Study On The Physiological Effect Of Tested Rats By Oral Administration Of Capsaicinoids

This study focused first of all on the acute toxicity test of capsaicinoids to determine the possible LD₅₀ and to have some knowledge about their toxicity effects and affected organs, and at the same time to provide an orientation for further sub-chronic test concerning the dose design and indicative items to be analyzed. Then 30 days feeding experiment of capsaicinoids was undertaken so to have a further understanding about the sub-chronic toxicities of capsaicinoids and their influence on the growth of mice and to determine the no-observed adverse effect level (NOAEL) of capsaicinoids to mice. Finally hypolipidemic and anti-oxidation effects of capsaicinoids were systematically studied so to provide some basic data for further exploitation of capsaicinoids.The acute toxicity test of capsaicinoids was undertaken as stressed in the relevant National Standard of Acute Toxicity Test GB 15193.3-1994 and 30 days feeding experiment according to the National Standard of Sub-Chronic Toxicity Test 15193.13-2003. Study on hypolipidemic and anti-oxidation effects of capsaicinoids in induced hypercholesterolemic rats was as following:60 SD male rats were randomly divided into 6 groups with an average body weight of 206.3±5.4 g, then all 6 groups were orally administered by I.g daily for 8 weeks as followings:1) Basal diet control group (BDC); Basal diet+lml distilled water; 2) High Cholesterol control group (HCC); High Cholesterol diet+1ml salad oil brand "Jinlongyu"; 3) Jiaogulan pill positive control group (JPC):High Cholesterol diet+1 ml Jiaogulan solution with concentration of 7.000 mg/ml; 4) Low dosage of capsaicinoids(LD):High Cholesterol diet+1 ml Salad oil brand "Jinlongyu"in which the concentration of capsaicinoids is 3.0171 mg·g^-1.5) Medium dosage of capsaicinoids(MD):High Cholesterol diet+1 ml Salad oil brand "Jinlongyu"in which the concentration of capsaicinoids is 4.0281 mg·g^-16) High dosage of capsaicinoids(HD):High Cholesterol diet+1ml Salad oil brand "Jinlongyu"in which the concentration of capsaicinoids is 5.0145 mg·g^-1. At the end of experiment, overnight fasted rats were sacrificed under light ether anesthesia. Serum and related hepatic Triglyceride(TG), Total cholesterol(TC), High density lipoprotein cholesterol (HDL-C),Low density lipoprotein cholesterol (LDL-C), Superoxide dismutase (SOD),Glutathione peroxidase (GSH-Px) and Malondialdehyde(MDA) were analyzed and determined.The acute toxicity test of capsaicinoids showed that the acute oral administration of capsaicinoids at high dosage by I.g was lethal to mice and the LD₅₀ of capsaicinoids was 190 mg/kg. The histopathological observation of stomach of dead mice also showed congestive phenomena in the stomach, indicating that capsaicinoids at acute oral administration dosage is somewhat toxic indeed.30 days feeding experiment showed that first of all, oral administration of capsaicinoids at sub-chronic dosage by I.g would affect the behavior of treated mice such as excessive exciting, trembling or burying its head in the litter etc. But usually all these abnormal behavior of mice would disappear in 2-3 hrs and no lethal effect was observed, indicating that capsaicinoids at sub-chronic dosage was relatively safe. Secondly sub-chronic dosage of capsainoids affected blood parameters of mice to some extent, for instance, the administration of capsaicinoids at tested groups increased the RBC count, Hb content, WBC and platelet count and in some cases even significantly compared with that of control group (P<0.05), this was especially true for female mice. Thirdly, sub-chronic dosage of capsainoids also influenced some of the hematological index of treated mice such as ALT activity, BUN and TC content in serum. The administration of capsaicinoids significantly reduced the ALT activity (P<0.05), BUN and TC content in serum compared to that of the control group (P <0.05) indicating that oral administration of capsaicinoids at sub-chronic dosage might also affect liver, but not kidney and actually even promote the metabolism and decrease the TC in serum. Further, no side or harmful effects were observed concerning possible injury to stomach or gastric of treated mouse compared to that of control group, neither did it to the coefficient of liver/bw ratio, kidney/bw