Oxidative storm in a patient with acute rotenone-containing plant poisoning.

A 64-year-old woman presented with coma, seizure, and lactic acidosis after ingesting 80 yam bean seeds. This rotenone-containing seeds cause cellular asphyxia via blockage of the mitochondrial electron transport. Subsequent oxidative stress results in the formation of lipid peroxidation (LPO). Rotenone analysis via liquid chromatography mass spectrometry revealed the following: 31,590 ng/mL in cooked yam bean seed and 100 ng/mL in the blood. We attempted to use N-acetylcysteine to alleviate oxidative stress and documented the continuous decline in the plasma concentration of LPO.

Pesticidal suicide: adult fatal rotenone poisoning.

Rotenone is a pesticide and a piscicide derived from the derris root. The mechanism for the cytotoxicity is at mitochondrial level affecting cellular respiration. A suicide by rotenone poisoning in an adult is described. An innovative laboratory methodology was developed for the principal requirement of the Coroner to determine a positive or negative result to assist in the investigation of the death. The antemortem concentrations detected were 4.05 ng/ml [0.00405 ppm] in the blood and 0.55 ng/ml [0.00055 ppm] in the serum. Toxicity in human is rare and therefore the interpretation of the toxicology results is complicated by the unavailability of a data bank. The cause of death was attributed to rotenone toxicity based on the circumstantial evidence and expert pathological opinion on a balance of probability acceptable under the Coroners Act 1988 and Coroners Rules 1984 in England and Wales. The forensic clinicopathology of rotenone toxicity is discussed.

A delivery strategy for rotenone microspheres in an animal model of Parkinson's disease.

In order to study the pathogenesis of Parkinson's disease (PD), and explore therapeutic drug or approaches, the accurate animal model of PD with inexpensive, biocompatible and convenient administration was necessary. The aim of the present work was to investigate a delivery strategy for rotenone microspheres in an animal model of PD. The rotenone microspheres were prepared by solvent evaporation technique. The rotenone microspheres showed high entrapment efficiency (97.4+/-2.2%) with particle size about 100 microm. In vitro release of rotenone microspheres demonstrated different profiles from medium with different pH or concentration of isopropyl alcohol. The most consistent medium with in vivo rotenone levels in rat plasma was PBS (pH 5.8) with 20% isopropyl alcohol, and the cumulated release amount of rotenone over 30 days was 95.4% in it. The rotenone microspheres (9 mg/kg) produced typical PD symptoms in rats, for example, the cataleptic behavior test demonstrated a obviously prolonged descent latency compared with control animals after administration, and the tyrosine hydroxylase (TH) immunohistochemistry tests showed typical histological evidence of selective degeneration of the nigrostriatal dopaminergic system (striatum and substantia nigra) in rotenone microspheres-treated rats. In addition, this delivery system for rotenone model showed many noticeable advantages such as inexpensive, biocompatible and expedient administration by direct subcutaneous injection. This information suggested that rotenone microspheres as a delivery strategy for setting up an ideal animal model of PD was feasible.

Role of nitric oxide in rotenone-induced nigro-striatal injury.

Rotenone, a widely used pesticide, causes a syndrome in rats that mimics, both behaviorally and pathologically, the symptoms of Parkinson's disease. The present study evaluated the role of nitric oxide in rotenone-induced nigro-striatal injury. After administration of rotenone in rats for 40 days, there was a moderate but significant injury of the nigro-striatal pathway indicated by a 47% decrease in striatal dopamine levels and a 28% loss of substantia nigra tyrosine hydroxylase-immunopositive neurons. Furthermore, a significant (37%) increase in the number of cells positive for nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) in the striatum was observed, accompanied by a 83% increase in nitric oxide synthase (NOS) activity and a significant increase in the production of 3-nitrotyrosine (3-NT). There was a significant increase (45%) in the optical density of NADPH-d staining and an increase (72%) in NOS activity in the substantia nigra. Moreover, administration of the neuronal NOS inhibitor 7-nitroindazole significantly attenuated the increased NOS activity and 3-NT production, and provided significant protection against rotenone-induced nigro-striatal injury. Our data suggest that chronic rotenone administration can lead to significant injury to the nigro-striatal system, mediated by increased generation of nitric oxide.

Pharmacokinetics of deguelin, a cancer chemopreventive agent in rats.

PURPOSE: To study the pharmacokinetics of deguelin, a naturally occurring potential cancer chemopreventive agent, in rats. METHODS: [3H]Deguelin was administered intravenously (i.v.) under anesthesia, and blood samples were collected over 24 h. [3H]Deguelin and metabolites were extracted from plasma with ethyl acetate, and quantified by HPLC. Data were analyzed with the WinNolin pharmacokinetic software package to determine pharmacokinetic parameters. A three-compartment first-order elimination model was used to fit the plasma concentration-time curve. In addition, deguelin concentrations in tissues after i.v. and intragastric (i.g.) administration were determined by HPLC, and excretion (feces and urine) was evaluated over a 5-day period after i.g. administration. RESULTS: Deguelin exhibited a mean residence time (MRT) of 6.98 h and terminal half-life (t1/2(gamma)) of 9.26 h. The area under the curve (AUC) and total clearance (Cl) were 57.3 ng.h/ml and 4.37 l/h per kg, respectively, with an apparent volume of distribution (V) and volume of distribution at steady-state (Vss) of 3.421 l/kg and 30.46 l/kg, respectively. Following i.v. administration, the relative levels of tissue distribution were as follows: heart > fat > mammary gland > colon > liver > kidney > brain > lung. Following i.g. administration, the relative levels of tissue distribution were as follows: perirenal fat > heart > mammary gland > colon > kidney > liver > lung > brain > skin. Within 5 days of i.g. administration, about 58.1% of the [3H]deguelin was eliminated via the feces and 14.4% via the urine. Approximately 1.7% of unchanged deguelin was found in the feces, and 0.4% in the urine. CONCLUSIONS: An initial pharmacokinetic investigation of deguelin showed that this rotenoid has a relatively long MRT and half-life in plasma in the rat. The compound distributed in the tissues and excreted as metabolites, mainly via the feces.

Assay of [3H]dihydrorotenone binding to complex I in intact human platelets.

We have developed an assay for the binding of [3H]-dihydrorotenone ([3H]DHR), an analogue of the pesticide rotenone, to the mitochondrial enzyme, complex I, in intact human platelets. The highly hydrophobic nature of dihydrorotenone, which diffuses easily through biological membranes, rendered the isolation of mitochondrial fractions unnecessary. This allowed us to reduce the amount of blood required and to shorten the processing of samples considerably. [3H]-DHR binding was saturable, specific, and highly reproducible. We also found that MPP+ (1-methyl-4-phenyl-pyridinium species), which is accumulated actively by platelets, inhibited [3H]DHR specific binding in a concentration-dependent manner. This method could provide a simple tool for the study of complex I in those disorders, such as Parkinson's disease (PD), in which a defect of this enzyme has been suggested.