大蒜素的临床应用进展

就大蒜素的临床应用进展作一综述。     

大蒜素治疗大鼠肺孢子虫肺炎的实验研究

目的观察大蒜素对大鼠肺孢子虫肺炎(PCP)的治疗效果。方法采用皮下注射醋酸泼泥松龙的方法建立PCP大鼠模型。将受试大鼠随机分为正常对照组(A)、未治疗对照组(B)、TMP-SMZ治疗对照组(C)、大蒜素治疗组(D)和青蒿素治疗组(E)。各组从第7周开始灌服相应药物5d,停药后观察1周,用肺重/体重比和肺虫荷量考核疗效。结果PCP大鼠6周内的病死率为16.7%,满6周时抽样进行病原、病理检查,证实均已成功诱导PCP。5组受试大鼠的平均肺重/体重比分别为0.75±0.090、1.05±0.174、0.77±0.091、0.79±0.114和0.85±0.188。B~E组受试大鼠肺虫荷量分别为1490、74、296和219个包囊/mg肺。统计学分析显示,经大蒜素治疗的大鼠平均肺重/体重比、肺虫荷量均显著低于未治疗对照组(P<0.05),与TMP-SMZ治疗对照组和青蒿素治疗组比较差异无显著性(P>0.05)。结论大蒜素对大鼠PCP有显著疗效,效果与TMP-SMZ和青蒿素接近。     

The antimicrobial and antibiofilm properties of allicin against Candida albicans and Staphylococcus aureus – A therapeutic potential for denture stomatitis

The objective of this study is to determine the therapeutic efficacy of allicin against Candida albicans (C. albicans) and Staphylococcus aureus (S. aureus), the common etiological agents for denture stomatitis (DS). The minimum inhibitory concentration (MICs), minimum bactericidal concentrations (MBCs) and minimum fungicidal concentration (MFCs) of allicin were determined by the broth microdilution method followed by checkerboard microdilution method for a synergistic interaction between allicin + nystatin and allicin + CHX. The potential of allicin to eradicate C. albicans and S. aureus biofilms was assessed by treating biofilm formed on self- polymerized acrylic resin with allicin at a sub-MIC concentration for 5 min. The commercial denture cleanser (brand X) was used as a positive control. A Kruskal-Wallis test followed by the post-hoc Mann-Whitney U test was applied (SPSS 20.0), and the level of significance was set at P < 0.05. Allicin exhibited antimicrobial activity against C. albicans (MIC:8 µg/ml and MFC:16 µg/ml) and S. aureus (MIC:8 µg/ml and MBC:8 µg/ml). A synergistic interaction was observed between allicin + nystatin and allicin + CHX (FICI ≤ 0.5). Allicin exhibited significant biofilm eradication against C. albicans and S. aureus biofilms with percentages of 50.0% and 52.6%, respectively. The results of this study suggest a possible application of allicin in treating C. albicans and S. aureus infection in DS.     

大蒜素对HL-60细胞端粒酶活性的影响

目的 研究大蒜素对人早幼白血病HL-60细胞端粒酶活性的影响。方法 不同浓度的大蒜素作用HL-60细胞后,MTT法测细胞的生长和增殖情况,TRAP-PCR-ELISA法研究细胞端粒酶活性的变化。结果 大蒜素能明显地抑制HL-60细胞的生长,且呈时间、浓度依赖性。不同浓度的大蒜素能下调HL-60细胞的端粒酶活性,且同样呈时间、浓度依赖性。结论 大蒜素可抑制HL-60细胞的端粒酶活性,可能是其诱导HL-60细胞凋亡的重要机制之一。     

