Brassinosteroids are a group of plant steroid hormones that are responsible for many plant physiological processes, including plant growth, plant development and immunity (1).
Scientists believe these plant hormones can one day help humans build lean muscle mass, increase physical stamina and treat and prevent such diseases as breast cancer and prostate cancer.
Plant hormones are as important to plants as steroid hormones are to the human body.
Medical researchers have been intrigued for quite some time by the presence of brassinosteroids in common Brassica plants such as mustard, cabbage and broccoli.
Why? Through their studies, they have found that these plant steroids are structurally similar to cholesterol-derived animal steroid hormones and have the ability to trigger a physiological response in rats that is similar to anabolic steroids (2).
They are hoping that these substances naturally found in plants can be used by humans to provide an effective, yet natural treatment alternative for muscle loss due to age or disease, as well as improve physical endurance and stamina (3).
While research is lacking on the efficacy and safety of these plant hormones when used by humans, scientists are hoping to learn more about the role of brassinosteroids. Future studies will focus on whether or not there is a connection between brassinosteroids and the ability to treat or prevent diseases and increase physical performance in humans.
Brassinosteroids may increase muscle protein. A team of three researchers studying the effects of brassinosteroids on muscles in rats presented the results of their initial study at the Society for In Vitro Biology World Congress in June 2012 (4). The team consisted of Dr. Debora Esposito, postdoctoral associate, Rutgers University; Dr. Slavko Komarnytsky, metabolic biologist and assistant professor, Plants for Human Health Institute; and Dr. Ilya Raskin of Rutgers.
In their study, they exposed rat skeletal muscle cells to different amounts of homobrassinolide (a type of brassinosteroid found in the mustard plant) and found that muscle cells responded by increasing protein synthesis and decreasing protein degradation. The result was a significant increase in net muscle protein (5).
Brassinosteroids may increase the number and size of muscle fibers. In the second phase of the same study, healthy rats were fed homobrassinolide each day for a total of 24 days, while other rats in the same study were not fed the plant steroid. The rats that were fed the plant steroid showed an increase in lean body mass, over those that were not fed the substance.
The study also revealed a measurable increase in the number and size of fiber crucial for increased physical performance (6). Untrained rats fed homobrassinolide also showed a 6.7 percent increase in lower extremity strength after undergoing a measured grip test and showed an improvement in physical fitness (7).
Unlike anabolic steroids, the oral application of homobrassinolide also appears to have a muscle-building effect with little to no androgenic side effects (8). Typical androgenic side effects include severe acne, an increase in facial or body hair, increased aggression, heart disease, high blood pressure, deeper voice and reduced breast size in women and low sperm count (9).
Brassinosteroids may help to repair damaged muscle. The amount of beneficial plant steroids currently found in mustard plants, broccoli, cabbage and other Brassica plants is too low to have any positive effect in humans via food consumption. The group of researchers is hopeful, however, that in the future, plants can be bred to have a higher brassinosteroid content to produce power foods that can treat or prevent diseases and increase performance (10).
Brassinosteroids may help those fighting prostate cancer. In a study published in 2012 on the effects of brassinosteroids on prostate cancer cells, researchers found that these plant steroids inhibited cell growth and led to the destruction of some cancer cells (11). Researchers are hopeful that these positive early results may lead to a possible future form of anticancer drug treatment for those fighting this type of cancer.
Brassinosteroids may play a role in future breast cancer treatment. A published 2010 study showed that brassinosteroids inhibited breast cancer cell growth and induced blocks in the G(1) cell cycle phase. The study further explained that the application of brassinosteroids to breast cancer cells resulted in G(1) phase arrest. What’s more, there is preliminary evidence that some brassinosteroids are capable of promoting a cell growth inhibitory response in several human cancer cells without affecting healthy, non-tumor cell growth (12).
There are also findings that indicate the possibility of brassinosteroids playing a role in the prevention of metastatic cancers (13).
Brassinosteroids may have an antiviral effect against herpes virus. Natural brassinosteroid and a series of synthetic derivatives were found to be good inhibitors of herpes simplex virus type 1 (HSV-1) (14).
Brassinosteroids may provide antiviral activity against measles. In a study first published in 2002, researchers concluded that certain plant derivatives showed good antiviral activity against the measles virus in cell
The safety of humans eating high concentrations of plant-derived steroids is completely unknown. There is currently no information available on the side effects of the consumption of brassinosteroids.
The use of plant hormones in humans is still very much in the early stages of research. Studies performed have been limited to animals. There are currently no brassinosteroid supplements or products available, and therefore, no recommended dosages.
Brassinosteroids are plant steroid hormones that are responsible for many of the important processes during the life cycle of plants. They are structurally similar to cholesterol-derived animal steroid hormones, and limited studies show they have the ability to trigger a physiological response in rats that is similar to anabolic steroids. The results of one study in particular performed on rat skeletal muscle cells showed that brassinosteroids led to an increase in lean body mass and an increase in the size of muscle fibers.
Other studies show that brassinosteroids may inhibit the growth of certain types of cancer cells such as prostate and breast, without affecting normal, healthy cells. Therefore, researchers are hopeful that these plant hormones may play a potential future role in cancer treatment (16).
While these results are promising, human studies have not been performed and much more research is needed to determine the efficacy and safety of these plant hormones.