BACKGROUND: The etiology of benign prostatic hyperplasia (BPH) is not completely understood, but hormonal changes in aging men seem to be pivotal. Dihydrotestosterone, a potent, active metabolite of testosterone, is formed by the enzymatic action of prostate 5 alpha-reductase and causes cell growth and hyperplasia. Consistent with this action, male sexual dysfunction has been clinically documented to be among the drug-related adverse events associated with 5 alpha-reductase inhibitors. The lipidosterolic extract of saw palmetto (LESP) fruit (Serenoa repens) has been used to treat BPH. D-004, a lipid extract of Roystonea regia Royal palm fruit, has been found to prevent prostatic hyperplasia induced by testoste-rone in rodents and to competitively inhibit prostate 5(x-reductase activity in vitro. OBJECTIVE: The purpose of this study was to assess the effects of D-004 and LESP, administered as single or repeated doses, on the sexual activity in male rats. METHODS: This controlled, experimental study was conducted at the Pharmacology Department, Centre of Natural Products, National Centre for Scientific Research, Havana City, Cuba. Adult male Wistar rats weighing 250 to 300 g were randomized into 5 groups: 2 groups treated orally with D-004 (400 and 800 mg/kg); 2 groups treated orally with LESP (400 and 800 mg/kg); and I control group orally administered a water vehicle. Sexual activity behavior (the number of mounts and intromissions, mount latency, and intromission latency) was assessed during 2 observation periods: 90 minutes after the initial dose and at the end of the 30-day treatment. Latency was defined as time elapsed between the first mount and intromission. RESULTS: A total of 50 rats (mean [SD] age, 10 [3] weeks; mean [SD] weight, 295 [10] g) were included in the experiment. There were no significant differences in the mean number of mounts, intromissions, mount latency, or intromission latency in the groups treated with single or repeated doses of D-004 or LESP (400 and 800 mg/kg) compared with the controls. There was also no between-group difference in mating behavior among the active treatment groups. All rats survived up to study completion, with normal behavior (weight gain, food intake, daily observations, without any sign of toxicity). There were no observable adverse events during the study. CONCLUSIONS: D-004 and LESP administered as a single dose or repeated doses for 30 days did nor significantly affect male rat sexual activity behavior compared with a vehicle control group.
