Ação neuroprotetora e potencial antioxidante do extrato hidroalcoólico e frações do cajuizeiro anacardium microcarpum ducke no modelo de drosophila melanogaster

Abstract

The plant Anacardium microcarpum Ducke popularly known as cajuizeiro is found in natural populations of various ecosystems of the Northeast of the country, mainly in the Cerrado. Become Ethnopharmacological studies found astringent activity, antidiabetic, anti-inflammatory, antirheumatic and antiulcerogenic for the genus Anacardium. However, there is lack of studies focusing on the neuroprotective and antioxidant potential of this species. This study aims to evaluate the neuroprotective effect and antioxidant potential in vivo and in vitro of the hydroalcoholic extract and two different fractions: methanol and acetate of the Anacardium microcarpum. All tests were performed with adult flies (both sexes and 0-4 days). For the toxicity test 25 flies were treated with standard medium containing 0, 1 and 10mg/ml extract and fractions for 5 days. For the tests of neuroprotection, six groups of 25 flies were treated for 72 hours with a solution of 1% sucrose (control) or Paraquat (PQ 5mM) in the presence or absence of extract and fractions (1 to 10 mg / ml). At the end of the treatments was analyzed the number of dead flies, behavioral changes, production of hydroperoxides and antioxidant enzymes. It was also evaluated the antioxidant effects in vitro and quantification of phenolic compounds. Toxicity tests have shown that treatment with extract and fractions did not affect the survival and showed no cytotoxic effect. On the other hand, PQ 5mM induced a increase of the 85% in mortality and locomotor deficit. This effect was completely reversed by co-treatment with the hydroalcoholic extract and methanol fraction. The PQ also induced oxidative damage, being reversed to the control level when co-treated with hydroalcoholic extract and methanol fraction. The fraction of acetate 10mg/ml increased the activity of GST, SOD and CAT. The fraction of methanol 10mg/ml stimulated CAT activity. Enzymes such as CAT and SOD are essential for intracellular defense system and promote cellular protection against potentially induced reactive molecules. GST is an enzyme of phase II detoxification metabolism acting in the excretion of xenobiotics. In vitro, the % scavenging of ABTS radical was similar between extracts. The acetate fraction showed higher reducing potential of Fe3+ and nearly three times the levels of phenolic compounds. In conclusion, this study demonstrated that the hydroalcoholic extract and methanol fraction were more effective antioxidants in vivo, although the acetate fraction has shown higher levels of phenolic compounds and antioxidant potential in vitro. This study reflects the presence of neuroprotective compounds, especially the biological effects of cajuizeiro as a potential therapeutic agent for neurodegenerative diseases.