Efficacy and Tolerability of a Standardized Herbal Product from Galphimia glauca on Generalized Anxiety Disorder. A Randomized, Double-Blind Clinical Trial Controlled with Lorazepam

• Abstract
• Abbreviations
• Introduction
• Materials and Methods
• Plant material and extract preparation
• HPLC analysis
• Calibration curve
• GB quantification
• GgHP formulation
• Control formulation
• Subjects
• Study procedure
• Statistical analysis
• Results and Discussion
• Aknowledgements
• References

Abstract

Galphimia glauca Cav. is a plant used in Mexican traditional medicine as a ”nerve tranquilizer”. Previous studies have demonstrated that the methanolic extract from this plant species possess an anxiolytic effect. Galphimine B (GB, a nor-seco-triterpene), is the active principle, with an innovative action mechanism. Against this background, a standardized herbal medicinal product was developed from the aqueous extract of G. glauca (GgHP). The present work compared the therapeutic effectiveness, safety, and tolerability of the new GgHP with lorazepam on patients with generalized anxiety disorder (GAD). By means of a controlled, randomized, double-blind clinical trial, outpatients of either sex who matched the DSM-IV diagnostic criteria with a score of ≥ 19 points on the Hamilton Anxiety Scale (HAM-A) were included. The experimental group was treated orally with GgHP in capsules twice a day for 4 weeks. The control group received lorazepam (1 mg) under the same conditions and presentation. A total of 152 patients were included in the trial (72 in the experimental group). From the first week of treatment, GgHP showed important anxiolytic effectiveness, very similar to that produced with lorazepam. Both treatments showed therapeutic safety (no alterations on biochemical analysis of hepatic and renal function). Nevertheless, concerning side effects, GgHP evidenced a considerably higher tolerability than lorazepam.

Abbreviations

ALP: alkaline phosphatase

ALT: alanine aminotransferase

AST: aspartate aminotransferase

GAD: generalized anxiety disorder

GB: galphimine B

GgHP: standardized herbal medicinal product from the aqueous extract of Galphimia glauca

HAM-A: Hamilton anxiety scale

SSRI: selective serotonin reuptake inhibitors

Introduction

Generalized anxiety disorder (GAD) is included among (DSM IV) anxiety disorders and affects between 3 and 7 % of adult population, predominating in the female sex [1], [2], [3]. Conventional treatment mainly consists of chronic administration of benzodiazepine derivatives such as alprazolam, bromazepam, and lorazepam, which produce multiple known and predictable side effects (principally, excessive sedation and dependence) that in many cases contraindicate and limit their prescription [4], [5]. There are other anxiolytics, such as antihistaminics, selective serotonin reuptake inhibitors (SSRI), partial GABA agonists, and azapirones; nonetheless, these have different inconvenient side effects [6], [7], [8]. It is necessary to develop a therapeutic alternative for treating anxiety with innovative action mechanisms and with similar or better rates of therapeutic effectiveness than those reported for the common anxiolytics, but with fewer side effects and shorter latency of action.

The plant species Galphimia glauca Cav. (Malpighiaceae), popularly known in Spanish as calderona amarilla, has for many years been used in Mexican traditional medicine as a ”nerve tranquilizer” [9], [10]. In vivo pharmacological studies have demonstrated the anxiolytic activity of the methanolic extract obtained from G. glauca [11], [12]. Galphimine B (GB) is the active principle, a nor-seco-triterpene [13], [14], [15]. This compound exhibited an innovative action mechanism and selectively inhibited dopaminergic neurons discharges in the ventral tegmental area [16] without exhibiting interaction with the GABAergic system [17]. More recently, other galphimines (that exhibited spasmolytic activity) have been identified in this plant species, including GE, GA, GJ, and GF [18]. Different extracts from G. glauca including the aqueous extract have been submitted to toxicological evaluation without showing toxic or genotoxic effects [19]. By means of biotechnology methods, G. glauca has been micropropagated; thus, the plant material is obtained from a controlled crop [20]. Based on the described results, a standardized herbal product was developed from dried G. glauca aqueous extract and standardized on 0.348 mg of GB per dose for evaluation in patients with GAD.

