The Ameliorative Effect of Ashwagandha- Withania somnifera (L.) Dunal on park25 Induced Neurodegeneration in Drosophila melanogaster Parkinson’s Disease Model

Ashwagandha - Withania somnifera (L.) Dunal is a perennial shrub belonging to the family Solanaceae. Ashwagandha has been used for over 3000 years in traditional Indian Ayurveda for treatment of various neurological, and stress disorders. The root of Ashwagandha (ASH) is regarded as a tonic, aphrodisiac, narcotic, diuretic, anthelmintic, astringent, thermogenic and stimulant. Ashwagandha with other herbal decoctions was recognized to treat Kampavatha (Parkinson’s Disease) since 18th century. With this wide array of ethnopharmacological relevance, Ashwagandha has been recognized as one of the prominent complementary and alternative medicine to treat many neurodegenerative diseases like Alzheimer’s (AD) and Parkinson’s disease (PD). There is a prominent increase in the cases of AD and PD all over the world and it demands the requirement of complementary and alternative herbal remedies with no/minimal side effects. Many genetic factors are responsible for the onset and progression of PD. Loss-of-function mutations in the parkin gene are a major cause of early onset of autosomal recessive juvenile parkinsonism (AR-JP). Drosophila park25 loss of function mutants exhibit significantly increased number of mitochondria-endoplasmic reticulum contacts and a significantly decreased number of dopaminergic neurons in the adult brain which is the main cause of PD condition. Several studies have demonstrated the ability of Ashwagandha in imparting neuroprotection, improved locomotory ability, memory and learning abilities. The challenge lies in scrutinizing the mechanism and the pathways involved in the neuroprotective properties of this well-known herb. Here in our study, we test the possible neuroprotective effect of Ashwagandha on park25 mutants of Drosophila using lifespan analysis and climbing disability as a disease marker. Parkinson’s mimicking flies were administered with aqueous extraction of Ashwagandha-root mixed with the fly food and subjected to negative geotaxis assay. We observed that there is a prominent increase in the climbing ability in park25 treated flies compared to its age-matched untreated flies. This is the first report showing that, aqueous extraction of Ashwagandha-root extract was able to ameliorate the disease phenotype in the park25 Drosophila Parkinson’s disease model.

olf413 Gene Controls Taste Recognition, Preference and Feeding Activity in Drosophila melanogaster

Recognition and responsiveness to food taste becomes a crucial event in foraging and feeding behaviour of an organism. Adjusting the feeding behaviour through a sophisticated and robust taste system is critical to fulfil their nutritional needs and facilitate its survival in environment. Palatability of food sources depends on the sensory and motor cues provided by the brain, in co-ordination with the other body systems to enable decisive feeding. Drosophila melanogaster is an apt model organism to decipher these behavioural paradigms. Octopamine a neurotransmitter, is required in regulation of feeding behavioural responses. olf413, a paralogue of TH, is a gene predicted for its involvement in octopamine biosynthesis. The biological function of this gene is yet to be unravelled. Here we propose this gene function in taste recognition, food preference and feeding activity. We test the olf413 loss of function mutants for food preference between two fruit extracts using CAFE and horizontal box methods. In our study we have used olf413 gene disruption strain, olf413MI02014 homozygous and in transheterozygous condition with another allele isolated in our lab, olf413SG1.1. The results show that olf413 mutants display a severe phenotype in feeding behaviour and there is an allele specific phenotypic distinction between the two strains. Thus implying that olf413 gene function is required for taste recognition, starvation driven initiation and execution of feeding behaviour of the flies.

Male- and female-specific variants of doublesex gene products have different roles to play towards regulation of Sex combs reduced expression and sex comb morphogenesis in Drosophila.

Sexually dimorphic characters have two-fold complexities in pattern formation as they have to get input fromboth somatic sex determination as well as the positional determining regulators. Sex comb development in Drosophila requires functions of the somatic sex-determining gene doublesex and the homeotic gene Sex combs reduced. Attempts have not been made to decipher the role of dsx in imparting sexually dimorphic expression of SCR and the differential function of sex-specific variants of dsx products in sex comb development. Our results in this study indicate that male-like pattern of SCR expression is independent of dsx function, and dsxF must be responsible for bringing about dimorphism in SCR expression, whereas dsxM function is required with Scr for the morphogenesis of sex comb.