Posted by Melanie-00 on December 15, 2010, at 20:09:16
In reply to Re: Non-prescription therapy for anxiety (GAD): ideas?, posted by Melanie-00 on December 15, 2010, at 15:51:38
I've crossed passionflower off of my list for now. Not comfortable with the level of research backing this herb. (See my other thread on this board - titled "High-quality, Standardized Passionflower in the US".) But in the course of looking more into passionflower, I came across this abstract, which would seem to give quite a bit of support to the experience of bleauberry, as discussed in an earlier post on this thread.
From: http://www.ncbi.nlm.nih.gov/pubmed/18066140/
Can J Physiol Pharmacol. 2007 Sep;85(9):933-42.
Effects of traditionally used anxiolytic botanicals on enzymes of the gamma-aminobutyric acid (GABA) system.
Awad R, Levac D, Cybulska P, Merali Z, Trudeau VL, Arnason JT.Ottawa-Carleton Institute of Biology, University of Ottawa, Ottawa, ON K1N6N5, Canada.
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.
poster:Melanie-00
thread:973355
URL: http://www.dr-bob.org/babble/alter/20101202/msgs/973656.html