Materials and Methods

Plant material and extract preparation

Observing World Health Organization (WHO) guidelines on good medicinal-plant agricultural and collection practices [21], G. glauca leaves and stems were obtained from a controlled crop located in Morelos State, Mexico. A specimen voucher was prepared and identified by Abigail Aguilar-Contreras, M.Sc., and deposited for reference in the IMSSM herbarium. Plant material (20 kg) was dried under dark conditions and environmental temperature for 2 weeks; once the plant was dried (6 kg), it was milled with electrical equipment until obtaining 1 - 3 mm particles. The extract was obtained by maceration in water at 60 °C for 2 h and was dried in two steps: first by distillation under reduced pressure, and then by dry Niro, BE 1448 spray (Copenhagen, Denmark) with a 130 °C entrance temperature and a 77.58 mL/min flow rate. HPLC analysis of the obtained extract showed no GB concentration modification due to the drying method. Each gram of the obtained extract (1,500 g) contained 1.122 mg of GB, and was stored at -20 °C until GgHP formulation.

HPLC analysis

The dried G. glauca extract was analyzed in a modular HPLC system (Merck-Hitachi; Darmstadt, Germany) comprising an intelligent pump L-6200A connected to a photodiode array detector and equipped with an AS-200 autosampler and corresponding Chromatography Data Acquisition software (Merck-Hitachi). The wavelength was set to 232 nm (spectral acquisition data, 200 - 400 nm). The method was developed with a reverse-phase column (Chromolith, 4.5 × 100 mm, Merck). The mobile phase consisted of an isocratic system with 35 : 65 acetonitrile/water, flow rate 1.7 mL/min, total run time, 12 min.

Calibration curve

GB, previously obtained from the G. glauca extract was used as standard. Purity and identity were confirmed by comparison with ¹H- and ¹³C-NMR spectroscopic data of authentic material.

Four samples of GB were prepared (50, 100, 200, and 400 μg/mL) and injected into the HPLC in triplicate (70 μL). The curve calibration was obtained by measuring the corresponding peak area (T_R. = 7.8 min, R ² = 0.99).

GB quantification

The extract (10 mg) was partitioned with CHCl₃/water, the obtained organic fraction (4 mg) was dissolved in methanol (4 mg/mL), and samples were injected in triplicate (70 μL).

GgHP formulation

Each capsule was filled with 310 mg of G. glauca extract, with a final concentration of 0.348 mg of GB per dose. Capsules were packed in 10-piece aluminum blisters. Based on Mexican official rules NOM-059-SSA1-1993 and NOM-073-SSA1-1993 and Mexican pharmacopeia [22], different methodologies were used to evaluate extract and final product quality.

Control formulation

Identical capsules were used for preparing the control treatment. Each capsule was filled with the same excipient, but in this case, a small tablet of lorazepam (1 mg) was included. In addition, capsules were packed in 10-piece aluminum blisters.

Subjects

With the authorization of the Institutional Ethics Committee, outpatients of either sex, 18 - 65 years of age, with the diagnosis of GAD and without pharmacological treatment for this disease (at least 4 weeks prior to study initiation), without drug or alcohol addiction or abuse (for at least 6 months prior to study initiation), without suicidal behavior or psychiatric co-morbidity of higher clinical importance than GAD (major depression or psychotic disorder) were included. These subjects were required to match the DSM-IV criteria for GAD and to obtain ≥ 19 score points on the HAM-A scale.

