[Correlation between drug-induced liver injury in rats caused by Xianling Gubao oral preparation and extraction process].

In light of the liver injury risk associated with the oral administration of Xianlin Gubao oral preparation, this study compared the differences in liver injury induced by two different extraction processes in rats and explored the correlation between hepatotoxicity and extraction process from the perspective of the differences in the content of the relevant components. Thirty male Sprague-Dawley(SD) rats were randomly divided into a normal group, tablet extract groups of different doses, and capsule extract groups of different doses, with 6 rats in each group. Each group received continuous oral administration for 4 weeks. The assessment of liver injury caused by different extracts was conducted by examining rat body weight, liver function blood biochemical indicators, liver coefficient, and liver pathological changes. In addition, a high-performance liquid chromatography(HPLC) method was established to simultaneously determine the content of icariin, baohuoside I, and bakuchiol in the extracts to compare the differences in the content of these three components under the two extraction processes. The results showed that both extracts caused liver injury in rats. Compared with the normal group, the tablet extract groups, at the studied dose, led to slow growth in body weight, a significant increase in triglyceride levels(P<0.05), a significant decrease in liver-to-brain ratio(P<0.05), and the appearance of hepatic steatosis. The capsule extract groups, at the studied dose, resulted in slow growth in body weight, a significant increase in aspartate aminotransferase levels(P<0.05), a significant decrease in body weight, liver weight, and liver-to-brain ratio(P<0.05), and the presence of hepatic steatosis and inflammatory cell infiltration. In comparison, the capsule extraction process had a higher risk of liver injury. Furthermore, based on the completion of the liquid chromatography method, the content of icariin and baohuoside Ⅰ in the capsule extract groups was 0.83 and 0.81 times that in the tablet extract groups, respectively, while the bakuchiol content in the capsule extract group was 29.80 times that in the tablet extract groups, suggesting that the higher risk of liver injury associated with the capsule extraction process may be due to its higher bakuchiol content. In summary, the differences in rat liver injury caused by the two extracts are closely related to the extraction process. This should be taken into consideration in the formulation production and clinical application.

Density Gradient Ultracentrifugation for Investigating Endocytic Recycling in Mammalian Cells.

Endosomal trafficking is an essential cellular process that regulates a broad range of biological events. Proteins are internalized from the plasma membrane and then transported to the early endosomes. The internalized proteins could be transited to the lysosome for degradation or recycled back to the plasma membrane. A robust endocytic recycling pathway is required to balance the removal of membrane materials from endocytosis. Various proteins are reported to regulate the pathway, including ADP-ribosylation factor 6 (ARF6). Density gradient ultracentrifugation is a classical method for cell fractionation. After the centrifugation, organelles are sedimented at their isopycnic surface. The fractions are collected and used for other downstream applications. Described here is a protocol to obtain a recycling endosome-containing fraction from transfected mammalian cells using density gradient ultracentrifugation. The isolated fractions were subjected to standard Western blotting for analyzing their protein contents. By employing this method, we identified that the plasma membrane targeting of engulfment and cell motility 1 (ELMO1), a Ras-related C3 botulinum toxin substrate 1 (Rac1) guanine nucleotide exchange factor, is through ARF6-mediated endocytic recycling.