Ginsenoside Rb1 inhibit apoptosis in rat model of Alzheimer's disease induced by Aβ_1-40

Alzheimer's disease (AD) is the most common form of dementia and lacks disease-altering treatments. Ginsenoside Rb1 (GsRb1), the key active compounds of ginsenoside found in ginseng. The present study aimed to determine whether GsRb1 could prevent cognitive deficit and take neuroprotective effects in Aβ_1-40-induced rat model through apoptotic signaling pathway. Injection of soluble Aβ_1-40 into the hippocampus caused impairment in learning and memory. Daily administration of Rb1 (12.5, 25, and 50 mg/kg, i.p.) for 14 consecutive days. All rats were tested for their capabilities of spatial navigation and memorization by Morris water maze. Apoptosis was tested using TUNEL staining in hippocampus neuronal cells. RT-PCR, immunohistochemical staining and western blotting were employed to confirm the expressions of Bcl-2, Bax and Cleaved Caspase-3. The results showed that Rb1 administration could prevent cognitive deficit, and significantly decreased the levels of Bax and Cleaved Caspase-3 meanwhile up regulation the level of Bcl-2 in the hippocampus. We suggest that GsRb1 may be effective for preventing or slowing the development of Alzheimer's disease, which improving cognitive and memory functions by inhibiting the levels of pro-apoptosis mediators and improving the levels of anti-apoptosis mediators in the rat brain.