黄酮类化合物抗炎和抗肿瘤共同作用机制的研究进展

临床和实验室研究认为黄酮类化合物抗炎和抗肿瘤作用间有重要联系。炎症细胞和介质参与了肿瘤诱发和增殖,黄酮类化合物对炎症反应的干预可能是其抗肿瘤的原因之一。本文就黄酮类化合物抗炎、抗肿瘤作用中涉及的共同机制进行综述。     

荧光分光光度法测定大山楂丸中黄酮类化合物的含量

设定荧光激发/发射波长为281/352 nm,激发和发射光狭缝宽度为5 nm,在300~500 nm波长范围内测定荧光光谱。对酸度、表面活性剂、温度、反应时间及铝离子浓度等影响因素进行考察,优化试验条件。结果：在盐酸酸性介质中、无表面活性剂、常温下、反应时间30 min、铝离子浓度为2×10-4mol/L时,体系的荧光强度最大且稳定。当槲皮素的浓度范围在0.2×10-5~1.5×10-5mol/L之间时,荧光强度（F）和槲皮素浓度（c）呈良好的线性关系;检测限为2.4×10-8mol/L。3批大山楂丸中总黄酮的平均含量分别为24.56、27.85、25.13 mg/g,与《中国药典》方法测定结果基本一致。结论：本方法操作简便、快速、准确,可用于测定大山楂丸中总黄酮的含量。     

黄酮抗氧化和促氧化双重性初探

本文用自旋捕捉ESR方法比较也研究黄酮对羟基和超氧阴离子自由基的清除特性，清除能力与分子的结构有关，例如分子中OH基团的数目和位置，用分子模拟方法对分了及其单电子氧化后的产物进行量化计算的结果与ESR实验的结果相对应，自旋标记ESR的实验结果表明某些黄酮化合物能损伤人红细胞膜膜蛋白的构象，象是氧化性损伤并且与分子结构及浓度有关。黄酮的抗氧化和促氧化双重性值得进一步研究。     

Toxicological and pathophysiological roles of reactive oxygen and nitrogen species

‘Oxidative and Nitrative Stress in Toxicology and Disease’ was the subject of a symposium held at the EUROTOX meeting in Dresden 15th September 2009. Reactive oxygen (ROS) and reactive nitrogen species (RNS) produced during tissue pathogenesis and in response to viral or chemical toxicants, induce a complex series of downstream adaptive and reparative events driven by the associated oxidative and nitrative stress. As highlighted by all the speakers, ROS and RNS can promote diverse biological responses associated with a spectrum of disorders including neurodegenerative/neuropsychiatric and cardiovascular diseases. Similar pathways are implicated during the process of liver and skin carcinogenesis. Mechanistically, reactive oxygen and nitrogen species drive sustained cell proliferation, cell death including both apoptosis and necrosis, formation of nuclear and mitochondrial DNA mutations, and in some cases stimulation of a pro-angiogenic environment. Here we illustrate the pivotal role played by oxidative and nitrative stress in cell death, inflammation and pain and its consequences for toxicology and disease pathogenesis. Examples are presented from five different perspectives ranging from in vitro model systems through to in vivo animal model systems and clinical outcomes.     

Effect of ECQ on Iodoacetamide-Induced Chronic Gastritis in Rats

This study investigated effect of extract containing quercetin-3-O-β-D-glucuronopyranoside from Rumex Aquaticus Herba (ECQ) against chronic gastritis in rats. To produce chronic gastritis, the animals received a daily intra-gastric administration of 0.1 ml of 0.15% iodoacetamide (IA) solution for 7 days. Daily exposure of the gastric mucosa to IA induced both gastric lesions and significant reductions of body weight and food and water intake. These reductions recovered with treatment with ECQ for 7 days. ECQ significantly inhibited the elevation of the malondialdehyde levels and myeloperoxidase activity, which were used as indices of lipid peroxidation and neutrophil infiltration. ECQ recovered the level of glutathione, activity of superoxide dismutase (SOD), and expression of SOD-2. The increased levels of total NO concentration and iNOS expression in the IA-induced chronic gastritis were significantly reduced by treatment with ECQ. These results suggest that the ECQ has a therapeutic effect on chronic gastritis in rats by inhibitory actions on neutrophil infiltration, lipid peroxidation and various steps of reactive oxygen species (ROS) generation.     

