Human tau E14 Mutation Induced Neurodegeneration in Drosophila melanogaster is Ameliorated by Developmental Supplement of Ashwagandha Root Extract

Withania somnifera (L.) Dunal (WS) known as Ashwagandha, has been used for centuries in Ayurvedic medicine to promote longevity and vitality. The use of herbal plant extract in treating several diseases has been documented from the very beginning in Ayurveda. The ethnopharmacological properties of this ‘‘Indian Ginseng’’ plant include adaptogenic, hypnotic, sedative, and diuretic. The root extract of WS has shown the properties of neuronal regeneration by stimulating axon and dendrite outgrowth in neurons in culture. Hence, in the recent decade Ashwagandha has been widely studied for its neuroprotective properties in many rodent models and cell lines. Here, we have used transgenic Drosophila model carrying human tauE14. The mutant protein codes for pseudophosphorylated Tau protein which is specifically expressed in photoreceptor neurons using GMR-Gal4 driver to induce photoreceptor neuronal degeneration. We treated these tauopathy mimicking flies with different concentrations of Ashwagandha to evaluate the neuroprotective/remedial effect of Ashwagandha at different stages of fly development. Our results demonstrated that Ashwagandha can rescue the neurodegeneration phenotype in Drosophila TauE14 disease model only when administered during development.