镉对植物生长的影响及植物耐镉机理研究进展

镉污染问题是全球面临的重大环境污染问题之一。镉污染土壤不仅影响植物的生长发育,而且严重威胁人类的生命健康,一直是国内外研究的热点。概述了不同浓度镉对植物生长的影响、植物吸收、转运镉及植物耐镉机理,指出了今后的主攻方向。     

镉胁迫对紫花苜蓿生长及植株镉含量的影响

采用盆栽实验,以多叶苜蓿和准格尔苜蓿2个品种为材料,研究了Cd胁迫(0、5、10、20、50mg·kg-1)对紫花苜蓿生长和植株Cd含量的影响。结果显示,Cd处理质量分数为5mg·kg-1时,2个品种的株高、主根长、干质量较之对照组均有所提高,但差异不显著;随Cd处理质量分数增加,上述指标呈显著降低趋势,尤其是当处理质量分数达到50mg·kg-1时,其下降幅度则多叶苜蓿明显小于准格尔苜蓿;在重度Cd胁迫下,2个品种地上部和根部的Cd含量都增大,准格尔苜蓿的Cd含量高于多叶苜蓿。试验表明,在Cd质量分数超过10mg·kg-1的土壤中不宜种植紫花苜蓿。     

镉对植物光合作用的影响

从光合速率、叶绿体及叶绿素、光化学反应、电子传递、光合作用中CO2同化等方面概述了镉（Cd）对植物光合作用的影响，力图阐明Cd影响植物光合作用的生理机制。     

镧对镉离子胁迫下黑曲霉抗氧化酶活性变化的影响

分别应用含有120μmol·L-1 La3+,50μmol·L-1 Cd2+,100μmol·L-1 Cd2+,50μmol·L-1 Cd2++120μmol·L-1 La3+,100μmol·L-1Cd2++120μmol·L-1 La3+的培养基培养黑曲霉,3 d后测定黑曲霉菌球的生物量及其胞内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、过氧化物酶(POD)和谷胱甘肽-S-转移酶(GST)活性及脂质过氧化产物(MDA)的变化。结果表明,50和100μmol.L-1Cd2+降低了黑曲霉生物量和五种抗氧化酶活性,并诱导了MDA产物的升高。与Cd2+单一处理比较,50μmol·L-1 Cd2++120μmol·L-1 La3+和100μmol·L-1 Cd2++120μmol·L-1 La3+处理组均不同程度上诱导了五种抗氧化酶活性的升高,并降低了MDA的积累水平。其中,120μmol·L-1 La3+对50μmol·L-1 Cd2+氧化胁迫的缓解效应明显高于100μmol·L-1 Cd2+。因此,La对黑曲霉中低剂量Cd胁迫的缓解效应比较显著,而对高剂量Cd的拮抗效应不明显。     

火焰原子吸收光谱法研究五种螯合剂对染镉小鼠睾丸中镉钙铁锌浓度的影响

采用火焰原子吸收光谱法分别对染镉小鼠和N-对羟甲苯甲基-D-葡糖二硫代氨基甲酸钠(HBGD)、N-苯甲基-D-葡糖二硫代氨基甲酸钠(BGD)、二乙基二硫代氨基甲酸钠(DDTC)、二巯基丙醇(BAL)、乙二胺四乙酸(EDTA)等五种螯合剂治疗组小鼠睾丸中镉、钙、铁、锌等金属浓度进行了测定和研究.结果表明:镉染毒(Cd 2.5 mg·kg-1,腹腔注射)后,小鼠睾丸中镉、钙、铁、锌等金属浓度显著高于对照组(p＜0.05),染镉30 min后用各螯合剂治疗(0.400 mmol·kg-1,腹腔注射),24 h后除EDTA外,其余螯合剂能明显降低睾丸中镉的浓度并抑制钙、铁、锌浓度的增加(p＜0.05);染镉24 h后注射各螯合剂,治疗24 h后,HBGD、BGD和DDTC显著降低了小鼠睾丸中各金属浓度(p＜0.05);提示HBGD和BGD有望成为染镉中毒的理想解毒剂.     

