Multivariate Data Analysis Guided Identification of Anticancer Constituents of Spina Gleditsiae for Human Hepatoma Cells

Abstract

Spina Gleditsia has been traditionally used as a lead ingredient of many formulas for cancer treatment in Traditional Chinese Medicine. This work aimed to reveal the phytochemical foundation of Spina Gleditsiae and underpin a fundamental understanding of its anticancer activities. The growth inhibition activities were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay of 7 solvent extracts of Spina Gleditsia in the human liver cancer cell line HepG2. The activities were then mapped onto the secondary metabolite profile of crude extracts by principal components analysis (PCA) of High Performance Liquid Chromatography-Ultraviolet (HPLC-UV) data. The top 5 PCA components of the map discriminated extract activities, mainly based on the differential content of 3 compounds. The identified compounds were then tested individually using cytotoxic assay on cancer cells in vitro. Principal components analysis constructed secondary metabolite mapping quickly identified functional compounds from the crude herbal extracts. (2 R,3 R)-7,3′,4′-Trihydroxy-5-methoxy-flavanonol, (2 R,3 R)-5,7,3′-trihydroxy-4′-methoxy-flavanonol, and isovitexin inhibited the growth of human liver cancer cell line growth with activities of 38.6 ± 1.9, 40.7 ± 0.9, and 41.5 ± 3.1 μg/mL, respectively, comparable with that of cisplatin (IC50: 41.6 ± 2.9 μg/mL). (2 R,3 R)-7,3′,4′-Trihydroxy-5-methoxy-flavanonol, (2 R,3 R)-5,7,3′-trihydroxy-4′-methoxy-flavanonol, and isovitexin are, for the first time, identified as the anticancer constituents of Spina Gleditsia. It thus strongly underpins a fundamental understanding of the anticancer activities of Spina Gleditsia and supports its ongoing clinical uses in China.