The aim of the present study is to investigate the potential role of L-arginine or L-citrulline in rats fed high-fat and high-cholesterol (HFC) diet. HFC feeding increased significantly serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, urea and all lipid profiles and decreased significantly serum high-density lipoprotein-cholesterol (HDL-c) and non significantly serum nitric oxide levels. L-arginine or L-citrulline administration reversed the increase in serum AST and ALT activities, urea and all lipid profiles. These effects were associated with a concomitant increase in HDL-c and nitric oxide levels. In general, rats fed HFC diet and orally treated with L-arginine or L-citrulline had higher relative percentage of 18:0, 20:0 and 22:6 and lower 16:0 fatty acids than rats fed HFC diet. Light and transmission electron microscopic findings of the thoracic aorta confirmed the biochemical results and demonstrated structural changes in the endothelial cells of the intimal layer, medial smooth muscle cells as well as in the adventitial layer in HFC fed-animals. However, these findings indicate little structural alterations in animals supplemented with L-arginine or L-citrulline along with HFC feeding. In the present study, L-arginine or L-citrulline was effective hypocholesterolemic and hypolipidemic agents in rats.

This study aimed to investigate the role of the phytoestrogen (chrysin) in the treatment or protection of NMU-induced preneoplastic lesions in mammary glands of postmenopausal female rats. Rats (n=105) were divided into seven groups (n=15/group); group1(negative control group).Groups 2&3 (positive control groups), rats were injected intraperitoneally (i.p.) with 4 doses of NMU (75 mg/kg b.w.,once/5days) before or after oral administration of glycofurol. Groups 4 &5(treatment groups),rats received 4 doses of NMU (75 mg/kg b.w., once/5days,i. p.), left for 6 weeks then followed by 3 doses, per week, of chrysin (125 or 250 mg/kg b.w., orally; p.o), respectively, for another 6 weeks. Groups 6 & 7(protective groups), rats received 3 doses, per week, of chrysin(125 or 250 mg/kg b.w.,p.o.), for 6 weeks then followed by 4 doses of NMU (75 mg/kg b.w., once/5days, i.p.) then left for another 6 weeks. The NMU injection caused significant decrease in PLT count, lymphocytes %, Hb, MCH, MCHC, E 2 , TAC levels as well as GST and CAT activities. The results also showed that NMU significantly elevated WBC count, granulocytes%, monocytes %, MCV, RDW%, CRP, CEA levels and arginase activity. Either treatment or protection with chrysin modulated the adverse effects of NMU and ameliorated the change in the biochemical parameters. The biochemical observations were also confirmed by histological studies. In conclusion, phytoestrogens may relieve the severity of postmenopausal pre-cancerous disorders, especially when consumed in high dose for a while before the incidence of lesions.