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

Ferula hermonis impairs sexual behavior in hormone-primed female rats

The influence of Ferula hermonis root extract on sexual behavior was studied in female rats. Sexual receptivity, proceptivity and paced mating behavior were evaluated in ovariectomized females primed with estradiol benzoate (EB) and progesterone (P) and then treated with F hermonis extract acutely (30 and 60 mg/kg) or subehronically (1 and 10 mg/kg daily for 10 consecutive days). A significant reduction in lordosis responses was observed in rats after acute (60 mg/kg) or subehronic (1 and 10 mg/kg) administration of the plant extract. Similarly, a decrease in proceptive behaviors was exhibited by F hermonis treated rats in comparison with EB + P controls. No difference was found in the patterns of paced mating behavior between control and treated animals. The present results demonstrate that the acute or repeated ingestion of F hermonis specifically impairs the receptive and proceptive components of female sexual behavior. The effect could be the consequence of an antiestrogenic action of the extract in hormone-primed female rats

Sedative and anxiolytic properties od chrysin, a constituent of Passiflora incarnata

The behavioral effects of acute administration of chrysin, contained in Passiflora incarnata, were studied in rats. The data demonstrate that in our experimental conditions, chrysin was able to reduce locomotor activity when injected in rats at a minimal effective dose of 25 mgrkg. However, chrysin exhibited a clear anxiolytic effect when injected at the dose of 1 mgrkg,. The sedative effect of the flavonoid cannot be ascribed to an interaction with GABA]benzodiazepine receptors, since it was not counteracted by the benzodiazepine antagonist Flumazenil. To the contrary, the anxiolytic effect of chrysin, which was blocked by the injection of Flumazenil, could be linked to an activation of the GABAA receptor unit

New insight in the neuropharmacological activity of Humulus lupulus L

The purpose of the present study was to investigate the effects of Humulus lupulus CO2 extract and its fraction containing \u3b1-acids on the central nervous system of rats. Both tested substances were able to prolong pentobarbital sleeping time, without affecting the latency to the loss of the righting reflex. This effect was dose-dependent, starting from a minimal dose of 10 mg/kg. Neither the extract nor its \u3b1-acid fraction affected the locomotor activity in the open field test or exerted an anxiolytic effect in rats submitted to the elevated plus-maze test. Interestingly both compounds reduced the immobility time during the behavioral despair test when administered three times (24, 5 and 1 h) before the test. In conclusion this report shows that Humulus lupulus CO2 extract exerts: (a) a pentobarbital sleep-enhancing property without influencing the motor behavior of rats; (b) an antidepressant activity. The same effects were elicited by the administration of the Humulus lupulus fraction containing \u3b1-acids, which can be considered as the major responsible for the enhanced pentobarbital effect and for the antidepressant property

Pharmacological characterisation of beta-acids fraction of hops

Humulus lupulus (hops) is traditionally used as a tranquilizing herbal remedy. Here, we investigated the in vivo and in vitro effect of hop -acids on central nervous system function. Oral administration of -acids (5\u201310 mg/kg) in rats produced an increased exploratory activity in the open field, a reduction in the pentobarbital hypnotic activity and a worsening of picrotoxin-induced seizures. When dosed at 10 mg/kg, -acids increased, in the elevated plus maze, open arm entries reducing in parallel those in closed arms. In the forced swimming test, we observed a reduction in the immobility time that could suggest an antidepressant-like activity. Electrophysiological studies performed on cerebellar granule cells in culture showed that the -acids fraction decreased GABA-evoked current in a dose-dependent way. The effect was not inhibited by the benzodiazepine antagonist Ro 15-1788. Benzodiazepine receptors involvement was also excluded by [3H]-Ro 15-1788 binding assay. In conclusion, the behavioraleffects of -acids fraction could be explained by a reduction in the GABAergic activity although we cannot rule out the involvement of other neurotransmitter systems

Definizione delle attività farmacologiche dell'iperforina e relativi meccanismi d'azione

nel nostro studio abbiamo preso in considerazione l'effetto dell'iperforina sul comportamento motorio del ratto e la sua influenza in modelli sperimentali di ansia. In tali esprimenti abbiamo messo a confronto l'attività dell'iperforina acetato con quella di un estratto totale di iperico ottenuto con la tecnica della CO2 supercritica

Caratterizzazione dell'attività farmacologica dell'iperforina in confronto all'estratto di Hypericum perforatum

Allo scopo di chiarire il meccanismo con cui l'iperforina svolge la sua azione ansiolitica, sono stati eseguiti studi preliminari con antagonisti famcaologici che hanno suggerito un possibile coinvolgimento del sistema serotoninergico e una scarsa implicazione del sistema recettoriale benzodiazepinico