Effect of Scoparia dulcis on noise stress induced adaptive immunity and cytokine response in immunized Wistar rats

BACKGROUND: Noise acts as a stressor and is reported to have impact on individual health depending on nature, type, intensity and perception. Modern medicine has no effective drugs or cure to prevent its consequences. Being an environmental stressor noise cannot be avoided; instead minimizing its exposure or consuming anti-stressor and adaptogens from plants can be considered. OBJECTIVES: The present study was carried out to evaluate the anti-stressor, adaptogen and immunostimulatory activity of Scoparia dulcis against noise-induced stress in Wistar rat models. MATERIAL AND METHODS: Noise stress in rats was created by broadband white noise generator, 100 dB A/4 h daily/15 days and S. dulcis (200 mg/kg b.w.) was administered orally. 8 groups of rats were used consisting of 6 animals each; 4 groups for unimmunized and 4 groups for immunized. For immunization, sheep red blood cells (5 × 10(9) cells/ml) were injected intraperitoneally. RESULTS: Sub-acute noise exposed rats showed a significant increase in corticosterone and IL-4 levels in both immunized and unimmunized rats whereas lymphocytes, antibody titration, soluble immune complex, IL-4 showed a marked increase with a significant decrease in IL-2, TNF-α, IFN-γ cytokines only in unimmunized rats. Immunized noise exposed rats presented increased leukocyte migration index and decreased foot pad thickness, IL-2, TNF-α, IFN-γ with no changes in the lymphocytes. CONCLUSION: S. dulcis (SD) has normalized and prevented the noise induced changes in cell-mediated and humoral immunity and it could be the presence of anti-stressor and immuno stimulant activity of the plant.