Anti-Estrogen Brassaiopsis glomerulata

Brassaiopsis glomerulata is powerful aromatase inhibitor (in vitro)

Brassaiopsis glomerulata is a is a large shrub that can be found mostly in southeast Asia. It is a member of the Araliaceae and has several reported medicinal uses. Brassaiopsis glomerulata extracts are sold as a bodybuilding supplements due to its possible aromatase (enzyme responsible for the biosynthesis of estrogens [1]) inhibitors present in the plant.

In VitroAromatase Inhibition ofBrassaiopsis GlomerulataExtracts

Balunas, Marcy J., et al. [4] isolated and characterised aromatase inhibitors from brassaiopsis glomerulata. They isolated 13 compounds. Among them 6β-hydroxystimasta-4-en-3-one, N-benzoyl-L-phenylalanine methyl ester and (−)-dehydrololiolide showed aromatase inhibition properties. (−)-dehydrololiolide was found to be as effective as Letrozole (FDA approved non-steroidal aromatase inhibitor).

The strong aromatase inhibition of the hexane extract of brassaiopsis glomerulata was noted in both enzyme- and cell-based assays [4]. Further investigations of brassaiopsis glomerulata are needed on the mechanism of aromatase inhibition and in vivo testing. There is no evidence that brassaiopsis glomerulata inhibits aromatase in vivo.

Why are Aromatase Inhibitors Used?

Bodybuilders that take anabolic steroids often use aromatase inhibitors in order to minimize or avoid estrogenic effect (such as gynecomastia). Aromatase inhibitors prevent elevated levels of testosterone from being converted to excess estrogen [2]. Aromatase inhibitors have also been shown to reverse age-related decline in testosterone [3].

Possible Side Effects of Aromatase Inhibition

Common side effects from aromatase inhibitors are decreased rate of bone maturation and growth, infertility, aggressive behavior, adrenal insufficiency, kidney failure, and liver dysfunction. Consumers with liver, kidney, adrenal, or prostate abnormalities are at higher risk for developing adverse events [5].


  1. Johnston, Stephen RD, and Mitch Dowsett. “Aromatase inhibitors for breast cancer: lessons from the laboratory.Nature Reviews Cancer 3.11 (2003): 821-831.
  2. Plourde, Paul V., et al. “Safety and efficacy of anastrozole for the treatment of pubertal gynecomastia: a randomized, double-blind, placebo-controlled trial.Journal of Clinical Endocrinology & Metabolism 89.9 (2004): 4428-4433.
  3. Leder, Benjamin Z., et al. “Effects of aromatase inhibition in elderly men with low or borderline-low serum testosterone levels.Journal of Clinical Endocrinology & Metabolism 89.3 (2004): 1174-1180.
  4. Balunas, Marcy J., et al. “Isolation and characterization of aromatase inhibitors from Brassaiopsis glomerulata(Araliaceae).Phytochemistry letters 2.1 (2009): 29-33.
  5. Aromatase Inhibitors in Products Marketed as Dietary Supplements: Recall Retrieved 25. Feb 2013