改性活性炭对土壤镉的吸附性影响

目的研究3种改性活性炭对菜地、河流底泥、荷花底泥镉吸附性的影响。方法对活性炭进行酸改性、碱改性和氧化改性,采用双硫腙分光光度法测定镉含量。结果对实验土样,最佳活性炭添加量为0.025 g/g。随着初始镉含量的升高,土壤对镉的吸附量不断增大。结论 3种改性活性炭相比普通活性炭对湿地土壤的镉吸附量均有不同程度的提升,荷花底泥中,酸性、氧化改性活性炭相比普通活性炭,吸附效果提高7.7%,8.3%,吸附效果提升显著。     

镉及镉锌交互作用的植物效应

镉是植物生长的非必需元素，而锌是植物生长必需的微量元素。虽然它们对植物的作用截然相反，但它们之间存在着复杂的交互影响关系。总结了镉对植物的生物效应，镉锌交互作用对植物的影响，包括：对元素的吸收积累，酶活性，细胞分裂等，论述了其主要影响因素，并探讨了Cd—Zn拮抗和Cd—Zn协同作用的可能机理。     

试剂加入次序不同造成镉对肝脂质过氧化的诱导或拮抗作用

采用TBA检测方法，体外观察了CaCl2对大鼠线粒体脂质过氧化产物丙二醛(MDA)生成的毒性作用和对半胱氨酸-Fe^2 诱导的线粒体脂质过氧化的影响。结果表明，1 μmol／L～1mol／L CdCl2均能诱导肝线粒体的脂质过氧化，使MDA含量增加，但只有CdCl2浓度高于1 mmol／L时，诱导作用才与对照组有显著性差异。在Fe^2 -Cd^2 半胱氨酸共同对肝线粒体作用时，由于试剂加入顺序的不同，100～1000 mmol／L CdCl2对线粒体脂质过氧化可产生诱导或拮抗作用。结果提示，CdCl2可直接诱导线粒体脂质过氧化，在做几种金属离子体外协同对肝脂质过氧化影响的实验时，应考虑试剂加入顺序所产生的不同影响。     

土壤中镉及镉的赋存形态研究进展

综述了土壤中镉及镉的赋存形态研究进展,包括:土壤环境中镉及其污染来源,土壤中镉的赋存形态,镉赋存状态同镉生物活性的关系,土壤性状对镉赋存形态的影响,土壤中镉的测定方法等。     

锌,镉及金属硫蛋白在大鼠前列腺的定位研究

测定了Wister大鼠前列腺不同部位锌、镉含量，发现背侧叶、背前叶及腹叶含锌量依次为890．0±80．2、294.0±32.5和35.8±6．7μg／g干组织，含镉量依次为0.257±0．030、0.128±0．012和0．060±0．009μg／g干组织。各叶之间锌含量有显著性差异（P＜0.01），镉含量的差异具有统计学意义（P＜0．05），而且各叶中锌的含量明显高于镉。免疫组化测定将金属硫蛋白定位于腺体上细胞核和细胞液中，各叶均为阳性，其强度依次为背侧叶最强，背前叶其次，腹叶最弱，与锌、镉分布一致。     

Lycopene: A Potent Antioxidant for the Amelioration of Type II Diabetes Mellitus

Nutrition is of utmost importance in chronic disease management and has often been described as the cornerstone of a variety of non-communicable diseases. In particular, type II diabetes mellitus (T2DM) represents a prevalent and global public health crisis. Lycopene, a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables, has been extensively studied for its biological activities and treatment efficiency in diabetes care. Epidemiological investigations indicate that lycopene has potential antioxidant properties, is capable of scavenging reactive species, and alleviates oxidative stress in T2DM patients. This review aims to summarize the characteristics and mechanisms of action of lycopene as a potent antioxidant for T2DM. In addition, the evidence demonstrating the effects of lycopene on glycemic control and oxidative stress biomarkers in T2DM are also highlighted using animal and human studies as literature approach.     