依达拉奉治疗老年糖尿病周围神经病变的研究

目的观察依达拉奉治疗老年糖尿病周围神经病变（DPN）的临床疗效并探讨其机制。方法老年DPN患者61例,随机分为治疗组33例和常规组28例．两组均予基础治疗,治疗组加用依达拉奉联合前列地尔,常规组予弥可保及前列地尔,疗程均为2周。治疗前后分别判定症状。检查神经传导速度。测定血清MDA、LPO浓度及SOD活力。结果与常规组（53．6％）相比,治疗组症状显著改善（81．8％,P〈0．05）;神经传导速度增快（P〈0．05）;常规组血清MDA（6．13±1．46VS6．25±1．56μmol·L^-1,P〉0．05）、LPO（14．82±2．25VS15．24±2．49μmol·L^-1,P〉0．05）、SOD活力（57．14±9．28VS55．75±11．21U·mL^-1,P〉0．05）无明显变化,而治疗组MDA（4．32±1．09VS6．15±1．34μmol·L^-1,P〈0．05）、LPO（10．80±2．37vs14．55±2．25μmol·L^-1 P〈0．05）浓度明显降低。SOD活力（76．85±10．76VS61．27±12．98U·mL^-1 P〈0．05）显著升高。结论依达拉奉可有效改善DPN患者的临床症状,其机制可能与抗氧化作用有关。     

Protective effect of taurine on TNBS-induced inflammatory bowel disease in rats

We had previously reported that the protective effect of taurine against indomethacin-induced gastric mucosal injury was due to its antioxidant effects, which inhibited lipid peroxidation and neutrophil activation. In this study, we examined the effect of taurine on reducing the inflammatory parameters of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD), in rats. In order to induce IBD, ethanolic TNBS was given to rats intracolonically. Then they received 500 mg/kg/day of taurine orally and were sacrificed one week after IBD induction. While ulceration and inflammation of distal colon with formation of granuloma in the vehicle-treated IBD rats two days after administration of TNBS were observed, treatment with taurine ameliorated colonic damage and decreased the incidence of diarrhea and adhesion. Also, colon weight as an index of tissue edema, which was markedly increased in the IBD rats, became significantly lower after taurine treatment. Myeloperoxidase (MPO) activity in the vehicle-treated IBD rats was substantially increased, compared with that of normal control. The taurine-treated animals significantly reduced MPO activity (35% lower) when compared with that of the vehicle-treated animals. Taurine treatment decreased both basal and formyl-methionyl leucyl phenylalanine-stimulated reactive oxygen generation from colonic tissue in the IBD rats. These results suggest that the administration of taurine reduce the inflammatory parameters in this IBD rat model by increasing defending capacity against oxidative damage.     

Gastroprotective Effect of the Three Glucuronopyranoside Flavonoids in Rats

In this study, we investigated the protective action of glucuronopyranoside flavonoids (QGC, AGC, LGC) on gastritis in rats. QGC, AGC and omeprazole decreased the gastric volume significantly, and each ID₅₀ was 0.75, 0.54 and 8.5 mg/kg, respectively, thus the order of potency was AGC, QGC and omeprazole. They also decreased acid output, and each ID₅₀ was 7.81, 0.58 and 6.71 mg/kg, respectively, thus the order of potency was AGC, omeprazole and QGC. They inhibited gastritis induced by indomethacin, and it recovered significantly by increasing the GSH levels in gastritis. The gastric MPO activity in the gastritis group increased more than in the normal group. QGC, LGC, or AGC administration reduced moderately the MPO activity in a dose-dependent manner. This study demonstrated that AGC, QGC, or LGC showed potent efficacy on the gastritis, by preventing oxidative stress. These results suggest that QGC, AGC, or LGC have gastroprotective effect in rats.     

