Silymarin is an extract from the milk thistle plant. In a hospital study it has been shown to significantly lower liver enzymes (AST and ALT) after only four weeks, at a dosage of 420 mg per day (Luper, 1998). Luper (1998) informs us that Silymarin acts in numerous ways to improve liver function, including its anti-oxidant activity, ability to enhance detoxification, prevent lipid peroxidation (cellular damage), decrease tumour promoter activity, improve immune modulation, anti-inflammatory properties and reduces liver scarring (antifibrotic).
In a recent study, researchers from the University of Calcutta, found that silymarin nanoparticles were strongly protective against hepatic damage when tested in a paracetamol overdose hepatotoxicity model (Das, Roy, Auddy & Mukherjee, 2011). It is well understood that paracetamol can induce hepatic (liver) injuries, and increase cytoplasmic liver enzymes (AST and ALT). Paracetamol is converted to a toxic reactive intermediate called N-acetyl-p-benzoquinone imine following metabolism by numerous isozymes of cytochrome P450 (Das, Roy, Auddy & Mukherjee, 2011). The mass production of reactive oxygen species (result in cellular damage) can lead to the depletion of protective physiological moieties (functional molecules in the body). For example, the mass production of reactive species can significantly deplete glutathione levels in the liver. Glutathione is a potent antioxidant that can support and optimise liver function. In the foregoing study, Das, Roy, Auddy & Mukherjee (2011) showed that the use of silymarin, after paracetamol hepatic damage, increased the efficiency of glutathione regeneration in the liver to a level of 11.3 µmol/g in hepatic tissue. This being so, silymarin can reduce hepatotoxicity and increase the anti-oxidant capacity of antioxidants within the liver.
Das, S., Roy, P., Auddy, R.G. & Muherjee, A. 2011. Silymarin nanoparticle prevents paracetamol induced hepatotoxicity. International Journal of Nanotechnology, 6, 1291-1301.
Luper, S. 1998. A review of plants used in the treatment of liver disease: Part 1. Alternative Medicine Review, 6, 4, 10-21.