Lycopene Improves Metabolic Disorders and Liver Injury Induced by a Hight-Fat Diet in Obese Rats

Epidemiological studies have shown that the consumption of a high-fat diet (HFD) is positively related to the development of obesity. Lycopene (LYC) can potentially combat HFD-induced obesity and metabolic disorders in rats. This study aimed to investigate the effect of LYC on metabolic syndrome and assess its anti-inflammatory and antioxidant effects on the liver and adipose tissue in rats fed an HFD. Thirty-six male Wistar albino rats were divided into three groups. Group Ι (the control group) was fed a normal diet, group ΙΙ (HFD) received an HFD for 16 weeks, and group ΙΙΙ (HFD + LYC) received an HFD for 12 weeks and then LYC (25 mg/kg b.wt) was administered for four weeks. Lipid peroxidation, antioxidants, lipid profile, liver function biomarkers, and inflammatory markers were determined. The results showed that long-term consumption of an HFD significantly increased weight gain, liver weight, and cholesterol and triglyceride levels. Rats on an HFD displayed higher levels of lipid peroxidation and inflammatory markers. Moreover, liver and white adipose tissue histopathological investigations showed that LYC treatment mended the damaged tissue. Overall, LYC supplementation successfully reversed HFD-induced changes and shifts through its antioxidant and anti-inflammatory activity. Therefore, LYC displayed a therapeutic potential to manage obesity and its associated pathologies.     

Ameliorative Potential of Hydroethanolic Leaf Extract of Parquetina nigrescens on d-Galactose-Induced Testicular Injury

Background: There is an increasing need for botanicals to be used as an alternative and complementary medicine in the management of male infertility. Male infertility has been a major health/social challenge to people all over the world. This study, therefore, investigated the ameliorative potential of hydroethanolic leaf extract of Parquetina nigrescens (HELEPN) against d-galactose-induced testicular injury. Methods: Thirty male Wistar rats were randomly allotted into six groups (n = 5). Group I (Normal control), Group II (300 mg/kg b.w. d-galactose), Group III and IV (250 and 500 mg/kg b.w. HELEPN, respectively), Group V and VI (both received 300 mg/kg b.w. of d-galactose with 250 and 500 mg/kg b.w of HELEPN, respectively). d-galactose administration started two weeks prior to HELEPN treatment which lasted for six weeks. All assays were carried out using established protocols. Results: Administration of HELEPN at 250mg/kg and 500mg/kg concomitantly with d-galactose improved paired and relative testicular weights, levels of gonadotropins (LH and FSH) and testosterone, and poor sperm quality. HELEPN treatment reduced the levels of oxidative stress biomarkers (MDA, 8-OHDG, and AGEs) and inflammatory response (TNF-alpha and NO) to normal, as well as restoring the reduced activities of antioxidant enzymes (glutathione peroxidase, superoxide dismutase, and catalase). In addition, HELEPN treatment mitigated testicular DNA fragmentation and down-regulated caspase 3-activities. HELEPN at 500 mg/kg was observed to have the greatest ameliorative effect. Conclusion: HELEPN protects against d-galactose-induced testicular injury through antioxidative, anti-inflammatory, and antiapoptotic mechanisms.     

Oxymatrine Alleviates Gentamicin-Induced Renal Injury in Rats

Gentamicin is an aminoglycoside antibiotic commonly used to treat Gram-negative bacterial infections that possesses considerable nephrotoxicity. Oxymatrine is a phytochemical with the ability to counter gentamicin toxicity. We investigated the effects and protective mechanism of oxymatrine in rats. The experimental groups were as follows: Control, Oxymatrine only group (100 mg/kg/d), Gentamicin only group (100 mg/kg/d), Gentamicin (100 mg/kg/d) plus Oxymatrine (100 mg/kg/d) group (n = 10). All rats were treated for seven continuous days. The results indicated that oxymatrine alleviated gentamicin-induced kidney injury, and decreased rats’ kidney indices and NAG (N-acetyl-beta-d-glucosaminidase), BUN (blood urea nitrogen) and CRE (creatine) serum levels. The oxymatrine-treated group sustained less histological damage. Oxymatrine also relived gentamicin-induced oxidative and nitrative stress, indicated by the increased SOD (superoxidase dismutase), GSH (glutathione) and CAT (catalase) activities and decreased MDA (malondialdehyde), iNOS (inducible nitric oxide synthase) and NO (nitric oxide) levels. Caspase-9 and -3 activities were also decreased in the oxymatrine-treated group. Oxymatrine exhibited a potent anti-inflammatory effect on gentamicin-induced kidney injury, down-regulated the Bcl-2ax and NF-κB mRNAs, and upregulated Bcl-2, HO-1 and Nrf2 mRNAs in the kidney tissue. Our investigation revealed the renal protective effect of oxymatrine in gentamicin-induced kidney injury for the first time. The effect was achieved through activation of the Nrf2/HO-1 pathways. The study underlines the potential clinical application of oxymatrine as a renal protectant agent for gentamicin therapy.     

