Clinical Research of Silymarin
Silymarin is a flavonolignans extracted from the milk thistle Silybum marianum (L.) gaernt.
Silymarin has been shown to possess various pharmacological properties like hepatoprotective, antioxidant, antiinflammatory, anticancer, and cardioprotective activities. Although it has been proved by clinical trials that silymarin is safe at high doses (>1500 mg/day) in humans, pharmacokinetic studies revealed poor absorption, rapid metabolism, and ultimately poor oral bioavailability of silymarin.
El-Sherbiny et al.had developed a biodegradable pH-responsive alginate-poly (lactic-co-glycolic acid) nano/microhydrogel matrix for oral delivery of silymarin conferring sustained oral release of silymarin with enhanced overall dissolution and oral bioavailability. Nanosilymarin showed protection against γ-radiation-induced oxidative stress evaluated by the reduction in micronucleus frequency and ROS generation, microscopy analysis, and cell-cycle estimation in cultured human embryonic kidney cells. Oil-based nanocarrier for silymarin improved the oral efficacy of silymarin in vitro and in vivo studies exhibiting hepatoprotection. Silymarin-loaded SLNs by cold homogenization method than hot homogenization was found to highly efficient with the relative bioavailability at 2.79-fold higher compared to free silymarin solution. Lu and Park improved oral bioavailability of silymarin with binary lipids-based NLCs. Chen et al. successfully developed silymarin-loaded SNEDDS, which improved the dissolution, permeability, and oral bioavailability of silymarin. Oral delivery of silymarin loaded SLNs in Beagle dogs showed enhanced bioavailability. Bile-salt containing liposomes loaded with silymarin developed by supercritical fluid technology improved the dissolution and bioavailability compared of silymarin powder. Maryana et al. developed silymarin-loaded phytosomes with the aim of increasing the stability and oral bioavailability of silymarin.
SNEDDS developed was found to improve the drug malabsorption in rats with roux-en-Y gastric bypass surgery. Gupta et al. showed enhanced activity of silymarin when loaded in chitosan NPs in passive targeted therapy in its hepatoprotective action against CCl4 induced hepatotoxicity in Swiss albino mice. Silymarin-loaded SLNs enhanced the oral bioavailability of silymarin in Beagle dogs as experimental model compared to free silymarin.