Interactions of Magnolia and Ziziphus extracts with selected central nervous system receptors

Biological activity and toxicity of the Chinese herb Magnolia officinalis Rehder & E. Wilson (Houpo) and its constituents

“…In vitro radioligand binding and cellular functional assays revealed that Magnolia bark supercritical carbon dioxide extracts interact with the adenosine A1 receptor, dopamine transporter, and dopamine D5 receptor (antagonist activity), serotonin receptors (5-HT1B and 5-HT6, antagonist activity) and the GABA benzodiazepine receptor at a concentration of 100 μg/ml or lower (Koetter et al, 2009). Honokiol and magnolol exhibit neurotrophic function by enhancing hippocampal ACH release, and magnolol modulates the central serotonergic activity (Nakazawa et al, 2003).…”

Magnolia Extract, Magnolol, and Metabolites: Activation of Cannabinoid CB2 Receptors and Blockade of the Related GPR55

“…1,2 The pharmacological effects were proposed to be mainly mediated by the neolignans honokiol (1), 4-methoxyhonokiol (2), magnolol (3), and (R)-8,9-dihydroxydihydromagnolol (4). 2−4 An intensive search for their molecular targets revealed an interaction of honokiol and magnolol with a variety of enzymes and receptors at micromolar concentrations.…”

“…9 Furthermore, the neolignans share structural similarity with some highly potent synthetic CB receptor ligands, such as CP55,940 (5), but also plant-derived biaryl CBs. 8,10,11 CB receptors belong to the G protein-coupled receptor (GPCR) superfamily and are divided into two distinct subtypes designated CB 1 and CB 2 , both of which are linked to an inhibition of adenylate cyclase. 12 CB 1 activation mediates analgesia, stimulation of appetite, and euphoria, among other effects.…”

Adenosine Signaling in Anxiety

“…Conversely, adenosine receptor antagonism is responsible for the anxiogenic responses elicited by moderate to high doses of caffeine, theophylline (Imaizumi et al, 1994;Kulkarni et al, 2007;Pechlivanova et al, 2010), or other adenosine receptor antagonists (Imaizumi et al, 1994;Florio et al, 1998;Koetter et al, 2009;Zhao et al, 2009) in rodents and humans (Lara, 2010). It has also been suggested that the anxiolytic effect of the adenine derivative BWA78U in the LD box involves adenosine receptor activation (Willard et al, 1990), and that adenosine is the active principle in the Longan Arillus extract (Okuyama et al, 1999), a traditional Asian remedy for mild anxiety.…”

“…Yet another study showed the both CPA and CPX (A 1 antagonist) decreased the anxiolytic activity of ifenprodil (a glutamate NMDA antagonist; Fraser et al, 1996). Likewise, antagonism of A 1 receptors has been implicated in the actions of magnolia and ziziphus extracts, traditional Eastern treatment of mild anxiety and nervousness (Koetter et al, 2009). Where pharmacology has failed to illustrate a consistent role for the A 1 receptor in anxiety-like behavior, genetic methods have yielded a much clearer picture.…”