Neuromodulatory potential of aqueous extracts of Cumin, Cinnamon: evidence from rotenone model in Drosophila: Implications to Parkinson’s Disease

Abstract

AIM: Spice extracts and their bioactive molecules have been well recognized for their innumerable beneficial effects against various chronic diseases. However, experimental data regarding their potential to abrogate oxidative stress and neurotoxicity in animal models of Parkinson’s disease (PD) are rather limited. In the current study, we aimed to assess the neuromodulatory potential of aqueous extracts of spices viz., cumin and cinnamon and their bioactives (Cuminaldehyde (CU) and Cinnamaldehyde (CN) using a neurotoxin model of Drosophila.

MATERIALS AND METHODS: Adult male flies (Oregon K) were fed medium enriched (0.1–0.2%) with aqueous extract of Cumin or Cinnamon and their bioactives CU/ CN with without ROT (500 µM) for 7 days. The propensity of extracts or biaoctives to protect flies against ROT-induced lethality, locomotor phenotype, oxidative stress and neurotoxicity was determined. Both the extracts significantly protected the flies against ROT-induced locomotor phenotype and mortality. CU and CN-enrichment markedly reduced the mortality induced by ROT, improved the locomotion and significantly abrogated the degree of oxidative impairments. Both the bioactives also augmented the antioxidant enzyme activities and restored ROT-induced mitochondrial dysfunctions. Interestingly, ROT -induced elevation of the activity of acetylcholinesterase and depletion of dopamine levels were also restored. Further, flies given prophylactic treatment with bioactives exhibited significant resistance to an acute challenge to Paraquat (PQ). In a parallel study, both the bioactives were found to significantly delay the onset of locomotor deficits among ROT-stressed flies besides extending their survival.

CONCLUSION: We hypothesise that the efficacy aqueous extract and their bioactives to attenuate ROT-mediated neurotoxicity may be largely related to the combined antioxidant activity of bioactives resulting in improved locomotor performance , abrogation of oxidative stress and mitochondrial dysfunction. Based on these results, we propose that cumin and cinnamon extracts may be exploited as therapeutics against PD and other neurodegenerative diseases.