Cadmium exposure induces vascular injury due to endothelial oxidative stress: the role of local angiotensin II and COX-2

Rosmarinic Acid Attenuates Cadmium-Induced Nephrotoxicity via Inhibition of Oxidative Stress, Apoptosis, Inflammation and Fibrosis

The present investigation was executed to reveal the protective mechanism of rosmarinic acid (RA) against cadmium (Cd)-induced nephrotoxicity. RA exhibited a concentration-dependent anti-apoptotic effect against CdCl2 in isolated mouse proximal tubular epithelial cells. Cd treatment significantly (p < 0.01) imparted oxidative stress to the renal cells via excessive ROS production, triggering NO level, NADPH oxidase activation, and impairment of cellular redox defense system. Cd-mediated oxidative stress significantly (p < 0.01) endorsed apoptosis to the murine kidney cells by triggering NF-κB/PKC-δ/TNFR2 activation. In addition, CdCl2 induced renal fibrosis by triggering TGF-β1/SMAD3/α-SMA/collagen signaling within renal cells. On the other hand, RA significantly (p < 0.05-0.01) attenuated Cd-provoked oxidative stress and associated pathological signal transduction in murine renal cells. RA treatment also could significantly (p < 0.05-0.01) reciprocate Cd-mediated pathological changes in blood and urine parameters in mice. In addition, histological data supported the pharmacological findings. In silico chemometric analyses predicted the possible interactions between RA and different signal proteins and anticipated drug-likeness characteristics of RA. Hence, RA can potentially be applied as a therapeutic agent to treat Cd-mediated nephrotoxicity in future.

A soybean-based diet modulates cadmium-induced vascular apoptosis

Cadmium (Cd) exposure has been associated with an increased risk of cardiovascular diseases. The diet is a modifiable source of protecting or damaging factors that may affect this risk. Herein we tested the hypothesis that a soybean-based diet (SBD) protects the vascular wall of the aorta against Cd-induced pro-inflammatory and pro-apoptotic effects. To test this hypothesis, we fed male Wistar rats for 60 days with a casein-based diet (CBD) or an SBD. These animals were also exposed to tap-water without (CBD-Co/SBD-Co) or with 15(CBD-15Cd/SBD-15Cd) or 100 (CBD-100Cd/SBD-100Cd) ppm of Cd. Inflammatory parameters (mRNAs and/or proteins) were measured in thoracic aorta tissue. These included inducible and endothelial nitric oxide synthases, cyclooxygenase-2, intracellular-adhesion molecule-1, and vascular cell-adhesion molecule-1. As pro-apoptotic parameters, we measured Bax and Bcl-2 mRNA/protein, as well as TUNEL positive cells in the aorta tissue. Compared to CBD-Co, inflammatory and apoptosis markers increased in the aorta with the concentration of Cd in the drinking water. These effects were not observed in either SBD-15Cd or SBD-100Cd, which were similar to CBD-Co. Cd content in serum and in aortas from animals fed CBD-Co/SBD-15Cd or CBD-Co/SBD-100Cd were similar suggesting that, if any, the effect of SBD is not due to changes in Cd bioaccumulation, but due to secondary effects linked to the composition of the dietary soybean flour. Our findings are consistent with a protective effect of an SBD against Cd-induced inflammation and apoptosis in the thoracic aorta in a rat model.

Chronic Cadmium Exposure Accelerates the Development of Atherosclerosis and Induces Vascular Dysfunction in the Aorta of ApoE-/- Mice

