Modulation of Altered Immune Parameters IL-2 and TNF-α in Diabetic Animal Models: A Therapeutic Insinuation of Metformin Beyond Diabetes

Background: Immunomodulatory drugs target the overall immune system, hence producing numerous toxic effects on the other organs with serious health manifestations. Due to these safety concerns, there is a need to introduce or repurpose a new drug with immunomodulatory effects with good safety, efficacy, and better tolerance. Metformin, a standard antidiabetic drug, was evaluated for its immunomodulatory effects in diabetic models in the current study. Methodology: The diabetic model was developed by intraperitoneal (IP) administration of streptozotocin (60 mg/kg). The experimental rats were divided into six groups (three diabetic and three non-diabetic) with six rats in each group. Metformin (50 mg/kg and 80 mg/kg) was given orally to both diabetic and non-diabetic groups, once a day, for 42 days. Immunomodulatory cytokines interleukin (IL)-2, IL-4, IL-5, tumor necrosis factor (TNF)-α, and interferon gamma (INF-ɣ) were analyzed from blood samples by BD FCAP flow cytometer. Results: The results revealed a significant (p=0.002) decrease in IL-2 and TNF-α in diabetic groups in comparison to control rats. However, no significant changes were observed in IL-4, IL-5, and INF-ɣ levels. Importantly, the treatment of metformin at both doses, i.e., 50 and 80 mg/kg, significantly reduced the elevated levels of IL-2 and TNF-α when compared to untreated diabetic groups. Conclusion: Metformin may be considered as an optimum drug candidate to reduce pro-inflammatory cytokines, IL-2 and TNF-α, that can lead to the reduction of long-term diabetic complications.