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Stephany Hoffelt


Effects of traditionally used anxiolytic botanicals on enzymes of the gamma-aminobutyric acid (GABA) system.

Abstract: In Canada, the use of botanical natural health products (NHPs) for anxiety disorders is on the rise, and a critical evaluation of their safety and efficacy is required. The purpose of this study was to determine whether commercially available botanicals directly affect the primary brain enzymes responsible for gamma-aminobutyric acid (GABA) metabolism. Anxiolytic plants may interact with either glutamic acid decarboxylase (GAD) or GABA transaminase (GABA-T) and ultimately influence brain GABA levels and neurotransmission. Two in vitro rat brain homogenate assays were developed to determine the inhibitory concentrations (IC50) of aqueous and ethanolic plant extracts. Approximately 70% of all extracts that were tested showed little or no inhibitory effect (IC50 values greater than 1 mg/mL) and are therefore unlikely to affect GABA metabolism as tested. The aqueous extract of Melissa officinalis (lemon balm) exhibited the greatest inhibition of GABA-T activity (IC50 = 0.35 mg/mL). Extracts from Centella asiatica (gotu kola) and Valeriana officinalis (valerian) stimulated GAD activity by over 40% at a dose of 1 mg/mL. On the other hand, both Matricaria recutita (German chamomile) and Humulus lupulus (hops) showed significant inhibition of GAD activity (0.11-0.65 mg/mL). Several of these species may therefore warrant further pharmacological investigation. The relation between enzyme activity and possible in vivo mode of action is discussed.

Pub.: 11 Dec '07, Pinned: 29 Nov '17

Pharmacokinetics of valerenic acid after single and multiple doses of valerian in older women.

Abstract: Insomnia is a commonly reported clinical problem with as many as 50% of older adults reporting difficulty in falling and/or remaining asleep. Valerian (Valeriana officinalis) is a commonly used herb that has been advocated for promoting sleep. Valerenic acid is used as a marker for quantitative analysis of valerian products with evidence of pharmacological activity relevant to the hypnotic effects of valerian. The objective of this study was to determine the pharmacokinetics of valerenic acid in a group of elderly women after receiving a single nightly valerian dose and after 2 weeks of valerian dosing. There was not a statistically significant difference in the average peak concentration (C(max)), time to maximum concentration (T(max)) area under the time curve (AUC), elimination half-life (T(1/2)) and oral clearance after a single dose compared with multiple dosing. There was considerable inter- and intra-subject variability in the pharmacokinetic parameters. C(max) and AUC deceased and T(1/2) increased with increased body weight. The variability between the capsules was extremely low: 2.2%, 1.4% and 1.4%, for hydroxyvalerenic acid, acetoxyvalerenic acid and valerenic acid, respectively. In conclusion, large variability in the pharmacokinetics of valerenic acid may contribute to the inconsistencies in the effect of valerian as a sleep aid.

Pub.: 30 Sep '10, Pinned: 29 Nov '17

Modulation of postsynaptic potentials in rat cortical neurons by valerian extracts macerated with different alcohols: involvement of adenosine A(1)- and GABA(A)-receptors.

Abstract: Valeriana officinalis (valerian) is used traditionally as a mild sedative. Research into valerian is sparse, and studies differ greatly with respect to design, measures and preparations used. This study compares the action of a methanol (M-E), ethanol (E-E) and an extract macerated with ethylacetate (EA-E) from roots of valerian (Valeriana officinalis L., Valerianaceae) on postsynaptic potentials (PSPs) in cortical neurons. Intracellular recordings were performed in rat brain slice preparations containing pyramidal cells of the cingulate cortex. PSPs were induced by electrical field stimulation. The M-E induced strong inhibition in the concentration range 0.1-15 mg/mL, whereas the E-E (1-10 mg/mL) did not influence significantly the PSPs. The maximum inhibition induced by the M-E was completely antagonized by 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 0.1 microm), an antagonist on the adenosine A(1) receptor. Contrary to the M-E, the EA-E (10 mg/mL) induced an increase of the PSPs, which was completely blocked by the GABA(A) receptor antagonist picrotoxin (100 microm). The data suggest that activation of adenosine A(1) and GABA(A) receptors is mediated by different components within the valerian extract. The two mechanisms may contribute independently to the sleep-inducing effect of valerian.

Pub.: 22 Jun '07, Pinned: 29 Nov '17

Effects of aqueous, methanolic and chloroform extracts of rhizome and aerial parts of Valeriana officinalis L. on naloxone-induced jumping in morphine-dependent mice.

Abstract: In the present study, the effects of rhizomes and aerial parts extracts of Valeriana officinalis L. on morphine dependence in mice have been investigated. Animals were treated subcutaneously with morphine (50, 50 and 75 mg/kg) three times daily (10 am, 1 pm and 4 pm) for 3 days, and a last dose of morphine (50 mg/kg) was administered on the fourth day. Withdrawal syndrome (jumping) was precipitated by naloxone (5 mg/kg) which was administered intraperitoneally 2 hours after the last dose of morphine. To study the effects of the aqueous, methanolic and chloroform extracts of both aerial parts and rhizome of the V. officinalis L. on naloxone-induced jumping in morphine-dependent animals, 10 injections of morphine (three administrations each day) for dependence and a dose of 5 mg/kg of naloxone for withdrawal induction were employed. Intraperitoneal injection of different doses (1, 5, 25 and 50 mg/kg) of aqueous, methanolic and chloroform extracts of the rhizome of V. officinalis L. 60 minutes before naloxone injection decreased the jumping response dose-dependently. Pre-treatment of animals with different doses (1, 5, 25, 50 and 100 mg/kg) of aqueous and methanolic extracts of aerial parts of V. officinalis L. 60 minutes before naloxone injection caused a significant decrease on naloxone-induced jumping. The chloroform extract of the aerial parts of V. officinalis L. did not show any significant changes on jumping response in morphine-dependent animals. It is concluded that the extracts of V. officinalis L. could affect morphine withdrawal syndrome via possible interactions with inhibitory neurotransmitters in nervous system.