Cadmium exposure is related to cardiovascular diseases, including hypertension, atherosclerosis, increased oxidative stress, endothelial dysfunction, and specific biochemical changes induced by this metal. Thus, we aimed to investigate whether cadmium exposure induces endothelial dysfunction, accelerates atherosclerotic plaque formation in the aorta, and enhances oxidative stress in apolipoprotein E knockout (ApoE^-/-) mice. Experiments were performed in 14-week-old male wild-type and ApoE^-/- mice. ApoE^-/- mice received cadmium (CdCl₂ 100 mg/L in drinking water for 28 days) or vehicle (distilled water). After treatment, vascular reactivity to phenylephrine, acetylcholine, and sodium nitroprusside was analyzed using isolated aorta. Bone marrow cells were isolated to assess the production of nitric oxide and reactive oxygen and nitrogen species. ApoE^-/- cadmium-treated mice had higher cholesterol levels than non-exposed mice. Cadmium exposure decreased the vasodilatation response to acetylcholine in aortic ring of ApoE^-/- mice, though no changes in phenylephrine or sodium nitroprusside responses were observed. L-NAME reduced vasodilator responses to acetylcholine; this effect was lower in ApoE^-/- cadmium-treated mice, suggesting reduction in nitric oxide (NO) bioavailability. Moreover, in bone marrow cells, cadmium decreased cytoplasmic levels of NO and increased superoxide anions, hydrogen peroxide, and peroxynitrite in ApoE^-/- mice. Morphological analysis showed that cadmium exposure increased plaque deposition in the aorta by approximately 3-fold. Our results suggest that cadmium exposure induces endothelial dysfunction in ApoE^-/- mice. Moreover, cadmium increased total cholesterol levels, which may promote the early development of atherosclerosis in the aorta of ApoE^-/- mice. Our findings support the hypothesis that cadmium exposure might increase the risk of atherosclerosis.

Molybdenum and Cadmium exposure influences the concentration of trace elements in the digestive organs of Shaoxing duck (Anas platyrhyncha)

To investigate the toxic effects of Molybdenum (Mo) and Cadmium (Cd) on trace elements in digestive organs of Shaoxing duck (Anas platyrhyncha), 120 Shaoxing ducks were randomly divided into control group and 5 treatment groups which were treated with a commercial diet containing different dosages of Mo and Cd. On the 60th and 120th days, the beak, esophagus, glandular stomach, muscular stomach, small intestine, large intestine and feces were collected to determine contents of Mo, Cd, copper (Cu), iron (Fe), zinc (Zn) and selenium (Se), then correlation analysis was performed. The results showed that Cd content in digestive organs significantly increased in co-treated groups compared to single treated groups and Mo concentration increased in Mo-treated groups compared to control group, whereas Cu, Fe, Zn and Se concentrations in digestive organs decreased in co-treated groups. Furthermore, Cd and Mo were mainly accumulated in the small intestine and esophagus, respectively. There was a strongly positive correlation between Cd and Mo while they had negative correlation with Cu, Fe, Zn and Se, respectively. In feces, Mo and Fe contents in high dose of Mo group and high Mo combined with Cd group were significantly higher than those in control group, and Cu content in all treated groups significantly increased and Cd, Zn and Se concentrations had no difference. The results indicated that dietary Mo or/and Cd might disturb homeostasis of trace elements in digestive organs of Shaoxing duck. Moreover, the two elements presented a synergistic relationship.

Preliminary Studies of Acute Cadmium Administration Effects on the Calcium-Activated Potassium (SKCa and BKCa) Channels and Na+/K+-ATPase Activity in Isolated Aortic Rings of Rats

Cadmium is an environmental pollutant closely linked with cardiovascular diseases that seems to involve endothelium dysfunction and reduced nitric oxide (NO) bioavailability. Knowing that NO causes dilatation through the activation of potassium channels and Na⁺/K⁺-ATPase, we aimed to determine whether acute cadmium administration (10 μM) alters the participation of K⁺ channels, voltage-activated calcium channel, and Na⁺/K⁺-ATPase activity in vascular function of isolated aortic rings of rats. Cadmium did not modify the acetylcholine-induced relaxation. After L-NAME addition, the relaxation induced by acetylcholine was abolished in presence or absence of cadmium, suggesting that acutely, this metal did not change NO release. However, tetraethylammonium (a nonselective K⁺ channels blocker) reduced acetylcholine-induced relaxation but this effect was lower in the preparations with cadmium, suggesting a decrease of K⁺ channels function in acetylcholine response after cadmium incubation. Apamin (a selective blocker of small Ca²⁺-activated K⁺ channels-SK_Ca), iberiotoxin (a selective blocker of large-conductance Ca²⁺-activated K⁺ channels-BK_Ca), and verapamil (a blocker of calcium channel) reduced the endothelium-dependent relaxation only in the absence of cadmium. Finally, cadmium decreases Na⁺/K⁺-ATPase activity. Our results provide evidence that the cadmium acute incubation unaffected the calcium-activated potassium channels (SK_Ca and BK_Ca) and voltage-calcium channels on the acetylcholine vasodilatation. In addition, acute cadmium incubation seems to reduce the Na⁺/K⁺-ATPase activity.

