A comprehensive review in Phytotherapy Research journal identified 10 herbal remedies (phytomedicines) with preclinical and clinical evidence of modulating GABA‐pathways with similar or stronger anti-anxiety effect as the currently available pharmaceuticals.
Gamma-aminobutyric acid (GABA) is the inhibitory neurotransmitter that counteracts the action of the excitatory neurotransmitter glutamate. Many pharmacologic agents used for the treatment of anxiety disorders target the GABA system.
Centella asiatica (Gotu cola/kola, pennywort) is a native Asian plant used commonly as a whole plant extract in Indian Ayurvedic and Chinese Traditional Medicine. Modern indications are for dermatotic, antimicrobial, nociceptive, cognition‐enhancing, anxiolytic, and anti‐depressive purposes. The main constituents are triterpenoid glycogens (saponins), sterols, flavonoids, tannins, and stearic acids. Investigations of constituents have mainly involved the saponins brahmoside and brahminoside and the asiatic and ursolic acids.
Humulus lupulus (Hops, Cannabaceae) has flowering cones with sedative/
hypnotic, antibacterial, anti‐inflammatory traditional indications.
The plant is mainly cultivated worldwide for alcoholic beverages
derived from malted grain, namely beer. Modern medicinal indications exist for anxiety and insomnia, mostly associated with principal terpenoid and flavonoid alpha and beta acid constituents, such as humulene and myrcene.
The ginkgo tree (Ginkgo biloba) is one of the oldest angiosperm species,
with the nuts and leaves being used for a range of therapeutic effects. Active constituents are mainly flavonoids quercetin and catechin, unique terpenoids ginkgolides and bilobalides, and proanthocyanidins. Constituents from the leaves as standardised extract have potent neuroprotective and anti‐apoptotic properties, as well as vasculatory benefits via nitric oxide (NO)
Matricaria recutita/Matricaria chamomilla (Chamomile, German chamomile) is a flowering plant widespread throughout Eurasia and has been utilised for centuries, mainly as a tea, for calming/sedative effects. The bioactive constituents include sesquiterpenes, coumarins (herniarin, umberlliferone, among others), and flavonoids including apigenin, luteolin and rutin, and phenylpropanoids.
Melissa officinalis (lemon balm) is holds longstanding use for millennia. It is native to Eurasia as a member of the Lamiaceae (mint) family, with a number
of phytochemicals including phenolic acids, terpenes, rosmarinic and caffeic acids, eugenol acetate, and tannins. Indications are for antibacterial,
anti‐stress, hypnotic, and gastrointestinal symptom benefit.
Passiflora incarnata (Passion flower) is native to the Americas having been utilised for millennia for conditions of nervousness, anxiety, and sleep issues
The main identified constituents include alkaloids such as chrysin, flavonoids such as schaftoside, isoschaftoside and swertisina, and phenolic compounds.
Kava (Piper methysticum) is a plant native to the South Pacific, where the
roots have been used in traditional medicine for a range of conditions via
its anxiolytic, nootropic and neuroprotective, nociceptive, and dysphoric
actions. The chief bioactive constituents are the six lipophilic kavalactones, of which kawain and dihydrokawain are evidenced to exert the strongest anxiolytic activity.
Scutellaria lateriflora (Scullcap, Blue Skullcap) is native to America and Europe with use in Native American practice and Western medicine for anti‐anxiety, relaxant, and antispasmodic effects. Identified chief bioactive
constituents include a number of flavonoids: scutelaterin A, baicalin,
bacalein, apigenin, oroxylin A, and wogonin.
Valeriana officinalis (Valerian) is a perennial plant native to mainly Europe, with the root extract utilised medicinally for millennia as a sedative and anxiolytic. The bioactive constituents include alkaloids, flavonones, and terpenes.
Withania somnifera (Ashwagandha, Indian ginseng, winter cherry) is an alkaloid‐rich plant from the nightshade family, traditionally utilised in Indian Ayurvedic medicine for the adaptogenic or “rasayana” properties of the root extract.The constituents include glycosides (withanolides), alkaloids
(withanine, ashwagandhine, ashwaganidhine, and somniferine), and steroidal
triterpenoid lactones, which are related to the ginsenosides, hence the common name “Indian ginseng”.