大蒜素与细胞周期特异性化疗药联合应用抗肿瘤的实验研究

目的: 探讨大蒜素对人胃癌细胞株BGC-823、SGC7901生长的影响及其与细胞周期特异性化疗药联合应用抗肿瘤作用。 方法: MTT法测定细胞增殖抑制率并测定药物半数抑制率(IC50);流式细胞仪检测细胞周期的改变,大蒜素与NVB、5-FU、MMC、PDD四种化疗药联合应用,观察细胞毒活性的改变。 结果: 大蒜素对BGC-823和SGC-7901两种细胞的生长均有明显的抑制作用,72hIC50分别为:30μg/ml和20μg/ml。以72hIC50浓度大蒜素分别作用于两种胃癌细胞株24h、48h后,流式细胞仪检测与对照组比G0/G1期细胞减少,G2/M期细胞明显增加,提示两种胃癌细胞株经大蒜素处理后,细胞周期阻滞于G2/M期。大蒜素与四种化疗药联合应用,结果发现作用于BGC-823细胞,NVB72h的IC50值由原来单独应用时的9.0μg/ml降至2.25μg/ml。作用于SGC-7901细胞,NVB72h的IC50值由原来单独应用时的43.0μg/ml降至12.5μg/ml,显示大蒜素与作用于G2/M期的细胞周期特异性化疗药NVB联合应用时可增强其对肿瘤细胞的杀伤作用。 结论: 大蒜素可使BGC-823和SGC-7901两种细胞的增殖受到抑制,细胞周期被阻滞在G2/M期。大蒜素与G2/M期特异性化疗药联合应用,可能具有协同抗肿瘤作用。     

大蒜素对小鼠膀胱癌的体内及体外抗肿瘤效果的实验研究

目的了解大蒜素对小鼠膀胱肿瘤的抗肿瘤效果与机制。方法通过MTT实验评定了大蒜素的直接细胞毒活性,动物实验显示大蒜素在体内有明显的抗肿瘤效果,并用LDH释放法测细胞毒活性。结果大蒜素对膀胱肿瘤有直接细胞毒作用。大剂量治疗组与对照组相比,肿瘤的生长速度明显受到抑制(P<0.01),大蒜素治疗后产生了针对B16肿瘤细胞的淋巴细胞。结论大蒜素对膀胱肿瘤有明显的抗肿瘤作用。这种效果可能与直接细胞毒作用和免疫反应有关。大蒜素可能是一种有效的表浅膀胱癌腔内治疗药物。     

Allicin, a major component of garlic, inhibits apoptosis of macrophage in a depleted nutritional state

OBJECTIVE: Allicin is believed to be the main component responsible for the biological activity of garlic. The regulation of cell death might have therapeutic potential in many diseases, and previous studies have demonstrated that allicin stimulates the functional activity of macrophages. Therefore, this study examined the effects of allicin on the apoptosis of macrophages induced by serum- and amino acid-free culture. METHODS: The apoptosis of peritoneal macrophages was examined after pretreating them with allicin and incubating them in a depleted nutritional state. The rate of apoptosis was determined using propidium iodide staining analysis using flow cytometry, DNA fragmentation, and a caspase-3 assay. Western blot analysis was used to examine the changes in the pro- or antiapoptotic protein expression levels. RESULTS: DNA fragmentation and propidium iodide staining analyses revealed that allicin decreased the malnutrition-induced apoptosis of macrophages. The level of Bax expression, the amount of cytochrome-c released from the mitochondria, and the caspase-3 activity were also lower in the allicin-treated macrophages than in the untreated macrophages in a depleted nutritional state. Moreover, the MEK (mitogen-activated protein kinase/extracellular signal-regulated kinase-kinase) inhibitor suppressed the allicin-induced inhibition of apoptosis in a depleted nutritional state and allicin increased the level of ERK1/2 phosphorylation. CONCLUSION: Allicin inhibits the apoptosis of macrophages in a depleted nutritional state through the MEK/extracellular signal-regulated kinase pathway.     

