| The experiment was designed to observe the effects of SIF on testicular morphology and testosterone level in high-fat diet-induced obese rats, as well as the impact on key enzymes related to the synthesis and secretion of testosterone, offering the scientific evidence for the latter clinical trials.Food-induced obese rat model was established by feeding with high oil diet in 9 weeks. The criterion for obese rats has two points:firstly, the body weight of rats in HFD group (n=60) were significantly higher than those of in control group (n= 15) with 1.4 times of standard deviation. Secondly, the liver lipid droplet content and lipid levels have the significant differences between the two groups. After successfully establishing the animal model, we picked out 20 obese rats randomly divided into 4 groups (Group ?-?) fed with SIF 0 (control group),50 (low dose group),250 (medium dose group) and 500 (high dose group) mg·kg-1 body weight, respectively. The 4 four groups both fed with high oil diet. Then 5 normal rats fed with basal diet were the control group (Group ?).The 5 groups maintain the condition for 4 weeks. At the end of the experiment, the liver lipid droplet stained by Oil Red O:sections of liver and testis were prepared and stained by HE; Testosterone levels were detected by ELISA; the positive rates and mRNA expressions of the main enzymes including StAR?P450scc?P450c17?3?-HSD?17?-HSD?ANXA5were surveyed and evaluated by SABC immunohistochemistry and RT-PCR.1. The body weight and lipid levels in HFD group rats were significantly higher than those of in control group when successfully established the Food-induced obese rat model (P<0.05), specially the levels of TC?TG?LDL-C (P<0.01). Supplying the SIF plays an important role for losing the bodyweight of obese rats in a dose-dependent. SIF can obviously decrease the lipid levels of obese rats, especially under the high doses (P<0.05). The lipids level in control group had a very slow growing trends and gradually reached a steady state during the growth, however the lipid levels in HFD control group were in a stable high-level state during the intervention. Different doses of SIF has different effect on lipid levels. In the low dose, both the TC?TG?HDL-C levels were increasing firstly then followed, while the LDL-C had the opposite situation, but all of them were higher than the base level group. The TC, TG levels were firstly rising and then followed, the HDL-C? LDL-C levels were firstly decreased then rising,at lastly gradually reached a steady state in medium dose group. TC. TG, HDL-C at high dose SIF group rats decreased significantly, but TG, LDL-C levels were higher than those group basis. TC, HDL-C were significantly lower than group basis. Oil Red O staining displayed that HFD control group rats had a large accumulation of lipid droplets in uniform, while the other groups supplied with different SIF doses whose liver lipid droplets decreased from the perivascular and showed a dose-dependent manner.2. The HE staining showed that in HFD control group rats whose testis structure had changed, seminiferous tubule wall were thinning, tubular cell layers and various types of spermatogenic cells significantly reduced (P<0.05), arranged in sparse, some students seminiferous tubules atrophy, necrosis, most of the seminiferous tubules no mature sperm. Seminiferous tubule loosely arranged, mesenchymal become significantly thinner and the numbers of leydig cells were decreased, interstitial vascular congestion significantly. The testis morphology in obese rats in each experimental group with SIF had significant recovery, the number of spermatogenic cells increased, cells and small tubes arranged closely compared with HFD control group, especially in the middle and high dose group, while the low dose group testis seminiferous tubules are arranged relatively loose. Liver HE staining showed that in the HFD control group liver the cells was swelling, fatty degeneration and necrosis, inflammatory cells and heme iron increasing. The liver morphology in obese rats in each experimental group with SIF had also significant recovery, the medium dose group almost completely restored to normal morphology, however in the low and high dose group the liver blood vessel walls were seen a lot of inflammatory cells, there are also distributed within the organization and a small amount of liver cell necrosis.3. ELISA detection of testosterone levels of rats, hyperlipidemia group and the low dose SIF group rat testis testosterone were lowest, and testosterone in basic group rats and middle dose group was the highest-tech, high-dose group testosterone level in the middle. The results showed that obese rats significantly reduced testosterone levels in vivo, SIF in medium and high doses groups can significantly promote the synthesis and secretion of testosterone, the effect is more pronounced in medium group than high dose group, the difference between the groups was significant (P<0.05).4. Immunohistochemical SABC results:P450scc, P450c17,3?-HSD,17?-HSD, ANXA5, StAR were mainly expressed in the testis interstitial cell cytoplasm and cytoplasm of spermatogonia, in which the expression of StAR and P450scc were the most, SIF can significantly improve the expression levels that obesity lead to a decline. In addition to ANXA5, the expression of others had the sane expression trends:the expression in hyperlipidemia group was the least amount, basic group and middle dose group were the most, in low and medium dose SIF showed a dose-dependent manner, high dose group was lower than medium group(P<0.05). The expression of ANXA5 in the testis was different, based group was the highest, hyperlipidemia group was the least, ANXA5 in SIF groups were both higher than hyperlipidemia group with a dose-dependent manner (P<0.05) RT-PCR results were similar with SABC immunohistochemical results. For each key factor mRNA expression correlation analysis found a link between P450scc, P450c17,3?-HSD. 17?-HSD, StAR close to each other (P<0.05), there is no clear correlation between ANXA5 with other factors.The results showed that high-fat diet can successfully establish a stable rat model of obesity in a short time and supplemented with different doses of SIF can significantly dose-dependent reduce the levels of body weight and lipids. The high-fat diet-induced obesity can cause irreversible impact on the reproductive system of rats, while SIF can be more quickly restore its structure and function. The enhancement of SIF on the reproductive system was by increasing testosterone levels achieved, in particular regulation the expression of the key factors P450scc, P450c17,3?-HSD,17?-HSD. ANXA5, StAR involved in testosterone synthesis to recover testicular morphological structure integrity. But the most important thing is when SIF exposure dose exceeds 500mg/Kg·BW, the recover effects was a little bad during our study, the mechanism is not clear at the present. |
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