Cannabidiol Improves Antioxidant Capacity and Reduces Inflammation in the Lungs of Rats with Monocrotaline-Induced Pulmonary Hypertension

Cannabidiol (CBD) is a plant-derived compound with antioxidant and anti-inflammatory properties. Pulmonary hypertension (PH) is still an incurable disease. CBD has been suggested to ameliorate monocrotaline (MCT)-induced PH, including reduction in right ventricular systolic pressure (RVSP), a vasorelaxant effect on pulmonary arteries and a decrease in the white blood cell count. The aim of our study was to investigate the effect of chronic administration of CBD (10 mg/kg daily for 21 days) on the parameters of oxidative stress and inflammation in the lungs of rats with MCT-induced PH. In MCT-induced PH, we found a decrease in total antioxidant capacity (TAC) and glutathione level (GSH), an increase in inflammatory parameters, e.g., tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), nuclear factor kappa B (NF-κB), monocyte chemoattractant protein-1 (MCP-1), and cluster of differentiation 68 (CD68), and the overexpression of cannabinoid receptors type 1 and 2 (CB₁-Rs, CB₂-Rs). Administration of CBD increased TAC and GSH concentrations, glutathione reductase (GSR) activity, and decreased CB₁-Rs expression and levels of inflammatory mediators such as TNF-α, IL -1β, NF-κB, MCP-1 and CD68. In conclusion, CBD has antioxidant and anti-inflammatory effects in MCT-induced PH. CBD may act as an adjuvant therapy for PH, but further detailed preclinical and clinical studies are recommended to confirm our promising results.     

Antioxidant Cardioprotection against Reperfusion Injury: Potential Therapeutic Roles of Resveratrol and Quercetin

Ischemia-reperfusion myocardial damage is a paradoxical tissue injury occurring during percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) patients. Although this damage could account for up to 50% of the final infarct size, there has been no available pharmacological treatment until now. Oxidative stress contributes to the underlying production mechanism, exerting the most marked injury during the early onset of reperfusion. So far, antioxidants have been shown to protect the AMI patients undergoing PCI to mitigate these detrimental effects; however, no clinical trials to date have shown any significant infarct size reduction. Therefore, it is worthwhile to consider multitarget antioxidant therapies targeting multifactorial AMI. Indeed, this clinical setting involves injurious effects derived from oxygen deprivation, intracellular pH changes and increased concentration of cytosolic Ca²⁺ and reactive oxygen species, among others. Thus, we will review a brief overview of the pathological cascades involved in ischemia-reperfusion injury and the potential therapeutic effects based on preclinical studies involving a combination of antioxidants, with particular reference to resveratrol and quercetin, which could contribute to cardioprotection against ischemia-reperfusion injury in myocardial tissue. We will also highlight the upcoming perspectives of these antioxidants for designing future studies.     

