Low dose effects of a Withania somnifera extract on altered marble burying behavior in stressed mice

Abstract

Aim: Withania somnifera root (WSR) extracts are often used in traditionally known Indian systems of medicine for prevention and cure of psychosomatic disorders. The reported experiment was designed to test whether low daily oral doses of such extracts are also effective in suppressing marble burying behavior in stressed mice or not.

Materials and methods: Groups of mice treated with 10, 20, or 40 mg/kg daily oral doses of WSR were subjected to a foot shock stress-induced hyperthermia test on the 1(st), 5(th), 7(th), and 10(th) day of the experiment. On the 11(th) and 12(th) treatment days, they were subjected to marble burying tests. Stress response suppressing effects of low dose WSR were estimated by its effects on body weight and basal core temperature of animals during the course of the experiment.

Results: Alterations in bodyweight and basal core temperature triggered by repeated exposures to foot shock stress were absent even in the 10 mg/kg/day WSR treated group, whereas the effectiveness of the extract in foot shock stress-induced hyperthermia and marble burying tests increased with its increasing daily dose.

Conclusion: Marble burying test in stressed mice is well suited for identifying bioactive constituents of W. somnifera like medicinal plants with adaptogenic, anxiolytic and antidepressant activities, or for quantifying pharmacological interactions between them.

Keywords: Bioassay; Withania somnifera; foot shock stress; marble burying test; thermoregulation; treatment regimen.

Figure 1

Effect of WSR extract on (a) basal rectal temperature and (b) stress induced hyperthermia in male mice. WSR: Withania somnifera root extract, CMC: Carboxymethyl cellulose, SEM: Standard error of the mean. Values are mean±SEM (n = 6). *denotes statistically significant difference (two-way analysis of variance followed by Bonferroni post hoc test) relative to the corresponding values of the stress control group (*P < 0.05)

Figure 2

Effect of WSR extract in mice marble burying test: (a) Standard condition on day 11 and (b) Two-zone condition on day 12. WSR: Withania somnifera root extract, CMC: Carboxymethyl cellulose, SEM: Standard error of the mean. Values are mean±SEM (n = 6). *denotes statistically significant difference (analysis of variance followed by Student - Newman-Keuls multiple comparison test) relative to the values of the corresponding stress control group (*P < 0.05)