Geroprotektoren sind Substanzen, die den Alterungsprozess verlangsamen.
Im Jahre 2009 gab es 24 bekannte Geroprotektoren. Mittlerweile kennen wir weit über 200 Substanzen, die das Altern hinauszögern können. Doch nach welchen Kriterien kann man eine "Best of"-Liste erstellen?
Alexey Moskalev und Brian K. Kennedy schlagen dafür folgende Kriterien vor:
Hauptkriterien
Verlängerung der Lebensspanne
Günstige Beeinflussung von Alters-Biomarkern
Geringe Toxizität
Geringe Nebenwirkungen bei therapeutischer Dosierung
Verbesserung der Lebensqualität
Nebenkriterien
Evolutionär konservierter Wirkmechanismus
Wirksamkeit über viele Spezies hinweg
Einfluss auf mehrere altersassoziierte todesverursachende Erkankungen
Erhöhung der Stressresistenz
Sortiert man mit diesem Algorithmus unter den bekannten Geroprotektoren, ragen folgende Substanzen heraus, die in den Augen der Autoren großes Potential auch beim Menschen haben könnten:
Zitat:
Acarbose Acarbose is an α-glucosidase inhibitor used to treat diabetes mellitus. Treated with this compound, male UM-HET3 mice had 22% longer lifespan (Harrison et al., 2014). It has acceptable acute toxicity – mouse LD50 oral is 24 gm kg−1 (Tomasulo, 2002). Acarbose is considered to be well-tolerable drug with adverse effects not significantly differing from placebo (Hotta et al., 1993). Acarbose reduces blood glucose concentrations, blood pressure, triglycerides, the progression of intima media thickness, and incidence of cardiovascular events and of newly diagnosed hypertension, and it demonstrates beneficial effects on overweight individuals and downregulates biomarkers of low-grade inflammation (Hanefeld & Schaper, 2008). Deprenyl Deprenyl is a selective MAO-B inhibitor used to treat major depression and early-stage Parkinson disease. It prolongs lifespan in male rat (Kitani et al., 1993). No significant acute toxicological data for this compound were identified in literature search (mouse LD50 intraperitoneal 200 mg kg−1) (Kane et al., 1988). Deprenyl is also well tolerated (Robottom, 2011). Deprenyl protects human neurons from apoptosis induced by various kinds of insults by interfering with early apoptotic signaling events and may be applicable to delay the deterioration of neurons during advancing aging (Maruyama & Naoi, 1999; Magyar et al., 2004). D-glucosamine D-glucosamine is an amino sugar and a potent drug for the treatment of arthritis, although its effectiveness is controversial (Burdett & McNeil, 2012). Nevertheless, it is able to promote lifespan of nematodes and C57BL/6NRj mice (Weimer et al., 2014). This compound has very low acute toxicity and is safe for everyday use (Reginster et al., 2001). Current use of glucosamine was associated with a significant decreased risk of death from cancer (HR 0.87 95% CI 0.76-0.98) and with a large risk reduction for death from respiratory diseases (HR 0.59 95% CI 0.41-0.83) (Pocobelli et al., 2010; Bell et al., 2012). Glucosamine supplementation can significantly decrease risk of lung cancer in humans (Brasky et al., 2011). A meta-analysis has shown that glucosamine has lowest risk of adverse effects compared with other treatments (Diarecin and NSAIDs) (Kongtharvonskul et al., 2015). The oral supplementation of glucosamine can potentially improve cutaneous aging in human and reduce the appearance of visible wrinkles and fine lines of the skin (Murad & Tabibian, 2001). Dihydroergocristine methanesulfonate Dihydroergocristine methanesulfonate is an fungally derived alkaloid salt and a potent vasodilator (Valli et al., 1984). It is one of the 60 compounds identified in a screen for increased longevity in C. elegans (Ye et al., 2014). In two studies (Aranda et al., 1992; Milvio, 1992), dihydroergocristine was shown as safe and well tolerated with rare side effects including mild gastralgia, nausea, and dyspepsia in aged patients with senile dementia of Alzheimer type. Dihydroergocristine methanesulfonate in some