The effect of dietary wild pistachio oil on serum leptin concentration and thyroid hormones in the female rat

Abstract

Background: Unsaturated fatty acids decrease serum leptin level and wild pistachio oil is rich of them. With attention to this effect and reciprocal effects between leptin and thyroid hormones, the aim of the present study was to investigate the impact of dietary wild pistachio oil on serum leptin concentration and its relationship with thyroid hormones. Materials and Methods: 28 healthy adult female rats were selected and divided randomly to four equal groups. Group 1 as the control group and other three groups received normal diet a long with, 5, 10 and 20% of wild pistachio oil, respectively. RIA for thyroid hormones assay (T3 and T4) and ELISA for leptin, fT3 and fT4 measurement were used. Results: Serum leptin level reduced with increasing wild pistachio oil concentration in the diet after 60 days. In the control group with normal diet important alterations weren't observe. The differences between groups were significant. Pearson correlation coefficients were calculated between leptin and thyroid hormones in the different sampling times. Control group had not any significant correlation. In group 2 (feeding with 5% wild pistachio oil), leptin concentration had a positive significant correlation with fT4(r=0.87; P