FYI: Hector Valenzuela has asked me to forward any questions you may have on this ongoing study below.
Nutraceuticals are natural compounds that contain both nutritional as well as medicinal benefits. Various nutraceuticals (curcumin and resveratrol) obtained from plant extracts have been shown to improve fitness and extend lifespan by various mechanisms. In addition other compounds have also been shown to extend lifespan (rapamycin, spermidine and nicotinamide mononucleotide). Although the end result for these compounds maybe extension of lifespan, comparison of their signaling pathways remains to be determined. The objective of our research was to compare the signaling pathway of these compounds on both normal human T cells and Jurkat cell lines. We used RT-PCR to measure gene expression of NF-Κβ, AMPK, sirtuin 1-7 and autophagy specific genes (ATG5 and MAPILC3B/LC3) for all of these compounds. In addition, we show a direct correlation between concentrations of treatment and the upregulation of gene expression to the viability of the cells.
Methods:
Resveratrol, Curcumin and Spermidine were obtained from RevGenetics. The equivalent of 0.05 gm of each compound was dissolved in 10 ml of Ethanol to achieve stock concentrations of 5 x 10-3 gm/mL. Serial dilutions ranging between 10-3, 10-4, 10-5 and 10-6 gm/mL were tested for each compound on our cell cultures. The total volume of the compounds added for each concentration into the experimental cultures represented 0.1% of the final volume. CD4 and CD8 T cells were purified from the PBMC by negative selection, using a C4 and CD8 T cell isolation kit (Miltenyi Biotec) according to the manufacturer's instructions. The T cells were stimulated with CD2/CD3/CD28 antibody-coated beads. The cells (donor’s T cells and/or Jurkat cells) were treated with the compounds and samples taken 24 hours later. Cell samples were taken for telomerase analysis(RT-PCR Millipore kit) and gene expression using RT-PCR (Bio-Rad). Statistical analysis was done using a two tail Student’s t test and significance established with a p value of < 0.05.
(GAPDH was used as a housekeeping gene for normalization ie. internal control.)
Conclusions (so far)...
Curcumin has traditionally been used for centuries by India and China as herbal teas that promote health. Resveratrol is the active ingredient in red wine that is believed to provide cardiovascular and cancer protection. Recent scientific studies have shown that both compounds are anti-inflammatory and may work through similar pathways. Our results, show that both curcumin and resveratrol can modulate sirtuin expression. However, not all extracts versions can stimulate sirtuins and/or telomerase activity to the same degree. Further studies on normal cells should help confirm or change our observations. Nevertheless, we feel that this preliminary study begins to lay the foundation for, not only comparing different forms of curcumin or resveratrol, but also other natural telomerase activators such as spermidine
For those wondering about the last sentence in the conclusion... yes Cells treated with spermidine increased telomerase activity by 2.3 fold.