抗氧化剂SS-31肽对脓毒症小鼠海马神经元凋亡与炎症反应的影响

目的：观察抗氧化剂 SS-31肽对脓毒症小鼠海马神经元凋亡与炎症反应的影响。方法：成年雄性 C57BL/6小鼠65只随机分为3组：假手术组（Sham 组,15只）、脓毒症组（CLP 组,25只）和脓毒症+SS-31肽组（SS-31肽组,25只）。 CLP 组和 SS-31肽组建立盲肠结扎穿孔模型。术毕 SS-31肽组腹腔注射 SS-31肽（5 mg·kg-1）,Sham 组和 CLP 组注射等容生理盐水,连续单次注射6天。记录术后7天内死亡率;随后处死小鼠取海马组织,检测线粒体活性氧自由基（ROS）水平,Western bloting 检测总细胞色素 C（Cyt C）、细胞质 Cyt C、caspase 3和 Nlrp 3含量;酶联免疫吸附法（ELISA）检测白细胞介素1β（IL-1β）和神经元特异性烯醇化酶（NSE）水平。结果：与CLP 组相比,SS-31肽组7天死亡率明显降低（52% vs 24%）,线粒体 ROS 水平、细胞质 Cyt C、caspase 3和 Nlrp 3含量以及 IL-1β、NSE 水平均减少（P<0.05）。结论：抗氧化剂 SS-31肽可降低脓毒症小鼠脑海马组织中线粒体 ROS 水平,抑制凋亡和炎症反应,改善损伤,降低死亡率。     

Direct and indirect effects of particulate matter on the cardiovascular system

Human exposure to particulate matter (PM) elicits a variety of responses on the cardiovascular system through both direct and indirect pathways. Indirect effects of PM on the cardiovascular system are mediated through the autonomic nervous system, which controls heart rate variability, and inflammatory responses, which augment acute cardiovascular events and atherosclerosis. Recent research demonstrates that PM also affects the cardiovascular system directly by entry into the systemic circulation. This process causes myocardial dysfunction through mechanisms of reactive oxygen species production, calcium ion interference, and vascular dysfunction. In this review, we will present key evidence in both the direct and indirect pathways, suggest clinical applications of the current literature, and recommend directions for future research.     

Effects of TiO2 nanoparticles on ROS production and growth inhibition using freshwater green algae pre-exposed to UV irradiation

This study investigated the possibility that titanium dioxide nanoparticles (nano-TiO₂) toxicity in Pseudokirchneriella subcapitata involves reactive oxygen species (ROS) production, using the dichlorodihydrofluorescein (DCF) assay. Algae were exposed to nano-TiO₂ under laboratory fluorescent lamps supplemented with UV irradiation for 3 h, with or without a UV filter. Results showed that nano-TiO₂ increased ROS production in UV-exposed cells, with or without a UV filter (LOEC values were 250 and 10 mg/L, respectively). Sublethal effects of nano-TiO₂ on UV pre-exposed algae were also examined. Toxicity studies indicated that exposure to nano-TiO₂ agglomerates decreased algal growth following 3 h pre-exposure to UV, with or without a UV filter (EC₅₀s were 8.7 and 6.3 mg/L, respectively). The present study suggests that the growth inhibitory effects of nano-TiO₂ in algae occurred at concentrations lower than those that can elevate DCF fluorescence, and that ROS generation is not directly involved with the sublethal effects of nano-TiO₂ in algae.     

Airborne particulate matter modulates the production of reactive oxygen species in human polymorphonuclear granulocytes

Causal relationships between airborne particles (especially particulate matter < 10 μm in diameter) and increases in prevalences and symptoms of respiratory diseases have been postulated in many epidemiologic studies. Polymorphonuclear leukocytes (PMN) in the nasal or bronchial epithelium can be exposed to particulate matter (PM) and may upon exposure produce reactive oxygen species (ROS). Release of ROS can result in cellular and tissue damage and initiate or exacerbate inflammation. To elucidate the effect of PM on inflammatory reactions, we exposed human PMN to PM extracts. PM were collected with high volume samplers in two cities, Düsseldorf and Duisburg, in Germany and reflect sites with high traffic and industrial emissions respectively. The collected particles were extracted using water and then dichloromethane, resulting in an aqueous and an organic extract. The production of ROS was determined using luminol-enhanced chemiluminescence (LCL) of resting and zymosan-stimulated PMN. The present study shows that extracts of PM alone significantly stimulated the production and release of ROS in resting PMN. The effects of the PM extracts were inhibited by superoxide dismutase (SOD), catalase and sodium azide (NaN₃). Zymosan-induced LCL was, however, diminished by coincubation with PM extracts. The chemical composition is important when considering the effects of particles. Our study shows that only organic substances adsorbed to particles stimulate LCL. SOZ-induced LCL is inhibited by both types of extracts, but aqueous extracts have a stronger inhibitory effect. It is at present unclear which substances are responsible for these effects.     

