In contrast, administration of all current treatment options to type 2 diabetes-induced rats produced a significant reduction in serum leptin levels compared to the untreated group (p < 0.01), and 10 mg/kg CurNP and 50 mg/kg ZnONP showed a more efficient decrease in serum leptin levels than other doses (Table 3, p < 0.01). The gene discussed is LEP; the disease is type 2 diabetes mellitus.