Study procedure

A controlled, randomized, double-blind clinical trial was conducted in the Mexican Institute of Social Security (IMSS) General Hospital in Cuernavaca, Morelos State, Mexico. Experimental group patients were treated with capsules containing 310 mg of dried aqueous G. glauca extract (with 0.348 mg of GB), twice a day for 4 weeks, while the control group received (following the same procedure) identical capsules with 1 mg lorazepam. Main outcome variable was therapeutic effectiveness, considered when the HAM-A scale was < 18 score points. Secondary variables included tolerability, absence of excessive sedation that required patient withdrawal from the study, and safety, absence of pathological alterations in biochemical tests of renal and hepatic function (AST, ALT, ALP, urea, creatinine). From the first week of treatment, the therapeutic effect was evaluated by means of the HAM-A scale, the clinical global impression scale (CGI), and the patient global evaluation (PGE). Treatment compliance was evaluated weekly (by counting and replacing the empty blister pack with a new one), as well as side effects by a 50-item scale that evaluates disease severity.

Statistical analysis

In order to compare media with normal distribution, a two-way ANOVA was used, while the Wilcoxon test was utilized for comparing matched data. The Mann-Whitney U test was employed for independent groups, and the χ² test was used for comparing proportions. Values of p ≤ 0.05 were utilized for rejecting the nullity hypothesis.

Results and Discussion

A total of 152 patients were included (72 in the experimental group). Mean age was 37.8 years, while GAD evolution time average was 4.1 years. General characteristics of the population under study did not show differences between groups (ANOVA p ≥ 0.20) (Table [1]). It is important to mention that 117 patients (76.97 %) were females, 36 (23.68 %) referred from smoking, and 27 (17.63 %) have had an alcohol or drug addiction (11, 7.23 %). Only three patients had used anxiolytic drugs (1.97 %). These parameters showed no differences between groups (χ², p ≥ 0.17).

Thirty-eight subjects were excluded from the study (21 from the control group), twenty because of a side effect (excessive sedation), the majority of these (16) were from the control group. The remainder (18 patients) were excluded due to non-medical causes. A total of 114 subjects concluded the study (55 from the experimental group), and were then included in the effectiveness analysis. Only 113 patients were included in the safety analysis (because one patient from the control group did not permit the final blood test). For the tolerability analysis, the 20 patients who presented excessive sedation were included (134 in total, 59 of these from the experimental group).

The results obtained allowed us to identify the anxiolytic effectiveness produced by the G. glauca standardized extract, previously demonstrated with animal models [13], [14].

At the end of the study, both treatments significantly lowered (Wilcoxon p ≤ 0.0001) the scales used for evaluating effectiveness, these including HAM-A, CGI, and PGE. GgHP reduced HAM-A scale from 29 to 9 score points (65.62 %), the CGI from 9 to 4, and PGE from 9 to 4. As shown in Fig. [1], the GgHP anxiolytic effect was evident from the first week of treatment, with a 43.2 % reduction on the HAM-A scale, reaching nearly 90 % at the end of the third week of administration, this effect was not different from that produced by lorazepam.

The therapeutic effect observed with both treatments and measured as the percentage and absolute reduction of HAM-A was similar; G. glauca reduced these by 17.65 score points (61.2 %) and lorazepam, by 17.65 score points (60.29 %). Table [2] compares basal values and shows the ability of both treatments to reduce (absolute values and percentage) the somatic and mental anxiety sub-scales, both from the HAM-A scale and without denoting differences between groups.

The anxiolytic effect was confirmed with the reduction of the CGI and PGE scales, which showed that clinical evaluation and patient auto-evaluation always denoted improvement. The experimental treatment showed a tendency to improve on the CGI and PGE scales, but without reaching significant differences (Figs. [2] and [3]). The therapeutic effectiveness was similar with both treatments, 80 % with the experimental, and 81.3 % with the control group. Clinically and statistically, the only important difference observed between the treatments under study corresponded to tolerability. Control treatment produced considerably more cases of excessive sedation (21.33 %) than experimental treatment (6.78 %). Safety in both groups was 100 %.