In utero and postnatal exposure to a phytoestrogen-enriched diet increases parameters of acute inflammation in a rat model of TNBS-induced colitis

Inflammatory bowel disease (IBD) is very common in Europe and USA. Its incidence in East Asia has been traditionally low, albeit the risk of IBD increases in Asian immigrants adopting western lifestyles, suggesting a strong role of environmental/dietary factors in IBD. A lifelong exposure to phytoestrogen-rich diets has been associated with a decreased risk of developing breast cancer and might also be protective against IBD. We studied the influence of in utero and postnatal exposure to a phytoestrogen (PE)-rich diet on acute inflammation in an animal model of TNBS-induced colitis. Wistar rats were exposed in utero and postnatally to high (genistein: 240 μg/g feed; daidzein: 232 μg/g feed) or very low levels (genistein and daidzein <10 μg/g feed) of phytoestrogen isoflavones fed to pregnant dams with the diet and throughout nursing. After weaning, the offspring had free access to these diets. At the age of 11 weeks, colitis was induced with an enema of TNBS. After 3 days, animals were sacrificed and tissues were collected for histological evaluation and analysis of molecular markers of inflammation. Animals kept on a PE-rich diet (PRD) had higher colon weights than animals on low PE-levels (PDD), suggesting enhanced acute inflammation by phytoestrogens. This result was supported by histological findings and by analysis of myeloperoxidase activity. Interestingly, relative mRNA and protein expression of cyclooxygenase-2 (COX-2) were modulated in rats on PRD, providing evidence that COX-2, the inducible isoform of the enzyme, is involved in the management of colonic inflammation. Our results suggest that early-in-life exposure to PE might not protect against the development of IBD but enhances the extent of acute inflammation.     

Effect of liquiritigenin,a flavanone existed from Radix glycyrrhizae on pro-apoptotic in SMMC-7721 cells

Liquiritigenin is a flavanone existed in Radix glycyrrhizae. The objective of this study is to explore the effects of liquiritigenin on SMMC-7721 cells and its possible mechanism. The viability of liquiritigenin treat cells was decreased in a dose-dependent manner assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylterazolium bromide (MTT), and apoptotic morphological changes also be observed, such as chromatin condensation and nuclear fragmentation. Assessment of apoptotic cells by flow cytometry indicated that cells fell into apoptosis after 0.4 mM liquiritigenin treatment. In addition, a concomitant time-dependent increase in caspase-3 activity was also observed. The level of p53 protein increased and Bcl-2 protein decreased time-dependently. Further studies found the induction of apoptosis by liquiritigenin was accompanied with the production of reactive oxygen species (ROS), disruption of mitochondrial membrane potential and depletion of antioxidant enzymes. The significant ROS generation was firstly found at 3 h and being time-dependent until 9 h. A time-dependent decrease in membrane potential occurred, and significant loss appeared at 9 h and 12 h. Furthermore, pretreatment of N-acetyl-cysteine (NAC), ROS production and apoptosis induced by liquiritigenin were both suppressed. In sum, this paper indicated the cytotoxicity of liquiritigenin on SMMC-7721 cells may via effect on generation of ROS, later lead to cell apoptosis.     

Cathepsins: key modulators of cell death and inflammatory responses

Apoptosis is a key mechanism in the build up and maintenance of both innate and adaptive immunity as well as in the regulation of cellular homeostasis in almost every organ and tissue. Central to the apoptotic process is a family of intracellular cysteine proteases with aspartate-specificity, called caspases. Nevertheless, there is growing evidence that other non-caspase proteases, in particular lysosomal cathepsins, can play an important role in the regulation of apoptosis. In this review, the players and the molecular mechanisms involved in the lysosomal apoptotic pathways will be discussed as well as the importance of these pathways in the immune system and the pathogenesis of diseases.     

