Potential mutagenic activity of some vitamin preparations in the human gut.

Rutin is a nonmutagenic flavonol glycoside, whereas its aglycone quercetin is mutagenic. Cell-free preparations from fecal cultures (fecal preparations) contain a beta-glucosidase that, when incubated with rutin, hydrolyzes it to quercetin. This activity can be further induced when rutin is added to the fecal culture from which the cell-free preparation is made. When vitamin pills that contain rutin are added to the cultures, this induction is equally effective. The vitamin extracts by themselves, like rutin, were nonmutagenic; however, when the vitamin extracts were incubated with fecal preparations containing induced beta-glucosidase, a great increase in mutagenicity was observed.