Microscopic worms can live 15 percent longer when given small quantities of Rhodiola rosea, write cell biologists from the University of Utrecht in Biogerontology. This Russian herb, which is sold as an energy supplement, probably has a mild stress effect and gives a small boost to anti-aging mechanisms in cells.
Sports supplements manufacturers found out about Rhodiola rosea from obscure Russian studies, in which extracts of the roots of the plant increased the stamina of lab animals. The studies suggest that one of Rhodiola’s effects is that it gets more muscle cells to make more ATP. Some human studies have shown that athletes who take Rhodiola rosea do improve their performance, but there are other human studies in which the supplement has no effect. The negative studies did use low doses and only for a short period.
Dosage and length of time play an important role in the Dutch study. The researchers exposed the nematode Caenorhabditis elegans to an extract containing 3 percent salidroside, an active ingredient of Rhodiola. They mixed the extract into the culture medium of the nematodes.
The optimum concentration was 10 microgram Rhodiola extract/ml. At this concentration the nematodes lived 15 percent longer. At higher concentrations the lifespan of the worms decreased, however.
Nematodes live for about 2 weeks. Exposure to Rhodiola rosea worked better when the nematodes were exposed from birth, than when they were given Rhodiola extracts for the first time on day 7 [Rho 10 – early].
The researchers also subjected the nematodes to stress factors such as heat and the pesticide paraquat. Rhodiola reduced the life-shortening effect of these.
The researchers in Utrecht discovered that Rhodiola activates the longevity gene DAF16. As a result the cell invests more energy in maintenance processes – and delays the speed of aging. The plant probably does this by damaging something in the cell, which induces a reaction: fuel for the supporters of the hormesis theory.
In similar experiments, extracts of Ginkgo biloba, green tea or grapes have also extended lifespan. It is unlikely that all these substances work in the same way. “Apart from a search for responsible single components, a parallel approach aimed at identifying synergy between single compounds is of interest”, the researchers write.
Researchers at McMaster University are probably rubbing their hands with glee – they get mice to live longer by giving them a cocktail of anti-aging supplements.
Plant adaptogens increase lifespan and stress resistance in C. elegans.
Abstract
Extracts of plant adaptogens such as Eleutherococcus senticosus (or Acanthopanax senticosus) and Rhodiola rosea can increase stress resistance in several model systems. We now show that both extracts also increase the mean lifespan of the nematode C. elegans in a dose-dependent way. In at least four independent experiments, 250 microg/ml Eleutherococcus (SHE-3) and 10-25 microg/ml Rhodiola (SHR-5) significantly increased life span between 10 and 20% (P < 0.001), increased the maximum lifespan with 2-3 days and postponed the moment when the first individuals in a population die, suggesting a modulation of the ageing process. With higher concentrations, less effect was observed, whereas at the highest concentrations tested (2500 microg/ml Eleutherococcus and 250 microg/ml Rhodiola) a lifespan shortening effect was observed of 15-25% (P < 0.001). Both adaptogen extracts were also able to increase stress resistance in C. elegans: against a relatively short heat shock (35 degrees C during 3 h) as well as chronic heat treatment at 26 degrees C. An increase against chronic oxidative stress conditions was observed in mev-1 mutants, and during exposure of the wild type nematode to paraquat (10 mM) or UV stress, be it less efficiently. Concerning the mode of action: both adaptogens induce translocation of the DAF-16 transcription factor from the cytoplasm into the nucleus, suggesting a reprogramming of transcriptional activities favoring the synthesis of proteins involved in stress resistance (such as the chaperone HSP-16) and longevity. Based on these observations, it is suggested that adaptogens are experienced as mild stressors at the lifespan-enhancing concentrations and thereby induce increased stress resistance and a longer lifespan. PMID: 18536978 [PubMed - indexed for MEDLINE] Source: http://www.ncbi.nlm.nih.gov/pubmed/18536978
