• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.67-71
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• 2004

Pata de Vaca (Bauhinia forficata) Is a tree which grows naturally in the rainforests and tropical parts of Peru and Brazil, as well as tropical zones of Asia, eastern Paraguay and northeastern Argentina. The active fraction (Pata-50) of the 70% ethanol extract from Pata de Vaca was sequentially fractionated by HP-20 Diaion column chromatography and C-18 column chromatography, and its characteristics were investigated. The growth of all cancer cells tested except for MCF-7 was Inhibited in a concentration-dependent manner by Pata-50. Its $IC_{50}$ values were estimated to be 40.4 $\mu\textrm{g}$/$m\ell$ on AGS, 51.3 $\mu\textrm{g}$/$m\ell$ on HT-29, 52.1$\mu\textrm{g}$/$m\ell$ on HepG2, 65.2$\mu\textrm{g}$/$m\ell$ on A549, and 77.5$\mu\textrm{g}$/$m\ell$ on HeLa cells. A flow cytometric analysis of HepG2 cells revealed induction of apoptosis, but cell cycle regulation was not affected. The HepG2 cell population of apoptosis region increased In a concentration-dependent manner by Pata-50.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1262-1268
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• 2006

In the search for a novel cytotoxic substance from medicinal plants, HY53 ($C_{17}H_{32}O_2N_2$; molecular weight 296) was isolated from the leaves of Pata de Vaca (Bauhinia forficata). The growth of the HepG2 cells was inhibited in a dose-dependent manner when treated with 0.07 to 0.40 mM HY53 for 24 h (IC$_{50}$: 0.13 mM). Furthermore, nuclear DAPI staining revealed the typical nuclear features of apoptosis in the HepG2 cells exposed to 0.27 mM HY53, whereas a flow cytometric analysis of the HepG2 cells using propidium iodide showed that the apoptotic cell population increased gradually from 8% at 0 mM to 23% at 0.14 mM and 45% at 0.40 mM after being exposed to each concentration of HY53 for 24 h. Moreover, a TUNEL assay also exhibited the apoptotic induction of the HepG2 cells treated with HY53. To obtain further information on the HY53-induced apoptosis, the expression level of certain apoptosis-associated proteins was examined using a Western blot analysis. Treatment of the HepG2 cells with HY53 resulted in the activation of caspase-3, and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). Consequently, the results confirmed that the apoptosis in the HepG2 cells was induced by HY53 and the involvement of caspase-3-mediated PARP cleavage in the apoptotic process.