Stratified analysis showed that patient sex, age, and disease evolution time did not modify therapeutic effectiveness, while patients > 38 years of age or with a basal HAM-A scale value of ≤ 30 showed higher percentages of therapeutic effectiveness (p < 0.03) with the experimental treatment (data not shown). Because of the definition of the therapeutic effectiveness variable, it was highly probable to obtain higher effectiveness in patients with lower HAM-A basal rates; nonetheless, therapeutic effectiveness finding in patients aged > 38 years remains an open matter.

It is important to mention that the anxiolytic effect produced by G. glauca was evident from the first week of administration, while other drugs such as azapirones and SSRI commence with the anxiolytic effect after the third or fourth week of administration [23]; this fact possesses interesting therapeutic implications, because patients could rapidly become beneficiaries of this. It is noteworthy that according to the traditional use of the plant, 1 L of infusion prepared with 3 g of G. glauca leaves is consumed throughout the day.

Scientific reports related with the evaluation of other plant extracts on patients with GAD could be found. Piper methysticum and Valeriana officinalis reduced the HAM-A scale by14.89 and 8.2 score points, respectively [24], [25]. Unfortunately, the possible risk of hepatotoxicity in the case of Kava products is an unsolved issue, while studies on Valeriana officinalis studies are limited [26], [27]. Results obtained with GgHP were similar to those obtained in previous clinical studies with different anxiolytics; these studies have reported the ability of alprazolam (benzodiazepine), or escitalopram (SSRI) after 4 weeks of administration, in lowering the HAM-A scale > 10 score points in patients with GAD, with rates of side effects and forlornness lower than those of benzodiazepine and similar to that of the SSRI [28], [29]. It is important to mention that in this study, due to ethical reasons, no placebo group was included. In addition, it must be considered that anxiety frequently constitutes a chronic disease; thus, 4 weeks of treatment and observation could be too short. Taking into account these limitations of the study, with the obtained results, we are able to conclude that GgHP administered twice daily for 4 weeks shows anxiolytic equivalence with lorazepam, but with considerably lower rates of withdrawal due to excessive diurnal sedation.

