Mesembrine is an alkaloid that has been found in S. tortuosum and has serotonin (5-HT) reuptake inhibitory activity.1 It selectively binds to the 5-HT transporter (SERT; IC50 = 4.3 µg/ml) over a variety of receptors (IC50s = 148->750 µg/ml).2 Mesembrine inhibits the reuptake of 5-HT in vitro (Ki = 1.4 nM). It has analgesic effects in the hot plate test when administered at a dose of 20 mg/kg but does not induce a preference in the conditioned place preference test (CPP).2,3
1.Krstenansky, J.L.Mesembrine alkaloids: Review of their occurrence, chemistry, and pharmacologyJ. Ethnopharmacol.19510-19(2017) 2.Harvey, A.L., Young, L.C., Viljoen, A.M., et al.Pharmacological actions of the South African medicinal and functional food plant Sceletium tortuosum and its principal alkaloidsJ. Ethnopharmacol.137(3)1124-1129(2011) 3.Loria, M.J., Ali, Z., Abe, N., et al.Effects of Sceletium tortuosum in ratsJ. Ethnopharmacol.155(1)731-735(2014)