as a note- recent studies and research into the older (oddly unavailable studies) indicates that guggulsterones are not effective as thyrotrophic agent nor as a cholesterol lowering agent.
their only positive effect seems to be on the FXR (farsenoid x receptor) which may reduce bile acidity.
this study indicates very negative effects, ones that might lower cholesterol at significant dosage, but as you read you will see what negative impacts (from an athletic stanpoint it might have)
Mol Pharmacol. 2005 Mar;67(3):948-54. Epub 2004 Dec 15. Related Articles, Links
The hypolipidemic natural product guggulsterone is a promiscuous steroid receptor ligand.
Burris TP, Montrose C, Houck KA, Osborne HE, Bocchinfuso WP, Yaden BC, Cheng CC, Zink RW, Barr RJ, Hepler CD, Krishnan V, Bullock HA, Burris LL, Galvin RJ, Bramlett K, Stayrook KR.
Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA.
[email protected]
Guggulsterone (GS) is the active substance in guggulipid, an extract of the guggul tree, Commiphora mukul, used to treat a variety of disorders in humans, including dyslipidemia, obesity, and inflammation. The activity of GS has been suggested to be mediated by antagonism of the receptor for bile acids, the farnesoid X receptor (FXR). Here, we demonstrate that both stereoisomers of the plant sterol, (E)- and (Z)-GS, bind to the steroid receptors at a much higher affinity than to FXR. Both stereoisomers bind to the mineralocorticoid receptor (MR) with a Ki value of approximately 35 nM, which is greater than 100 times more potent than their affinity for FXR. Both (E)- and (Z)-GS also displayed high affinity for other steroid receptors, including the androgen (AR), glucocorticoid (GR), and progesterone receptors (PR) with Ki values ranging from 224 to 315 nM. In cell-based functional cotransfection assays,
GSs behaved as antagonists of AR, GR, and MR, but as agonists of PR. Agonist activity was also demonstrated with estrogen receptor (ER) alpha; however, the potency was very low (EC50 > 5000 nM). In addition, GS displayed activity in functional assays in cell lines expressing endogenous AR, GR, ER, and PR. These data suggest that the variety of pharmacological effects exhibited by GS may be mediated by targeting several steroid receptors.
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