Aknowledgements

CONACyT SALUD 2004-1059, and IMSS/FOFOI 2004-042

References

• 1 American Psychiatric Association. Diagnostic and statistical manual of mental disorders, fourth edition, text revision. Washington DC; American Psychiatric Association 2000: 472-6.
  Search in Google Scholar
• 2 Kessler R C, Brandenburg N, Lane M, Roy-Byrne P, Stang P D, Stein D J. et al . Rethinking the duration requirement for generalized anxiety disorder: evidence from the National Comorbidity Survey Replication.  Psychol Med. 2005;  35 1073-82.
  CrossrefPubMedSearch in Google Scholar
• 3 Kessler R C, McGonagle K A, Zhao S, Nelson C B, Hughes M, Eshleman S. et al . Lifetime and 12-month prevalence of DSM-III-R psychiatric disorders in the United States. Results from the National Comorbidity Survey.  Arch Gen Psychiatry. 1994;  51 8-19.
  PubMedSearch in Google Scholar
• 4 Couvee J E, Zitman F G. The benzodiazepine withdrawal symptom questionnaire: psychometric evaluation during a discontinuation program in depressed chronic benzodiazepine users in general practice.  Addiction. 2002;  97 337-45.
  CrossrefPubMedSearch in Google Scholar
• 5 Rickels K, Schweizer E, DeMartinis N, Mandos L, Mercer C. Gepirone and diazepam in generalized anxiety disorder: a placebo-controlled trial.  J Clin Psychopharmacol. 1997;  17 272-7.
  CrossrefPubMedSearch in Google Scholar
• 6 Llorca P M, Spadone C, Sol O, Danniau A, Bougerol T, Corruble E. et al . Efficacy and safety of hydroxyzine in the treatment of generalized anxiety disorder: a 3-month double-blind study.  J Clin Psychiatry. 2002;  63 1020-7.
  PubMedSearch in Google Scholar
• 7 Bielski R J, Bose A, Chang C C. A double-blind comparison of escitalopram and paroxetine in the long-term treatment of generalized anxiety disorder.  Ann Clin Psychiatry. 2005;  17 65-9.
  CrossrefPubMedSearch in Google Scholar
• 8 Feltner D E, Crockatt J G, Dubovsky S J, Cohn C K, Shrivastava R K, Targum S D. et al . A randomized, double-blind, placebo-controlled, fixed-dose, multicenter study of pregabalin in patients with generalized anxiety disorder.  J Clin Psychopharmacol. 2003;  23 240-9.
  CrossrefPubMedSearch in Google Scholar
• 9 Martínez M. Las plantas medicinales de México, 5th edition.  Mexico: Andres. Botas;  1969 402-3.
  PubMedSearch in Google Scholar
• 10 Estrada E. Jardín botánico de plantas medicinales. Mexico; Universidad Autónoma de Chapingo. Departamento de Fitotécnia 1985: 15.
  Search in Google Scholar
• 11 Tortoriello J, Lozoya X. Effect of Galphimia glauca methanolic extract on neuropharmacological tests.  Planta Med. 1992;  58 234-6.
  Thieme ConnectPubMedSearch in Google Scholar
• 12 Herrera-Ruiz M, Jimenez-Ferrer J E, De Lima T C, Aviles-Montes D, Perez-Garcia D, Gonzalez-Cortazar M. et al . Anxiolytic and antidepressant-like activity of a standardized extract from Galphimia glauca .  Phytomedicine. 2006;  13 23-8.
  CrossrefPubMedSearch in Google Scholar
• 13 Herrera-Ruiz M, Gonzalez-Cortazar M, Jimenez-Ferrer E, Zamilpa A, Alvarez L, Tortoriello J. et al . Anxiolytic effect of natural galphimines from Galphimia glauca and their chemical derivatives.  J Nat Prod. 2006;  69 59-61.
  CrossrefPubMedSearch in Google Scholar
• 14 Tortoriello J, Ortega A. Sedative effect of galphimine-B, a nor-seco-triterpenoid from Galphimia glauca .  Planta Med. 1993;  59 398-400.
  Thieme ConnectPubMedSearch in Google Scholar
