Evaluation of oxidative stress indicators as toxicity parameters after chronic exposure of Drosophila melanogaster to free curcumin and curcumin-loaded nanocapsules.

We investigated a possible toxic effect induced by chronic exposure to free curcumin and curcumin-loaded nanocapsules in Drosophila melanogaster, enabling safe applications. Flies of both sexes were divided into groups: control group; free curcumin at concentrations of 10, 30, 100, 300, 900, and 3000 µM; curcumin-loaded nanocapsules at concentrations of 10, 30, 100, and 300 µM. Initially, the diet consumption test was evaluated in flies exposed to different concentrations. During the 10-day treatment, the flies were evaluated for percentage survival. After the treatment, behaviors (geotaxis negative and open field), acetylcholinesterase activity (AChE), and oxidative stress parameters (reactive species (RS) and thiobarbituric acid reactive substances (TBARS) levels, Glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) enzymes activity, erythroid-derived nuclear factor 2 (Nrf2) immunoreactivity, and cellular metabolic capacity, were assessed. No significant difference in diet consumption, indicating that the flies equally consumed the different concentrations of free curcumin and the curcumin-loaded nanocapsules. Was observed that free curcumin and curcumin-loaded nanocapsules increased survival, locomotor and exploratory performance, decreased AChE activity, RS and TBARS levels, increased GST, SOD and CAT activity, Nrf2 and viable cells compared to the control. The chronic treatment did not cause toxicity, suggesting that nanoencapsulation of curcumin could be explored.

Bisphenol A exposure is involved in the development of Parkinson like disease in Drosophila melanogaster.

The pathogenesis of Parkinson's disease has not been fully clarified yet but its cause is known to be multifactorial. One of these factors is oxidative stress induced by exposure to environmental toxifiers. We studied the effect of Bisphenol A (BPA) at concentrations of 0.5 mM and 1 mM, the concentration of 1 mM corresponding to Lowest Observed Adverse Effect Level (LOAEL) for humans in adult Drosophila melanogaster. The BPA induced oxidative stress was established by increased levels of malondialdehyde, reactive species, and decreased activity of the antioxidant enzymes superoxide dismutase and catalase, and detoxificant enzyme glutathione-S-transferase. Associated with oxidative stress, there was a reduction of acetylcholinesterase activity and a reduction of dopamine levels, which are related to the decreased locomotion activity as observed in negative geotaxis, open field and equilibrium behaviors in group exposed to 1 mM of BPA. Oxidative stress also impaired mitochondrial and cellular metabolic activity in the head causing an increase in the mortality of flies exposed to both BPA concentrations. Therefore, BPA induced Parkinsonian-like changes in flies and it is possible that the oxidative stress is closely related to this effect, providing new insights for future studies.