Abstract:

Proanthocyaidins were extracted from lotus seedpod (LSPC) and lotus seed hulls (LSHPC) with 1% NaHSO3 solution by boiling for 15 min and purified with AB-8 macroporous resin. After incubated with culture medium containing different concentrations of the proanthocyaidins from LSPC and LSHPC for 48 h and 72 h, the viability of mouse melanoma B16 cells was measured by MTT assay, and their morphology was observed under inverted microscope and fluorescence microscope after 72 h incubation with medium containing the two proanthocyaidins at 100μg/ml. The in vivo inhibitory effect against the proliferation of mouse melanoma B16 cells was investigated by using C57BL/6J mice, and the levels of superoxide dismutase (SOD) and malonicaldehyde (MDA) in mouse serum were determined by xanthine oxidase assay and thiobarbituric acid assay. Results showed that both the proanthocyaidins from LSPC and LSHPC were able to significantly inhibit proliferation of B16 cells in vitro, and the inhibition rates were 87.4％ and 78.2％, respectively. The morphological alterations of melanoma B16 cell membrane damage caused by them were observed. Both the two proanthocyaidins could significantly reduce the volume and mass increases of melanoma B16 in in vivo experiments, and their inhibition rates at 120 mg/kg bw against the mass of melanoma B16 reached 55.3％ and 46.7％, respectively. Serum MDA level was reduced by administration of the proanthocyaidins from LSPC and LSHPC accompanied with the enhancement in serum SOD activity.

Key words: lotus seedpod, lotus seed hulls, proanthocyanidins, melanoma B16, inhibitory effect