3-(甲基硒基)-L-丙氨酸又叫L-硒甲基硒代半胱氨酸，常用作硒营养强化剂。它是第21种人体必需氨基酸—L-硒代半胱氨酸的硒甲基化衍生物，它广泛存在于黄芪、大蒜、洋葱和椰菜等植物以及富硒酵母中，具有化学结构明确、毒性小、生物利用率高、补硒效果好等优点，不仅对多种肿瘤（如乳腺癌，前列腺癌，肝癌等）有预防作用，而且对癌症治疗有辅助作用，具有广阔的应用前景。 2002年，硒-甲基硒代半胱氨酸被美国FDA认定为最新一代硒源类饮食补充剂；2009年3-(甲基硒基)-L-丙氨酸被我国卫生部批准为新型营养强化剂（食品添加剂新品种2009年第11号公告）。
2-氨基-3-甲基硒基丙酸是DMBA诱导的乳腺肿瘤的抑制剂。
Se-Methylselenocysteine (100-400 μM; 3 days) induces apoptosis in SKOV-33 cells. Se-Methylselenocysteine (100-400 μM; 3 days) induces caspase-3 mediated apoptosis.
Apoptosis Analysis
Western Blot Analysis
Se-Methylselenocysteine (0.2 mg/mouse; p.o.; daily for 14 days) potentiates the antitumour activity of CDDP and Cyclophosphamide in nude mice bearing human FaDu and A253 head and neck xenografts. Alzheimer's disease (AD) mice are treats with Se-Methylselenocysteine (0.75 mg/kg BW per day) in their drinking water for 10 months. Se-Methylselenocysteine reduces oxidative stress and neuro-inflammation; Se-Methylselenocysteine modulates the distribution and levels of several metal ions; Se-Methylselenocysteine decreases amyloid-β peptide (Aβ) generation by inhibiting the expression of its precursor protein APP and β-secretase (BACE1), and attenuates tau hyperphosphorylation and neurofibrillary tangles (NFT) formation via promoting protein phosphatase 2A (PP2A) activity, thereby preserving synaptic proteins and neuron activities and finally improving spatial learning and memory deficits in AD model mice.