Hepatoprotective Activity of Vitamin E and Metallothionein in Cadmium-Induced Liver Injury in Ctenopharyngodon idellus

As an environmental and industrial pollutant, cadmium (Cd) can cause a broad spectrum of toxicological effects. Multiple organs, especially the liver, are considerably affected by Cd in both humans and animals. We investigated the protective effects of metallothionein (MT) and vitamin E (VE) supplementation on Cd-induced apoptosis in the grass carp (Ctenopharyngodon idellus) liver. Grass carp were divided into four groups: the control group, Cd + phosphate-buffered saline (PBS) group, Cd + VE group, and Cd + MT group. All fish were injected with CdCl₂ on the first day and then VE, MT, and PBS were given 4 days postinjection, respectively. The results showed that Cd administration resulted in liver poisoning in grass carp, which was expressed as an increase in Cd contents, malondialdehyde (MDA) concentration, percentage of hepatocyte apoptosis, and apoptosis-related gene mRNA transcript expression. However, VE and MT treatments protected against Cd-induced hepatotoxicity in grass carp by decreasing Cd contents, lipid peroxidation, and histological damage and reducing the percentage of hepatocyte apoptosis by regulating related mRNA transcript expression. These data demonstrate that oxidative stress and activation of the caspase signaling cascade play a critical role in Cd-induced hepatotoxicity. However, VE and MT alleviate Cd-induced hepatotoxicity through their antioxidative and antiapoptotic effects, and MT has a more powerful effect than VE.

Environmental exposure to cadmium-a risk for health of the general population in industrialized countries and preventive strategies

Cadmium (Cd) is a heavy metal belonging to the group of the main chemical pollutants of the natural and occupational environment in economically developed countries. The forecasts indicate that contamination of the environment with this toxic metal, and thus the exposure of the general population, will increase. Food (particularly plant products) is the main source of the general population exposure to this element. Moreover, an important, and often the main, source of intoxication with Cd is habitual tobacco smoking. Recent epidemiological studies have provided numerous evidence that even low-level environmental exposure to this toxic metal, nowadays occurring in numerous economically developed countries, creates a risk for health of the general population. The low-level lifetime exposure to this metal may lead to the damage to the kidneys, liver, skeletal system, and cardiovascular system, as well as to the deterioration of the sight and hearing. Moreover, it has been suggested that environmental exposure to this xenobiotic may contribute to the development of cancer of the lung, breast, prostate, pancreas, urinary bladder, and nasopharynx. Taking the above into account, the aim of this review article is to draw more attention to Cd as an environmental risk factor for the health of the general population and the need to undertake preventive actions allowing to reduce the risk of health damage due to a lifetime exposure to this toxic metal.

Arsenic, cadmium, and mercury-induced hypertension: mechanisms and epidemiological findings

Arsenic (As), cadmium (Cd), and mercury (Hg) are toxic elements widely distributed in the environment. Exposure to these elements was attributed to produce several acute and chronic illnesses including hypertension. The aim of this review is to provide a summary of the most frequently proposed mechanisms underlying hypertension associated with As, Cd, and Hg exposure including: oxidative stress, impaired nitric oxide (NO) signaling, modified vascular response to neurotransmitters and disturbed vascular muscle Ca²⁺ signaling, renal damage, and interference with the renin-angiotensin system. Due to the complexity of the vascular system, a combination rather than a singular mechanism needs to be considered. In addition, epidemiological findings showing the relationship between various biomarkers of metal exposure and hypertension are described. Given the complex etiology of hypertension, further epidemiological studies evaluating the roles of confounding factors such as age, gender, and life style are still necessary.

Cadmium, Carotid Atherosclerosis, and Incidence of Ischemic Stroke

Background

Exposure to cadmium has been associated with carotid plaques, inflammation in carotid plaques, and increased risk of ischemic stroke. This study examined the separate and interacting effects of blood cadmium levels and carotid plaques on the risk of incident ischemic stroke.

