Cytotoxic effect of white forsythia (Abeliophyllum distichum Nakai) extracts on human melanoma SK-MEL-2 cells

Abeliophyllum distichum Nakai, a monotypic genus with a single species of deciduous shrub in the olive family, has been used as an ornamental plant due to its horticultural value. Current pharmaceutical studies have revealed the pharmaceutical application of A. distichum based on its anti-diabetic activity [1] and anti-inflammatory effect [2]. Although these indicate the considerable potential of A. distichum as a crude drug and a dietary health supplement, studies on the biological activity of A. distichum have been limited. In this study, the methanolic extracts of of A. distichum leaves, stems and fruits were evaluated for cytotoxicity to human melanoma cell (SK-MEL-2). MTT assay revealed that leaf extract at 50 μg/ml, 100 μg/ml and 200 μg/ml reduced cell viability to 48.02%, 21.88% and 13.69% respectively. Annexin V+ cell populations, increasing activity of caspase 3 further demonstrated that apoptosis induced by leaf extract. To investigate the molecular mechanisms underlying apoptosis induction, cells were treated with leaf extract for 48 h, and western blot analysis was performed using specific antibodies. Western blot analysis suggested that anti-proliferation and apoptosis induction by leaf extract should be associated with MEK–ERK-dependent caspase activation. Taken together, these results suggest that A. distichum leaves have compounds with cytotoxicity against SK-MEL-2 cells, and could be developed as a potential source for improving human health.

• References

• 1 Li HM, Kim JK, Jang JM, Cui CB, Lim SS. Analysis of the inhibitory activity of Abeliophyllum distichum leaf constituents against aldose reductase by using high-speed counter current chromatography. Arch Pharm Res 2013; 36: 1104-1112
• 2 Choi JH, Seo EJ, Sung J, Choi KM, Kim H, Kim JS. et al. Polyphenolic compounds, antioxidant and anti-inflammatory effects of Abeliophyllum distichum Nakai extract. J Appl Bot Food Qual 2017; 90: 266-273