NADPH oxidase catalyzes the univalent reduction of molecular oxygen and produces superoxide, which has modest antibacterial activity but serves as a precursor for more toxic substrates, such as hydrogen peroxide and hydroxyl radicals [ 40].
Because arylesterase activity, using phenyl acetate as the substrate instead of the more toxic organophosphates as substrates, is frequently monitored as an index of PON1 activity, we also determined arylesterase activity in this study.
The products of these reactions are four orders of magnitude more toxic than the substrates [ 10].
Additionally, the relatively high primary biodegradation rate and low mineralization may suggest the occurrence of biotransformation processes, which lead to the formation of more toxic metabolites compared to the initial substrate, however more data is needed to verify this hypothesis.
If Hayakawa et al. is correct, then the products are more toxic and carcinogenic than the inorganic As III) substrate.
Quinones that are good substrates for hNQO1 are more toxic to the NQO1 containing or expressing cell lines (H460 and BE-NQ) than the NQO1 deficient cell lines (H596 and BE-WT).
Ginkgolic acid (15:1) (GA (15:1)) and ginkgolic acid (17:1) (GA (17:1)), two substrates metabolized by CYP3A4 to more toxic metabolites 18, 19, were used to examine the impact of CYP3A4 shRNAs on chemosensitivity.
We hypothesized that ClO3– could be more toxic to K. pneumoniae that actively reducing NO3– is as a respiratory substrate.
CYP2E1 metabolizes and activates many toxicologically important substrates, including ethanol, carbon tetrachloride, acetaminophen, and N-nitrosodimethylamine, to more toxic products [ 35, 36].
