Effect of Withanolide-A on Mice Subjected to Simulated Chronic Jetlag/Shift Work

Abstract

Objective: Circadian rhythm is maintained by central and peripheral clocks that regulate an organism’s physiological functions. Frequent trans-meridian travel, an irregular sleep-wake cycle, light exposure during the rest period, rotating shift work, and other factors cause desynchronization of central and peripheral clocks, impairing social and occupational behavior. Withanolide-A (WA) is used for its powerful nootropic and neuroprotective properties.Methods: Effects of 13 days consecutive pre-dosing of WA (10 μmol/kg/day) on circadian rhythm disruption caused due to 9 h advance-delay chronic jetlag light-dark shift was studied on re-entrainment rate analyzed through locomotor activity recording of mice using the ClockLab setup, learning and memory studied through Y-maze and Barnes maze tests. In the hippocampus, gene expression of <i>PER1</i> and <i>BDNF</i> was assessed using reverse transcription-quantitative polymerase chain reaction. The effect of WA treatment was also studied on superoxide dismutase, catalase, reactive oxygen species (ROS), and lipid peroxidation in hippocampal tissue.Results: The results showed that WA treatment leads to faster re-entrainment and better performance during Y-maze and Barnes maze tests. <i>PER1</i> and <i>BDNF</i> genes expression was upregulated in the treated group compared to chronic jetlag exposure groups in the hippocampus and suprachiasmatic nuclei. Moreover, the WA-treated group produced fewer ROS and superoxide radicals, and there was also less lipid peroxidation in the treated group.Conclusion: These results suggest that the WA may act as a chronobiotic and neuroprotective agent as treated group mice took fewer transient cycles to re-entrain after chronic light-dark shift. Neuroprotective property is supported by learning-memory behavioral tests, gene studies and biochemical assays.