There’s a kernel of truth in the hyperbole-ridden ads for ThermoLife’s bodybuilding supplement E-Bol. [thermolife.com] E-Bol contains an extract of Ajuga turkestanica, a plant that is packed with ecdysteroids. And it so happens that recent in-vitro and animal studies have shown that Ajuga turkestanica does indeed have a muscle-strengthening effect.
Turkesterone [structural formula shown on right] is not an anabolic steroid, but if we are to believe old Russian animal studies, turkesterone has a greater anabolic effect than methandienone, the active ingredient in Dianabol. [Pharmaceutical Chemistry Journal Volume 34, Number 4 / April, 2000 193-197] Turkesterone is found in Ajuga turkestanica, a plant related to mint that grows in Asia Minor.
This was the reason why American sports scientists looking for ways to treat age-related muscle weakness, aka sarcopaenia, studied the effect of Ajuga turkestanica on old mice. Their study was published in the little known scientific journal European Review for Medical and Pharmacological Sciences.
The Americans gave their lab animals Ajuga turkestanica extract mixed in their feed every day for four weeks. The human equivalent of this dose – based on someone weighing 80 kg – would be 400 mg extract per day. The extract contained 40 percent ecdysteroids, and the composition is shown below.
At the end of the experiment the researchers studied muscle cells from the mice’s triceps and they found that the ecdysteroids had activated the Notch receptor. [Figure above] When substances activate stem cells via de Notch-receptor, the stem cells develop into new muscle cells. [Science. 2003 Nov 28;302(5650):1575-7.]
The researchers discovered that Ajuga turkestanica also seemed to stimulate muscle growth via the Wnt pathway.
Researchers suspect that sarcopaenia arises as the Notch and Wnt pathways die out. “It is possible that the phytoecdysteroid-induced alterations in Notch and Wnt signaling will better prepare aged skeletal muscle for repair following exposure to muscle injury”, the Americans concluded.
Ajuga turkestanica and myostatin
Another study on the anabolic effects of Ajuga turkestanica was published in 2012 in Chinese Medicine, an obscure scientific journal. [Chinese Medicine, 2012, 3, 215-222.]
The researchers were working for PoliNat, a Spanish company that sells plant-based bioactive extracts – including an extract from Ajuga turkestanica. [polinat.eu]
The researchers observed that at a concentration of 1 micromole Ajuga turkestanica ecdysteroids the muscle cells started to make less myostatin. The researchers repeated the experiment and exposed the muscle cells this time to 1 micromole methandienone – the active ingredient in Dianabol. And, lo and behold – the ecdysteroids turned out to be more effect myostatin inhibitors than methandienone.
Animal studies and in-vitro studies are not human studies of course, and what works in a petri dish or in a mouse doesn’t automatically work in humans. For this reason alone you can’t just extrapolate the results of this study to people. But there’s another problem: most Ajuga turkestanica extracts available on the market only contain about 2 percent ecdysteroids. So if you weigh 80 kg, you’d need 8 g extract daily. And that’s a lot.
Do all those bodybuilding supplements contain enough ecdysteroids to actually have an effect?
Ajuga turkestanica increases Notch and Wnt signaling in aged skeletal muscle.
The declining myogenic potential of aged skeletal muscle is multifactorial. Insufficient satellite cell activity is one factor in this process. Notch and Wnt signaling are involved in various biological processes including orchestrating satellite cell activity within skeletal muscle. These pathways become dysfunctional during the aging process and may contribute to the poor skeletal muscle competency. Phytoecdysteroids are natural adaptogenic compounds with demonstrated benefit on skeletal muscle.
To determine the extent to which a phytoecdysteroid enriched extract from Ajuga turkestanica (ATE) affects Notch and Wnt signaling in aged skeletal muscle.
MATERIALS AND METHODS:
Male C57BL/6 mice (20 months) were randomly assigned to Control (CT) or ATE treatment groups. Chow was supplemented with either vehicle (CT) or ATE (50 mg/kg/day) for 28 days. Following supplementation, the triceps brachii muscles were harvested and immunohistochemical analyses performed. Components of Notch or Wnt signaling were co-labelled with Pax7, a quiescent satellite cell marker.
ATE supplementation significantly increased the percent of active Notch/Pax7+ nuclei (p = 0.005), Hes1/Pax7+ nuclei (p = 0.038), active B-catenin/Pax7+ nuclei (p = 0.011), and Lef1/Pax7+ nuclei (p = 0.022), compared to CT. ATE supplementation did not change the resting satellite cell number.
ATE supplementation in aged mice increases Notch and Wnt signaling in triceps brachii muscle. If Notch and Wnt benefit skeletal muscle, then phytoecdysteroids may provide a protective effect and maintain the integrity of aged skeletal muscle.
PMID: 25268108 [PubMed – in process]