Immunomodulatory role of leptin treatment in experimental sepsis caused by gram negative bacteria

Aim: To investigate the effect of leptin treatment on circulating inflammatory cytokines and on tissue damage in experimental rat model of gram-negative sepsis. Materials and methods: Adult male Wistar rats, 28 in total, were randomly divided into 4 groups (n = 7): sham, leptin, sepsis, and sepsis group treated with leptin (sepsis+leptin). Sepsis was induced by intraperitoneal (ip) injection of 2 × 10^10 CFU of Escherichia coli ATCC 25922. Leptin and sepsis+leptin groups received a single dose ip 0.1 mg/kg leptin, while sham group received 1 mL of ip saline. Rats were sacrificed 24 h after the induction of sepsis. Blood samples, lung, and kidney tissues were collected for analysis. Results: The sepsis group had significantly higher serum TNF-α, IL-6, and endothelin levels than the sham group (P = 0.05, P 0.001, P = 0.003, respectively). The sepsis+leptin group had significantly lower IL-6 and endothelin levels (P = 0.001 and P = 0.020, respectively), and higher lung and kidney tissue myeloperoxidase activities when compared with the sepsis group (P = 0.039, P = 0.033, respectively). Conclusion: According to our results, leptin has a profound influence on sepsis, and to some extent it restricts the inflammatory events in sepsis. ̀