The Antioxidant Effect of Curcumin and Rutin on Oxidative Stress Biomarkers in Experimentally Induced Periodontitis in Hyperglycemic Wistar Rats

Background: There is a growing interest in the correlation between antioxidants and periodontal disease. In this study, we aimed to investigate the effect of oxidative stress and the impact of two antioxidants, curcumin and rutin, respectively, in the etiopathology of experimentally induced periodontitis in diabetic rats. Methods: Fifty Wistar albino rats were randomly divided into five groups and were induced with diabetes mellitus and periodontitis: (1) (CONTROL)—control group, (2) (DPP)—experimentally induced diabetes mellitus and periodontitis, (3) (DPC)—experimentally induced diabetes mellitus and periodontitis treated with curcumin (C), (4) (DPR)—experimentally induced diabetes mellitus and periodontitis treated with rutin (R) and (5) (DPCR)—experimentally induced diabetes mellitus and periodontitis treated with C and R. We evaluated malondialdehyde (MDA) as a biomarker of oxidative stress and reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG and catalase (CAT) as biomarkers of the antioxidant capacity in blood harvested from the animals we tested. The MDA levels and CAT activities were also evaluated in the gingival tissue. Results: The control group effect was statistically significantly different from any other groups, regardless of whether or not the treatment was applied. There was also a significant difference between the untreated group and the three treatment groups for variables MDA, GSH, GSSG, GSH/GSSG and CAT. There was no significant difference in the mean effect for the MDA, GSH, GSSG, GSH/GSSG and CAT variables in the treated groups of rats with curcumin, rutin and the combination of curcumin and rutin. Conclusions: The oral administration of curcumin and rutin, single or combined, could reduce the oxidative stress and enhance the antioxidant status in hyperglycemic periodontitis rats.     

Protective Effect of Lycium ruthenicum Polyphenols on Oxidative Stress against Acrylamide Induced Liver Injury in Rats

Acrylamide (ACR) is formed during tobacco and carbohydrate-rich food heating and is widely applied in many industries, with a range of toxic effects. The antioxidant properties of Lycium ruthenicum polyphenols (LRP) have been established before. This study aimed to research the protective effect of LRP against ACR-induced liver injury in SD rats. Rats were divided into six groups: Control, ACR (40 mg/kg/day, i.g.), LRP (50, 100, and 200 mg/kg/day, i.g.) plus ACR, and LRP groups. After 19 days, we evaluated oxidative status and mitochondrial functions in the rat’s liver. The results showed that glutathione (GSH) and superoxide dismutase (SOD) levels increased after LRP pretreatment. In contrast, each intervention group reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels compared to the ACR group. Meanwhile, alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver mitochondrial ATPase activity, mRNA expression of mitochondrial complex I, III, and expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) and its downstream proteins were all increased. This study suggested that LRP could reduce ACR-induced liver injury through potent antioxidant activity. LRP is recommended as oxidative stress reliever against hepatotoxicity.     

Cardioprotective Effects of 6-Gingerol against Alcohol-Induced ROS-Mediated Tissue Injury and Apoptosis in Rats

The present study investigated the cardioprotective properties of 6-gingerol against alcohol-induced ROS-mediated cardiac tissue damage in rats. Experiments were conducted on 4 groups of rats, orally treated with control, 6-gingerol (10 mg/kg body weight), alcohol (6 g/kg body weight) and combination of 6-gingerol plus alcohol for two-month. In the results, we found 6-ginger treatment to alcohol-fed rats substantially suppressed ROS production in cardiac tissue. Alcohol-induced elevated 8-OHDG and protein carbonyls which represent oxidative modification of DNA and proteins were completely reversed by 6-gingerol. This was further endorsed by restored superoxide dismutase and catalase activities with 6-gingerol against alcohol-induced loss. The elevated cardiac biomarkers (CK-MB, cTn-T, cTn-I) and dyslipidemia in alcohol-intoxicated rats was significantly reversed by 6-gingerol. Furthermore, alcohol-induced apoptosis characterized by overexpression of cytochrome C, caspase-8 and caspase-9 was diminished with 6-gingerol treatment. Transmission electron microscope images conferred the cardioprotective properties of 6-gingerol as we have seen less structural derangements in mitochondria and reappearance of myofilaments. Our findings conclude that 6-ginger effectively protect alcohol-induced ROS-mediated cardiac tissue damage, which may be due to its potent antioxidant efficacy. Therefore, 6-gingerol could be a potential therapeutic molecule that can be used in the treatment of alcohol-induced myocardial injury.