Steroid plant hormones: Effects outside plant kingdom

• Brassinosteroids exert a wide spectrum of biological effects on non-plant organisms.
• Anticancer, antiviral, anabolic and other properties of brassinosteroids are discussed.
• Brassinosteroids are of interest as a source of novel leads in the drug development.

Brassinosteroids (BS) are the first group of steroid-hormonal compounds isolated from and acting in plants. Among numerous physiological effects of BS growth stimulation and adaptogenic activities are especially remarkable. In this review, we provide evidence that BS possess similar types of activity also beyond plant kingdom at concentrations comparable with those for plants. This finding allows looking at steroids from a new point of view: how common are the mechanisms of steroid bioregulation in different types of organisms from protozoa to higher animals.