1. Mesembrine is an alkaloid present in Sceletium tortuosum.
2. It has been shown to be an
extremely potent serotonin reuptake inhibitor, active at dosages as low as 100μg (micrograms).
3. It has also been shown to be a PDE4-inhibitor.3 Mesembrine may
contribute to the
antidepressant effects of kanna.