Biological and neuroprotective activity of Thai edible plant extracts

Polyphenols present in plant-diets as natural antioxidant substances play important roles in prevention of Alzheimer's disease associated with deposits of amyloid beta (A beta) peptide. A beta is peptide pathogenesis which increases reactive oxygen species production in neuron, resulting cell death. This study aimed to quantify various biological and neuroprotective activities in some varieties of Thai edible plants. Total phenolic content (TPC), flavonoid content (TFC), antioxidants, and other neuroprotective activities work against A beta aggregation in human neuroblastoma cells (SK-N-SH) are all investigated. Cytotoxicity was also analyzed. The highest TPC and TFC were observed in an extract from Anacardium occidentale L. leaves. The highest antioxidant activity by DPPH radical scavenging and Ferric reducing antioxidant power assays was found in the extracts from leave and flower of Careya sphaerica Roxb. In the SK-N-SH cell, the high protective effect of Anacardium occidentale L. significantly ameliorated cytotoxic effects induced by H2O2. Leaves of Anacardium occidentale L. demonstrated to be the most active extract against A beta fibril induced by A beta peptide aggregation. The results conclude that Anacardium occidentale L. contains some antioxidant compounds that can potentially be used to treat neurodegenerative diseases as well as other plants.