Protective effect of Melissa officinalis aqueous extract against Mn-induced oxidative stress in chronically exposed mice.
Manganese (Mn) is an essential element for biological systems; however occupational exposure to high levels of this metal may lead to neurodegenerative disorders, resembling Parkinson's disease (PD). While its mechanisms of neurotoxicity have yet to be fully understood, oxidative stress plays a critical role. Thus, the main goal of this study was to investigate the efficacy of aqueous extract of Melissa officinalis in attenuating Mn-induced brain oxidative stress in mice. Sixteen male mice were randomly divided into two groups and treated for 3 months: the first group consumed tap water (control group) and the second group was treated with Mn (50 mg/kg/day for habituation during the first 15 days followed by 100 mg/kg/day for additional 75 days) in the drinking water. After 3 months both groups were sub divided (n=4 per group) and treated for additional 3 months with Mn and/or M. officinalis in the drinking water. The first group (control) was treated with water and served as control; the second group (M. officinalis) was treated with M. officinalis (100 mg/kg/day); the third group was treated with Mn (100 mg/kg/day); the fourth group (Mn+M. officinalis) was treated with both Mn and M. officinalis (100 mg/kg/day each). Mn-treated mice showed a significant increase in thiobarbituric acid reactive species (TBARS) levels (a marker of oxidative stress) in both the hippocampus and striatum. These changes were accompanied by a decrease in total thiol content in the hippocampus and a significant increase in antioxidant enzyme activity (superoxide dismutase and catalase) in the hippocampus, striatum, cortex and cerebellum. Co-treatment with M. officinalis aqueous extract in Mn-treated mice significantly inhibited the antioxidant enzyme activities and attenuated the oxidative damage (TBARS and decreased total thiol levels). These results establish that M. officinalis aqueous extract possesses potent antioxidative properties, validating its efficacy in attenuating Mn-induced oxidative stress in the mouse brain.
Laboratório de Bioquímica e Toxicologia de Produtos Naturais e Sintéticos, Universidade Federal do Pampa, BR 472 Km 585 Sala 403, CEP 97500-970 Uruguaiana, RS, Brazil.
Eduarda N
EN
Martins
Naira T C
NT
Pessano
Luiza
L
Leal
Daniel H
DH
Roos
Vanderlei
V
Folmer
Gustavo O
GO
Puntel
João Batista Teixeira
JB
Rocha
Michael
M
Aschner
Daiana Silva
DS
Ávila
Robson Luiz
RL
Puntel
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D060766:Drinking Water / Q000737:chemistry; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008345:Manganese / Q000494:pharmacology*; D031334:Melissa / Q000737:chemistry*; D051379:Mice; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D060766:Drinking Water; D018696:Neuroprotective Agents; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances; D008345:Manganese