Natural products of marine origin exhibit extensive biological activities, and display a vital role in the exploration of new compounds for drug development.

Depression is a common mental disturbance that can be categorized as mild, moderate or severe. Mesemberine alkaloids, the main recognized phytoconstituents of some plants belonging to family Mesembryanthemaceae, are well-known as serotonin reuptake inhibitors. Therefore, the objective of this study is to evaluate the antidepressant activity of the alkaloidal fraction of Mesembryanthemum cordifolium L.f. (Aptenia cordifolia) roots, family Mesembryanthemaceae using forced swimming test, assisted by metabolomic analysis and in silico ligand-based and structure-based screening. Results showed that the alkaloidal fraction displayed an antidepressant activity superior to imipramine hydrochloride, a standard antidepressant agent. Nine alkaloids were annotated from the metabolomic analysis. Interestingly, among the dereplicated constituents, mesembrane (5) displayed strong binding affinity to SERT protein, which is slightly higher than the antidepressant drug venlafaxine. In conclusion, the alkaloidal fraction of the M. cordifolium (A. cordifolia) root exhibits an antidepressant activity which can be attributed in part to mesembrane (5).

Chemical investigation of Aptenia cordifolia roots extract, using chromatographic and spectroscopic techniques, resulted in isolation and identification of eight known compounds.

Plants are considered rich attractive sources for producing new bioactive compounds which exhibit a wide range of pharmacological activities. Family Aizoaceae is considered to be one of the South Africa largest succulent plant families, and it consists of four subfamilies named Sesuvioideae, Aizooideae, Ruschioideae, and Mesembryanthemoideae. Genus Aptenia consists of four species; A. cordifolia, A. geniculiflora, A. haeckeliana, and A. lancifolia, Besides Aptenia species are rich sources of natural metabolites from diverse chemical classes including oxyneolignans, flavonoids, sterols, lignans, amides and alkaloids with powerful anti-inflammatory activity. This review covers the literature until December 2018, providing a complete investigation of different isolated compounds from genus Aptenia with their available biological activities.