Methods and Results

Cadmium levels were measured in 4156 subjects (39.2% men; mean±SD age 57.3±5.9 years) without history of stroke, from the Malmö Diet and Cancer cohort. The right carotid artery was examined using B‐mode ultrasound examination at baseline. Incidence of ischemic stroke was monitored over a mean follow‐up of 16.7 years. Carotid plaque was present in 34.5% of participants. Cadmium was significantly higher in subjects with plaque (mean±SD: 0.53±0.58 μg/L versus 0.42±0.49 μg/L; P<0.001). A total of 221 subjects had ischemic stroke during the follow‐up. Incidence of ischemic stroke was associated both with carotid plaque (hazard ratio 1.44, 95% confidence interval, 1.09–1.90, P=0.009) and cadmium (hazard ratio for quartile [Q] 4 versus Q1–3: 1.95, confidence interval, 1.33–2.85, P=0.001), after adjustment for risk factors. There was a significant interaction between cadmium and plaque with respect to risk of ischemic stroke (P=0.011). Adjusted for risk factors, subjects with plaque and cadmium in Q4 had a hazard ratio of 2.88 (confidence interval, 1.79–4.63) for ischemic stroke, compared with those without plaque and cadmium in Q1 to Q3.

Conclusions

Cadmium was associated with incidence of ischemic stroke, both independently and in synergistic interaction with carotid plaques. This supports the hypothesis that cadmium promotes vulnerability of carotid plaques, thereby increasing the risk of rupture and ischemic stroke.

Declining exposures to lead and cadmium contribute to explaining the reduction of cardiovascular mortality in the US population, 1988-2004

Background

Lead and cadmium exposures have markedly declined in the USA following the implementation of large-scale public health policies and could have contributed to the unexplained decline in cardiovascular mortality in US adults. We evaluated the potential contribution of lead and cadmium exposure reductions to explain decreasing cardiovascular mortality trends occurring in the USA from 1988-94 to 1999-2004.

Methods

Prospective study in 15 421 adults ≥40 years old who had participated in the National Health and Nutrition Examination Survey 1988-94 or 1999-2004. We estimated the amount of change in cardiovascular mortality over time that can be independently attributed to the intermediate pathway of changes in blood lead and urine cadmium concentrations.

Results

There was a 42.0% decrease in blood lead and a 31.0% decrease in urine cadmium concentrations. The cardiovascular mortality rate ratio [95% confidence intervals (CIs)] associated with a doubling of metal levels was 1.19 (1.07, 1.31) for blood lead and 1.20 (1.09, 1.32) for urine cadmium. The absolute reduction in cardiovascular deaths comparing 1999-2004 to 1988-94 was 230.7 deaths/100 000 person-years, in models adjusted for traditional cardiovascular risk factors. Among these avoided deaths, 52.0 (95% CI 8.4, 96.7) and 19.4 (4.3, 36.4) deaths/100 000 person-years were attributable to changes in lead and cadmium, respectively.

Conclusions

Environmental declines in lead and cadmium exposures were associated with reductions in cardiovascular mortality in US adults. Given the fact that lead and cadmium remain associated with cardiovascular disease at relatively low levels of exposure, prevention strategies that further minimize exposure to lead and cadmium may be needed.

Heavy metals exposure levels and their correlation with different clinical forms of fetal growth restriction

Background

Prenatal heavy metals exposure has shown a negative impact on birth weight. However, their influence on different clinical forms of fetal smallness was never assessed.

Objectives

To investigate whether there is a differential association between heavy metals exposure and fetal smallness subclassification into intrauterine growth restriction (IUGR) and small-for-gestational age (SGA).

Method

In this prospective case-control study, we included 178 mother–infant pairs; 96 of appropriate for gestational age (AGA) and 82 of small fetuses diagnosed in third trimester. The small ones were further subclassified into IUGR, n = 49 and SGA, n = 33. Cadmium (Cd), mercury (Hg), lead (Pb), arsenic (As) and zinc (Zn) levels were measured in the maternal and cord serum, and in the placentas of the three groups.

Results

Maternal serum level of Cd (p<0.001) was higher in the small fetuses compared to AGA. Fetal serum level of Cd (p<0.001) was increased in the small fetuses compared to AGA. Fetal serum level of Hg (p<0.05) showed an increase in SGA compared to both IUGR and AGA. Fetal serum level of Zn was increased in the AGA (p < 0.001) compared to each of the small fetuses groups. Only differences in the levels between the small fetuses’ subgroups were detected in the fetal serum levels of Cd and Hg. Fetal birth weight was negatively correlated with the fetal serum level of Cd (p < 0.001). No differences in the placental heavy metal levels were observed among the groups.

