| Description |
SRT1720 is a selective SIRT1 activator with EC50 of 0.16 μM in a cell-free assay, but is >230-fold less potent for SIRT2 and SIRT3. |
| In vitro |
The maximum activation ratio of SRT1720 versus the closest sirtuin homologues, SIRT2 (EC1.5 = 37 μM) and SIRT3 (EC1.5 > 300 μM) is up to 781%. SRT1720 binds to the SIRT1 enzyme-peptide substrate complex at an allosteric site amino-terminal to the catalytic domain and lower the Michaelis constant for acetylated substrates. SRT1720 could reduce fed glucose levels. Glucose excursion during an intraperitoneal glucose tolerance test is also significantly reduced in the SRT1720 group, and comparable to rosiglitazone, a PPARγ activator that has been used to treat type 2 diabetes. SRT1720 does not have an effect on fasting glucose in chow-fed mice, revealing that pharmacological SIRT1 activation is unlikely to induce hypoglycaemia. SRT1720 significantly reduces the hyperinsulinaemia after 4 weeks, partially normalizing increased insulin levels similar to rosiglitazone treatment. SRT1720 treatment increases mitochondrial capacity by 15% in gastrocnemius muscle as measured by citrate synthase activity. Higher concentrations of SRT1720 (15 μM) induces a modest (10-20%) decrease in normal cell viability. SRT1720 also significantly inhibits VEGF-dependent MM cell migration. |
| In vivo |
In DIO mice SRT1720 mimics several of the effects observed after calorie restriction including improved insulin sensitivity, normalized glucose and insulin levels, and increased mitochondrial capacity. In addition, in diet-induced obese and genetically obese mice, SRT1720 improves insulin sensitivity, lower plasma glucose, and increase mitochondrial capacity. Thus, SRT1720 is a promising new therapeutic agent for treating diseases of ageing such as type 2 diabetes. Consistent with improved glucose tolerance, the glucose infusion rate required to maintain euglycaemia is approximately 35% higher in SRT1720-treated fa/fa rats, and the total glucose disposal rate is increased by approximately 20%. SRT1720 also prevents multiple myeloma tumor growth. SRT1720 increases the cytotoxic activity of bortezomib or dexamethasone. |
China
