Molecular Effects of Cinnamon Bioactive Compounds for Neuroprotection in D. Melanogaster

We previously reported that treatment with cinnamon bioactive compounds delay paralysis and extend lifespan in C. elegans and D. melanogaster. Here, we investigated the molecular effects of the bioactive compounds (10–25 mg/ml of sodium benzoate, cinnamic acid, cinnamaldehyde, ethyl cinnamate, and cinnamyl acetate) in D. melanogaster models of neurodegeneration. Alzheimer's and Parkinson's disease‐like neurodegeneration was induced in the flies by the UAS/GAL4 tissue specific expression system. Neurotoxicity was modeled by exposure to the neurotoxin rotenone (0.5 M). Samples of flies were frozen on days 0, 10, 15, and 30. We evaluated the catalytic activity of two important antioxidants, SOD and catalase. Additionally, we assessed the extent of lipid peroxidation in the flies by quantifying lipid hydroperoxides. For amyloid‐ beta induced neurodegeneration, we observed that treatment with the compounds modulated the activity of both SOD (FC=.89–1.66) and catalase (FC=0.89–2.44). The levels of lipid hydroperoxides were also variable when compared to control (FC=0.84–2.56). We also measured the level of SOD mRNA in the flies and found fold changes between 0.45–4.60. For flies with a‐synuclein‐induced neurodegeneration, SOD activity was higher in all treatment groups compared to control (FC=1.11–1.98); mRNA levels ranged from 1.0–4.0 relative to control. We also observed the catalytic activity of catalase in the flies was also modulated between treatment groups (FC=0.81–2.48). In flies that were treated with rotenone, the catalytic activity of SOD (FC=0.32‐.67) and catalase (.50–1.01) was reduced for all treatment samples. The mRNA levels of SOD ranged from 0.002–1.059 relative to control. Lipid hydroperoxides were reduced after treatment with cinnamyl acetate (FC=0.80) and cinnamic acid (FC=0.81), while elevated levels were observed in cinnamaldehyde (FC=1.24) and ethyl cinnamate (FC=1.19) treatment groups. These results suggest that cinnamon bioactive compounds may be neuroprotective and extend lifespan through the modulation of critical antioxidant pathways.