In vitro evaluation of anti-Alzheimer effects of dry ginger (Zingiber officinale Roscoe) extract.

As the disease modifying therapies against Alzheimer's disease (AD) continue to exist as a major challenge of this century, the search for newer drug leads with lesser side effects is on the rise. A large number of plant extracts and phytocompounds are being actively pursued for their anti-Alzheimer effects. In the present study, the antioxidant activity, cholinesterase inhibition, anti-amyloidogenic potential and neuroprotective properties of methanolic extract of dry ginger (GE) have been evaluated. The extract contained 18 +/- 0.6 mg/g gallic acid equivalents of total phenolic content and 4.18 +/- 0.69 mg quercetin equivalents/g of dry material. GE expressed high antioxidant activity with an IC50 value of 70 +/- 0.304 microg/mL in DPPH assay and 845.4 +/- 56.62 microM Fe(II) equivalents/g dry weight in FRAP assay respectively. In Ellman's assay for the cholinesterase inhibitory activity, GE had an IC50 value of 41 +/- 1.2 microg/mL and 52 +/- 2 microg/mL for inhibition of acetyl- and butyrylcholinesterase respectively. Also, GE increased the cell survival against amyloid beta (Abeta) induced toxicity in primary adult rat hippocampal cell culture. Aggregation experiments with the thioflavin T binding studies showed that GE effectively prevented the formation of Abeta oligomers and dissociated the preformed oligomers. These findings suggest that methanolic GE influences multiple therapeutic molecular targets of AD and can be considered as an effective nontoxic neutraceutical supplement for AD.