studies has statistically significant positive effects on symptoms of age-related cognitive dysfunction (Wadworth & Chrisp, 1992). Ellagic acid Ellagic acid is a natural polyphenol found in numerous edible plants. Its ability to prolong C. elegans lifespan is proposed to be due to a hormetic effect (Saul et al., 2011). This substance has also low acute toxicity – rat LD50 oral > 20 gm kg−1 (Tomasulo, 2002). Study on rats showed a potentially good tolerability (Tasaki et al., 2008). Ellagic acid prevents collagen destruction and inflammatory responses caused by UV-B-induced photoaging in HaCaT keratinocytes and human dermal fibroblasts (Bae et al., 2010). Glutathione Glutathione is a tripeptide with notable antioxidant effect. Glutathione prevents aging-associated oxidation of proteins in the crystalline lens (Kamei, 1993).It is also able to promote C. elegans lifespan (Shibamura et al., 2009) and has rather low acute toxicity – mouse LD50 oral 5 gm kg−1 (Tomasulo, 2002). A recent study showed that glutathione was well tolerated with few side effects (Richie et al., 2015). Metformin Metformin is an oral antidiabetic drug of the biguanide class that is widely prescribed as an early-stage drug for type II diabetes. It enhances longevity is a range of model organisms: C. elegans (Cabreiro et al., 2013), D. melanogaster (Slack et al., 2012), and M. musculus (Martin-Montalvo et al., 2013). However, it should be noted that there are studies showing no effect or only a very small effect of metformin in rats and rodents with normal genetics and longevity (https://www.ncbi.nlm.nih.gov/pubmed/20304770, http://www.ncbi.nlm.nih.gov/pubmed/23900241). It has acceptable acute toxicity – mouse LD50 oral 1450 mg kg−1 (Tomasulo, 2002) – and is well tolerated (Giugliano et al., 1993). Serious but rare adverse effects include lactic acidosis (mostly linked to alcoholism due to depletion of NAD+ stores), heart failure, respiratory disease (due to inadequate oxygenation of tissues), and impaired renal function. Metformin treatment confers insulin sensitivity, leads to weight loss, and improves lipid profiles (Salpeter et al., 2008). Rapamycin Rapamycin is an antifungal agent with immunosuppressive and antiproliferative effects. It has a lifespan-prolonging effect in several studies on different model organisms, including S. cerevisiae (Powers et al., 2006; Medvedik et al., 2007), C. elegans (Robida-Stubbs et al., 2012), D. melanogaster (Moskalev & Shaposhnikov, 2010), and M. musculus (Harrison et al., 2009; Fok et al., 2014; Miller et al., 2014). It has acceptable acute toxicity – mouse LD50 oral > 2500 mg kg−1 (Vezina et al., 1975) – although it can induce a range of reversible but concerning side effects (Soefje et al., 2011). Other rapamycin derivatives (termed rapalogs) appear to have similar effects. A majority of reports also indicate that rapamycin delays pathologies of aging in mice and protects against age-related diseases, including cardiac and neurodegenerative syndromes, as well as neoplasms (Johnson et al., 2013; Lamming et al., 2013). Rapamycin also is reported to suppress nuclear defects in cells isolated from Hutchinson–Gilford progeria syndrome, although reports of the drug have not been reported in mouse models of the disease (Oyanagui, 1984; Pocobelli et al., 2010).67,68
Spermidine Spermidine is a natural polyamine compound found in animal tissues. It is reported to promote lifespan of yeast, flies, worms, human cells, and mice (Eisenberg et al., 2009). Spermidine has acceptable acute toxicity – mouse LD30 oral 1 gm kg−1 (Oyanagui, 1984). Administration of spermidine, whose intracellular concentration declines during human aging, markedly extends the lifespan of human immune cells. In aging human cells, spermidine treatment triggers epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases, enhances autophagic flux, and suppresses oxidative stress and necrosis (Eisenberg et al., 2009).
