Effect of constituents from samaras of Austroplenckia populnea (Celastraceae) on human cancer cells

Abstract

Background: Aiming the continuity of the studies of Austroplenckia populnea, Brazilian species of the Celastraceae family, in the present study, it was investigated the effect of crude extracts obtained with ethanol, ethyl acetate and chloroform and two purified constituents, proanthocyanidin A and 4'-O-methylepigallocatechin, both isolated from its samaras, on cancer cell proliferation assays.

Materials and methods: The human cancer cells lines MCF-7 (ductal breast carcinoma), A549 (lung cancer), HS578T (ductal breast carcinoma) and non-cancer HEK293 (embryonic kidney cells) were treated with different concentrations of extracts and constituents and the effect was observed through the acid phosphatase method. The chemical structures of the purified compounds were identified by the respective IR and (1)H and (13)C nuclear magnetic resonance spectral data.

Results: While crude extracts from samaras of the folk medicine A. populnea can trigger cell proliferative effects in human cell lines, the purified compounds (proanthocyanidin A and 4'-O-methyl-epigallocatechin) isolated from the same extracts can have an opposite (anti-proliferative) effect.

Conclusion: Based on the results, it was possible to suggest that extracts from samaras of A. populnea should be further investigated for possible cancer-promoting activities; and the active extracts can also represent a source of compounds that have anti-cancer properties.

Keywords: Austroplenckia populnea; Celastraceae; cancer cell proliferation; samaras.

Figure 1

Chemical structures of 4’-O-methyl epigallocatechin (a) and proanthocyanidin A (b)

Figure 2

Impact on cell proliferation after 24 and 48 h treatment with three crude extracts isolated from samaras of Austroplenckia populnea, on four cell lines: MCF-7, A549, HS578T and HEK293. Treatment of chloroform extract (a) (24 h) and (b) (48 h), ethyl acetate extract (c) (24 h) and (d) (48 h), ethanol extract € (24 h) and (f) (48 h). Final median concentration of extracts was 125 µg/mL (light blue), 250 µg/mL (red), 500 µg/mL (green) and 1000 µg/mL (dark blue). Data are represented as mean relative percentage (%) and standard deviation of three replicates. Significant differences based on the control were established using Student’s t-test and are represented by asterisks (P < 0.05: *, P ≤ 0.01: **, P ≤ 0.001: ***)

Figure 3

Impact on cell proliferation post 24 and 48 h treatment of two purified compounds from samaras of Austroplenckia populnea on four cell lines MCF-7, A549, HS578T and HEK293. Treatment of proanthocyanidin A (24 h) (a) and (48 h) (b), 4’-O-methylepigallocatechin (24 h) (c) and (48 h) (d). Final concentration of extracts in media was 50 µg/mL (light blue), 100 µg/mL (red), 250 µg/mL (green) and 500 µg/mL (dark blue). Data are shown as relative percentage (%) mean and one standard deviation of three replicates. Significant differences to the control were analyzed using Student’s sssss-test and are represented by asterisks (P < 0.05: *, P ≤ 0.01: **)