Chemical Evaluation of Liquidambar styraciflua L. Fruits Extracts and Their Potential as Anticancer Drugs.

Liquidambar styraciflua L. is an aromatic species, popularly used in traditional Chinese medicine to treat diarrhea, dysentery, coughs, and skin sores. The present study was designed to investigate the chemical composition and biological potential of extracts obtained from the fruits of this plant. For the chemical evaluation, it was used mainly liquid and gas chromatography, plus NMR, and colorimetric methods. The aqueous extract (EA) originated two other fractions: an aqueous (P-EA) and an ethanolic (S-EA). The three extracts were composed of proteins, phenolic compounds, and carbohydrates in different proportions. The analyses showed that the polysaccharide extract (P-EA) contained pectic polysaccharides, such as acetylated and methyl esterified homogalacturonans together with arabinogalactan, while the fraction S-EA presented phenolic acids and terpenes such as gallic acid, protocathecuic acid, liquidambaric acid, combretastatin, and atractyloside A. EA, P-EA, and S-EA showed antioxidant activity, with IC50 values of 4.64 µg/mL, 16.45 µg/mL, and 3.67 µg/mL, respectively. The cytotoxicity followed the sequence S-EA > EA > P-EA, demonstrating that the toxic compounds were separated from the non-toxic ones by ethanol precipitation. While the fraction S-EA is very toxic to any cell line, the fraction P-EA is a promising candidate for studies against cancer due to its high toxicity to tumoral cells and low toxicity to normal cells.

Effect of the extract from leaves of Liquidambar formosana Hance on S180 cells.

We examined the effects of the extract from leaves of Liquidambar formosana Hance on S180 cells and screened for antitumor active sites in the plant. Solvent extraction was conducted to prepare extracts from the leaves of L. formosana Hance and conduct preliminary separation, an MTT assay to determine the effect of leaf extract on the proliferation of S180 cells, and inverted microscopy to observe the effect of chloroform extract on the morphology of S180 cells. Double-staining (Annexin V/propidium iodide) with flow cytometry was conducted to determine the effect of the chloroform extract on S180 cell apoptosis. At some concentrations, the different extracts from the leaves of L. formosana Hance dose-dependently inhibited the proliferation of S180 cells. Among all extracts, the chloroform extract showed the strongest inhibitory effect on S180 cell proliferation. The IC50 values for the chloroform extract, ethyl acetate extract, n-butanol extract, and water layer were 0.238, 0.471, 0.844, and 0.411 mg/mL, respectively. We observed cell shrinkage, volume reduction, and varying sizes by inverted microscopy. Additionally, with increasing drug concentration, the number of cells decreased and debris increased. The cells showed typical apoptotic morphological changes. The chloroform extract induced the apoptosis of S180 cells in a dose-dependent manner. Different extracts from the leaves of L. formosana Hance inhibited the proliferation of S180 cells, and the chloroform extract was the main antitumor component. This extract from the leaves of L. formosana Hance inhibited the proliferation of S180 cells in part by inducing apoptosis.