Tyrosol Tyrosol is natural phenolic antioxidant, a derivative of phenethil alcohol. It is able to increase both mean and maximum lifespan in C. elegans (Canuelo et al., 2012) and is well tolerated (Tuck & Hayball, 2002). Tyrosol can afford considerable protection against aging-associated heart deterioration (Owen et al., 2000). Several studies showed a cardioprotective role of tyrosol (Samuel et al., 2008; Smol'iakova et al., 2010; Sun et al., 2015). Tyrosol's cardiovascular benefits are likely due to its ability to prevent oxidation of LDL (Covas et al., 2006; Castaner et al., 2012). Also, tyrosol ameliorated hyperglycemia by regulating key enzymes of carbohydrate metabolism in streptozotocin-induced diabetic rats (Chandramohan et al., 2015). A human study of tyrosol-rich products (white wine and virgin olive oil) demonstrated an anti-inflammatory effect (Migliori et al., 2015). Tyrosol has a potent anti-allergic effect by inhibiting the degranulation of mast cells and expression of inflammatory cytokines (Je et al., 2015). Tyrosol has very low acute toxicity (LD50 was found to be 2700 and 1700 mg kg−1 in mice after intragastric and intraperitoneal injection, respectively, and 7079 mg kg−1 in rats after intragastric administration). No toxicity was observed after 3 months of chronic intragastric administration of p-tyrosol at the doses of 200 mg kg−1 in male rats and 10 mg kg−1 in dogs (Saratikov & Krasnov, 2004). Vinpocetine Vinpocetine is a semisynthetic derivative of the alkaloid vincamine with nootropic effects. It is another of the 60 compounds identified in a recent screen for enhanced longevity in C. elegans (Ye et al., 2014). It has acceptable acute toxicity – mouse LD50 oral 534 mg kg−1 (Cholnoky & Domok, 1976). In an 18-month study, vinpocetine was reported safe and had a good tolerability during the whole study period (Valikovics et al., 2012). In another study, vinpocetine failed to show effectiveness in treatment Alzheimer disease, but there also were no significant side effects from drug therapy (Thal et al., 1989). Vinpocetine significantly inhibits in vitro aging of human erythrocytes (Bayer et al., 1988).
Zur Acarbose: Die müsste sich doch zum Abnehmen eignen? Als Nebeneffekt wird eine Zunahme der Buttersäure in Wiki genannt. Buttersäure sollte evtl. bei Reizdarm helfen.
Acarbose ist zwar "nur" ein Zucker, ist aber in Deutschland verschreibungspflichtig und zur alleinigen Gewichtreduktion nicht zugelassen (= deine Partnerin bekommt kein Rezept).
Acarbose-Einnahme bei Reizdarm halte ich außerdem für keine gute Idee, da die häufigsten Nebenwirkungen Blähungen, Darmgeräusche, Durchfall und Bauchschmerzen sind (=Symptomverschlechterung bei Reizdarm)!
Abgesehen davon ist Acarbose aber eine relativ harmlose Substanz.
Danke Prometheus, Ich denke auch das Acarbose keine gute Idee bei Reizdarm ist. Zum Abnehmen würde es bei meiner Freundin wohl auch nichts bringen, denn sie i(s)st seeehr süß, und bei Zucker bringt Acarbose nicht viel.
Vielen dank für den Link Prometheus, mir war bisher der Ausdruck "Geroprotektor" nicht bekannt.
Die 3 Stoffe Vinpocetin, Dihydroergocristin methanesulfonat und Tyrosol hatte ich bisher auch noch gar nicht auf dem Schirm in dieser Hinsicht! Ich dachte bisher, die positive Wirkung von Olivenblättertee wäre fast nur dem Oleuropein zu verdanken.
Aber, was ich merkwürdig finde ist, dass EGCG und Theaflavine nicht als vielversprechend angesehen werden. Assozoziationsstudien zeigen doch eine allgemein verringerte Mortalität bei Teetrinkern und diese Stoffe binden an die Telomere und schützen sie so vor einer zu schnell verkürzung durch freie radikale und Strahlung. Damit wäre auch eine gute Erklärung für den Wirkmechanismus vorhanden, auch scheint es ja völlig ungefährich zu sein (nur theoretisch soll die Leber eventuell überlastet werden können) Was denkst du, ist die Datenlage noch zu gering oder befürchten sie doch irgend welche Nebenwirkungen bei hohen Dosen?
Was ist das Problem bei EGCG und Theaflavine, übersehen haben sie diese Stoffe mit Sicherheit nicht, dafür sind sie viel zu bekannt.
Andererseits wundert mich, dass Ellagsäure hier dabei ist! Ich kannte Ellagsäure bisher nur als Beschleuniger der Fettverbrennung und eben Antioxidantium, dem man auch eine gewisses Potential zur Krebsvorsorge zutraut.
Zitat von La_Croix im Beitrag #6Was denkst du, ist die Datenlage noch zu gering oder befürchten sie doch irgend welche Nebenwirkungen bei hohen Dosen?