大蒜素对人胃癌细胞SGC-7901及BGC-823 G2/M期的阻滞调节机制

目的:研究大蒜素对人胃癌细胞SGC-7901及BGC-823G2/M期阻滞作用及其调节机制.方法:应用MTT法测定大蒜素对人胃癌细胞株SGC-7901和BGC-823细胞增殖抑制率及72h的IC50.通过流式细胞仪检测IC50浓度的大蒜素对SGC-7901和BGC-823细胞周期的影响.应用免疫组化染色检测大蒜素作用前后SGC-7901和BGC-823细胞CDC2和CyclinB蛋白表达.结果:不同浓度的大蒜素可以抑制人胃癌细胞株SGC-7901和BGC-823的增殖,且随着大蒜素浓度的增大,抑制率逐渐增高.大蒜素抑制SGC-7901细胞增殖50%的药物浓度(IC50):72h为23mg/L;大蒜素抑制BGC-823细胞增殖50%的药物浓度(IC50):72h为35mg/L.大蒜素作用于两种细胞,其细胞周期均发生了明显的变化,主要表现为G0/G1期细胞减少,G2/M期细胞增多(SGC-7901细胞24,48hvs对照:26.47±2.54%,28.88±2.75%vs24.30±2.74%,P<0.01;BGC-823细胞24,48hvs对照:22.78±1.45%,24.87±1.61%vs20.32±1.34%,P<0.01),S期细胞无明显变化.未经大蒜素处理的两种细胞,CDC2和CyclinB蛋白表达均为阳性,大蒜素处理后,CDC2和CyclinB蛋白表达下降.SGC-7901细胞经23mg/L大蒜素处理后,CDC2蛋白相对阳性表达率为87.2%;CyclinB蛋白相对阳性表达率为59.3%.BGC-823细胞CDC2蛋白在35mg/L大蒜素作用后,相对阳性表达率为84.4%;CyclinB蛋白相对阳性表达率为62.8%,与对照组相比均有显著性差异(P<0.01).结论:大蒜素使人胃癌细胞株SGC-7901和BGC-823停滞于G2/M期,其机制是通过CDC2和CyclinB蛋白表达下降实现的.     

大蒜素对肝癌细胞QGY-7701增殖和凋亡的影响

大蒜素是大蒜中主要生物活性成分的总称,其抗癌、防癌作用已成为人们关注的热点[1].本研究通过体外实验系统地研究了大蒜素对肝癌细胞QGY-7701增殖和凋亡的影响,为大蒜素在人类癌症预防中更广泛地应用提供理论依据.     

Allicin,a natural antimicrobial defence substance from garlic,inhibits DNA gyrase activity in bacteria

Allicin (diallylthiosulfinate) is a potent antimicrobial substance, produced by garlic tissues upon wounding as a defence against pathogens and pests. Allicin is a reactive sulfur species (RSS) that oxidizes accessible cysteines in glutathione and proteins. We used a differential isotopic labelling method (OxICAT) to identify allicin targets in the bacterial proteome. We compared the proteomes of allicin-susceptible Pseudomonas fluorescens Pf0-1 and allicin-tolerant PfAR-1 after a sublethal allicin exposure. Before exposure to allicin, proteins were in a predominantly reduced state, with approximately 77% of proteins showing less than 20% cysteine oxidation. Protein oxidation increased after exposure to allicin, and only 50% of proteins from allicin-susceptible Pf0-1, but 65% from allicin-tolerant PfAR-1, remained less than 20% oxidised. DNA gyrase was identified as an allicin target. Cys₄₃₃ in DNA gyrase subunit A (GyrA) was approximately 6% oxidized in untreated bacteria. After allicin treatment the degree of Cys₄₃₃ oxidation increased to 55% in susceptible Pf0-1 but only to 10% in tolerant PfAR-1. Allicin inhibited E. coli DNA gyrase activity in vitro in the same concentration range as nalidixic acid. Purified PfAR-1 DNA gyrase was inhibited to greater extent by allicin in vitro than the Pf0-1 enzyme. Substituting PfAR-1 GyrA into Pf0-1 rendered the exchange mutants more susceptible to allicin than the Pf0-1 wild type. Taken together, these results suggest that GyrA was protected from oxidation in vivo in the allicin-tolerant PfAR-1 background, rather than the PfAR-1 GyrA subunit being intrinsically less susceptible to oxidation by allicin than the Pf0-1 GyrA subunit. DNA gyrase is a target for medicinally important antibiotics; thus, allicin and its analogues may have potential to be developed as gyrase inhibitors, either alone or in conjunction with other therapeutics.