Amygdalin's neuroprotective effects on acute ischemic stroke in rats

Amygdalin, a key component of Peach kernel (semen persicae), also known as Taoren, is a traditional Chinese herb known for promoting blood circulation and alleviating blood stasis, especially in stroke treatment. This study aimed to explore the effects of amygdalin on neurological function in a rat model of acute ischemic stroke.

We induced acute ischemic stroke in Sprague-Dawley rats by occluding the right middle cerebral artery (MCAO) for 30 min, followed by reperfusion. Amygdalin was administered intraperitoneally at doses of 5 mg, 10 mg, and 20 mg per kilogram starting 24 h post-reperfusion for three consecutive days. We assessed cerebral infarct volume and neurological function, and analyzed the brain tissue using western blotting.

Amygdalin significantly reduced cerebral infarct volume resulting from MCAO in the 5-mg group (amygdalin 5 mg/kg; 18.02 ± 7.51 %), 10-mg group (amygdalin 10 mg/kg; 16.25 % ± 6.35 %) and 20-mg group (amygdalin 20 mg/kg; 12.26 ± 6.69 %) compared to the sham group (phosphate buffer saline; 28.99 ± 6.36 %) (all p < 0.001). The 10-mg and 20-mg groups showed significantly lower modified neurological severity scores (mNSS) than the sham group 5 days post-reperfusion (p < 0.05, p < 0.0001, respectively). Performance on the rotarod test also improved significantly in the 10-mg group (p < 0.05) and 20-mg group (p < 0.0001) compared to the sham group, and the distance traveled in the open-field test increased significantly in the 5-mg group (p < 0.001), 10-mg group (p < 0.0001) and 20-mg group (p < 0.0001) compared to the sham group. Western blotting revealed that the expression of uncleaved caspase-3 in the cerebral cortex was greater in the sham group compared to the control (without MCAO and treatment) and the 20-mg groups (both p < 0.05), while the expression of caspase-9 was greater in the control and 20-mg groups than in the sham group (both p < 0.05).

Intraperitoneal administration of amygdalin for three days reduced cerebral infarct volume and improved neurological function in a rat model of acute ischemic stroke. Additionally, amygdalin decreased uncleaved caspase-3 expression and increased caspase-9 expression. The findings suggest that amygdalin plays a neuroprotective role through modulation of apoptosis process via the intrinsic pathway.