Objective To explore the influence of Linggui Zhugan Decoction (LGZGD) on high glucose induced podocyte autophagy
Methods LGZGD containing serum were prepared by intragastric administation of 4.2 g·kg^{-1 (}low dose⁾, 8.4 g·kg^-1 (medium dose), and 12.6 g·kg^-1 (high dose) LGZGD into SD rats respectively. MPC5 and AB8/13 cells were treated with 60 mmol/L glucose to establish diabetic nephropathy podocyte model in vitro. Podocytes, MPC5 and AB8.13, were divided into control group, high glucose group, low dose LGZGD group, medium dose LGZGD group, and high dose LGZGD group, respectively. For the three LGZGD groups, before LGZGD intervention, podocytes were treated with 60 mmol/L glucose for 3 days. After treated with LGZGD containing serum, cells were collected to analyze cell migration using Transwell assay, proliferation using CCK8, apoptosis and cell cycle using flow cytometry,, autophagosome formation using transmission electron microscopy, and expression levels of Beclin-1, Atg5, LC3II/I, and P62 proteins using western blot.
Results Compared with the control group, the proliferation and migration of MPC5 and AB8.13 cells in high glucose group showed slightly decreased, whereas these parameters restored after intervention with low and medium concentrations of LGZGD, with the medium dose LGZGD having the best effect. Flow cytometry analysis showed that the medium dose LGZGD group had a lower apoptosis rate (P < 0.05) and higher survival rate (P > 0.05) compared to the high dose group. High glucose arrested podocytes in G1 phase, whereas LGZGD shifted podocytes from being predominant in G1 phase to increasing into G2. High dose LGZGD significanly reduced increased autophagosome formation due to high glucose in both podocytes (P < 0.05). Western blot analysis showed that Beclin-1, Atg5, LC3Ⅱ/Ⅰ, and P62 expressions were increased in MPC5 cells treated with high glucose, and reversed after adminstration of low and medium doses of LGZGD (P < 0.05).
Conclusion LGZGD reduced apoptosis and enhanced autophagy in high glucose treated podocytes via regulating Beclin-1/LC3II/I/Atg5 expression.

Key words: diabetic nephropathy, podocyte, Linggui Zhugan decoction, apoptosis, autophagy