• 15 Toscano R A, Ortega A, Maldonado E, Gaviño R, Lozoya X, Tortoriello J. Structure of galphimine B.  Acta Cryst C. 1993;  49 774-6.
  CrossrefPubMedSearch in Google Scholar
• 16 Tortoriello J, Ortega A, Herrera-Ruíz M, Trujillo J, Reyes-Vázquez C. Galphimine-B modifies electrical activity of ventral tegemental area neurons in rats.  Planta Med. 1998;  64 309-13.
  Thieme ConnectPubMedSearch in Google Scholar
• 17 Prieto-Gomez B, Tortoriello J, Vazquez-Alvarez A, Reyes-Vazquez C. Galphimine B modulates synaptic transmission on dopaminergic ventral tegmental area neurons.  Planta Med. 2003;  69 38-43.
  Thieme ConnectPubMedSearch in Google Scholar
• 18 González-Cortazar M, Tortoriello J, Álvarez L. Norsecofriedelanos as spasmolytics. Advances of structure activity relationships.  Planta Med. 2005;  71 711-6.
  Thieme ConnectPubMedSearch in Google Scholar
• 19 Aguilar-Santamaría L, Ramírez G, Herrera-Arellano A, Zamilpa A, Jiménez J, Alonso-Cortes D. et al . Toxicological and cytotoxic evaluation of standardized extracts of Galphimia glauca .  J Ethnopharmacol. 2007;  109 35-40.
  CrossrefPubMedSearch in Google Scholar
• 20 Rojas G, Aranda E, Navarro V, Zamilpa A, Tortoriello J. In vitro propagation of Galphimia glauca and content of the sedative compound galphimine-B in wild and micropropagated plants.  Planta Med. 2005;  71 076-8.
  PubMedSearch in Google Scholar
• 21 Organización Mundial de la Salud. Directrices de la OMS sobre buenas prácticas agrícolas y de recolección (BPAR) de plantas medicinales. Ginebra; Organización Mundial de la Salud 2003.
  Search in Google Scholar
• 22 Comisión permanente de la farmacopea de los estados unidos mexicanos. Farmacopea de los Estados Unidos mexicanos, 8th edition. México; Secretaría de Salud 2004: 311-572.
  Search in Google Scholar
• 23 Alpert J E, Franznick D A, Hollander S B, Fava M. Gepirone extended-release treatment of anxious depression: evidence from a retrospective subgroup analysis in patients with major depressive disorder.  . 2004;  65 1069-75.
  PubMedSearch in Google Scholar
• 24 Boerner R J, Sommer H, Berger W, Kuhn U, Schmidt U, Mannel M. Kava-Kava extract LI 150 is as effective as Opipramol and Buspirone in generalised anxiety disorder - an 8-week randomized, double-blind multi-centre clinical trial in 129 out-patients.  Phytomedicine. 2003;  10 38-49.
  CrossrefPubMedSearch in Google Scholar
• 25 Andreatini R, Sartori V A, Seabra M L, Leite J R. Effect of valepotriates (valerian extract) in generalized anxiety disorder: a randomized placebo-controlled pilot study.  Phytother Res. 2002;  16 650-4.
  CrossrefPubMedSearch in Google Scholar
• 26 Schulze J, Raasch W, Siegers C P. Toxicity of kava pyrones, drug safety and precautions-a case study.  Phytomedicine. 2003;  10 68-73.
  CrossrefPubMedSearch in Google Scholar
• 27 Hadley S, Petry J J. Valerian.  Am Fam Physician. 2003;  67 1755-8.
  PubMedSearch in Google Scholar
• 28 Rickels K, Pollack M H, Feltner D E, Lydiard R B, Zimbroff D L, Bielski R J. et al . Pregabalin for treatment of generalized anxiety disorder: a 4-week, multicenter, double-blind, placebo-controlled trial of pregabalin and alprazolam.  Arch Gen Psychiatry. 2005;  62 1022-30.
  CrossrefPubMedSearch in Google Scholar
• 29 Goodman W K, Bose A, Wang Q. Treatment of generalized anxiety disorder with escitalopram: pooled results from double-blind, placebo-controlled trials.  J Affect Disord. 2005;  87 161-7.
  CrossrefPubMedSearch in Google Scholar

