From the aerial parts of Salsola oppositofolia, S. soda and S. tragus an alkaloid extract was obtained and tested to evaluate antioxidant and anti-cholinesterase activities. The in vitro study of the antioxidant activity by the DPPH method revealed a significant activity of Salsola alkaloid extracts with IC(50) values ranging from 16.30 microg/mL for S. oppositifolia to 26.17 microg/mL for S. tragus. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. S. tragus alkaloid extract exerted the highest inhibitory activity against AChE (IC(50) of 30.2 microg/mL) and BChE (IC(50) of 26.5 microg/mL). Interestingly, S. soda and S. oppositifolia exhibited a selective inhibitory activity against BChE with IC(50) values of 34.3 microg/mL and 32.7 microg/mL, respectively. Tetrahydroisoquinoline alkaloids were identified and quantified by GC/MS analysis.