ABSTRACT
Silymarin is a combination of flavonolignans, containing silybinA, silybin B, isosilybin A, isosilybin B, silychristin, and silydianin, which is extracted from the plant Silybum marianum (milk thistle). Although silymarin has been mainly known as a hepatoprotective phytochemical, other functions such as antioxidant, anti-inflammatory, anticancer, and adipogenesis inhibitory properties have also been reported. Studies have described that silybin, a major constituent of silymarin, could restrain lipid accumulation in zebrafish and 3T3-L1 cells as well. In clinical application, silymarin has been used for treating liver diseases like cirrhosis, hepatitis, toxin exposure, and alcoholic liver disease. Moreover, it has clinical applications in Amanita mushroom poisoning and psoriasis and also has been clinically used for its neurotropic and neuroprotective activity. Water solubility and enteral absorption of silymarin is poor, and it is instable in gastric juices. To improve the bioavailability and solubility of silymarin, several approaches regarding novel drug delivery systems have been evaluated. These approaches included incorporating of silymarin into solid nanoparticles, lipid emulsion, solid dispersion, self-microemulsifying system, proliposomes, niosomes, and bilosomes. In this chapter, firstly the chemical/structural features of silymarin are illustrated, then, its various biochemical activity is discussed and its current and future potential for clinical applications will be stated. As the main challenge of the chapter, diverse drug delivery systems studied so far, including liposomes, nanoparticles, micro-emulsions, and polymer-based systems, are classified and the pros and cons of each system will be discussed.