Pub.: 28 Jun '06, Pinned: 29 Nov '17

Interaction of valerian extracts of different polarity with adenosine receptors: identification of isovaltrate as an inverse agonist at A1 receptors.

Abstract: A series of extracts of valerian roots (Valeriana officinalis L.) was prepared with solvents of different polarity. Polar as well as nonpolar extracts were found to interact with adenosine A(1) receptors. While polar extracts activated A(1) receptors (partial agonistic activity), nonpolar extracts showed antagonistic or inverse agonistic activity at A(1) receptors, as demonstrated by GTPgammaS binding assays at human recombinant A(1) receptors stably expressed in Chinese hamster ovary (CHO) cells. Guided by radioligand binding assays, fractionation of a lipophilic petroleum ether:diethyl ether (1:1) extract led to the isolation of isovaltrate, which was characterized as a potent, highly efficacious inverse agonist at adenosine A(1) receptors (K(i) rat A(1): 2.05 microM). In experiments at rat brain slices measuring post-synaptic potentials (PSPs) in cortical neurons, isovaltrate at least partly reversed the reduction in the PSPs induced by the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA). Isovaltrate may serve as a new lead structure for the development of inverse agonists at adenosine A(1) receptors. The common use of hydrophilic, but not lipophilic valerian extracts as mild sleep-inducing agents is consistent with the opposite actions of hydrophilic and lipophilic extracts on adenosine receptors.

Pub.: 14 Nov '06, Pinned: 29 Nov '17

Ethnophytotherapeutical research in the high Molise region (Central-Southern Italy).

Abstract: In the years 2003-2005 research was carried out concerning ethno-medicine in the high Molise (central- southern Italy), a region that has been the object of very little investigation from the ethnobotanical point of view. Upper Molise is a continuation of the mountain profiles of the Abruzzi Appenines: a series of hills, steep slopes and deep fluvial valleys making communications difficult. Primordial traditions (e.g. harvest feasts) are typical of the region.Field data were collected through open interviews in the field. These were conducted on both an individual and group level, fresh plants gathered from surrounding areas being displayed. In other cases, individual interviews were conducted by accompanying the person involved to the places where they perform their activities (for example, in the woods with woodcutters, kitchen gardens and fields with housewives, pastures with shepherds, etc.). In total 54 individuals were interviewed.Data of 70 taxa belonging to 39 families were gathered. Among the species, 64 are used in human therapy, 5 as insect repellents, 11 in veterinary medicine, 1 to keep eggs and cheeses and 4 for magic purposes. The most important findings in ethno-medicine relate to the lichen Lobaria pulmonaria (L.) Hoffm. (wounds) and to some vascular plant species: Asplenium trichomanes L. and Ceterach officinarum Willd. (to regularize menstruation), Cyclamen hederifolium (chilblains), Centaurium erythraea Rafn. and Pulmonaria apennina Cristof. & Puppi (bruises), while in the ethno-veterinary field, we have Valeriana officinalis L. (wounds sustained by mules). Also worthy of note, given the isolation of the area, is the number of plants used to protect foodstuffs from parasites, among which Allium sativum L. and Capsicum frutescens L.The research revealed a deep-rooted and widespread habit of husbanding the family's resources. Whilst isolation and snowfalls contributed to the widespread knowledge of means of conserving foodstuffs, they also led to the use of products easily available within each home. The values of E.I. (ethnobotanicity index) for the upper Molise region are considered amongst the highest in Italian areas. Nevertheless, like the values for other areas of Italy, they are lower than those of many Spanish areas, perhaps (and not only) because of the more rapid cultural erosion experienced in Italy.

Pub.: 13 Mar '08, Pinned: 29 Nov '17

Extract of valerian root (Valeriana officinalis L.) vs. placebo in treatment of obsessive-compulsive disorder: a randomized double-blind study.

Abstract: Obsessive-Compulsive Disorder (OCD) is a common neuropsychiatric condition. Many herbs with psychotropic effects exist which can have fewer side effects compared to more conventional medications. Valeriana Officinalis L. is a well-known medicinal plant with a long history of usage in the world with an effect on GABA. This plant is reported to be safe on humans. Our objective in this study was to compare the efficacy of the extract of Valeriana Officinalis L. with placebo in the treatment of OCD.The study was an 8-week pilot double-blind randomized trial. Thirty-one adult outpatients who met the DSM-IV-TR criteria for OCD based on the structured clinical interview participated in the trial. In this double-blind and randomized trial, patients were randomly assigned to receive either capsule of the extract (765 mg/day) or placebo (30 mg/day) for 8 weeks.The results showed significant difference between the extract and placebo in the end of treatment (P=0.000). Somnolence was the only significant difference between the two groups in terms of observed side effects (P=0.02).The results suggest that Valeriana Officinalis L. has some antiobsessive and compulsive effects. However, further studies are needed to confirm these findings. Psychiatrists often find that many patients cannot tolerate the side effects of psychiatry medicine Valeriana Officinalis L. is a well-known medicinal plant with a long history of usage in world with effect on GABA.The results showed significant difference between the extract and placebo in the treatment of OCD. There was also no significant difference between the two groups in terms of observed side effects.

Pub.: 01 Jan '11, Pinned: 29 Nov '17