Improved sexual behavior in male rats treated with a Chinese herbal extract: hormonal and neuronal implications

Aim: To investigate the influence of an extract obtained from five Chinese medicinal plants on sexual behavior ofadult male rats. Methods: The extract was administered at doses of 30, 60 and 120 mg/kg by oral gavage, acutely (onetime, 45 min before mating test) or subchronically (daily for 10 days) in sexually potent and sexually sluggish/impotentrats. Sexual behavior, serum levels of luteinizing hormone (LH) and testosterone (T) were evaluated in treatedrats and compared with controls receiving vehicle. The effect of the extract on central dopaminergic neurotransmissionwas assessed in the nucleus accumbens using a microdialysis technique. Results: In sexually potent rats, bothacute and subchronic treatment with the extract dosed at 30 and 60 mg/kg reduced mount latency and intromissionlatency. In sluggish/impotent rats, the acutely administered extract at the dose of 60 mg/kg shortened ejaculationlatency, whereas subchronically administered at the doses of 30 and 60 mg/kg, reduced mount, intromission andejaculation latencies, increasing also the percentage of mounting and ejaculating rats. The extract dosed at 60 mg/kgsignificantly increased LH and T following acute and subchronic administration and increased 3,4-dihydroxyphenylaceticacid levels in the nucleus accumbens, 30 min after the acute administration. Conclusion: The improvement in bothappetitive and consummatory components of sexual behavior observed in male rats treated with the extract could beascribed to increased serum T level in parallel with the activation of the central dopaminergic system.