Mulberry fruits are rich sources of bioactive phytochemicals with potential cardiovascular-relative bioactivity properties. In the present study, phenolic/alkaloid-enriched extracts from black (Morus nigra) and white (Morus alba) mulberries were chemically characterized and evaluated for their anti-atherogenic and antiplatelet activities in vitro. LC-HRMS analysis revealed distinct phytochemical profiles, with the black mulberry extract (BlackM) being characterized by a high abundance of anthocyanins, predominantly cyanidin- and pelargonidin-based glycosides, whereas the white mulberry extract (WhiteM) was particularly rich in pyrrolidine alkaloids, including morusimic acid isomers. Both extracts also contain flavonoids and phenolic acids, such as rutin, quercetin derivatives, and chlorogenic acid derivatives. BlackM markedly increased the resistance of low-density lipoprotein (LDL) to Cu²⁺-induced oxidation, whereas WhiteM more effectively inhibited the propagation phase of lipid peroxidation and significantly suppressed arachidonic acid-induced platelet aggregation. BlackM induced a modest, albeit non-significant, reduction in neutrophil extracellular trap (NET) formation. To the best of our knowledge, this is among the first studies to comparatively investigate the effects of black and white mulberry extracts on LDL oxidation, platelet aggregation and NETs formation. Overall, these findings support the potential use of mulberry-derived phytochemicals as functional food ingredients and nutraceuticals for the prevention of atherothrombotic cardiovascular disease.