The objectives of this study were to determine phytochemical compositions, chemiluminescence antioxidant activities, and neuroprotective effects on PC12 cells for water, methanol, and 95% ethanol extracts of the air-dried fruit ofTerminalia chebulaRetzius. The water extract afforded the greatest yield, and total phenolic and tannin content. The methanol extract yielded the greatest total triterpenoid content. Based on four chemiluminescence antioxidant assays, the three extracts showed various degrees of antioxidant activity. The methanol extract showed good antioxidant activity based on the horseradish peroxidase-luminol-hydrogen peroxide (H₂O₂) assay. The water extract appeared to have good antioxidant activities in cupric sulfate-Phen-Vc-H₂O₂and luminol-H₂O₂assays. Pyrogallol-luminol assay showed the 95% ethanol extract to have good antioxidant activity. The methanol and water extracts presented neuroprotective activities on H₂O₂-induced PC12 cell death at 0.5–5.0 μg/mL. Further investigations are necessary to verify these activitiesin vivo.

The objective of this study was to determine phytochemical characteristics, chemiluminescence antioxidant capacities, and neuroprotective effects on PC12 cells for methanol extracts ofSpatholobus suberectus, Uncaria rhynchophylla, Alpinia officinarum, Drynaria fortunei,andCrataegus pinnatifida. TheC. pinnatifidaextract (CPE) afforded the greatest yield and total phenolic content. TheS. suberectusextract (SSE) yielded the greatest total flavonoid content. TheU. rhynchophyllaextract (URE) produced the greatest total tannin content, and theA. officinarumextract (AOE) produced the greatest total triterpenoid content. TheD. fortuneiextract, assayed using horseradish peroxidase-luminol-hydrogen peroxide (H₂O₂), and AOE using pyrogallol-luminol assay each exhibited better antioxidant activity than the L-ascorbic acid and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid did. The CPE, SSE, and URE presented neurogrowth effects and neuroprotective activities on H₂O₂-induced PC12 cell death at 0.5–5.0 μg/mL. The CPE represents a promising medicinal plant source for the treatment of H₂O₂-induced neurodegenerative disease, because of its useful phytochemical characteristics.

Alzheimer’s disease (AD) is one of the most prevalent severe neurological disorders afflicting our aged population. The study was to determine neuroprotective effects of the Terminalia chebula extracts and ellagic acid by using beta-amyloid25-35 (Ab25-35)-induced cell cytotoxicity in undifferentiated rat pheochromocytoma (PC12) cellular model. The methanolic and water extracts of T. chebula and ellagic acid exhibited the strongest neuroprotective activity against Ab25-35-induced undifferentiated PC12 cell deaths at 0.5–5.0 ug/ml. The ellagic acid also exhibited the partial neuroprotective activity against H2O2-induced undifferentiated PC12 cell deaths at 0.5–5.0 ug/ml. The methanolic and water extracts of T. chebula and ellagic acid protected undifferentiated PC12 cells from the damaging effects of Ab25-35 in several ways: (1) by securing cell viability; (2) by suppressing reactive oxygen species production; and (3) by eliminating calcium ion influx. The T. chebula extracts maybe represent a promising plant-source for medicine in the application of the treatment of AD. Further investigation of the ellagic acid is necessary to verify the neuroprotective efficacy and mechanisms in vivo.