Chemical Composition and Antiproliferative Activity of the Ethanolic Extract of Cyperus articulatus L. (Cyperaceae)

Abstract

Cyperus articulatus L. (Priprioca) is a plant of the Cyperaceae family traditionally used in traditional medicine in the Amazon region. Studies of the essential oil of this species have identified many terpene compounds. However, little is known about the possible uses of solid waste generated by the extraction of essential oils. This study aimed to investigate the chemical composition of volatile compounds and to evaluate the antiproliferative activity of the ethanolic extract of solid residues generated by the extraction of the essential oil of C. articulatus L. rizhomes in experimental models in vitro using peritoneal macrophages of mice and human tumor cell lines. The analysis of the chemical composition of volatile compounds indicated the presence of sesquiterpenes and particularly sequiterpenic ketones as main constituents. The results showed that the treatment with ethanolic extract of C. articulatus L. reduced the activity of the enzyme arginase and proliferation of cancer cells (p < 0.0001). The extract also showed no cytotoxicity in macrophages in concentrations between 12.5; 25 and 50 mg/mL (p < 0.0001). The results indicated that the extract of C. articulatus L. exerts antiproliferative activity (p < 0.0001) with low toxicity on healthy cells in experimental models in vitro.

Keywords: anticancer; antiproliferative; arginase; cytotoxicity; medicinal plant.

Figure 1

The effect of EECA on the cell viability of peritoneal macrophages stimulated by LPS + IFN-γ and zymosan. Data were obtained from at least three independent experiments and are summarized as mean ± SD. *** p < 0.001 indicates a significant difference between the group stimulated by LPS + IFN-γ (1 μg/mL) and treated with EECA. # p < 0.1 represents a significant difference between the control group and the group stimulated by LPS + IFN-γ (1 μg/mL). EECA: ethanolic extract of the rhizome of C. articulatus.

Figure 2

The effect of EECA on the activity of the arginase enzyme in IFN-γ stimulated peritoneal macrophages and LPS + IFN-γ. Data were obtained from at least three independent experiments and are expressed as mean ± SD. ** p < 0.01 and *** p < 0.001 indicate a difference between the LPS + IFN-γ (1 μg/mL)-stimulated group and the EECA-treated group. ^### p < 0.001 indicates a significant difference between the control group (mean + 2% of DMSO) and the group stimulated by LPS + IFN-γ (1 μg/mL). EECA: ethanolic extract of the rhizome of C. articulatus.

Figure 3

(A) Cell proliferation curve as a function of the EECA concentration dissolved in a DMSO/RPMI/5% FCS medium. (B) Cell proliferation curve as a function of Doxorubicin concentration. The effective concentration resulting in TGI (total growth inhibition, concentration required for a total inhibition of cell proliferation) was calculated by sigmoidal, nonlinear regression. GI50: concentration that produces 50% cell growth inhibition or cytostatic effect; TGI: concentration that resulted in total cellular growth inhibition; LC50: concentration that produces 50% cell death or cytotoxic effect. EECA: ethanolic extract of the rhizome of C. articulatus.