Effects ofHumulus lupulusExtract on the Central Nervous System in Mice

Abstract

Huinulus lupulus L. (hop) (Cannabidaceae) has been reported to have hypnotic and sedative effects (1-3). But there have been few recent reports concerning the detailed behavioral effects of the hop. Thus, we have investigated the CNS effects of Humulus lupulus (hop) extract using several behavioral tests, such as spontaneous locomotor activity, rotarod test, potentiation of pentobarbital-induced sleep, hypothermic, analgesic, and anticonvulsant tests in mice. Hop extracts (Emil Flachsmann AG) was administered to ICR mice (30-40 g, 6-8 weeks of age) at the doses of 100, 250, or 500 mg/kg i.p., thirty minutes before each test. 1: Spontaneous locomotor activity: Spontaneous locomotor activity (Rhema-Lahoratechnic, Karl KoIb Co.) measured for 1 h was dose-dependently suppressed at doses above 250 mg/kg i.p.. 2: Rotarod performance: The time which mice wereable to remain on the rotarod (13 rev. min1, diameter of 5.5 cm, cutoff time of 2 mm) was decreased by 59% and 65%, at the dose of 250 and 500mg/kg i.p., respectively. 3: Anticonvulsant activity: Time of the onset of tonic extensor convulsion and survival time after administration of pentylenetetrazole (100 mg/kg i.p.) were significantly lengthened. 4: Potentiation of pentobarbital-induced sleep: Hop extract produced a dose-dependent increase in sleeping time in mice treated with pentobarbital (35 mg/kg, i.p.). 5: Anfinociceptive effect: Hop extract significantly increased the latency of licking the forepaws in hot plate tests (53 0.5 °C). 6: Hypothermic activity: Hop extract (500mg/kg, i.p.) caused a significant time-dependent fall in the rectal temperature.These results indicate that hop has hypothermic, antinociceptive, and anticonvulsant activities in addition to the sedative and hypnotic properties. Further investigations of the exact mechanism(s) of these actions are needed.

The pharmacognosy of Humulus lupulus L. (hops) with an emphasis on estrogenic properties

“…Reports have indicated that preparations of hops have sedative-like activity in frogs (Munch et al, 1933;Staven-Groenberg, 1928;Steidle, 1932), pigeons (Sikorski and Rusiecki, 1938), mice (Lee et al, 1993;Prokopenko et al, 1986), goldfish (Bouchardy, 1953), and golden carp (Grumbach and Mirimanoff, 1955). An understanding of the biochemical mechanism and the conclusive identification of compounds responsible for such activity have not yet been achieved.…”

New insight in the neuropharmacological activity of Humulus lupulus L.

“…The authors observed a reduction in spontaneous motor activity related to the type of solvent used in the extraction procedure, being the etheric extract the most active in comparison with the aqueous and alcoholic ones. The effect of an hops extract on the CNS was evaluated in mice by Lee et al (1993): hypotermic, analgesic and anticonvulsant activities were observed in addition to sedative and hypnotic properties. A research group attributed the sedative effect of hops to 2-methyl-3-butene-2-ol, deriving from hop constituents during storage but probably also formed in vivo by metabolization of ␣-acids (Hänsel et al, 1982).…”

Effect of non-alcoholic beer on Subjective Sleep Quality in a university stressed population

“…The mechanism of the action of these components is to activate the neurotransmitter γ-aminobutyric acid (GABA) by modulating brain GABA(A) receptors (24), thus inhibiting the central nervous system. In particular, this effect of hops on the nervous system has been reported in animal model studies (11,21,44), it also has a narcotic effect of high concentrations of hop extract due to its aforementioned 2-methyl-3-buten-2-ol component (9,42). Basic research on hops has been used to help healthy stress free human population to sleep (31,38).…”