA after 4 hours of fasting (*p<0.001 versus HFD+PBS, n=3 in each group). Error bars represent the SEM. Results shown in B, D and E are representative of three independent replicates that gave similar results (using different batches of rat sera).