Iso-suillin from Suillus flavus Induces Apoptosis in Human Small Cell Lung Cancer H446 Cell Line / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The suillin isoform iso-suillin is a natural substance isolated from a petroleum ether extract of the fruiting bodies of the mushroom Suillus flavus. Previous studies have found its inhibition effect on some cancer cells, and we aimed to study its effects on human small cell lung cancer H446 cell line.</p><p><b>METHODS</b>Cell viability was measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Cellular morphological changes (apoptosis and necrosis) were evaluated using an electron microscope and Hoechst 33258 staining detected by the inverted microscope. Flow cytometry was used to detect cell apoptosis, cell cycle distribution, and mitochondrial membrane potential. Protein expression was determined by Western blotting analysis.</p><p><b>RESULTS</b>Here, we describe the ability of iso-suillin to inhibit the growth of H446 cells in time- and dose-dependent way. Iso-suillin had no obvious impact on normal human lymphocyte proliferation at low concentrations (9.09, 18.17, or 36.35 μmol/L) but promoted lymphocyte proliferation at a high concentration (72.70 μmol/L). After treatment of different concentrations of iso-suillin (6.82, 13.63, or 20.45 μmol/L), the apoptosis rate of H446 cells increased with increasing concentrations of iso-suillin (16.70%, 35.54%, and 49.20%, respectively, all P < 0.05 compared with the control), and the expression of related apoptotic proteins in the mitochondrial pathway including cytochrome c and caspase-9 were up-regulated compared with the control (all P < 0.05). On the contrary, Bcl-2/Bax ratio was down-regulated compared with the control. Besides, the expression of pro-apoptotic proteins in the death receptor apoptosis pathway, including Fas-associating protein with a novel death domain and caspase-8, and the expression of caspase-3, a downstream regulatory protein of apoptosis, were also increased compared with the control (all P < 0.05). Inhibitors of caspase-9 and caspase-8 reversed the apoptosis process in H446 cells to varying degrees.</p><p><b>CONCLUSIONS</b>These results suggest that iso-suillin could induce H446 cell apoptosis through the mitochondrial pathway and the death-receptor pathway. Therefore, iso-suillin might have a potential application as a novel drug for lung cancer treatment.</p>

Protective effects of crude polysaccharides from Chroogomphus rutilus on SH-SY5Y cells impaired by MPP(+) / 生理学报

The aim of the present study was to investigate the protective effects of crude polysaccharides from Chroogomphus rutilus on dopaminergic neurons impaired by MPP(+). SH-SY5Y cells were pretreated with crude polysaccharides (200, 400 and 800 μg/mL), and then MPP(+) was added to cell medium. After 48 h of incubation, MTT method was used to detect the survival rate of SH-SY5Y cells damaged by MPP(+). Annexin V-FITC staining and flow cytometry were used to detect apoptotic rate. The results showed that pretreating SH-SY5Y cells with crude polysaccharides (400 and 800 μg/mL) increased the survival rates, and reduced the apoptotic rates of SH-SY5Y cells. To rule out the possibility that crude polysaccharides may decrease actual concentration of MPP(+) by direct binding, we washed off crude polysaccharides before MPP(+) addition. Under this experimental condition, MTT results showed the survival rates of the SH-SY5Y cells were still significantly increased by 800 μg/mL crude polysaccharides pretreatment. These results suggest a protective effect of polysaccharides on the SH-SY5Y cells. Most of this protection is contributed by direct action of polysaccharides on the cells, not by binding with MPP(+). It is indicated that the crude polysaccharides from Chroogomphus rutilus can be developed as a potential drug for Parkinson's disease prevention and treatment in the future.