| BackgroundCardiovascular diseases (CVD) are currently the leading cause of death in the world. Atherosclerosis (AS) is the pathological basis of CVD. During the development of AS, the endothelial injury induced by oxidized low density lipoprotein (ox-LDL) is the key initial point. Amount of experimental studies demonstrated that garlic and selenium (Se) could inhibit the risk factors of AS, and degrade the risk of CVD.In order to enhance its role of anti-AS, researchers considered the combination of garlic and Se from1990s. Our group had detected that, the combination of garlic and inorganic Se could reduce the rabbits’blood lipids, which were fed on high fat diet. It also could reduce the mortality rate of gastric cancer. However, both of garlic and inorganic Se would react against each other and reduce biological activity when mixed simply, for different pH values. Meanwhile, long-term usage of inorganic Se would cause damage for its toxicity and accumulation in liver and kidney. Although organic Se has lower toxicity, it’s costly and difficult to prepare. For all the conditions mentioned above, combining Se and garlic efficiently became a problem. Then, the successful cultivation of the selenium-enriched garlic (Se-garlic) offered a new strategy to solve the problem.Garlic can enrich Se from the environment. By imposing high-Se fertilizer, garlic can absorb inorganic Se, and transform it into organic form. Se-garlic has biological activity of both garlic and Se, and reduces the toxicity and accumulation of inorganic Se. If the role of Se-garlic on anti-AS could be confirmed, a new clue may be brought to preventing CVD, and also open wider market for its planting.Currently, there are few population studies on anti-AS with Se-garlic. For Se and garlic is the basic composition of Se-garlic, this study will explore the role of the two on AS. AS is a pathological change, which is hard to detect in clinical. So we will employ coronary heart disease (CHD) as object, and adapt Meta-analysis to assess the association of Se and garlic with prevention and treatment of CHD. If the association could be confirmed, the role of the two on AS may also be at a certain extent. Then the role of Se-garlic on that will also be confirmed.The existing studies on Se-garlic are mainly aspect on its role of antioxidation and anticancer. There are few about its role on endothelial cells, while the damage of that induced by ox-LDL is the key initial point of AS. So, its role could be confirmed from the perspective of the formation, if it could inhibit the endothelial injury induced by ox-LDL. An invitro experiment will be employed to determine the role of Se-garlic on cytoactive and apoptosis of endothelial cells induced by ox-LDL.Objectives1. A meta-analysis will be performed to assess the association of garlic or Se preparation with prevention and treatment of CHD.2. An invitro experiment will be preformed to detect the role of Se-garlic on cytoactive and apoptosis of ECV-304induced by ox-LDL. Compare the effect of that among Se-garlic, garlic, organic Se, and the combination of garlic and organic Se, under the conditions of the same exposure time and concentration.Methods1. Meta-analysisThe CNKI, Wan fang, VIP, CBM, Springer, Elsevier, and PubMed database were searched for randomized controlled trials, published before1,1,2012, both in English and Chinese. According to the inclusion and exclusion criteria, the eligible articles were selected. Then, the quality criteria of Jadad were adapted to assess researches’ quality, and the correlated data were abstracted. Heterogeneity was quantified with the I2statistic. An inverse-variance weighted fixed-effects model was adapted to pool relative risk estimates. Subgroup and sensitivity analyses were adapted if needed. We assessed publication bias with Egger’s test. Statistical analyses were conducted with Stata11.2.2. Invitro studySe-garlic oil and garlic oil were extracted by the method of organic solvent extraction. Hydride generation atomic fluorescence spectrometry was adapted to detect the content of Se in Se-garlic oil. Methyl thiazolyl tetrazoliums (MTT) assay was adapted to detect the effect of Se-garlic oil of different concentrations on the cytoactive of ECV-304, at24,48or72hours. Then, we employed a4x3x3factorial design to determine the effect of Se-garlic oil (Se-G), garlic oil (G), organic Se (Se), and the combination of garlic oil and organic Se (G+Se) at three concentrations,24,48or72hours on ECV-304induced by ox-LDL. Flow cytometry stained with Annexin V-FITC/PI was adapted to determine the effect of the four treatment measures on apoptosis of ECV-304induced by ox-LDL.Results1. Meta-analysis of Se preparation8randomized trials met our inclusion criteria. I2was40.9%, and the pooled RR was0.87(0.74,1.02). The articles were divided into two subgroups by the type of study design. One subgroup contained5clinical trials, and the other one contained3field trials. The pooled RR of the former was0.61(0.45,0.83), the latter0.99(0.82,1.20). Individual studies, whose quality score below4, were excluded for sensitivity analyses. The estimate did not modify substantially, with the pooled RR was0.97(0.81,1.16). Egger’s test suggested the presence of publication bias (P=0.004).2. Meta-analysis of garlic preparation7randomized trials met our inclusion criteria. I2was13.9%, and the pooled RR was0.75(0.51,1.10). One study, which employed field trials, was excluded for sensitivity analyses. The estimate modified substantially, while the pooled RR was0.64(0.42,0.99). Egger’s test didn’t suggest the presence of publication bias (P=0.936).3. Invitro experiment3.1The amount of Se in Se-garlic oil was198mg/kg. 3.2When the concentration of Se-G oil was below160μl/L and the exposure time was24or48hours, cytoactive of ECV-304induced by Se-G was above100%. It was below100%, when the time was72hours or the concentration was320μl/L.3.3The cytoactive of ECV-304, induced by Se-G oil and ox-LDL, was higher than that by ox-LDL (P<0.05), at any times and concentrations. Although the differences were not all significant, the cytoactive induced by Se-G and ox-LDL was higher than that by G and ox-LDL, or by G+Se and ox-LDL. At15μl/L, and24h, the cytoactive induced by Se-G and ox-LDL was higher than that by Se and ox-LDL (P=0.003). At60μl/L, the latter was higher (P<0.05).3.4There was no significant difference among the four treatment measures without ox-LDL and blank group (P>0.05), while lower than that by ox-LDL (P<0.05). The apoptosis rates of four treatment measures induced by ox-LDL were all significantly lower than that of ox-LDL, while with no significant difference against blank group.Conclusions1. Both of Se and garlic could reduce clinical symptoms of the patients with CHD.2. At a short exposure time and low concentration, Se-garlic oil could raise the cytoactive of endothelial cells, and inhibit at a long time or high concentration.3. Se-garlic could inhibit the reduction cytoactive and apoptosis of endothelial cells induced by ox-LDL. Se-garlic may play the role of anti-AS through this effect.4. The Se-garlic’s effect of inhibiting the reduction cytoactive was better than garlic, Se, or the combination of garlic and Se, while worse than Se only at high concentration. That of apoptosis was similar to garlic, Se, or the combination of garlic and Se. |
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