EGCG hat laut den in der Datenbank hinterlegten Studien eine Verlängerung der mittleren Lebenszeit um 10% beim Rundwurm und eine mediane Lebenszeitverlängerung von ca. 13% bei der Ratte gezeigt. Für eine "Top-Platzierung" reicht das wohl nicht.
Für Theaflavin(e) gibt es aktuell nur wenig Daten zur Lebensverlängerung. Die einzige mir bekannte Studie ist mit Schwarzteeextrakt (Einer Mischung aus Theaflavinen und Epicatechinen) durchgeführt worden:
Dafür gäbe es Beobachtungsstudien am Menschen, diese sind allerdings in der Datenbank nicht enthalten. Damit kann, außer Metformin, meines Wissens nach kein anderer der aufgelisteten Stoffe aufwarten.
EGCG bzw. grüner Tee haben unbestreitbar viele Vorteile, die ja auch hier schon ausführlich besprochen wurden. Es gibt aber auch Nachteile, wobei einer besonders hervorsticht: Grüner Tee kann eine Unterfunktion der Schilddrüse bei entsprechend anfälligen Menschen machen. Das gilt besonders für Frauen. So eine UF ist nichts erstrebenswertes, da sie uns müde und schlapp macht.
"Weißer Tee" scheint dagegen eine bessere Wirkung zu haben und außerdem noch besser gegen Krebs zu schützen und zwar durch Hemmung der Collagenase Aktivität::
Anti-collagenase activities were exhibited by sixteen plants of which the highest activity was seen in white tea (~87%),(Thring et al., 2009)
Collagenases are a family of metalloproteinases which may play a role in facilitating tumor cell invasion of the extracellular matrix. Tumor cells traverse two types of extracellular matrix: basement membranes and interstitial stroma, at multiple stages of the metastatic process. The matrix is a dense meshwork of collagen, proteoglycans, elastin and glycoproteins. Normally the matrix does not contain open spaces large enough for cell movement. Therefore numerous investigators have postulated that collagenolytic proteases, secreted by tumor cells or associated host cells, breakdown the extracellular matrix during tumor cell invasion. A large number of animal and human tumors have been shown to contain collagenase at a higher level than corresponding benign tissues. Separate collagenolytic metalloproteinases have been identified which degrade specific types of collagen. A basement membrane collagenolytic protease was shown to be elevated in a series of metastatic murine tumor cells. Therefore identification of collagenase in cultured lines of tumor cells is not an artifact of in vitro cultivation.
In some cases, tumor cells may induce host cells to produce collagenase. The best evidence to date that collagenases actually play a role in invasion is derived from experiments in which natural collagenase inhibitors block tumor cell invasion of extracellular matrix in vitro. (Liotta et al., 1982)
Ein weiterer Gesichtspunkt: Was passiert bei der Kombination von Geroprotektoren?
Denkbar wäre, dass sich die Wirkung addiert, oder sogar mutipliziert. Ebenfalls denkbar wäre aber auch das genaue Gegenteil. Ein guter Ansatz dazu von Josh Mitteldorf:
The AI that could uncover the secret of eternal youth: Russian researchers reveal new tool to find life-extending drugs - and say it has already uncovered ten potential therapies GeroScope algorithm can identify the substances that extend healthy life The tool can compare changes in cells of young and old patients Then it searches for the substances that could counteract these changes It has so far identified substances that have rejuvenating effects on cells
Scientists have revealed a new plan to find the key to eternal youth – and artificial intelligence will be leading the way.
Using computer simulations to screen hundreds of compounds, researchers have developed a tool that can identify geroprotectors, the substances responsible for extending healthy life.
Zitat GeroScope identifies geroprotectors, the substances responsible for extending healthy life.
The tool can compare changes in the cells of young and old patients and search for the drugs that counteract the processes.
Researchers used the new algorithm to identify 10 substances that could have life-extending potential.
They then conducted laboratory experiments on the substances using stem cell lines of human fibroblasts (connective tissue cells) to study two effects: cell ‘rejuvenation’ and survival.
This revealed a number of different effects on the cells.
A substance called NAC was found to have a mild rejuvenating effect, but dramatically decreases survival.
Myricetin, they found, has a mild rejuvenating effect, and EGCG has a strong rejuvenating effect.
