Silydianin is one of the major flavonolignans found in silymarin, the active extract from the seeds of Silybum marianum (milk thistle). Silymarin, which contains silydianin along with silybin, silychristin, and other related compounds, has a long history of use in traditional medicine for liver ailments. However, modern research has focused more on the collective effects of silymarin rather than isolating silydianin specifically.

Scientific studies have demonstrated that silymarin exerts hepatoprotective, antioxidant, and antifibrotic effects, which can be beneficial in the management of cirrhosis and other chronic liver diseases. Silydianin, as a component of silymarin, is believed to contribute to these effects, particularly by inhibiting hepatic enzymes involved in toxin metabolism and reducing oxidative stress. However, clinical trials evaluating silymarin’s effect on cirrhosis have produced mixed results, with some studies reporting improvements in liver function tests and histology, while others show minimal or no effect on clinical outcomes such as survival or progression of cirrhosis.

There is a lack of robust, high-quality clinical evidence specifically for silydianin as an isolated compound in the treatment of cirrhosis. Most available data pertain to silymarin as a whole. Therefore, while there is scientific rationale for the use of silymarin (and by extension, silydianin), the direct evidence for silydianin alone is limited, warranting a modest evidence rating.