Effects of sevoflurane or propofol on the cellular metabolism of SKOV3 cells
The metabolic profiles obtained from media samples of naïve control, vehicle control, sevoflurane, and propofol groups were analysed using unsupervised PCA analysis with 2 principal components. The PCA scores plot showed a clear grouping pattern among these four groups (Fig 3A ). Pair-wise comparisons of naïve control vs . sevoflurane group and vehicle control vs . propofol group were carried out using OPLS-DA analysis with one predictive component and one orthogonal component. Permutation p values showed both models of naïve control vs . sevoflurane (p = 0.005) and vehicle controlvs . propofol (p = 0.005) had significances. The permutation p values together with R2X, Q2X, and Q2Y of two models were summarised (Table 1 ). The OPLS-DA scores plots showed there were clear separations between naïve control and sevoflurane group (Fig 3B ), and vehicle control and propofol group (Fig 3D ). The OPLS-DA loadings plots showed that the concentrations of glucose and glutamine were decreased, and the concentration of isopropanol was increased in the sevoflurane group compared to the naïve control group (Fig 3C ). However, the concentrations of glucose and glutamine were increased, and the concentration of isopropanol was decreased in the propofol group in contrast to vehicle control group (Fig 3E ). After anaesthetics administration, the concentrations of lactate, pyruvate, acetate, alanine, valine, and leucine were increased by both sevoflurane and propofol. Furthermore, propofol also increased the levels of glycerol, fatty acids, asparagine, succinate, acetone, arginine, and isoleucine, but decreased the level of ethanol (Table 2 ).