Picrorhiza kurroa is a herb from Ayurveda that is commonly called Kutki or Kutaki. It contains a 'bitter principle' which is a mixture of two molecules, the irioid glycosides known as picroside I and picroside II (picroside II also being called kutkoside) and the mixture overall is then called kutkin or picroliv. Overall, these are the active components.
The herb itself, due solely to the kutkin molecules, appears to be potently hepatoprotective (protective of the liver) when ingested prior to or taken after exposure to a toxin. The protective effects seem to extend to all tested toxins or stressors that are known to alter liver function, and appear to also extend to states of intrinsic liver dysfunction (viral hepatitis and NAFLD from a high fat diet). Most notably it is protective against Tylenol, alcohol, and the deathcap mushroom with a potency that is greater than silymarins (the active parts of milk thistle supplementation).
This fairly remarkable hepatoprotection from picrorhiza kurroa is limited by its lack of human studies, as despite the multitude of animal research on the topic there appears to only be one study in humans which showed that a very low dose of the supplement (25mg kutkin) was effective against viral hepatitis. Future studies in humans are needed to confirm its protective effects, and currently picrorhiza kurroa is a remarkably promising herb.