Aconitum, widely used to treat rheumatoid arthritis for thousands of years, is a toxic herb that can frequently cause fatal cardiac poisoning. Aconitum toxicity could be decreased by properly hydrolyzing diester-diterpene alkaloids into monoester-diterpene alkaloids. Monoester-diterpene alkaloids, including benzoylaconine (BAC), benzoylmesaconine (BMA), and benzoylhypaconine (BHA), are the prim...

Objective. Potential interactions between herbal extracts and the cytochrome P450 (CYP) system lead to serious adverse events or decreased drug efficacy. Rhus verniciflua stoke (RVS) and its constituents have been reported to have various pharmacological properties. We evaluated the inhibitory potential of RVS and its constituents on the major CYP isoforms. Methods. The effects of allergen remo...

BACKGROUND Tamoxifen is the standard endocrine therapy for breast cancers, which require metabolic activation by cytochrome P450 enzymes (CYP). However, the lower and variable concentrations of CYP activity at the tumor remain major bottlenecks for the efficient treatment, causing severe side-effects. Combination nanotherapy has gained much recent attention for cancer treatment as it reduces th...

Catalytic promiscuity is a widespread, but poorly understood, phenomenon among enzymes with particular relevance to the evolution of new functions, drug metabolism, and in vitro biocatalyst engineering. However, there is at present no way to quantitatively measure or compare this important parameter of enzyme function. Here we define a quantitative index of promiscuity (I) that can be calculate...

Many heme enzymes show remarkable versatility and atypical kinetics. The fungal extracellular enzyme chloroperoxidase (CPO) characterizes a variety of one and two electron redox reactions in the presence of hydroperoxides. A structural counterpart, found in mammalian microsomal cytochrome P450 (CYP), uses molecular oxygen plus NADPH for the oxidative metabolism (predominantly hydroxylation) of ...

The root causes of the outcomes of the single-site mutation in enzymes remain by and large not well understood. This is the case of the F429H mutant of the cytochrome P450 (CYP) 2B4 enzyme where the substitution, on the proximal surface of the active site, of a conserved phenylalanine 429 residue with histidine seems to hamper the formation of the active species, Compound I (porphyrin cation ra...

The protective effects of propolis on biochemical and hematological parameters were appraised in the blood of Oncorhynchus mykiss exposed to cypermethrin (CYP). The fish were subjected to three sublethal concentrations of CYP (0.0041, 0.0082 and 0.0123 ppm) and propolis (10 ppm) for 96 h. The samples were analysed to changes in the biochemical parameters, such as the metabolits: glucose, total ...

The corneal epithelium metabolizes arachidonic acid by a cytochrome P450-(CYP) mediated pathway to 12(R)hydroxy-5,8,10,14-eicosatrienoic acid [12(R)-HETE] and 12(R)hydroxy-5,8,14-eicosatrienoic acid [12(R)-HETrE]. Both metabolites possess potent inflammatory properties with 12(R)-HETrE being a powerful angiogenic factor and assume the role of inflammatory mediators in hypoxia- and chemical-indu...

Commercially available St. John's wort (Hypericum perforatum) extracts, preparations that are used in the treatment of depression, were examined for the potential to inhibit human cytochrome P450 (CYP) enzyme activities, specifically CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4. Crude extracts demonstrated inhibition of each of these five enzymes, with CYP2D6, CYP2C9, and CYP3A4 being more sensi...

Acute kidney injury (AKI) is a common complication of critical illness, and evidence is emerging that suggests AKI disrupts the function of other organs. It is a recognized phenomenon that patients with chronic kidney disease (CKD) have reduced hepatic metabolism of drugs, via the cytochrome P450 (CYP) enzyme group, and drug dosing guidelines in AKI are often extrapolated from data obtained fro...