But, a substance called PD-98059 was found to have a very strong rejuvenating effect, and increases both short and long-term survival.
Future with is now needed to determine the effects of these compounds, and provide insight on the combinations that could be used to maximize the benefits while minimizing any side effects.
ZitatWieder einmal lieferte 1 µM Ivermectin die besten Ergebnisse in diesem Experiment, bei dem vier Medikamente verglichen wurden, mit einer um 8 % längeren mittleren Lebensdauer, einer um 13 % längeren mittleren Lebensdauer und einer um 19 % längeren maximalen Lebensdauer (Alter von 95 % Sterblichkeit) als die Kontrolle.
[...]
Ivermectin verzögerte jedoch die maximale Reproduktion im Alter von 4 bis 6 Tagen und verbesserte die Reproduktion in höheren Altersklassen. Die Lebensdauer wurde durch Exposition gegenüber 1 µM Erythromycin verlängert, was zu einer um 37 % längeren mittleren Lebensdauer, einer um 42 % längeren mittleren Lebensdauer und einer um 33 % längeren maximalen Lebensdauer führte. Im Vergleich dazu erzeugte die Behandlung mit 1 μM Ivermectin in diesem Experiment eine um 21 % längere mittlere Lebensdauer, eine um 33 % längere mittlere Lebensdauer und eine um 22 % längere maximale Lebensdauer als die Kontrolle.
Allerdings: Wenn die Medikamente nicht von Beginn an, sondern erst in der mittleren Lebensspanne hinzu kamen, waren die Effekte auf die maximale Lebensspanne sehr gering. Trotzdem beeindruckend die höhere Fitness:
Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used https://link.springer.com/article/10.100...kJZk9gHsDmvDYh0
Zitat von Speedy im Beitrag #18Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used https://link.springer.com/article/10.100...kJZk9gHsDmvDYh0
Das besondere hier es profitieren nur männliche Mäuse wirklich. Haben wir ja zum Beispiel auch bei Acarbose so.
Vinpocetin und/oder Vincamin sollen laut anekdotischen Berichten angeblich die Wirksamkeit anderer Stoffe im Gehirn erhöhen können. Falls sich das bewahrheitet, hätte man evtl. einen brauchbaren Enhancer für andere Nootropika.
Vinpocetin
ZitatVinpocetin ist ein halbsynthetischer Abkömmling des (+)-Vincamins, dem Hauptalkaloid des Kleinen Immergrün, und wird als Arzneistoff verwendet.
Updates of Recent Vinpocetine Research in Treating Cardiovascular Diseases
ZitatDue to its excellent safety profile at therapeutic dose regimen, vinpocetine has raised research interest in its new applications in various experimental disease models. Here we review recent studies that uncovered novel functions of vinpocetine in cardiovascular diseases, including atherosclerosis, obesity, neointimal hyperplasia, vasoconstriction, pathological cardiac remodeling and ischemia stroke. Molecular mechanisms underlined the protective effects of vinpocetine are also discussed. These novel findings may suggest a broadened usage of vinpocetine against relevant cardiovascular diseases in human.
Attenuated effects of topical vinpocetine in an imiquimod-induced mouse model of psoriasis
ZitatThis research provides new evidence that VNP, alone and in combination with clobetasol, may serve as a potential adjuvant for long-term management of autoimmune and autoinflammatory skin diseases, particularly psoriasis, by attenuating psoriatic lesion severity, suppressing cytokine generation, and limiting NF-κB-mediated inflammation.
Vinpocetine is the forthcoming adjuvant agent in the management of COVID-19
ZitatVPN may decrease hyper-inflammation-induced acute lung injury in COVID-19 through modulation of NF-κB pathway. Taken together, VPN has pulmonary and extra-pulmonary protective effects against COVID-19 through mitigation of OS and hyperinflammation.
Effect of vinpocetine on embryonic heart rate in vitro
ZitatThe FDA advises against vinpocetine use in pregnant and prospective mothers based on animal studies showing dose-dependent fetal mortality in rats and rabbits, and cardiovascular malformations in surviving fetuses. However, the mechanisms responsible for vinpocetine's fetal toxicity remain unclear. (...) These results suggest that the FDA's cautionary statement may generate undue anxiety, although re-evaluation of teratogenicity risk associated with vinpocetine should be revisited if a link to cardiac arrhythmias in adults is established.