Mustard brassinosteroids are anabolic in rodents

[Arnold]

Mustard brassinosteroids are anabolic in rodents
by Anthony Roberts ~ source

Research is mounting on the anabolic effects of brassinosteroids. I first saw these compounds discussed on Ergo-Log.com (check it out if you haven???t already), but a new(er) study has claimed that brassinosteroids may mimic the effects of anabolic steroids with less side effects.

Homobrassinolide, found in the mustard plant, boosts muscle mass along by both hyperplasia and hyperphasia (number and size of muscle fibres, respectively). In this study, rat skeletal muscle cells were exposed to homobrassinolide, after which their protein synthesis levels were measured in cell culture. The result: increased protein synthesis and decreased protein degradation. After it was proven anabolic in cell cultures, healthy rats were then given varying doses of homobrassinolide for 24 days. The result was an increase in lean body mass. The researchers then repeated their efforts, this time with a high-protein diet, and again, LBM was increased to a greater degree than without the high-protein feeding. Surgically castrated rodents were then used in yet another repeat-experiment, and both muscle size and strength increased again.

Interestingly, it shows no stimulatory activity on the androgen receptor, but still manages to exhibit low androgenic properties.

FASEB J. 2011 Jul 11. [Epub ahead of print]
Anabolic effect of plant brassinosteroid.
Esposito D, Komarnytsky S, Shapses S, Raskin I.
Source

*Biotech Center and.

Abstract

Brassinosteroids are plant-derived polyhydroxylated derivatives of 5a-cholestane, structurally similar to cholesterol-derived animal steroid hormones and insect ecdysteroids, with no known function in mammals. 28-Homobrassinolide (HB), a steroidal lactone with potent plant growth-promoting property, stimulated protein synthesis and inhibited protein degradation in L6 rat skeletal muscle cells (EC(50) 4 μM) mediated in part by PI3K/Akt signaling pathway. Oral administration of HB (20 or 60 mg/kg/d for 24 d) to healthy rats fed normal diet (protein content 23.9%) increased food intake, body weight gain, lean body mass, and gastrocnemius muscle mass as compared with vehicle-treated controls. The effect of HB administration increased slightly in animals fed a high-protein diet (protein content 39.4%). Both oral (up to 60 mg/kg) and subcutaneous (up to 4 mg/kg) administration of HB showed low androgenic activity when tested in the Hershberger assay. Moreover, HB showed no direct binding to the androgen receptor in vitro. HB treatment was also associated with an improved physical fitness of untrained healthy rats, as evident from a 6.7% increase in lower extremity strength, measured by grip test. In the gastrocnemius muscle of castrated animals, HB treatment significantly increased the number of type IIa and IIb fibers and the cross-sectional area of type I and type IIa fibers. These findings suggest that oral application of HB triggers selective anabolic response with minimal or no androgenic side-effects and begin to elucidate the putative cellular targets for plant brassinosteroids in mammals.-Esposito, D., Komarnytsky, S., Shapses, S., Raskin, I. Anabolic effect of plant brassinosteroid.