Jaime Tortoriello García

Centro de Investigación Biomédica del Sur

Instituto Mexicano del Seguro Social

Argentina 1

62790 Xochitepec

Morelos

México

Phone: +52-777-361-2155

Fax: +52-777-361-2155

Email: jtortora2@yahoo.es

References

• 1 American Psychiatric Association. Diagnostic and statistical manual of mental disorders, fourth edition, text revision. Washington DC; American Psychiatric Association 2000: 472-6.
  Search in Google Scholar
• 2 Kessler R C, Brandenburg N, Lane M, Roy-Byrne P, Stang P D, Stein D J. et al . Rethinking the duration requirement for generalized anxiety disorder: evidence from the National Comorbidity Survey Replication.  Psychol Med. 2005;  35 1073-82.
  CrossrefPubMedSearch in Google Scholar
• 3 Kessler R C, McGonagle K A, Zhao S, Nelson C B, Hughes M, Eshleman S. et al . Lifetime and 12-month prevalence of DSM-III-R psychiatric disorders in the United States. Results from the National Comorbidity Survey.  Arch Gen Psychiatry. 1994;  51 8-19.
  PubMedSearch in Google Scholar
• 4 Couvee J E, Zitman F G. The benzodiazepine withdrawal symptom questionnaire: psychometric evaluation during a discontinuation program in depressed chronic benzodiazepine users in general practice.  Addiction. 2002;  97 337-45.
  CrossrefPubMedSearch in Google Scholar
• 5 Rickels K, Schweizer E, DeMartinis N, Mandos L, Mercer C. Gepirone and diazepam in generalized anxiety disorder: a placebo-controlled trial.  J Clin Psychopharmacol. 1997;  17 272-7.
  CrossrefPubMedSearch in Google Scholar
• 6 Llorca P M, Spadone C, Sol O, Danniau A, Bougerol T, Corruble E. et al . Efficacy and safety of hydroxyzine in the treatment of generalized anxiety disorder: a 3-month double-blind study.  J Clin Psychiatry. 2002;  63 1020-7.
  PubMedSearch in Google Scholar
• 7 Bielski R J, Bose A, Chang C C. A double-blind comparison of escitalopram and paroxetine in the long-term treatment of generalized anxiety disorder.  Ann Clin Psychiatry. 2005;  17 65-9.
  CrossrefPubMedSearch in Google Scholar
• 8 Feltner D E, Crockatt J G, Dubovsky S J, Cohn C K, Shrivastava R K, Targum S D. et al . A randomized, double-blind, placebo-controlled, fixed-dose, multicenter study of pregabalin in patients with generalized anxiety disorder.  J Clin Psychopharmacol. 2003;  23 240-9.
  CrossrefPubMedSearch in Google Scholar
• 9 Martínez M. Las plantas medicinales de México, 5th edition.  Mexico: Andres. Botas;  1969 402-3.
  PubMedSearch in Google Scholar
• 10 Estrada E. Jardín botánico de plantas medicinales. Mexico; Universidad Autónoma de Chapingo. Departamento de Fitotécnia 1985: 15.
  Search in Google Scholar
• 11 Tortoriello J, Lozoya X. Effect of Galphimia glauca methanolic extract on neuropharmacological tests.  Planta Med. 1992;  58 234-6.
  Thieme ConnectPubMedSearch in Google Scholar
• 12 Herrera-Ruiz M, Jimenez-Ferrer J E, De Lima T C, Aviles-Montes D, Perez-Garcia D, Gonzalez-Cortazar M. et al . Anxiolytic and antidepressant-like activity of a standardized extract from Galphimia glauca .  Phytomedicine. 2006;  13 23-8.
  CrossrefPubMedSearch in Google Scholar
• 13 Herrera-Ruiz M, Gonzalez-Cortazar M, Jimenez-Ferrer E, Zamilpa A, Alvarez L, Tortoriello J. et al . Anxiolytic effect of natural galphimines from Galphimia glauca and their chemical derivatives.  J Nat Prod. 2006;  69 59-61.
  CrossrefPubMedSearch in Google Scholar
• 14 Tortoriello J, Ortega A. Sedative effect of galphimine-B, a nor-seco-triterpenoid from Galphimia glauca .  Planta Med. 1993;  59 398-400.
  Thieme ConnectPubMedSearch in Google Scholar
• 15 Toscano R A, Ortega A, Maldonado E, Gaviño R, Lozoya X, Tortoriello J. Structure of galphimine B.  Acta Cryst C. 1993;  49 774-6.
