Evaluation of the toxic activity of anorectic diethylpropion in Chinese hamster ovary cells.

Diethylpropion has been available in the market for treating obesity for over 50 years. Refined studies are lacking to fully elucidate its action spectrum. The aim of our study was to evaluate possible toxic effects of anorectic diethylpropion in Chinese hamster ovary (CHO) cells. Comet assay (detects breaks in the DNA strand), micronucleus test (detects clastogenic/aneugenic damage), and cell survival test (detects cytotoxic damage) were used to evaluate the toxic effects. In comet assay, we found that the damage scores with diethylpropion treatments at the concentrations of 20 and 40 µg/mL were more significant ( p < 0.05) than that of the negative control. When assessing the possible aneugenic and/or clastogenic damage caused by the drug in CHO cells, we found no difference ( p > 0.05) in the values of micronucleated cells when comparing different diethylpropion treatments and the negative control. Regarding the cell viability, for all the diethylpropion concentrations tested, higher values ( p < 0.05) of apoptosis were found compared with those of the negative control. In relation to the number of necrotic cells, no difference ( p > 0.05) was noted between the means of the three concentrations of diethylpropion evaluated and the negative control. In the experimental conditions, we conclude that diethylpropion has weak genotoxic and cytotoxic activities.

Use of buccal micronucleus assay to determine mutagenicity induced by amfepramone in humans and the protective effects of vitamin C.

The abusive use of amfepramone in Brazilian population has grown in recent years. Few studies have been conducted on amphetamine with respect to DNA damage, and there have been no apparent investigations examining the influence of amfepramone on humans. The aim of this study was to determine the possible mutagenic actions of amfepramone on humans using the micronucleus (MN) assay with buccal cells and the effects of supplementation with vitamin C as a potential protective agent. The study included 108 females with 52 as control and 56 taking amfepramone at 120 mg/d for at least the whole previous month. All women were intentionally selected to be nonsmokers and nondrinkers. After 30 d of amfepramone women were given amfepramone plus vitamin C use at 1000 mg/d for another month. Results showed a marked increase in the number of MN in amfepramone users in both basal and differentiated cells, indicating a mutagenic action. After vitamin C supplementation, a significant decrease in the frequency of MN and apoptosis was observed. Evidence indicates that the main mechanism of action of amfepramone in inducing DNA damage occurs through formation of reactive oxygen species (ROS), intercalation and topoisomerase binding, attributed to the presence of an N-dialkyl group. In addition, data demonstrated that vitamin C effectively inhibited amfepramone-induced DNA damage.

Effects of diethylpropion treatment and withdrawal on aorta reactivity, endothelial factors and rat behavior.

Diethylpropion (DEP) is an amphetamine-like compound used as a coadjutant in the treatment of obesity and which presents toxicological importance as a drug of abuse. This drug causes important behavioral and cardiovascular complications; however, the vascular and behavioral alterations during DEP treatment and withdrawal, have not been determined. We evaluated the effects of DEP treatment and withdrawal on the rat aorta reactivity to noradrenaline, focusing on the endothelium, and the rat behavior during DEP treatment and withdrawal. DEP treatment caused a hyporreactivity to noradrenaline in aorta, reversible after 2 days of withdrawal and abolished by both the endothelium removal and the presence of L-NAME, but not by the presence of indomethacin. Furthermore, DEP treatment increased the general activity of rats. Contrarily, DEP withdrawal caused a decrease in the locomotor activity and an increase in grooming behavior, on the 2nd and 7th days after the interruption of the treatment, respectively. DEP treatment also caused an adaptive vascular response to noradrenaline that seems to be dependent on the increase in the endothelial nitric oxide system activity, but independent of prostaglandins synthesis. The data evidenced chronological differences in the adaptive responses of the vascular and central nervous systems induced by DEP treatment. Finally, a reversion of the adaptive response to DEP was observed in the vascular system during withdrawal, whereas a neuroadaptive process was still present in the central nervous system post-DEP. These findings advance on the understanding of the vascular and behavioral pathophysiological processes involved in the therapeutic and abusive uses of DEP.

Neurotoxicity of diethylpropion: neurochemical and behavioral findings in rats.

The effects of diethylpropion (DEP), an amphetamine derivative and a well-known anorectic agent, on different neurochemical and behavioral markers of toxicity in rats were evaluated. Animals received a daily dose of DEP (5 mg/kg po) for 15 days, and all tests were performed 24 hours after the last DEP administration. As neurochemical markers, the brain regional levels of some amino acids, such as aspartate (Asp), glutamate (Glu), gamma-aminobutyric acid (GABA), and glutamine (Gln), as well as the brain regional rates of lipid peroxidation as a current index of oxidative stress were measured. As behavioral markers, the actions of DEP on both mercaptopropionic acid (MPA)-induced seizures and kainic acid (KA)-induced wet-dog body shakes were explored to investigate whether DEP induces behavioral sensitization to the effects of agents affecting the central activity of neuroactive amino acids. Treatment with DEP produced significant changes in the levels of Asp in the hypothalamus (Ht) and cortex (Cx); Glu in the Ht, Cx, midbrain (Mb), and striatum (S); and Gln in the Cx. The regional levels of GABA remain unchanged. Lipid peroxidation was increased in the hippocampus (Hc), Mb, and S. Also, latency to the first seizure induced by MPA (1.2 mmol/kg i.p.) and the total number of wet-dog body shakes induced by KA (10 mg/kg i.p.) were significantly affected by DEP treatment. These findings suggest that low doses of DEP may affect different neurochemical substrates, inducing changes in neuroactive amino acids along the brain regions, probably involving dopamine release. Consequently, behavioral changes could be the result of excitotoxic events related to excessive Glu or lack of an inhibitory process. Also, DEP is thought to involve free radical formation and oxidative stress as potential features of its regional pattern of neurotoxicity, as evidenced by lipid peroxidation.

Cardiovascular effects of amphepramone.

The i.v. administration of amphepramone in dogs induced a dose-related depressor reaction. This effect was due to a peripheral myotropic vasodilatation. When the drug was administered intracerebroventricularly it elicited a marked pressor response, due, to the release of catecholamines with its subsequent action on alpha-adrenergic receptors. Small doses of amphepramone administered in dogs, rats and rabbits, induced a sinus tachycardia. Larger doses brought about a sinus bradycardia, bradyarrhythmias, extrasystoles, ventricular bradycardia and ventricular fibrillation or asystolia. The respiratory movements as well as the EEG tracings were depressed by larger doses of amphepramone.