Effect of food restriction on reproductive-related genes and reproductive hormones in adult female rats.

OBJECTIVES: A number of factors involved in the control of energy balance and metabolism act as modulators of gonadal axis. Ghrelin, a peptide secreted from the stomach and hypothalamus, has emerged as an orexigenic food intake controlling signal acting upon hypothalamus. Recently, the potential reproductive role of ghrelin has received great attention. This study was designed to investigate the influence of food restriction and consequent metabolic hormone (ghrelin) on the level and gene expression of female reproductive hormones in adult rats. MATERIALS AND METHODS: To study the effect of chronic food restriction on ghrelin level in adult female rats and its relation to female reproductive hormones, 32 adult female Sprague Dawley rats divided into 4 groups: Group I (control group) comprised 8 rats fed ad libitum for 30 days, Group II, III and IV (food-restricted groups for 10, 20 and 30 days respectively) each consisted of 8 rats fed 50% of ad libitum intake determined by the amount of food consumed by the control group. RESULTS: Mean body weight of food restricted rats was observed to decrease during the period of the experiment. Food restriction produced significant increase of serum ghrelin with significant decrease of both gastric and hypothalamic ghrelin accompanied with significant increase in its gene expression in stomach and hypothalamus. Estradiol (E2), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels showed significant decrease correlated with down-regulation of gonadotropins, cyclin-dependent kinase (cdc2), cyclin B and kisspeptin (Kiss1) genes in food restricted rats compared with control group. CONCLUSIONS: Ghrelin could be one of the hormones responsible for the suppression of female reproductive axis in case of negative energy balance. Thus, ghrelin may operate as an autocrine/paracrine regulator of ovarian function. Overall, ghrelin may represent an additional link between body weight homeostasis and reproductive function.

Hypolipidemic influence of Sargassum subrepandum: mechanism of action.

OBJECTIVES: This study aimed to elucidate the role and mode of action of Sargassum subrepandum methanolic extract in management of dyslipidemia in adult female rats. MATERIAL AND METHODS: Forty adult female Sprague Dawley rats were assigned into four groups: (1) lean control rats fed on standard diet, (2) dyslipidemia control fed on the atherogenic diet, (3) lean rats orally administered with 100 mg/kg b. wt of Sargassum subrepandum methanolic extract and (4) dyslipidemia rats orally administered with Sargassum subrepandum methanolic extract. Plasma lipid profile, serum MDA, NO, leptin, TNF-alpha and adiponectin levels were demonstrated in the all studied groups. RESULTS: The results showed that feeding of rats with athrogenic diet caused significant elevation in plasma cholesterol, triglyceride, LDL, serum MDA, NO, leptin and TNF-alpha levels while, it produced significant decline in plasma HDL and serum adiponectin levels compared with lean control rats. However, treatment of dyslipidemia rats with Sargassum subrepandum methanolic extract induced significant improvement of plasma lipid profile, marked decrease in serum MDA, NO, leptin, TNF-alpha level in concomitant with remarkable increase in serum adiponectin level. CONCLUSIONS: These results indicated that Sargassum subrepandum extract plays a vital role in ameliorating dyslipidemia and its complications particularly oxidative stress and implication. This could be attributed to the hypolipidemic effect, antilipidperoxidative activity and antinflammatory property of Sargassum subrepandum methanolic extract.

Saccharomyces cerevisiae intervention for relieving flutamide-induced hepatotoxicity in male rats.

The aim of this work was to investigate the protective role of baker's yeast Saccharomyces cerevisiae against the hepatotoxic effect of the drug flutamide that is widely used for treatment of metastatic prostate adenocarcinoma. Administration of flutamide to adult male rats in a dose of 100 mg/kg b.w. daily for 15 days resulted in serious hepatic injury. Highly significant increase in each of serum ALT, ALP, bilirubin, bile acids and cholesterol level, relative to the control group, was observed. Also, a highly significant increase in the serum glutathione-S-transferase isoforms: alpha-GST and pi-GST and each of TNF-alpha and NO levels was recorded. Moreover, highly significant decrease in hepatic glutathione peroxidase and superoxide dismutase activities was observed. In addition, the authors noticed a significant increase in serum testosterone levels with concomitant highly significant increase in serum acid phosphatase activity. Prophylactic treatment of male rats with baker's yeast in a dose of 4.8 mg/kg b.w. daily for 15 days, followed by a combination of flutamide (100 mg/kg b.w.) and yeast (4.8 mg/kg b.w.) daily for other 15 days resulted in marked improvement in rat's liver function, whereas the serum testosterone and acid phosphatase levels retained values parallel to those recorded for the flutamide-treated rats. Histological examination of liver tissues showed that flutamide caused hydropic degeneration, necrotic areas and marked increase in Kupffer cells. The central vein is congested with blood and signs of apoptosis appeared in the hepatocytes in the form of fragmentation of the nuclei and blebbing of the cytoplasm. On the other hand, in the rats treated with both yeast and flutamide, the hepatic cords were more regularly arranged, signs of degeneration or apoptosis were less pronounced and some hepatocytes appeared binucleated. The authors postulate that each one of the powerful antioxidative components in S. cerevisiae effectively participated in attenuation of the oxidative stress caused by flutamide metabolites, and in promoting regeneration of new hepatocytes and meanwhile could restore liver function beyond normal status.