Distribution of N-methyl-(14)C-labeled selegiline in the rat

Preclinical Herb-Drug Pharmacokinetic Interaction of Panax ginseng Extract and Selegiline in Freely Moving Rats

Selegiline, an inhibitor of monoamine oxidase B, is prescribed during the early stages of Parkinson's disease. The nutritional herbal medicine Panax ginseng C.A. Meyer has been reported to show potential neuroprotective activity; however, the herb-drug pharmacokinetic interaction between selegiline and P. ginseng extract has not been characterized. Our hypothesis is that the ginseng extract and selegiline produce pharmacokinetic interactions at certain doses. To investigate this hypothesis, a validated ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to monitor selegiline in rat plasma. Experimental rats were divided into groups treated with selegiline alone (10 mg/kg, i.v.; 30 mg/kg, p.o.), with the low-dose ginseng extract (1 g/kg, p.o., for 5 consecutive days) or with the high-dose ginseng extract (3 g/kg, p.o., for 5 consecutive days). The pharmacokinetic results demonstrated that the oral bioavailability of selegiline alone was approximately 18%; however, when rats were pretreated with low and high doses of the ginseng extract, the bioavailability of selegiline was 7.2 and 29%, respectively. These results suggested that the ginseng extract may produce a biphasic pharmacokinetic phenomenon. In summary, ginseng alters the oral bioavailability of selegiline, and these observations might provide preclinical information concerning the pharmacokinetic interactions between selegiline and herbal supplements.

Effects on Sperms' Quality of Selegiline in Aged Rats

Background

Selegiline is used to treat Parkinsonian patients. Other indications of its use have recently been discovered.

Objective

Scouting special and beneficial side effects of selegiline treatment.

Method

Two-year old male Wistar rats were daily treated with 0.25 mg/kg of selegiline s.c. (subcutaneous injection). The rats were sacrificed following a four-weeks' treatment.

Results

Mass of testes, number of sperms, progressive motility of sperms, and their viability definitely increased.

Conclusion

Selegiline can successfully be used to stop/counterbalance certain symptoms of aging.

Monitoring the Level of 14C-Labelled Selegiline Following Oral Administration

Background:

Selegiline [(-)-deprenyl] is widely used for the treatment of Parkinson’s disease in humans.

Objective:

Time-dependence of tissue distribution of selegiline following per os administration to rats.

Method:

Oral administration of radiolabeled selegiline to rats resulted in a pattern of tissue distribution similar to that following intraperitoneal injection. Analyses were done using both reversed-phase HPLC and also by counting radioactivity in various body compartments of rats.

Results:

As a consequence of oral administration of 30 mg/kg of selegiline, its level in the stomach was extremely high (179.57 µg/g tissue through 54.67 µg/g at 15 min to 120 min), that is one magnitude higher than that in the serum level. High selegiline concentrations were also detected in the lacrimal glands (7.45 µg/g), kidneys (6.87 µg/g), livers (6.01 µg/g) and lungs (3.47 µg/g) after 30 minutes of application, which were higher than after intraperitoneal injections.

Conclusion:

The relatively high tissue levels remained for 120 min monitoring. Selegiline levels in the brain (1.69 µg/g) and in the testes (1.88 µg/g) were also considerably higher than following intraperitoneal administration during the entire period of observation (15 to 120 min).