Antioxidant Blend of Curcumin and Broccoli Seed Extract Exhibits Protective Effect on Neurodegeneration and Promotes Drosophila Lifespan

Abstract

Antioxidants and related compounds are anti-inflammatory and exhibit great potential in promoting human health. They are also often considered to be important elements in the process of neurodegeneration. Here we describe a antioxidant blend of Curcumin and Broccoli Seed Extract (BSE). Flies treated with the blend exhibit extended lifespan. RNA-seq analysis of samples from adult fly brains reveals a wide array of new genes with differential expression upon treatment with the blend. Interestingly, abolishing expression of some of the identified genes in dopaminergic (DA) neurons does not affect DA neuron number. Taken together, our findings reveal an antioxidant blend that promotes fly longevity and exhibits protective effect over neurodegeneration, demonstrating the importance of antioxidants in health and pathology.

Keywords: Drosophila; antioxidant; neurodegeneration.

Figure 1.

The Effect of the Tested Blend on Drosophila Lifespan. A–F: Survival curve of both female and male flies treated with the following: Curcumin at 0.5, 1, and 2 g/L (A,D), BSE at 0.3, 0.6, and 1.2 g/L (B,E) mixture of Curcumin and BSE at 0.8, 1.6, and 3.2 g/L (C,F). G–J: Mean lifespan of flies treated with Curcumin, BSE, or the blend. Average 200 flies were analyzed for each group. Data were shown as mean ± SEM. P-values of significance (indicated with asterisks, * p<0.05, ** p<0.01, *** p<0.001) were calculated using one-way ANOVA with Bonferroni multiple comparison test among three groups or above. Prism and SPSS software were used to complete the statistical analysis.

Figure 2.

Treatment With the Tested Blend Exhibit Protective Effect on DA Neurodegeneration. A: A schematic illustration of the posterior DA neuron clusters (PPL1, PPL2, PPM1/2, and PPM3, green) in adult fly brains. Representative confocal images (B) and quantifications (C) of DA neuron number and fluorescent intensities in brains of 3-day-old flies with the indicated genotypes. Transgenic flies expressing RNAi for candidate genes like Hsp70Ba, Hsp70Aa, CecA1, Amy-p, and Drs in DA neurons were analyzed. Note that no significant difference is detected in the DA neuron number between control and most RNAi groups. Representative confocal images (D) and quantifications (E) of DA neuron number in brains of 20-day-old flies with the indicated genotypes. Transgenic flies expressing RNAi for candidate genes like Hsp70Ba, Hsp70Aa, CecA1, Amy-p, and Drs in DA neurons were analyzed. Note that no significant difference is detected in the DA neuron number between control and most RNAi groups except Amy-p-RNAi in PPL1 and Hsp70Aa-RNAi in PPM2. DA neuron number in PPM3 cluster for all RNAi groups except Amy-p increases. F: Transgenic flies expressing the RNAi for candidate genes like Hsp70Ba, Drs, and Mdr50 were exposed to paraquat. Note that the RNAi expression increases fly survival rate. Average 10-15 brains were analyzed for each genotype. Data were shown as mean ± SEM. P-values of significance (indicated with asterisks, * p<0.05, ** p<0.01, *** p<0.001) were calculated using one-way ANOVA with Bonferroni multiple comparison test among three groups or above. Prism and SPSS software were used to complete the statistical analysis.