Effects of genistein and folic acid on neuronal membrane and mitochondrial membrane damaged by β-amyloid peptides 31-35 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe the neuro-protective effects of genistein (Gen) and folic acid (FA) on neurons membrane and mitochondrial membrane damaged by β-amyloid peptides 31-35 (Aβ31-35).</p><p><b>METHODS</b>The primary cultured rat cerebral cortical neurons were randomly divided into DMEM (control), Aβ31-35 (25 µmol/L), Gen (Gen 27 µg/ml), FA (FA 40 µg/ml) and Gen + FA (Gen 27 µg/ml + FA 40 µg/ml). Gen and/or FA were added two hours before Aβ31-35 addition. After twenty four hours, MTT assay was performed to measure the viability of cultured neurons. Fluorescence polarization was performed to observe the neuron cell membrane fluidity. The mitochondrial membrane potential (MMP) was determined to investigate the alteration of mitochondrial structure and function of neurons by laser scanning confocal microscope and a flow cytometer was used to investigate the activation of mitochondrial permeability transition pore (MPTP). Each experiment was repeated three times.</p><p><b>RESULTS</b>Compared with group Aβ31-35 (0.845 ± 0.050, F = 4.931, P < 0.05), the absorbance was significantly higher in group Gen (0.982 ± 0.110, t = 3.523, P < 0.01), FA (0.947 ± 0.061, t = 2.745, P < 0.01) and Gen + FA (0.996 ± 0.090, t = 3.966, P < 0.01). The viscosity of cell neuron membrane in group Gen (1.75 ± 0.28, t = 2.085, P < 0.05), FA (1.66 ± 0.37, t = 2.357, P < 0.05) and Gen + FA (1.50 ± 0.20, t = 3.784, P < 0.05) was significantly lower than that in group Aβ31-35 (2.11 ± 0.44, F = 5.529, P < 0.01), which indicated the cell membrane fluidity was significantly higher in group Gen and/or FA than that in group Aβ31-35. MMP was significantly decreased by Aβ31-35 (3.364 ± 1.140, t = 3.949, P < 0.01) when comparing to control group (6.383 ± 1.683), while it was significantly increased by Gen (5.286 ± 1.792, t = 2.406, P < 0.05), FA (5.884 ± 2.022, t = 2.887, P < 0.01) and Gen + FA (6.120 ± 2.124, t = 3.304, P < 0.01) when comparing to group Aβ31-35 (F = 7.585, P < 0.01). MPTP was activated by Aβ31-35 and Gen and/or FA could reverse this progress.</p><p><b>CONCLUSION</b>Gen and/or FA could protect the neuronal and mitochondrial membrane from the impairment induced by Aβ31-35.</p>

Lead and cadmium pollution in edible fungus sold in Beijing / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the lead and cadmium pollution in edible mushrooms sold in Beijing.</p><p><b>METHODS</b>146 samples of 14 species were collected form 25 markets during the period of Mar. through May, 2007 in Beijing. The pollution of lead and cadmium were analyzed respectively according to the standard of GB/T5009. 12-2003 and GB 7096-2003.</p><p><b>RESULTS</b>The content of lead and cadmium in edible mushrooms was ND--1.592 mg/kg, ND--0.550 mg/kg, respectively, both lower than the allowable content prescribed by The National Ministry of Health.</p><p><b>CONCLUSION</b>The contents of lead and cadmium in the mushrooms marketed in Beijing are in safe ranges. It is worthy of mentioning the variation coefficients of heavy metal concentrations existing in edible mushrooms.</p>