## 3 Results
### Identification of Potential Biomarkers
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Mass Fragment**} & \multirow{2}{*}{**Metabolites b**} & \multirow{2}{*}{**Adduct**} & \multirow{2}{*}{**Elemental Composition**} & \multicolumn{3}{c}{**Fold Change**} \\  & & & & & **with OVX Group a [FOOTNOTE:a]Footnote a: Comparison of OVX model group with sham group, SCE group, respectively, the putative identifications are increased (!) or decreased (!). * \(p<0.05\); **\(p<0.01\); *** \(p<0.001\), compared with OVX group. b Abbreviations: lysophosphatidylethanolclines (LysoPC); lysophosphatidylethanolamine (LysoPC); diacylglycerole end (DG); phosphatidic acid (PA); phosphatidic acid (PA); phosphatidic acid (PC). & \multicolumn{3}{c}{**Change Trend Compared with OVX Group a**} \\ \cline{4-7}  & & & & **OVX/Sham** & **SCE/OVX** & **Sham** & **SCE** \\ \hline
167.0206 & Uric acid & [M-H]- & C5H4N4O3 & 1.81 & 0.67 & \(\downarrow\) *** & \(\downarrow\) *** \\
204.1219 & Acetylcarnitineine & [M+H]+ & C9H18 NO4 & 0.77 & 1.65 & \(\uparrow\) & \(\uparrow\) *** \\
180.0662 & Tyrosine & [M-H]- & C9H11 NO3 & 2.06 & 0.59 & \(\downarrow\) *** & \(\downarrow\) *** \\
276.1477 & Glutarylcarnitineine & [M+H]+ & C12H22 NO6 & 1.32 & 0.95 & \(\downarrow\) *** & \(\downarrow\) \\
232.1546 & Butyrylcarnitineine & [M+H]+ & C11H21 NO4 & 1.75 & 0.55 & \(\downarrow\) ** & \(\downarrow\) *** \\
203.0828 & Typtophan & [M-H]- & C11H12N2O2 & 1.34 & 0.95 & \(\downarrow\) * & \(\downarrow\) \\
187.0996 & Nonate & [M-H]- & C9H16O4 & 1.30 & 1.08 & \(\downarrow\) * & \(\uparrow\) \\
349.2361 & Arachidic acid & [M+FA-H]- & C20H32O2 & 0.02 & 0.30 & \(\uparrow\) *** & \(\downarrow\) ** \\
407.2763 & Cholic acid & [M-H]- & C24H40O5 & 0.45 & 4.18 & \(\uparrow\) * & \(\uparrow\) ** \\
512.2966 & LysoPE(16:0) & [M+CH3 COO]- & C21H44 NO7P & 1.62 & 0.54 & \(\downarrow\) ** & \(\downarrow\) ** \\
494.3177 & LysoPC(16:1) & [M+H]+ & C24H48 NO7P & 1.44 & 0.39 & \(\downarrow\) ** & \(\downarrow\) *** \\
564.3281 & LysoPE(20:2) & [M+CH3 COO]- & C25H48 NO7P & 1.73 & 0.86 & \(\downarrow\) *** & \(\downarrow\) * \\
520.3392 & LysoPC(18:2) & [M+H]+ & C26H5 NO7P & 1.23 & 0.64 & \(\downarrow\) * & \(\downarrow\) ** \\
540.3308 & LysoPE(18:0) & [M+CH3 COO]- & C23H48 NO7P & 1.30 & 0.63 & \(\downarrow\) *** & \(\downarrow\) ** \\
570.3566 & LysoPC(22:5) & [M+H]+ & C30H52 NO7P & 0.31 & 3.19 & \(\uparrow\) *** & \(\downarrow\) *** \\
546.3596 & LysoPC(20:3) & [M+H]+ & C28H52O7 NP & 1.58 & 0.30 & \(\downarrow\) ** & \(\downarrow\) ** \\
566.3455 & LysoPE(20:1) & [M+CH3 COOO]- & C25H50 NO7P & 1.42 & 0.72 & \(\downarrow\) *** & \(\downarrow\) ** \\
605.4123 & DG(18:3/14:1) & [M+2N=H]- & C35H6005 & 0.21 & 4.41 & \(\uparrow\) ** & \(\uparrow\) ** \\
480.3074 & LysoPC(15:0) & [M-H]- & C23H48 NO7P & 1.51 & 0.62 & *** & \(\downarrow\) ** \\
568.3600 & LysoPC(17:0) & [M+CH3 COO]- & C25H52 NO7P & 1.29 & 0.73 & \(\downarrow\) *** & \(\downarrow\) ** \\
711.4693 & 14+HDoHE & [2M-H]- & C23H32O3 & 1.53 & 0.72 & \(\downarrow\) *** & \(\downarrow\) ** \\
711.4706 & PA(P-16:0/19:0) & [M+K-2H]- & C38H75O7P & 1.53 & 0.71 & \(\downarrow\) *** & \(\downarrow\) ** \\
601.3294 & PA(14:0/12:0) & [M+K-2H]- & C29H57O8P & 1.53 & 0.71 & \(\downarrow\) *** & \(\downarrow\) *** \\
854.5827 & PC(20:4/22:6) & [M+H]+ & C50H80 NO8P & 0.57 & 0.16 & \(\uparrow\) ** & \(\downarrow\) ** \\
850.5619 & PC(22:6/15:0) & [M+CH3 COO]- & C45H78 NO8P & 0.43 & 1.62 & \(\uparrow\) ** & \(\uparrow\) ** \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Identification of potential biomarkers in rat serum. Figure 2: Results of multivariate data analysis obtained from LC-QTOF/MS. (**A,B**) PCA score plots in different groups; (**C,D**) PLS-DA score plots among Sham, OVX, and SCE groups; (**E,F**) OPLS-DA score plots between Sham and OVX groups in positive mode and negative mode. The changes of 25 significant variables in the serum samples from the groups are shown in Figure 3. After SCE treatment, the levels of most of these metabolites were reversed and restored to near normal level.