Advance of studies on bioactivity of flavonoid-metal complexes / 中国中药杂志

The flavonoid-metal complexes showed obviously stronger bioactivities such as antibiosis, antivirus, anti-inflammatory, anti-tumor and anti-free-radical, possibly because of the stronger binding force caused by the change in complex structure and accessibility to target spots, or the synergy effect between flavonoids and metallic ions. This essay summarizes studies on bioactivity and mechanism of flavonoid-metal complexes, in order to provide reference for in-depth study and development on effective constituents contained in flavonoid traditional Chinese medicines.

Synthesis of baicalin-copper and baicalin-aluminium complex and its bioactivity / 中国中药杂志

<p><b>OBJECTIVE</b>To study synthesis of baicalin-copper and baicalin-aluminium complex and its antimicrobial, anti-tumor activity and anti-tumor effect against macrophages.</p><p><b>METHOD</b>Baicalin was reacted with metallic salt under a weak base condition to produce baicalin-copper and baicalin-aluminium complex. Baicalin and its synthesized complex were detected for antimicrobial activity against Staphylococcus aureus, Hay bacillus, Escherichia coli, Salmonella and Candida albicans by twofold broth dilution technique. Their anti-tumor activity against A549 and IC50 of HepG2 cells and anti-tumor effect against macrophages were detected by the MTT. And their phagocytic effect on macrophages was determined by the neutral red assay.</p><p><b>RESULT</b>The yields of baicalin-copper and baicalin-aluminium complex were 73.93% and 91.08%, respectively. The minimum inhibitory concentration (MIC) value against Staphylococcus aureus, Hay bacillus, Escherichia coli, Salmonella and Candida albicans was 0.0004, 0.0009, 0.0004, 0.0009, 0.000 4 mol x L(-1) for baicalin-copper complex and 0.0011, 0.0011, 0.0011, 0.0011, 0.0005 mol x L(-1) for baicalin-aluminium complex. The IC50 values against A549 and HepG2 cells were 89.6, 22.6 micromol x L(-1) for baicalin-copper complex, and 138.8, 97.2 micromol x L(-1) for baicalin-aluminium complex. The inhibitory ratio of macrophage on A549 cell was 43.52%, 80.89%, 52.66%, respectively, after the macrophages were stimulated by baicalin, baicalin-copper and baicalin-aluminium complex at a concentration of 160 micromol x L(-1).</p><p><b>CONCLUSION</b>The acute toxicity test in mice showed that the complex was nontoxic to mice. Baicalin-copper complex showed the highest antimicrobial, anti-tumor activity, and the strongest effect on the anti-tumor activity of macrophage, while baicalin showed the lowest activities compared with baicalin-copper and baicalin-aluminium complex.</p>