Microbial and heavy metal contamination in commonly consumed traditional Chinese herbal medicines

OBJECTIVE： The increasing popularity and widespread use of traditional Chinese herbs as alterna- tive medicine have sparked an interest in understanding their biosafety, especially in decoctions that are consumed. This study aimed to assess the level of microbial and heavy metal contamination in commonly consumed herbal medicine in Malay- sia and the effects of boiling on these contamination levels. METHODS： Four commonly consumed Chinese herbal medicine in Malaysia-＂Eight Treasure Herbal Tea＂, ＂Herbal Tea＂, Xiyangshen （Radix Panacis Quin- quefolii） and Dangshen （Radix Codonopsis） were evaluated in this study. Herbal medicines were pre- pared as boiled and non-boiled decoctions, and their microbial enumeration and heavy metal detection were conducted with plate assay and atom- ic absorption spectroscopy, respectively. RESULTS： Findings revealed that herbal medicines generally had 6 Iogl0cfu/mL microbial cells and that boiling had significantly reduced microbial contaminants, where no Bacillus spp., Staphylococcus spp. and Clostridium spp. were recovered. Heavy metals such as Mn, Cu, Cd, Pb, Fe and Zn were also detect- ed from all the samples, generally in low concentra- tions （〈1 mg/L） except for Mn （18.545 mg/L）. All de- coctions （after boiling） have reduced concentra- tions of Cu, while others were not significantly dif- ferent. Comparisons between samples with single and multi-herbs suggest level of microbial and metal contamination is not influenced by number of herbs in sample. CONCLUSION： Herbal medicines generally have microbial and heavy metal contaminants. However, the boiling process to generate decoctions was able to successfully reduce the number of microbes and Cu, ensuring safety of herbal medicines for consumption.

Nanomotor-based adsorbent for blood Lead(II)removal in vitro and in pig models

Blood lead(Pb(II))removal is very important but challenging.The main difficulty of blood Pb(II)removal currently lies in the fact that blood Pb(II)is mainly complexed with hemoglobin(Hb)inside the red blood cells(RBCs).Traditional blood Pb(II)removers are mostly passive particles that do not have the motion ability,thus the efficiency of the contact between the adsorbent and the Pb(II)-contaminated Hb is relatively low.Herein,a kind of magnetic nanomotor adsorbent with movement ability under alternating magnetic field based on Fe3O4 nanoparticle modified with meso-2,3-dimercaptosuccinic acid(DMSA)was prepared and a blood Pb(II)removal strategy was further proposed.During the removal process,the nanomotor adsorbent can enter the RBCs,then the contact probability between the nanomotor adsorbent and the Pb(II)-contaminated Hb can be increased by the active movement of nanomotor.Through the strong coordination of functional groups in DMSA,the nanomotor adsorbent can adsorb Pb(II),and finally be separated from blood by permanent magnetic field.The in vivo extracorporeal blood circulation experiment verifies the ability of the adsorbent to remove blood Pb(II)in pig models,which may provide innovative ideas for blood heavy metal removal in the future.