Liposome-Based Silibinin for Mitigating Nonalcoholic Fatty Liver Disease: Dual Effects via Parenteral and Intestinal Routes

Nonalcoholic fatty liver disease (NAFLD) is a clinicopathological entity that is typically characterized by intrahepatic ectopic steatosis. Nowadays, NAFLD has surpassed viral hepatitis and become the most common chronic liver disease worldwide, which poses a great threat to human health. Silibinin (Sil), a well-known natural product, has been widely used in clinical treatment for liver disorders and exhibited therapeutic potential for NAFLD. However, the suitability of Sil for NAFLD treatment still requires further investigation due to its limited absorption and low bioavailability. This study aimed to construct a Sil-loaded liposome (Sil-Lip) to overcome the limitations of Sil, thereby enhancing its beneficial effects on NAFLD and then investigate the underlying mechanisms of action of Sil-Lip. Herein, Sil-Lip was fabricated by a well-established thin-film dispersion method and carefully characterized, followed by evaluating their therapeutic efficacy using high-fat diet-induced NAFLD mice and free fatty acid -stimulated HepG2 cells. Then, liver transcriptome analysis and 16S ribosomal RNA (16S rRNA) sequencing were utilized to elucidate the potential mechanisms of action of Sil-Lip. Our data indicated that Sil-Lip harbored good gastrointestinal tract stability, mucus layer permeation, and excellent oral absorption and bioavailability. In vivo and in vitro NAFLD models demonstrated that Sil-Lip had better effects in alleviating lipid metabolism disorders, insulin resistance, and inflammation than did Sil alone. Further investigations revealed that the beneficial effects of Sil-Lip were mediated by modulating intrahepatic insulin resistance-related and nuclear factor-kappa B (NF-κB) signaling pathways and extrahepatic gut microbiota. Our study confirmed that Sil-Lip can effectively improve the absorption and bioavailability of Sil, resultantly potentiating its ameliorative effects on NAFLD through modulating intrahepatic insulin resistance-related and NF-κB signaling pathways and extrahepatic gut microbiota.