Background: Chronic stress decreases resilience of the body mainly due to hormonal imbalance. Neuropeptide Y-ergic system is abnormally regulated in chronic stress due to reduction-oxidation imbalance. The antioxidants such as alpha-tocopherol and ascorbic acid reduce this imbalance with positive effect on neuropeptide Y synthesis and release. This study was aimed to compare the protective effects of alpha-tocopherol and ascorbic acid on plasma neuropeptide Y levels in chronic stress.Material and Methods: This quasi-experimental study was done at Al-Nafees Medical College in collaboration with National Institute of Health Islamabad from January 2015 to January 2016 after taking institutional approval. Sixty male Sprague Dawley rats were obtained and divided equally into four groups; group I (control), group II (restraint stress group - chronic restraint stress six hours daily for 28 days), group III (restraint stress + alpha-tocopherol 50mg/kg body weight /day), and group IV (restraint stress + ascorbic acid 100mg /kg body weight /day). Cardiac puncture was done to obtain blood for biochemical analysis.Results: A significant decrease in plasma neuropeptide Y levels was seen in group II compared to group I, group III and group IV. However, alpha-tocopherol administration in group III showed positive effects on maintenance of plasma neuropeptide Y concentration with better p trend than that of ascorbic acid supplementation in group IV.Conclusions: Alpha-tocopherol supplementation has more potent effect than that of ascorbic acid on chronic restraint stress induced derangements in neuropeptide Y levels. It leads to less imbalance in neuropeptide Y levels during chronic stress.Key words: Ascorbic Acid, Alpha-Tocopherol, Chronic Stress, Neuropeptide Y

In chronic stress, release of catecholamines, adrenocorticoids and pituitary hormones result impaired release of neuromodulator - neuropeptide Y. The deregulated neuropeptide Y results imbalanced redox homeostasis reduced endogenous superoxide dismutase and raised malondialdehyde. Objectives: To find the effect of chronic stress on plasma neuropeptide Y, superoxide dismutase, and malondialdehyde levels. Study Design: Quasi-experimental. Setting: Al-Nafees Medical College & Hospital in collaboration with National Institute of Health, Islamabad. Period: January 2016 to December 2016. Material & Methods: After approval from institutional review board, thirty healthy male Sprague Dawley rats were included in the study and were divided equally into group I (control) and group II (restraint stress). The animals were housed in stainless steel cages, at humidity (40-60%), temperature (22 ± 2°C) and a 12-h light-dark cycle with lights on at 0700 am. After adaptation, group II was exposed to restraint stress of 6 hours daily for 28 days. The blood sampling for plasma neuropeptide Y, serum superoxide dismutase and malondialdehyde levels were taken. Results: There was significant decline in neuropeptide Y plasma and superoxide dismutase serum levels while an increase in malondialdehyde levels serum levels was noticed in restraint stress group. Conclusions: Chronic stress induces decrease in plasma NPY with subsequent increase in serum malondialdehyde and decrease in superoxide dismutase levels.