aka kanna, kougoed, sceletium
Traditional uses
Native to South Africa, particularly the San and Khoikoi tribes. Traditionally used for mood modulation, stress relief, fatigue, social and spiritual purposes, used by hunter-gatherers to quench their thirst.1
Mechanism of action
Kanna supports emotional balance and calmness by helping maintain healthy serotonin activity. It is anxiolytic and eases depression. It is also neuroprotective, and supports memory and attention.
The major alkaloids are mesembrine and mesembrenone alkaloids, which act on serotonin reuptake. Mesembrenone also contains notable PDE4 inhibitory activity.2 Mesembrine alkaloids have been associated with alleviating anxiety and depression, reducing stress, and improving cognitive function.3
Evidence-based research
A double-blind, randomized, placebo-controlled, 3-armed study of 60 subjects, Kanna was shown to promote the increase of alpha 1 and alpha 2 spectral power in the brain. Enhancing alpha 1 promotes calm and can lessen depression. Enhancing alpha 2 supports memory. Kanna’s induced frequency changes to the brain have also been correlated with enhanced attention.4
Kanna has exhibited downregulation of SERT expression and serotonin reuptake, and upregulaton of VMAT-2, thereby supporting serotonin levels. It demonstrated mild inhibition of MAO-A.5 It has also been shown to inhibit 5-HT and PDE4,6 thus providing anxiolytic effects.7
Kanna extract high in delta7-mesembrenone has displayed rich polyphenol content and antioxidant properties. Kanna extract high in the constituent mesembrine has demonstrated cytoprotective and anti-inflammatory properties. It has also been shown to reduce adrenal glucocorticoid synthesis, which has beneficial implications for obesity and diabetes.8
In a randomized double-blind placebo-controlled study of 16 health university participants, a single dose of 25mg of Zembrin (a kanna extract) – containing a total mesembrine alkaloid content of 100 ug - attenuated amygdala activity to neutral and fearful faces, and amygdala-hypothalamus coupling was also reduced, thus demonstrating kanna’s anxiolytic potential.
In a randomized double-blind placebo-controlled study of 21 healthy older adults, 25mg of Zembrin once daily for three weeks was shown to significantly enhance cognitive set flexibility and executive function compared to placebo group. Positive changes to mood and sleep were also noted.9
In a randomized double-blind placebo-controlled study of sixty healthy participants (32 males and 28 females) between 50-80 years old, the effects of 25 mg or 50 mg taken daily for six weeks was observed. Scores on the Hamilton Anxiety Rating Scale (HAM-A) were significantly decreased for those in the 50 mg group.9
Safety in Pregnancy
Due to insufficient data, it is advisable to avoid using kanna during pregnancy and lactation.
General Safety
Use caution with other agents that support serotonin levels, inhibit monoamine oxidase, or significantly depress the central nervous system.
Dosage
Traditional masticatory uses included dosages of 500-1500mg of kanna. Teas have incorporated about 500mg per day. Dietary supplements in South Africa have included 50-680mg daily. Animal studies have used Zembrin (a kanna product) dosages ranging from 25-100mg, with varying alkaloid content. 100mg dosages used in a study including cats and dogs reported no adverse effects. 25mg dosages have been used in clinical studies and were reported to be well tolerated.9