  CrossrefPubMedSearch in Google Scholar
• 16 Tortoriello J, Ortega A, Herrera-Ruíz M, Trujillo J, Reyes-Vázquez C. Galphimine-B modifies electrical activity of ventral tegemental area neurons in rats.  Planta Med. 1998;  64 309-13.
  Thieme ConnectPubMedSearch in Google Scholar
• 17 Prieto-Gomez B, Tortoriello J, Vazquez-Alvarez A, Reyes-Vazquez C. Galphimine B modulates synaptic transmission on dopaminergic ventral tegmental area neurons.  Planta Med. 2003;  69 38-43.
  Thieme ConnectPubMedSearch in Google Scholar
• 18 González-Cortazar M, Tortoriello J, Álvarez L. Norsecofriedelanos as spasmolytics. Advances of structure activity relationships.  Planta Med. 2005;  71 711-6.
  Thieme ConnectPubMedSearch in Google Scholar
• 19 Aguilar-Santamaría L, Ramírez G, Herrera-Arellano A, Zamilpa A, Jiménez J, Alonso-Cortes D. et al . Toxicological and cytotoxic evaluation of standardized extracts of Galphimia glauca .  J Ethnopharmacol. 2007;  109 35-40.
  CrossrefPubMedSearch in Google Scholar
• 20 Rojas G, Aranda E, Navarro V, Zamilpa A, Tortoriello J. In vitro propagation of Galphimia glauca and content of the sedative compound galphimine-B in wild and micropropagated plants.  Planta Med. 2005;  71 076-8.
  PubMedSearch in Google Scholar
• 21 Organización Mundial de la Salud. Directrices de la OMS sobre buenas prácticas agrícolas y de recolección (BPAR) de plantas medicinales. Ginebra; Organización Mundial de la Salud 2003.
  Search in Google Scholar
• 22 Comisión permanente de la farmacopea de los estados unidos mexicanos. Farmacopea de los Estados Unidos mexicanos, 8th edition. México; Secretaría de Salud 2004: 311-572.
  Search in Google Scholar
• 23 Alpert J E, Franznick D A, Hollander S B, Fava M. Gepirone extended-release treatment of anxious depression: evidence from a retrospective subgroup analysis in patients with major depressive disorder.  . 2004;  65 1069-75.
  PubMedSearch in Google Scholar
• 24 Boerner R J, Sommer H, Berger W, Kuhn U, Schmidt U, Mannel M. Kava-Kava extract LI 150 is as effective as Opipramol and Buspirone in generalised anxiety disorder - an 8-week randomized, double-blind multi-centre clinical trial in 129 out-patients.  Phytomedicine. 2003;  10 38-49.
  CrossrefPubMedSearch in Google Scholar
• 25 Andreatini R, Sartori V A, Seabra M L, Leite J R. Effect of valepotriates (valerian extract) in generalized anxiety disorder: a randomized placebo-controlled pilot study.  Phytother Res. 2002;  16 650-4.
  CrossrefPubMedSearch in Google Scholar
• 26 Schulze J, Raasch W, Siegers C P. Toxicity of kava pyrones, drug safety and precautions-a case study.  Phytomedicine. 2003;  10 68-73.
  CrossrefPubMedSearch in Google Scholar
• 27 Hadley S, Petry J J. Valerian.  Am Fam Physician. 2003;  67 1755-8.
  PubMedSearch in Google Scholar
• 28 Rickels K, Pollack M H, Feltner D E, Lydiard R B, Zimbroff D L, Bielski R J. et al . Pregabalin for treatment of generalized anxiety disorder: a 4-week, multicenter, double-blind, placebo-controlled trial of pregabalin and alprazolam.  Arch Gen Psychiatry. 2005;  62 1022-30.
  CrossrefPubMedSearch in Google Scholar
• 29 Goodman W K, Bose A, Wang Q. Treatment of generalized anxiety disorder with escitalopram: pooled results from double-blind, placebo-controlled trials.  J Affect Disord. 2005;  87 161-7.
  CrossrefPubMedSearch in Google Scholar

Jaime Tortoriello García

Centro de Investigación Biomédica del Sur

Instituto Mexicano del Seguro Social

Argentina 1

62790 Xochitepec

Morelos

México

Phone: +52-777-361-2155

Fax: +52-777-361-2155

Email: jtortora2@yahoo.es