Lupeol against high-glucose-induced apoptosis via enhancing the anti-oxidative stress in rabbit nucleus pulposus cells.

PURPOSE: This study aimed to investigate the potential mechanism and value of lupeol in inhibiting high-glucose-induced apoptosis in rabbit nucleus pulposus cells (NPCs). METHODS: NPCs were divided into four groups: control (CON), high glucose (HG), LUP, and HG + LUP. Viability, reactive oxygen species (ROS) levels, and apoptosis were examined in NPCs. The protein expression levels of Bax, Bcl-2, cytochrome C, and caspase 9/3 were measured using reverse transcription-polymerase chain reaction and Western blot assay. RESULTS: The apoptotic rate and total ROS level of the HG group significantly increased compared with the CON group (P < 0.01). The total ROS level in the HG + LUP group significantly decreased compared with the HG group(P < 0.05). The mRNA expression of Bcl-2 was significantly upregulated, whereas the expression of Bax, cytochrome C, and caspase 9/3 was downregulated in the HG + LUP group compared with those in the HG group(P < 0.05).The Western blot assay showed that the expression of Bcl-2 was upregulated, but the expression of Bax, cytochrome C, and caspase 9/3 was significantly downregulated in the HG + LUP group compared with the HG group (P < 0.05). CONCLUSIONS: Lupeol inhibited high-glucose-induced apoptosis in NPCs by enhancing the anti-oxidative stress in the mitochondria. This study suggested lupeol as a potential therapeutic drug for treating intervertebral disc degeneration under hyperglycaemic conditions. These slides can be retrieved under Electronic Supplementary Material.

Critical hydraulic gradient and fine particle migration of sand under upward seepage flow.

In order to study the mechanism of seepage-induced geotechnical damage and characteristics of fine particle migration in sandy soil, a one-dimensional upward seepage test device was used and a series of upward seepage flow tests of sand were conducted. In these experiments, the permeability, fine particle migration and redistribution under different hydraulic gradients were investigated. The results show that local hydraulic gradient in the sand sample is larger than the critical hydraulic gradient calculated by the Terzaghi's Equation. The seepage force will induce the fine soil particles to migrate along water flow direction and then cause the redistribution and reconsolidation of sand particles. Under the test condition, fine particles (< 0.075 mm) and fine sand particles (0.075-0.25 mm) dominate in the lost soil particles. Soil particles larger than 0.6 mm are hardly to lose.