Effects of selenocystine on lead-exposed Chinese hamster ovary (CHO) and PC-12 cells

Lead is a pervasive environmental toxin that affects multiple organ systems, including the nervous, renal, reproductive, and hematological systems. Even though it is probably the most studied toxic metal, some of the symptoms of lead toxicity still cannot be explained by known molecular mechanisms. Therefore, lead-induced oxidative stress has recently started to gain attention. This in vitro study confirms the existence of oxidative stress due to lead exposure. Administration of lead acetate (PbA) to cultures of Chinese hamster ovary cells (CHO) had a concentration-dependent inhibitory effect on colony formation and cell proliferation. This inhibition was eliminated by 5 microM selenocystine (SeCys). In order to evaluate the nature of SeCys's effect, we measured glutathione (GSH), its oxidized form glutathione disulfide (GSSG), malondialdehyde (MDA), catalase, and GSH peroxidase (GPx) activities in lead-exposed CHO cells both in the presence and absence of SeCys. Increases in MDA, catalase, and GPx activities were observed in cultures that received only PbA, but supplementation with SeCys returned these measures to pretreatment levels. The ratio of GSH to GSSG increased in lead-exposed cells incubated in SeCys-enhanced media but declined in cultures treated with PbA only. In order to determine whether SeCys also reverses lead-induced neurotoxicity, a neuronal cell line, PC-12 cells, was used. Lead's inhibition on neurite formation was significantly eliminated by SeCys in PC-12 cells. Our results suggest that SeCys can confer protection against lead-induced toxicity in CHO cells and neurotoxicity in PC-12 cells.     

淋巴细胞基因表达谱揭示淫羊藿总黄酮重建衰老免疫稳态的分子机制

目的 探讨淫羊藿总黄酮重建衰老免疫稳态的基因调控模式。方法①采用流式细胞技术定量分析老年组、年轻组及淫羊藿总黄酮组大鼠脾淋巴细胞凋亡百分率。②采用基因芯片技术分析各组淋巴细胞基因表连谱。结果①细胞凋亡百分率：老年组与年轻组比较，淫羊藿总黄酮与老年组比较，差异均有著性（P〈0．01）。②基因表连：与年轻组比较，老年组上调的基因有116个，下调的基因有215个。与老年组比较，淫羊藿总黄酮上调的基因有447个，下调的基因有456个。涉及细胞凋亡、细胞增殖调控等方面。结论①以促凋亡基因表达上调、抗调亡基因表达下调为主要特微的表达模式是衰老免疫稳能失横的重要基因背景。②淫羊藿总黄酮的作用规律在于逆转功能对立的促凋亡基因与抗凋亡基因、促增殖基因与抗增殖基因在衰老淋巴细胞中表达的异常，重塑基因表达的良性平衡，重建衰老免疫稳能。     

淫羊藿总黄酮的抗炎作用

淫羊藿总黄酮对巴豆油所致小鼠耳肿胀、醋酸所致小鼠腹腔毛细血管通透性增加、角叉菜胶所致大鼠足肿胀及巴豆油所致肉芽组织增生具有显著抑制作用．对佐剂关节炎大鼠的原发性足肿胀和继发性足肿胀均有显著抑制作用．初步机理研究表明：淫羊藿总黄酮能显著降低炎症渗出物中前列腺素Ｅ和丙二醛的含量,提高小鼠红细胞过氧化氢酶的活力．对去肾上腺小鼠耳肿胀仍然有抑制作用,对大鼠肾上腺重量和肾上腺内维生素Ｃ含量无明显影响     

二甲双胍对糖基化终末产物诱导的成骨细胞氧化应激和凋亡的影响

目的:观察二甲双胍对糖基化终末产物(AGEs)诱导的大鼠颅骨成骨细胞内氧化应激产物活性氧簇(ROS)、细胞早期凋亡的影响.方法:分离培养大鼠颅骨成骨细胞,2 '7'-二乙酰二氯荧光素(DCFH-DA)作为荧光探针,流式细胞检测技术检测细胞内ROS水平,膜联蛋白V-异硫氰酸荧光素/碘化丙啶(Annexin V-FITC/ PI)双染色分析细胞早期凋亡率.结果:与未经葡萄糖处理的牛血清白蛋白(BSA)组对比,500 μg/mLAGEs显著促进成骨细胞内ROS形成和细胞凋亡(均P＜ 0.01);给予二甲双胍(100～500μmol/L)呈浓度依赖性抑制BSA组及AGEs组成骨细胞内ROS形成和细胞凋亡,浓度分别为500、400 μmol/L时,对细胞内ROS形成和细胞凋亡的抑制作用达到最强.结论:AGEs显著诱导原代成骨细胞内ROS的形成和细胞凋亡,而二甲双胍能够呈浓度依赖性抑制AGEs诱导的成骨细胞内ROS的形成和细胞凋亡,减轻AGEs对成骨细胞的损害.