Protective effects of chrysin against the neurotoxicity induced by aluminium: In vitro and in vivo studies.

Chronic exposure to aluminium (Al) can contribute to the progression of several neurological and neurodegenerative diseases. Al is a metal that promotes oxidative damage leading to neuronal death in different brain regions with behavior, cognition, and memory deficits. Chrysin is a flavonoid found mainly in honey, passion fruit, and propolis with antioxidant, anti-inflammatory, and cytoprotective properties. In this study, we used an integrated approach of in vitro and in vivo studies to evaluate the antioxidant and neuroprotective effects of chrysin against the neurotoxicity elicited by aluminium chloride (AlCl3). In in vitro studies, chrysin (5 µM) showed the ability to counteract the early oxidative stress elicited by tert-butyl hydroperoxide, an oxidant that mimics the lipid peroxidation and Fenton reaction in presence of AlCl3 as well as the late necrotic death triggered by AlCl3 in neuronal SH-SY5Y cells. In vivo studies in a mouse model of neurotoxicity induced by chronic exposure to AlCl3 (100 mg/kg/day) for ninety days then corroborated the antioxidant and neuroprotective effect of chrysin (10, 30, and 100 mg/kg/day) using the oral route. In particular, chrysin reduced the cognitive impairment induced by AlCl3 as well as normalized the acetylcholinesterase and butyrylcholinesterase activities in the hippocampus. In parallel, chrysin counteracted the oxidative damage, in terms of lipid peroxidation, protein carbonylation, catalase, and superoxide dismutase impairment, in the brain cortex and hippocampus. Lastly, necrotic cells frequency in the same brain regions was also decreased by chrysin. These results highlight the ability of chrysin to prevent the neurotoxic effects associated with chronic exposure to Al and suggest its potential use as a food supplement for brain health.

Aluminum exposure promotes histopathological and pro-oxidant damage to the prostate and gonads of male and female adult gerbils.

Since the industrial revolution, all living beings have become susceptible to numerous sources of aluminum (Al) exposure. In addition to causing proven toxicity in many organs and systems, Al can also have estrogenic activity when absorbed by the body. The reproductive organs are commonly affected by environmental pollutants with estrogenic activity, but little is known about the effects of Al on the prostate and gonads. Therefore, the aim of this study was to evaluate the effects of subchronic Al exposure on the prostate and gonads of male and female adult gerbils. After 30 days of oral exposure to aluminum chloride (10 mg/kg/day), the animals were euthanized and the organs processed for cytochemical, ultrastructural, and biochemical assays. Ventral male prostates exposed to Al became hyperplastic and showed signs of cell aging. In addition, the male prostate showed decreased catalase (CAT) and superoxide dismutase (SOD) activity. The female prostate was structurally more affected than the ventral male prostate, since it presented hyperplasia and punctual foci of inflammation and prostatic intraepithelial neoplasia. However, CAT and SOD activities did not change in this gland. In the testis, Al promoted immature germ cell detachment and degeneration, as well as reduced CAT activity. In the ovaries, Al caused reduction in folliculogenesis and decreased SOD activity. Together, these results indicate that Al is toxic to the prostate and gonads of adult gerbils and that continuous exposure to this metal can impair the fertility of individuals of both sexes.

Neuroprotective Effect of Caryocar brasiliense Camb. Leaves Is Associated with Anticholinesterase and Antioxidant Properties.

Pequi (Caryocar brasiliense) is an endemic species from Brazilian Cerrado, and their fruits are widely used in regional cuisine. In this work, a crude hydroalcoholic extract (CHE) of C. brasiliense leaves and its resulting fractions in hexane (HF), chloroform (CF), ethyl acetate (EAF), and butanol (BF) were investigated for their antioxidant properties and anticholinesterase activities. The antioxidant properties were evaluated by free radical scavenging and electroanalytical assays, which were further correlated with the total phenolic content and LC-MS results. The acetylcholinesterase and butyrylcholinesterase inhibitory activities were examined using Ellman's colorimetric method. The LC-MS analysis of EAF revealed the presence of gallic acid and quercetin. CHE and its fractions, EAF and BF, showed anticholinesterase and antioxidant activities, suggesting the association of both effects with the phenolic content. In addition, behavioral tests performed with CHE (10, 100, and 300 mg/kg) showed that it prevented mice memory impairment which resulted from aluminium intake. Moreover, CHE inhibited brain lipid peroxidation and acetyl and butyryl-cholinesterase activities and the extract's neuroprotective effect was reflected at the microscopic level. Therefore, the leaves of pequi are a potential source of phenolic antioxidants and can be potentially used in treatments of memory dysfunctions, such as those associated with neurodegenerative disorders.

Antioxidant and Neuroprotective Properties of Eugenia dysenterica Leaves.

Eugenia dysenterica ex DC Mart. (Myrtaceae), popularly known as "cagaita," is a Brazilian plant rich in polyphenols and other antioxidant compounds. Aiming to evaluate the potential use of cagaita in pathologies involving oxidative stress, such as neurodegenerative disorders, this study investigated its antioxidant potential and neuroprotective effect. Electrochemical approaches and aluminium-induced neurotoxicity were used to determine respectively in vitro and in vivo antioxidant properties of cagaita. Voltammetric experiments were carried out in a three-electrode system, whose working electrode consisted of glassy carbon. Male Swiss mice were administered with AlCl3 orally at a dose of 100 mg/kg/day and with cagaita leaf hydroalcoholic extract (CHE) at doses of 10, 100, and 300 mg/kg/day. The redox behavior of CHE presented similar features to that of quercetin, a widely known antioxidant standard. CHE prevented mouse memory impairment which resulted from aluminium intake. In addition, biochemical markers of oxidative stress (catalase, superoxide dismutase activity, and lipid peroxidation) were normalized by CHE treatment. The potential of CHE to prevent aluminium-induced neurotoxicity was reflected at the microscopic level, through the decrease of the number of eosinophilic necrosis phenotypes seen in treated groups. Moreover, the protective effect of CHE was similar to that of quercetin, which was taken as the standard. These findings showed that the CHE of cagaita leaves has a potential to protect the brain against oxidative-induced brain damage.