We have discussed tomatidine (an aglycon derivative of tomatine) and ursolic acid (a pentacyclic triterpenoid carboxylic acid) before on the forum for their potential anabolic and fat-lowering effects. In their natural forms tomatidine comes from tomato plants while ursolic acid can be found in apple skins.
Research into the two compounds is still in its infancy. However Korean researchers have previously shown ursolic acid to be effective at raising IGF-1, significantly lowering bodyfat and (slightly) increasing LBM in bodybuilders (see >>here<<).
In a more recent study, researchers discovered that tomatidine is about five times more effective than ursolic acid (in mice). Both compounds increase muscle mass, lower bodyfat, and increase muscle strength, it's just that tomatidine does this more efficiently. They also both inhibit muscle atrophy during fasting and from aging (sarcopenia).
As the researchers say in the study:
despite their structural differences, ursolic acid and tomatidine generate remarkably similar mRNA expression signatures, which, based on pathway analysis, appear to impact a broad range of cellular processes. Although these data do not speak to the direct or acute effects of ursolic acid and tomatidine in aged skeletal muscle, they do suggest that the end result of a 2-month treatment with either compound is a subtle reprogramming of skeletal muscle gene expression. Furthermore, these subtle changes in gene expression are accompanied by a reduction in age-related muscle weakness and atrophy and may reflect a moderation of at least some of the molecular effects of skeletal muscle aging
This is great news for the elderly, but even better for us bodybuilders since, as we already know ursolic acid works, we can infer tomatidine will probably do the same, but at 1/5th the dose.
And since ursolic acid appears to have no negative feedback on the HPTA and they both share so many pathways, we might expect tomatidine to be equally gentle and - potentially - produce a synergistic or additive effect with the use of exogenous AAS. I'm jumping ahead of myself here a little though
Anyway, here's the abstract:
Identification and Small Molecule Inhibition of an Activating Transcription Factor 4 (ATF4)-dependent Pathway to Age-related Skeletal Muscle Weakness and Atrophy
Aging reduces skeletal muscle mass and strength, but the underlying molecular mechanisms remain elusive. Here, we used mouse models to investigate molecular mechanisms of age-related skeletal muscle weakness and atrophy as well as new potential interventions for these conditions. We identified two small molecules that significantly reduce age-related deficits in skeletal muscle strength, quality, and mass: ursolic acid (a pentacyclic triterpenoid found in apples) and tomatidine (a steroidal alkaloid derived from green tomatoes). Because small molecule inhibitors can sometimes provide mechanistic insight into disease processes, we used ursolic acid and tomatidine to investigate the pathogenesis of age-related muscle weakness and atrophy. We found that ursolic acid and tomatidine generate hundreds of small positive and negative changes in mRNA levels in aged skeletal muscle, and the mRNA expression signatures of the two compounds are remarkably similar. Interestingly, a subset of the mRNAs repressed by ursolic acid and tomatidine in aged muscle are positively regulated by activating transcription factor 4 (ATF4). Based on this finding, we investigated ATF4 as a potential mediator of age-related muscle weakness and atrophy. We found that a targeted reduction in skeletal muscle ATF4 expression reduces age-related deficits in skeletal muscle strength, quality, and mass, similar to ursolic acid and tomatidine. These results elucidate ATF4 as a critical mediator of age-related muscle weakness and atrophy. In addition, these results identify ursolic acid and tomatidine as potential agents and/or lead compounds for reducing ATF4 activity, weakness, and atrophy in aged skeletal muscle.
>>Here's a link<< to the full FREE study.
And >>here's a link<< to Ergo-log's ever handy write-up (with graphs).