Immunomodulatory Potential of Melatonin in Immunosuppression: An in-vivo Study

To assess the immunomodulatory effects of melatonin on the acquired immunity of immunosuppressed male Wistar rats by checking Interleukin 6 (IL-6) levels, total leucocyte counts (TLC), and differential leucocyte counts.

Experimental study. Place and Duration of the Study: Animal laboratory, CMH Lahore Medical College, from June to October 2023.

Fifty male Wistar rats, weighing 180g to 200g, were included in this study with 10 rats in each of the five groups namely cyclophosphamide (CP), CP + melatonin, CP + immunomodulator, melatonin-only, and control. A calculated dose of CP was administered intraperitoneally for 30 days (from 13/06/23 to 13/07/23) to each group except the control groups. After this, the experimental group was given melatonin CP + Melatonin for 7 days (from 14/07/23 to 20/07/23). CP + Immunomodulatory group was kept for comparison of immunomodulatory effects. Blood samples were drawn from all 5 groups. IL-6 was estimated through ELISA. Other parameters assessed were TLC and absolute differential leucocyte counts.

Melatonin increased IL-6 levels significantly (p = 0.042) as well as the TLC levels (p <0.001) compared to the immuno-suppressed CP group. Melatonin was seen to have an upregulation of IL-6 levels in immunosuppression compared to the administration of immunomodulator preparation (p = 0.506) which was not as effective. Administration of melatonin significantly increased the TLC, neutrophil, lymphocyte, monocyte, and eosinophil count compared to known immunomodulators.

Melatonin as a supplement may have some role in activating multiple immune response processes in immune-depressed states. It was also established that it allows quick recovery of cell components from immunosuppressed states.

Melatonin, Immunomodulation, Rats, Interleukin-6, Acquired immunity, Cyclophosphamide.