Herbal extract

Mechanisms of action

Expected effects

Ref.

Camellia sinensis

Upregulation of tyrosine hydroxylase and dopamine release in the hippocampus and striatum

Enhancement of learning and memory

[59]

Bacopa monniera

Upregulation of glutamate decarboxylase and enhancement of the GABA_A receptor subunit synthesis in multiple brain regions

Reduction in hyperactivity, irritability, disorientation, anxiety, and depression

[60, 61]

Inhibition of acetylcholinesterase and/or activation of choline acetyltransferase in forebrain regions

Enhancement of sociability

[62]

Asparagus racemosus

Inhibition of monoamine oxidase and acetylcholinesterase in the hippocampus and cortex.

Reduction in depression, learning impairments, and memory deficits

[63]

Upregulation of BDNF synthesis and secretion in the hippocampus and frontal cortex

Enhancement of learning, memory, and sociability

[64]

Korean red ginseng

Upregulation of BDNF synthesis and secretion in multiple brain regions, particularly the amygdala and the frontal cortex

Enhancement of learning, memory, sociability, and motivational behavior

[65-67]

Oryza sativa

Upregulation of several hippocampal proteins, particularly the synaptic plasticity and neuronal trafficking markers α-synuclein and β-synuclein

Reinforcement of learning, memory, and adaptive behavior

[68]

Morus alba

Upregulation of GABA release in the whole brain

Reduction in hyperactivity, irritability, and repetitive behavior

[69, 70]

Prangos ferulacea (L.)

Modulation of cholinergic activity and blockade of L-type voltage-gated calcium channel in the gut

Enhancement of gut relaxation, eating behavior, and mood through the gut-brain axis

[71, 72]

Passiflora incarnata

Stimulation of GABA_A/benzodiazepine receptor

Reduction in hyperactivity, irritability, disorientation, anxiety, and depression

[73]

Ziziphus talanai (Blanco) Merr.

Preservation of Purkinje cells, granular layer, and molecular layer in the cerebellum

Enhancement of motor coordination and balance

[38]

Ginkgo biloba

Upregulation of dopamine and noradrenaline synthesis and release in the striatal and prefrontal regions

Enhancement of memory, mood, sociability, and motivational behavior

[74]

Clitoria ternatea L.

Down-regulation of acetylcholinesterase activity in the prefrontal cortex and hippocampus

Enhancement of learning, memory, and sociability

[75]