Janzowski C, Glaab V, Samimi E, Schlatter J, Eisenbrand G
Department of Chemistry, Division of Food Chemistry & Environmental Toxicology, University, Erwin-Schroedinger-Str. 52, D-67663, Kaiserslautern, Germany.
Food Chem Toxicol. 2000 Sep;38(9):801-9. doi: 10.1016/s0278-6915(00)00070-3.
5-(hydroxymethyl)-2-furfural (HMF), a common product of the Maillard reaction, occurs in many foods in high concentrations, sometimes exceeding 1 g/kg (in certain dried fruits and caramel products). The toxicological relevance of this exposure has not yet been clarified. Induction of aberrant colonic crypt foci had been reported for HMF, in vitro studies on genotoxicity/mutagenicity have given controversial results. To elucidate the toxic potential of HMF, cytotoxicity (trypan blue exclusion), growth inhibition (SRB assay), mutagenicity (HPRT assay), DNA damage (single-cell gel electrophoresis) and depletion of cellular glutathione were investigated in mammalian cells. Genotoxicity (SOS repair) was monitored in Salmonella typhimurium (umu assay). HMF induced moderate cytotoxicity in V79 cells (LC(50): 115 mM, 1 hr incubation) and in Caco-2 cells (LC(50): 118 mM, 1 hr incubation). Growth inhibition was monitored following 24 hr of incubation (V79, IC(50): 6.4 mM). DNA damage was detectable neither in these cell lines nor in primary rat hepatocytes up to the cytotoxic threshold concentration (75% absolute viability). Likewise, in primary human colon cells, obtained from biopsy material, DNA damage was not measurable. At 120 mM, already exhibiting some reduction in cell viability, HMF was weakly mutagenic at the hprt-locus in V79 cells (mutants/10(6) cells: HMF 120 mM: 16 vs control: 3). Intracelluar glutathione was depleted by HMF (>/=50 mM) in V79 cells, in the human colon adenocarcinoma cell line Caco-2 and in primary rat hepatocytes down to approximately 30% of control (120 mM). Genotoxicity was observed with HMF in the umu assay without external activation (16 mM: 185 rel. umu units, %, P<0.001). The genotoxic potential was not altered by addition of rat liver microsomes. By comparison, the natural flavour constituent (E)-2-hexenal (HEX) was already cytotoxic, mutagenic and depleted glutathione at about 1000-fold lower concentrations. It induced DNA damage in mammalian cells (200-400 microM). These results suggest that HMF does not pose a serious health risk, even though the highest concentrations in specific foods approach the biologically effective concentration range in cell systems.
5-（羟甲基）-2-糠醛（HMF）是美拉德反应的常见产物，在许多食品中含量很高，有时超过1克/千克（在某些干果和焦糖产品中）。这种暴露的毒理学相关性尚未阐明。已有报道称HMF可诱导异常结肠隐窝病灶，关于其遗传毒性/诱变性的体外研究结果存在争议。为了阐明HMF的潜在毒性，我们在哺乳动物细胞中研究了细胞毒性（台盼蓝排斥法）、生长抑制（SRB测定法）、诱变性（HPRT测定法）、DNA损伤（单细胞凝胶电泳）以及细胞内谷胱甘肽的消耗情况。在鼠伤寒沙门氏菌中监测遗传毒性（SOS修复）（umu试验）。HMF在V79细胞（LC50：115 mM，孵育1小时）和Caco-2细胞（LC50：118 mM，孵育1小时）中诱导了中度细胞毒性。孵育24小时后监测生长抑制情况（V79，IC50：6.4 mM）。在这些细胞系以及原代大鼠肝细胞中，直至细胞毒性阈值浓度（绝对活力75%），均未检测到DNA损伤。同样，从活检材料获得的原代人结肠细胞中也未检测到DNA损伤。在120 mM时，HMF已使细胞活力略有下降，在V79细胞的hprt位点具有弱诱变性（突变体/106细胞：HMF 120 mM时为16，对照为3）。在V79细胞、人结肠腺癌细胞系Caco-2以及原代大鼠肝细胞中，HMF（≥50 mM）可使细胞内谷胱甘肽消耗至对照的约30%（120 mM）。在umu试验中，未进行外部活化时，HMF表现出遗传毒性（16 mM时为185相对umu单位，%，P<0.001）。添加大鼠肝微粒体后，遗传毒性潜力未改变。相比之下，天然风味成分（E）-2-己烯醛（HEX）在浓度低约1000倍时就已具有细胞毒性、诱变性并消耗谷胱甘肽。它在哺乳动物细胞中诱导DNA损伤（200 - 400 microM）。这些结果表明，尽管特定食品中的最高浓度接近细胞系统中的生物学有效浓度范围，但HMF不会构成严重的健康风险。
