Extratos de folhas e sementes de Syzygium cumini (L.) Skeels protegem os linfócitos do dano oxidativo

Abstract

The use of medicinal plants for the purpose of treatment / prevention of diseases is common practice among the population, and has been associated with a lower risk for the development of several pathologies. Among these plants, Syzygium cumini (L.) Skeels (S. Cumini) stands out, popularly known as jambolão, whose leaves, seeds and fruits are widely used due to their relevant pharmacological activities such as: hypolipidemic, antioxidant, hypoglycemic, anti-inflammatory and antimicrobial. Considering the few studies on S. cumini in relation to oxidative changes in lymphocytes and the increasing use of medicinal plants by the population, the objective of this work was to evaluate the antioxidant activity and the protective effect of aqueous extracts of leaves and seeds of S. cumini LASc, SASc, respectively) as well as gallic acid (GA) used as a positive standard in an oxidative stress model promoted by 2,2-azobis-2-amidinopropane (AAPH) in human lymphocytes in vitro. The antioxidant activity of extracts and GA was evaluated by iron reducing power (FRAP), scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), and hydrogen peroxide (H2O2) besides, thiol-peroxidase-like activity. Lymphocytes obtained from blood samples from healthy donors were incubated with LASc and SASc (50, 100 and 500 μg/mL) and GA (100 μM) for 30 min at 37 ° C followed or not by incubation with AAPH (1 MM) for 2 h at 37 ° C. Afterwards, enzymatic activities, oxidative stress parameters and cytotoxicity were evaluated. Our results suggest that, in addition to LASc and SASc exhibit antioxidant activity against the free radicals tested, these extracts were also able to prevent the increased activity of Ecto-nucleoside triphosphate diphosphohydrolases (NTPDase), adenosine deaminase (ADA) and inhibition of Acetylcholinesterase activity (AChE) promoted by the AAPH. In addition, LASc, SASc and GA protected the protein (P-SH) groups from oxidation, decreased lipoperoxidation, nitric oxide (NO) production, and improved cell viability in the lymphocytes tested. In this way, it is possible to suggest that LASc and SASc are able to act on the purinergic and immune system, being able to modulate the activity of the enzymes NTPDase, ADA, AChE. In this way, the extracts of S. cumini showed great importance in maintaining levels of ATP, adenosine (Ado) and acetylcholine (ACh), exerting a possible anti-inflammatory property.