Collectively , the literature reveals pre clinical and clinical evidence for various phytomedicines modulating GABA-pathways , with comparative anxiolytic effect to the current array of pharmaceuticals , along with good safety and tolerability profiles
Anxiety disorders are chronic and functionally disabling conditions with high psychological stress , characterised by cognitive symptoms of excessive worry and focus difficulties and physiological symptoms such as muscle tension and insomnia .
Gamma-aminobutyric acid ( GABA ) is an inhibitory neurotransmitter within the central nervous system and is a key target of pharmacotherapies in the treatment of anxiety .
Although current pharmaceutical treatments are often efficacious , they may cause undesirable side effects including cognitive decrements and withdrawal symptoms .
Plant-based " phytomedicines " may provide novel treatment options , to act as an adjunctive or alternative to existing anxiolytic medications .
As such , we conducted a systematic review to assess the current body of literature on anxiolytic phytomedicines and /or phytoconstituents .
Kava for the treatment of generalised anxiety disorder (K-GAD): study protocol for a randomised controlled trial
Background Generalised anxiety disorder ( GAD ) is a chronic and pervasive condition that generates high levels of psychological stress , and it is difficult to treat in the long term . Current pharmacotherapeutic options for GAD are in some cases only modestly effective , and may elicit undesirable side effects . Through targeted actions on the gamma-aminobutyric acid ( GABA ) pathway , the South Pacific medicinal plant kava ( Piper methysticum ) is a non-addictive , non-hypnotic anxiolytic with the potential to treat GAD . The evidence for the efficacy of kava for treating anxiety has been affirmed through clinical trials and meta-analyses . Recent research has also served to lessen safety concerns regarding the use of kava due to hepatotoxic risk , which is reflected in a recent German court overturning the previous kava ban in that country ( which may in turn influence a reinstatement by the European Union ) . The aim of current research is to assess the efficacy of an ‘ aqueous noble cultivar rootstock extract ’ of kava in GAD in a larger longer term study . In addition , we plan to investigate the pharmacogenomic influence of GABA transporters on response , effects of kava on gene expression , and for the first time , the neurobiological correlates of treatment response via functional and metabolic imaging . Methods / Design This clinical trial is funded by the Australian National Health and Medical Research Council ( APP1063383 ) and co-funded by MediHerb ( Integria Healthcare ( Australia ) Pty . Ltd ) . The study is a phase III , multi-site , two-arm , 18-week , r and omised , double-blind , placebo-controlled study using an aqueous extract of noble kava cultivar ( st and ardised to 240 mg of kavalactones per day ) versus matching placebo in 210 currently anxious participants with diagnosed GAD who are non-medicated . The study takes place at two sites : the Centre for Human Psychopharmacology ( Swinburne University of Technology ) , Hawthorn , Melbourne , Australia ; and the Academic Discipline of Psychiatry ( The University of Queensl and ) based at the Royal Brisbane and Women ’s Hospital , Herston , Brisbane , Australia . Written informed consent will be obtained from each participant prior to commencement in the study . The primary outcome is the Structured Interview Guide for the Hamilton Anxiety Rating Scale ( SIGH-A ) . The secondary outcomes involve a range of scales that assess affective disorder symptoms and quality of life outcomes , in addition to the study of mediating biomarkers of response ( assessed via genomics and neuroimaging ) . Discussion If this study demonstrates positive findings in support of the superiority of kava over placebo in the treatment of GAD , and also is shown to be safe , then this plant-medicine can be considered a ’ first-line ‘ therapy for GAD . Genomic and neuroimaging data may reveal clinical response patterns and provide more evidence of the neurobiological activity of the plant extract . Trial Registration Information Clinical Trials.gov : NCT02219880 Date : 13 August 2014
Collectively , the literature reveals pre clinical and clinical evidence for various phytomedicines modulating GABA-pathways , with comparative anxiolytic effect to the current array of pharmaceuticals , along with good safety and tolerability profiles
Anxiety disorders are chronic and functionally disabling conditions with high psychological stress , characterised by cognitive symptoms of excessive worry and focus difficulties and physiological symptoms such as muscle tension and insomnia .
Gamma-aminobutyric acid ( GABA ) is an inhibitory neurotransmitter within the central nervous system and is a key target of pharmacotherapies in the treatment of anxiety .
Although current pharmaceutical treatments are often efficacious , they may cause undesirable side effects including cognitive decrements and withdrawal symptoms .
Plant-based " phytomedicines " may provide novel treatment options , to act as an adjunctive or alternative to existing anxiolytic medications .
As such , we conducted a systematic review to assess the current body of literature on anxiolytic phytomedicines and /or phytoconstituents .