Protective effect of catechin rich extract of Rhizophora mucronata against β-amyloid-induced toxicity in PC12 cells

Alzheimer's disease (AD) threatens to become the scourge of the 21st century, hence there is an urgent need for the exploration of multipotent drug in the treatment of AD. Rhizophora mucronata , tropical red mangrove has been widely used in traditional oriental medicine as astringent, antiseptic, antibacterial, anti-ulcerogenic and anti-inflammatory agent. The present study aimed to evaluate the neuroprotective effect of the catechin rich methanolic leaf extract of R. mucronata (MERM), against Aβ-induced neurotoxicity. Exposure of PC12 cells to Aβ (25–35) increased cellular oxidative stress, the number of apoptotic cells and caspase-3 activity ultimately leading to neuronal death. Pre-treatment with MERM (50 μg/ml) significantly attenuated cell death, decreased the level of intracellular reactive oxygen and nitrogen species thereby inhibiting lipid peroxidation and protein oxidation. MERM attenuated Aβ (25–35) induced apoptosis by stabilizing the mitochondrial membrane potential, and inhibiting caspase-3 activity. MERM also restored the antioxidant status of the Aβ (25–35) treated cells by effectively scavenging ROS/RNS species. HPTLC analysis of MERM illustrated the presence of (+)-catechin as major constituent. Results conclude that MERM effectively attenuated the neurotoxicity induced by Aβ-associated oxidative stress, implying that MERM can act as a potent drug for the treatment of AD.