Effect Of Dhea On Lipid Metabolism And Antioxidant Function In Rat And Broiler

Dehydroepiandrosterone (DHEA) is synthesized primarily by the zona reticularis ofadrenal cortex and to a lesser degree by the gonads(testicle and ovary). The conjugatesulfate (DHEAS) is the main form in the circulating blood. DHEA is a precursor of sexsteroid hormone biosynthesis. DHEA can transfer to estrogen, androgens, progesterone andcorticosterone with steroidogenic enzymes in peripheral tissues. DHEA has numerousbiological and biochemical effects, especially on the lipid metabolism, but on broiler lipidmetabolism has not been reported, so this test was focus on the lipid metabolism andantioxidant function of rat and broiler with exogenous DHEA. The purpose is to providetheoreticaland experimental evidence for regulating the lipid metabolism of rat and broiler.In experiment one, To explore the effect of DHEA on Lipid metabolism andantioxidant function in Rats. Forty healthy adult male SD rats were randomly divided intofour groups: After being given DHEA in dosages of 20,10 and 5 mg/kg BW respectivelyfor 35 days. The body weight was measured respectively per week. Blood and liver weredrawn from rat to detect the blood glucose (BG), triacylglycerol (TG), total cholesterol(TC),high-density lipoprotein-cholesterol(HDL-C), low-density lipoprotein -cholesterol(LDL-C),non-esterified fatty acid (NEFA),lipoprotein lipase(LPL),hepatic lipase (HL)aswell as superoxide dismutase (SOD) activity and malondiadehycle (MDA) content in serumand liver, respectively. The result showed that DHEA can reduce the levels of blood glucose,triacylglycerol, high density lipoprotein-cholesterol as well as malondiadehycle of serumand liver, but it can increase the level of low density lipoprotein -cholesterol of serum aswell as superoxide dismutase activity of liver. Body weight, serum total cholesterol,non-esterified fatty acid content, lipoprotein lipase, hepatic lipase and superoxide dismutaseactivity were not significantly affected by DHEA. In conclusion, DHEA possesses theeffect of reducing blood lipids and strengthening the antioxidant function in rats.In experiment two, Effect of different dehydroepiandrosterone (DHEA) supplementallevels in Arbor Acres broiler feed on lipid metabolism and related hormones and antioxidant function were studied. 180 day-old Arbor Acres broilers were randomlyallocated to three groups, each group included three replicates with 20 broilers each. DHEAwas not added in the basal feed (control group). The low DHEA and high DHEA treatedgroups were fed with the basal feed with the supplementation of 5 and 20 mg/kg from 1 to42 day-old, respectively. Twelve cocks and twelve hens per group were randomly chosenfor blood, liver, Abdominal fat, left breast and thigh muscle samples at 42 day-old. Thecontent of blood glucose(BG), triacylglycerol (TG), total cholesterol (TC), high densitylipoprotein-cholesterol(HDL-C),low density lipoprotein-cholesterol (LDL-C),non-esterifiedfatty acid (NEFA), activity of Lipoprotein lipase (LPL), triiodothyronine(T₃), thyroxin(T₄),free triiodothyronine(FT₃), free thyroxin(FT₄), glucagon, leptin, tumor necrosis factor-α(TNF-α), the activity of superoxide dismutase(SOD) and content of malondialdehyde(MDA) in both serum and liver were determined, respectively. The result showed that thebody weight, abdominal fat weight, percentage of abdominal fat weight and triacylglycerol(TG), total serum cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), FT₃, FT₄and MDA were significantly decreased (P＜0.05)and leptin was significantly increased byDHEA in both gender .The content of blood glucose(BG), LDL-C, TNF-αand SODactivity of serum and liver were not affected by DHEA. The content of NEFA wasobviously elevated in the cocks and decreased in the hens (P＜0.05) by DHEA. Theactivity of LPL and the content of glucagon in serum were significantly enhanced,T₄ andMDA were significantly decreased in the cocks(P＜0.05) by DHEA. The results impliedthat DHEA regulated lipid metabolism of broilers by enhancing the enzyme activity andhormone levels related to lipolysis.In conclusion, DHEA regulated lipid metabolism of rat and broiler through enhancinglipolysis and also increased antioxidant function. DHEA may have a different functionrelated to gender, the reasons for this need more research.