ratio or the appearance of liver or kidney. Finally, it was concluded that the no observed adverse effect level (NOAEL) for capsaicinoids to Kunming mice was 16.2 mg/kg. Study on the hypolipidemic and anti-oxidation effects of capsaicinoids in induced male hypercholesterolemic rats showed that:1) Feeding the rats with different concentration of capsaicinoids resulted in anxious behavior of the tested groups but returned to normal in 20-30 min. There were no significant differences regarding to the appearance, color and the fecal characteristics among tested groups compared with that of HCC group during 8 weeks feeding experiment.2) Feeding the rats with high fat, high cholesterol diet could significantly increase the body weight gain for male hypercholesterolemic rats compared with that of BDC group (P<0.05). However, there was no significant difference of body weight gain among rats of HCC and the other three capsaicinoids tested groups (P> 0.05), neither did the average daily feed intake.3) Compared with that of HCC group, the serum TC level of JPC, LD, MD and HD was lowered significantly(P<0.05). But no significant difference was observed between HCC group and the other three capsaicinoids groups (P>0.05) concerning the serum TG level.4) Further analysis showed that the lowering effect of serum TC by capsaicinoids in LD, MD and HD group was mainly due to the decrease of serum LDL-C level (P<0.05), however, there was hardly any significant difference observed concerning serum HDL-C level among male hypercholesterolemic rats.5) The oral administration of capsaicinoids at different dosage also improved the enzymatic activities of different kinds of anti-oxidation enzymes in serum such as SOD and GSH-Px. The serum enzymatic activities of SOD in LD, MD and HD group were increased significantly compared with that of HCC group (P<0.05). Similarly, the serum activities of GSH-Px were also increased significantly compared with that of HCC group(P<0.05). Thanks to the effect of capsaicinoids on these anti-oxidation enzymes in serum lipids profile, the level of MDA in LD, MD and HD group were significantly lower than that of HCC group (P<0.05).6) The liver cholesterol level was not significantly influenced in male hypercholesterolemic rats (P>0.05) However, the hepatic triglyceride level of LD, MD and HD rats were significantly lowered than that of HCC group(P<0.05).7) There was no significant difference between HCC group and the other three capsaicinoids groups (P>0.05) regarding to the hepatic enzymatic activities of SOD and neither did it to the hepatic GSH-Px activity indicating that capsaicinoids did not influence the hepatic enzymatic activities of SOD and GSH-Px significantly (P>0.05).8) Compared with the tested rats of HCC group, oral administration of capsaicinoids at set dosages significantly increased the excretion of fecal cholesterol and also the bile acid from fecal (P<0.05).From the acute toxicity test it is concluded the LD₅₀ of capsaicinoids by I.g is 190 mg/kg and therefore can be categorized as a kind of somewhat toxic substances. 30 days feeding experiment reveals that the no observed adverse effect level (NOAEL) for capsaicinoids to mice by I.g is 16.2 mg/kg. This amount is roughly 3-5 times that of average daily intake of ordinary chili consumers indicating that sub-chronic intake of capsaicinoids is actually safe. From the last experiment, it can be concluded that capsaicinoids at different dosage can significantly reduce the serum TC level but not necessarily the hepatic TC of tested rats and the main reducing fraction is actually due to the decrease of serum LDL-C. Similarly, oral administration of capsaicinoids also promotes the fecal excretion of cholesterol either directly or in form of bile acid. Hence the consumption of proper amount of capsaicinoids may be helpful in prevention of blood and heart diseases and possible accumulation of lipids in hepatic tissue. Simultaneously, Capsaicinoids may also enhance the activities of certain anti-oxidation enzymes in serum lipids profile such as SOD and GSH-Px so that the related serum MDA content is correspondingly decreased. However, such phenomenon is not observed in liver tissue of tested rats. All these indicated that capsaicinoids could function as a kind of potential anti-oxidative agent in lipids profile metabolism of rats.