Search

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide, CAP) is an important ingredient in spicy foods consumed throughout the world. Vinblastine (VBL) is a naturally occurring alkaloid prescribed to cancer patients. Many cancer patients treated with VBL were taking CAP at the same time. This study attempted to investigate the effect of CAP on the pharmacokinetics of VBL, which is the substrate of CYP3A, P-gp, and Mrp2. CAP, cyclosporine (CsA) or olive oil was given to rats for seven consecutive days, and on the seventh day, VBL (1.3 mg/kg) was administered intravenously. CsA was used as a CYP3A1/2 and transporter inhibitor, and olive oil was used as a vehicle. The results showed that pretreatment of rats with CAP (3.0 mg/kg) for seven consecutive days resulted in an increase in the AUC0-t of VBL of about 29.8% (P < 0.05) compared with the control group. Moreover, CAP decreased the CL of VBL to 75.5% (P < 0.05). At this time, CYP3A1/2 and Mrp2/Abcc2 in the liver was decreased at the mRNA and protein levels. These results demonstrate that chronic ingestion of CAP will increase systemic exposure and reduce clearance of VBL in rats. The food-drug interaction between CAP and VBL appears to be due to modulation of CYP3A1/2 and Mpr2 expression by CAP.

Chronic hypervitaminosis A can occur in many species after excessive dietary intake of Vitamin A (retinol). The most common presentation of chronic hypervitaminosis A is a polyarthropathy with hyperostosis and ankylosis of various joints. This case report describes a probable case of naturally occurring hypervitaminosis A-induced polyarthropathy in a rabbit after chronic ingestion of a diet made up almost exclusively of carrots. Carrots do not contain retinol, but are rich in provitamin A (or beta-carotene). Rabbits are unique in that they can convert 100% of dietary beta-carotene into retinol. A syndrome of naturally occurring hypervitaminosis A-induced polyarthropathy has not been described in a rabbit before.

Two cases of pulmonary toxicity associated with chronic ingestion of amiodarone are presented. Special emphasis is given to the radiological features which may aid in the clinical diagnosis of this disorder.

Male rats were chronically fed a diet containing dry powdered seeds of Garcinia kola, at the level of 10% w/w for 6 weeks. The effect of this diet was investigated on gastrointestinal motility, castor oil induced diarrhea, and pentobarbital sleeping times, as well as organ and body weights at the end of 6 weeks. Garcinia kola caused marked inhibition of gastrointestinal motility, protected against castor oil induced diarrhea, prolonged pentobarbital sleeping time, and caused marked retardation of growth but did not affect organ weights compared to pair-fed controls. There is a possibility that the observations may be due to the flavonoids contained in G. kola seeds.

The chronic ingestion of .5% butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT) by pregnant mice and their offspring resulted in a variety of behavioral changes. Compared to controls, BHA-treated offspring showed increased exploration, decreased sleeping, decreased self-grooming, slower learning, and a decreased orientation reflex. BHT-treated offspring showed decreased sleeping, increased social and isolation-induced aggression, and a severe deficit in learning.

Seizure-prone patients may be chronically treated with diphenylhydantoin, a mitogenic agent excreted in the urine. Chronic ingestion of diphenylhydantoin by 64 rats failed to demonstrate vesical epithelial tumor formation under conditions which demonstrate the tumorigenicity of other vesical carcinogens. Vesical neoplasms occurring in patients chronically ingesting diphenylhydantoin are probably co-incidental.