Effects of digested and undigested snakeweed ingestion and extracts on female Sprague-Dawley rats.

摘要

Three studies were conducted to examine effects of snakeweed (SW) ingestion and extracts on serum components in female Sprague-Dawley rats. In each experiment, 36 rats were used. In Exp. 1, rats were offered either ruminally digested SW (15% and 20% DSW) or undigested SW (15% USW). In Exp. 2, rats were offered undigested SW extracted with ethanol and hexane at 20% and 30% of diet. In Exp. 3, rats were offered ruminally digested SW extracted with ethanol and hexane at 20% and 30% of diet. Additionally, each of the treated rats was assigned a non-snakeweed control fed 5001 Rat Chow RTM diet. Control rats were fed based on the intake of their treated pair to eliminate any nutritional variation due to feed intake. The control diet was adjusted using corn meal or soybean oil to make the diet near isocaloric and isonitrogenous. Body weights (BW) were recorded pre-trial. Rats were fed for 10 d and BW was recorded. Blood samples were collected via heart puncture and rats were euthenized. Study 1 was replicated over time (Exp. 1 and Exp. 2). In Exp. 1, daily feed intake and BW were similar (P > 0.05) among treatments compared to controls. In Exp. 2, rats consuming 15% digested SW (15% DSW) and 15% undigested SW (15% USW) had greater ( P < 0.05) feed intake than rats consumed 20% digested SW (20% DSW). Additionally, rats consuming 15% DSW had greater (P < 0.05) feed intake compared to rats fed 15% USW on d 3, 5, 6 and 9. In Exp. 2, BW decreased (P 0.05) among treatments except for triglycerides which decreased ( P < 0.05) in Exp. 2 in rats consuming SW compared to controls. Lower triglyceride in Exp. 2 may be due to the reduction in BW in treated rats compared to controls, as body fat is most likely being mobilized. In Exp. 2, rats consuming 20% ethanol undigested SW extract (20% ESW) had decreased (P < 0.05) feed intake on d 1, 2, and 3 and increased (P < 0.05) on d 10, while those treated with 20% hexane undigested SW extract (20% HSW) showed increased (P < 0.05) in feed intake from d 6 through d 10 compared to pair-fed control rats. Treating rats with 30% ESW resulted in decreased (P < 0.05) feed intake on d 1, 2, and 3 and increased (P < 0.05) intake on d 8, 9, and 10. Feeding rats 30% HSW decreased feed intake on d 1, 2, 3, and 5 and increased intake (P < 0.05) on d 7, 9, and 10 compared to pair-fed controls. Feeding 30% HSW decreased ( P < 0.05) heart weight as percentage of carcass weight compared to pair-fed control. Serum enzymes were similar (P > 0.05) among treatments except for aspartate aminotransferase and alanine aminotransferase which were increased (P < 0.05) when feeding 20% and 30% HSW. Blood urea nitrogen, albumin, creatinine, calcium, and chlorine increased (P 0.05) on serum progesterone (P4) compared to their pair-fed controls. Numbers of pups did not have an effect (P > 0.05) on P4 concentration. Uterine weight had an effect (P < 0.05) on P4 concentration. These results indicate that undigested SW extracts may contain potential chemical compounds causing mild toxic effects in rats. In Exp. 3, 20% ethanol digested SW extract (20% EDSW), 20% hexane digested SW extract (20% HDSW), and 30% ethanol digested SW extract (30% EDSW) showed increased (P < 0.05) in feed intake compared to controls and 30% HDSW had decreased (P < 0.05) feed intake on d 1, 2, and 7. The 20% HDSW resulted in increase (P < 0.05) in liver weight and 30% HDSW induced a decrease (P 0.05) among treatments except for alkaline phosphatase, blood urea nitrogen, globulin, creatinine, potassium, and calcium which increased (P 0.05) on serum P4 compared to controls. Numbers of pups did not have an effect (P > 0.05) on serum P4 concentration while uterine weight had an effect (P < 0.05) on serum P4 concentration. These results indicate that digested SW extracts may contain potential chemical compounds causing a mild toxicity in rats but did not affect reproduction.;KEYWORDS: Snakeweed, Sprague-Dawley rats, Serum enzymes.