Extracts of Cistanche deserticola Can Antagonize Immunosenescence and Extend Life Span in Senescence-Accelerated Mouse Prone 8 (SAM-P8) Mice.

The senescence accelerated mouse prone 8 substrain (SAM-P8), widely accepted as an animal model for studying aging and antiaging drugs, was used to examine the effects of dietary supplementation with extracts of Cistanche deserticola (ECD) which has been used extensively in traditional Chinese medicine because of its perceived ability to promote immune function in the elderly. Eight-month-old male SAM-P8 mice were treated with ECD by daily oral administrations for 4 weeks. The results showed that dietary supplementation of 150 mg/kg and 450 mg/kg of ECD could extend the life span measured by Kaplan-Meier survival analysis in dose-dependent manner. Dietary supplementation of SAM-P8 mice for 4 weeks with 100, 500, and 2500 mg/kg of ECD was shown to result in significant increases in both naive T and natural killer cells in blood and spleen cell populations. In contrast, peripheral memory T cells and proinflammatory cytokine, IL-6 in serum, were substantially decreased in the mice that ingested 100 and 500 mg/kg of ECD daily. Additionally, Sca-1 positive cells, the recognized progenitors of peripheral naive T cells, were restored in parallel. Our results provide clear experimental support for long standing clinical observational studies showing that Cistanche deserticola possesses significant effects in extending life span and suggest this is achieved by antagonizing immunosenescence.

Biological activity, structural features, and synthetic studies of (-)-ternatin, a potent fat-accumulation inhibitor of 3T3-L1 adipocytes.

A series of studies, including preliminary screening, isolation, structure determination, synthesis, and biological evaluation, of (-)-ternatin (1) are described. A highly N-methylated cyclic heptapeptide isolated from the mushroom Coriolus versicolor, 1 shows an inhibitory effect on fat accumulation by 3T3-L1 murine adipocytes (EC50 = 0.02 microg mL(-1)). Detailed analysis of 1D and 2D NMR spectra, as well as amino acid analysis, suggested four stereoisomers as candidates for 1. For the complete structural elucidation of 1, chemical syntheses were carried out by solid-phase peptide synthesis. By comparing the spectroscopic data for the natural product with the data for the synthetic stereoisomers, the structure of 1 was confirmed to be cyclo[D-allo-Ile1-L-(NMe)Ala2-L-(NMe)Leu3-L-Leu4-L-(NMe)Ala5-D-(NMe)Ala6-(2R,3R)-3-hydroxy-Leu7].