Background: Fatty liver is the most prevalent chronic liver disease. The progressive form of fatty liver disease is non-alcholic steatohepatitis (NASH), which can lead to liver fibrosis and cirrhosis. Silymarin is a traditional liver treatment while, MSCs-CM is a new hope for treatment of chronic liver diseases.

Aim of the work: To evaluate the effect of MSCs-CM versus silymarin on experimentally induced fatty liver in adult male albino rats.

Material & Method: Fifty four adult male albino rats were divided into four groups: I (control group 27 rats) divided into 3 subgroups: (Subgroup Ia, Ib and Ic), II (FL group), III (FL-silymarin) and IV (FL-MSC-CM). Blood samples were collected for lipid profile. Liver tissue was prepared for H&E staining, Mallory's trichrome staining, osmic acid staining, immunohistochemical staining for alpha smooth muscle actin and caspase 3 and electron microscope examination. Statistical and morphometrical studies were performed.

Results: Regarding lipid profile, α-SMA and caspase-3 the highest mean values were observed in group II while the least in group IV.H&E-stained sections of group II showed degenerated hepatocytes with vacuolated cytoplasm and darkly stained nuclei. Ultra structurally, group II revealed , rarified cytoplasm with swollen mitochondria and bundles of collagen while in group III showed some improvement, group IV most of hepatocytes appeared normal.

Conclusion: MSCs-CM has a more ameliorative effect than silymarin on induced non alcoholic fatty liver disease through its antiapoptotic and anti-inflammatory effects.