Astragalus membranaceus Increases Leukocyte Telomere Length, but Does Not Suppress Development of Accelerated Senescence Signs in OXYS Rats

Astragalus membranaceus (AM) was used for millennia by traditional Chinese medicine to slow down aging and extend lifespan. It has been shown that AM can affect all key hallmarks of aging including compensating telomere shortening which is recognized as one of the most reliable biomarkers of aging. The telomere shortening in peripheral blood leukocytes is viewed as a promising biomarker in predicting the risk of age-related diseases as well as a biomarker of the effectiveness of treatment. However, findings from epidemiological studies on the links between leukocyte telomere length (LTL) and age-related diseases are rather contradictory. The present study is aimed to investigate the effect of AM on the LTL and the AM influence on the manifestation and development of the sings of accelerated senescence in OXYS rats. Animals were given AM root powder (100 mg/kg) from 3 to 6 months of age. Our study confirmed the ability of AM to activate telomerase, as evidenced by an increase in LTL in OXYS rats. However, LTL lengthening was not accompanied by a delay of the accelerated senescence of OXYS rats, manifested as the early development of cataract, retinopathy similar to age-related macular degeneration and accelerated brain aging. Thus, we have demonstrated a limitation of using LTL as indicator for assessing the effectiveness of anti-aging therapy.