Effects of Cape Cobra (Naja nivea) Venom and Its Isolated Protein on the Modulation of Platelet Activation.

The Cape cobra (Naja nivea), one of Africa's most lethal snakes, can cause rapid, life-threatening paralysis. However, the impact of this venom on platelet function and blood coagulation remains poorly understood. To address this gap, we investigated the enzymatic profiles and the impacts of N. nivea venom on multiple aspects of haemostasis using human whole blood. Our results illustrate that Cape cobra venom significantly increases clotting time in rotational thromboelastometry without affecting other coagulation parameters. This venom significantly inhibits platelet aggregation and activation yet does not exert cytotoxic effects on platelets. The venom was subsequently fractionated using reverse-phase high-performance liquid chromatography, and the most potent purified fraction was identified as a cytotoxin (three-finger toxin) through mass spectrometry. This purified fraction showed an inhibitory effect on platelet activity. These findings highlight that N. nivea venom can induce haemotoxicity in addition to neurotoxicity. Moreover, three-finger toxins may be promising candidates for bioprospecting to develop novel antithrombotic agents.