Catechin profile and hypolipidemic activity of Morinda citrifolia leaf water extract

Cardiovascular diseases (CVDs) are silent killers and hyperlipidemia is a high-risk factor. Morinda citrolia leaf (MCL), which is commonly consumed by many cultural groups and has high level of catechins, might exert antihyperlipidemic properties. In this study, the catechins profile of MCL water extract was determined via HPLC and ultraperformance liquid chromatography-traveling wave ion mobility-quadrupole time of flight mass spectrometry (UPLC-TWIMS-QTOF). The major catechin in MCL and the most widely studied catechin with hypolipidemic activity, epigallocatechin gallate (EGCG), was studied in a cytotoxicity test on HepG2 cells prior the in vitro anti-hyperlipidemic assay. The total catechins of MCL reached 141.88 ± 5.04 mg/g, with catechin gallate (CG) (75.27 ± 8.49 mg/g) as the major catechin. Catechin derivatives that were identified include epigallocatechin-3-O-gallate (EGCG) with m/z 459.0912 [M + H]⁺, epigallocatechin (EGC) with m/z 307.0818 [M + H]⁺, CG with m/z 443.0976 [M + H]⁺, epigallocatechin(4β→8)-gallocatechin with m/z 649.0951 [M + K]⁺, and gallocatechin(4α→8)-epicatechin with m/z 633.1 [M + K]⁺. Cell inhibitions of MCL, CG and EGCG were more than IC₅₀ of 100 μg/ml. MCL increased LDL-c uptake up to 1.11 ± 0.03-fold, but this was insignificant relative to control. CG and EGCG significantly increased LDL-c uptake up to 1.37 ± 0.19-fold and 1.59 ± 0.19-fold, respectively. Thus, MCL with CG has shown potential for modulating hyperlipidemia.