ABSTRACT
Stress is a condition or stimulus that threatens an organism's survival. Noise is an environmental stressor. It is well known that long term as well as acute exposure to noise led to oxidative stress. In the present study, it was investigated that the persistence of noise stress (100 dBA/4 h/d for 30 days) could cause memory impairment in rats and whether ethylacetate extract of AC EAAC (50 mg kg(-1) b.wt.) and alpha-Asarone (9 mg kg(-1) b.wt.). treatment can prevent or not. In order to understand the possible mechanism behind it, antioxidant status and acetylcholinesterase (AChE) activity in hippocampus was evaluated after rats were tested in Radial Eight-arm Maze (RAM). Heat shock protein 70 (hsp 70) expression in hippocampus was also evaluated to understand the intensity of stress level. Results showed that after noise stress exposure, time taken to visit all the baited arms, working and reference memory errors were increased in RAM. The superoxide dismutase, lipid peroxidation, AChE activity, hsp 70 were significantly increased with concomitant decrease in catalase, glutathione peroxidase activity and G6PD activity of non-enzymatic levels was observed in the 30 days noise stress exposed group. When rats were co-administrated with EAAC and alpha-Asarone prevents the noise stress induced alterations significantly. In Conclusion, noise stress induced oxidative stress, increased AChE activity, and over expression of hsp 70 in hippocampus region might have led to the impairment of spatial memory. EAAC and alpha-Asarone prevents this noise stress induced memory impairment.
Subject(s)
Acorus , Anisoles/pharmacology , Hippocampus/drug effects , Memory Disorders/drug therapy , Memory/drug effects , Noise/adverse effects , Nootropic Agents/pharmacology , Plant Extracts/pharmacology , Stress, Psychological/drug therapy , Acetylcholinesterase/metabolism , Allylbenzene Derivatives , Animals , Disease Models, Animal , GPI-Linked Proteins/metabolism , HSP72 Heat-Shock Proteins/metabolism , Hippocampus/metabolism , Hippocampus/physiopathology , Lipid Peroxidation/drug effects , Memory Disorders/etiology , Memory Disorders/metabolism , Memory Disorders/physiopathology , Memory Disorders/psychology , Motor Activity/drug effects , Oxidative Stress/drug effects , Phytotherapy , Plants, Medicinal , Rats , Rats, Wistar , Stress, Psychological/etiology , Stress, Psychological/metabolism , Stress, Psychological/physiopathology , Stress, Psychological/psychology , Superoxide Dismutase/metabolism , Time FactorsABSTRACT
In this modern world, stress and pollution are unavoidable phenomena affecting the body system at various levels. A large number of people are exposed to potentially hazardous noise levels in daily modern life, such as noise from work environments, urban traffic, and household appliances. A variety of studies have suggested an association between noise exposure and the occurrence of disorders involving extra-auditory organs such as disorders of the nervous, endocrine, and cardiovascular systems. In this study, Wistar strain albino rats were subjected to 100 dB broadband white noise, 4 h daily for 15 days. The high-pressure liquid chromatographic estimation of norepinephrine, epinephrine, dopamine, and serotonin in discrete regions of the rat brain indicates that noise stress can alter the brain biogenic amines after 15 days of stress exposure. Ocimum sanctum (OS), a medicinal herb that is widely claimed to posses antistressor activity and used extensively in the Indian system of medicine for a variety of disorders, was chosen for this study. Administration of the 70% ethanolic extract of OS had a normalizing action on discrete regions of brain and controlled the alteration in neurotransmitter levels due to noise stress, emphasizing the antistressor potential of this plant.
