Studies on the protective role of lycopene against polychlorinated biphenyls (Aroclor 1254)-induced changes in StAR protein and cytochrome P450 scc enzyme expression on Leydig cells of adult rats

Abstract

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental contaminants that disturb normal endocrine functions, including gonadal functions in humans and mammals. PCBs (Aroclor 1254) - induced toxic manifestations are associated with the production of free radicals. Lycopene belongs to the group of natural carotenoids, which are found in many fruits, vegetables and other green plants. Lycopene, the most potent antioxidant protects against oxidative damage. The present study was conducted to elucidate the protective role of lycopene against Aroclor 1254-induced changes in Leydig cellular steroidogenic acute regulatory (StAR) protein, cytochrome P450 side chain cleavage (P450 scc) enzyme expression and 3β-hydroxy steroid dehydrogenase (3β-HSD) activity. The rats were divided into four groups. Each group consists of six animals. Group I rats were administered with corn oil intraperitoneally (i.p.) for 30 days. Group II rats were treated with Aroclor 1254 (i.p.) 2 mg kg −1 body weight (bwt) day −1 for 30 days. Group III rats were treated with Aroclor 1254 (i.p.) 2 mg kg −1 bwt day −1 along with simultaneous supplementation of lycopene 4 mg kg −1 bwt day −1 (gavage) for 30 days. Group IV rats administered with lycopene alone at the dose of 4 mg kg −1 bwt day −1 (gavage) for 30 days. After 24 h of the last treatment, animals were decapitated, blood was collected and serum testosterone level was estimated by radioimmunoassay (RIA). Testes were removed and Leydig cells were isolated in aseptic condition. StAR protein, cytochrome P450 scc enzyme expression were studied by Western blot analysis and 3β-HSD activity was estimated spectrophotometrically. Aroclor 1254 treatment significantly reduced the serum testosterone level. Simultaneous supplementation of lycopene maintained the serum testosterone to near normal. Aroclor 1254 exposure decreased Leydig cellular StAR protein, cytochrome P450 scc enzyme expression and activity of 3β-HSD. However, simultaneous supplementation of lycopene improved Leydig cellular StAR protein, cytochrome P450 scc expression and activity of 3β-HSD. These results suggested that lycopene have ameliorative role against Aroclor 1254 induced Leydig cell dysfunction.