Serum Metabonomics Analysis of Fuzi Lizhong Decoction for the Treatment of Splenasthenic Syndrome

Fuzi lizhong decoction (FLD) derives from an ancient Chinese Pharmacopoeia: San Yin Ji Bing Zheng Fang Lun, composed of equal amounts of Aconitum carmichaeli Debeaux (ACD); Zingiber officinale Roscoe (ZOR); Glycyrrhiza uralensis Fisch. (GUF); Atractylodes macrocephala Koidz. (AMK); and Codonopsis pilosula Franch. (CPF). Its pill has been used for the treatment of gastrointestinal disorders for years. The objective of this study was to clarify the curative effect of FLD on splenasthenic syndrome and to identify biomarkers upon which FLD acts as a therapeutic agent based on a serum metabonomics analysis. Serum samples from a blank group (BG), a model group (MG), and a treatment group (TG) of rats were analyzed using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). Then, both the endogenous metabolites and metabolic pathways in the MG samples versus the BG samples were investigated. A partial least squares discriminant analysis (PLS-DA) was used to separate MG from BG and to filter the different endogenous metabolites between the two groups. Furthermore, analysis of variance (ANOVA) was used to select potential biomarkers that significantly differed in MG compared with those in BG to evaluate their callback situation in TG. Compound identification was performed based on retention time, accurate mass weight, and MS/MS spectra by searching online databases and references. The results showed that 166 of 1189 total detected ions were different between MG and BG according to the variable importance plot (VIP) values (>1.5) obtained through partial least squares discriminate analysis (PLS-DA), 62 of which were detected in positive mode and 104 of which were detected in negative mode. Fifteen compounds, including L -palmitoylcarnitine, 11Z -octadecenylcarnitine, LysoPC(14:0), LysoPC(16:1(9Z)), LysoPC(P-18:0), LysoPE(20:0/0:0), LysoPC(18:2(9Z,12Z)), LysoPC(18:1(9Z)), LysoPC(18:0), LysoPC(20:2(11Z,14Z)), LysoPC(20:0), uric acid, 2-phenylethanolglucuronide, LysoPC(15:0), and LysoPC(16:0), were identified and considered biomarkers of splenasthenic syndrome. Among them, LysoPC(15:0), LysoPC(16:0), L -palmitoylcarnitine, 11Z -octadecenylcarnitine, LysoPC(16:1(9Z)), and LysoPC(P-18:0) were retrieved after rats were cured with FLD in TG, and the related pathways involving fatty acid degradation and glycerophospholipid metabolism were identified. This experiment confirmed that FLD may treat splenasthenic syndrome by improving fatty acid degradation and glycerophospholipid metabolism and is expected to be developed as a beneficial pharmaceutical for the spleen. Graphical Abstract