Conclusion

Fetal serum levels of Cd showed differential correlation between small fetuses' clinical subclassification, which together with the increased Cd levels in both maternal and fetal serum of the small fetuses reinforce the negative influence of heavy metals on birth weight. These findings provide more opportunities to verify the role of heavy metals exposure in relation to small fetuses’ subclassification.

Associations of Blood Cadmium Levels With Depression and Lower Handgrip Strength in a Community-Dwelling Elderly Population: A Repeated-Measures Panel Study

BACKGROUND

Although biologically plausible, few studies have linked cadmium exposure to depression or muscle strength. Herein, we hypothesized that blood cadmium concentrations are associated with depression and lower handgrip strength in a community-dwelling elderly population.

METHODS

Data from 983 elderly participants who completed up to 3 surveys between 2012 and 2015 were analyzed. At every survey, we assessed depressive status using the Korean version of the Geriatric Depression Scale-Short Form (SGDS-K) and measured handgrip strength and blood cadmium levels (mean, 1.24 μg/L). We evaluated the associations of cadmium with depression using generalized linear mixed models, and handgrip strength using linear mixed models. All models were adjusted for sociodemographic factors, lifestyle factors including active and passive smoking, weight, height, and comorbidity status.

RESULTS

Interquartile-range increase (0.645 μg/L) in blood cadmium levels was associated with depression defined as SGDS-K score ≥8 (odds ratio = 1.27, 95% confidence interval: 1.06, 1.52) and lower handgrip strength (right hand: β = -0.40, 95% confidence interval: -0.75, -0.09; left hand: β = -0.36, 95% confidence interval: -0.69, -0.04). The association between cadmium levels and handgrip strength was robust after further adjustment for depressive status, although it attenuated in size by 14.7%-18.0%.

CONCLUSIONS

After adjusting for potential confounders, blood cadmium concentrations were associated with depression and lower handgrip strength in an elderly population. The participants' depressive status partially mediated the association between cadmium levels and handgrip strength.

Functional involvement of L-type calcium channels and cyclic nucleotide-dependent pathways in cadmium-induced myometrial relaxation in rats

Modulation of myometrial spontaneity by cadmium (Cd) and its regulatory pathways was studied in rat uterus in the absence and presence of blockers of different signaling pathways. Isometric tension in myometrial strips, under a resting tension of 1 g, mounted in organ bath containing Ringer-Locke solution (RLS) continuously aerated with carbogen, was measured using data acquisition system-based physiograph and Lab Chart Pro V7.3.7 software. Mean integral tension was measured for 8 min. Cd (1 nM-0.1 mM) not only produced concentration-dependent inhibitory effect on rat myometrium but it (10 µM) also significantly ( p < 0.05) inhibited calcium chloride and BAY K-8644-induced myometrial contraction. Glybenclamide (10 µM), 4-aminopyridine (1 mM), and propranolol (10 µM) failed to significantly attenuate Cd-induced inhibitory responses, while L-NAME (0.1 mM), 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 25 µM), and 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ 22536; 1 µM) significantly ( p < 0.05) produced inhibitory effects on Cd-induced myometrial relaxation. Phenylephrine (1 nM-10 µM) and salbutamol (0.01 nM-0.1 µM)-induced relaxant effects on rat myometrium were significantly potentiated by 10 µM Cd. Thus based on the results of present functional study, it may be inferred that inhibitory effects of Cd on rat myometrium are mediated through blockade of L-type calcium channels and activation of NOS-NO-sGC and/or AC-cAMP pathways.

Testicular damage and farming environments - An integrative ecotoxicological link

The exposure to agrochemicals during farming activities affects the function of the reproductive system, as revealed by the increasing worldwide evidence of male infertility amongst farmers. The main objective of this study was to untangle the link between agricultural practices and male reproductive impairment due to chronic exposure to xenobiotics (such as agrochemicals) in conventional and organic farming environments. For this purpose, male wild mice (Mus musculus) populations from sites representing two distinct farming practices (conventional and organic farming systems) were used as bioindicators for observable effects of testicular damage, namely on a set of histological and cellular parameters: (i) relative volumetric density of different spermatogenic cells and interstitial space; (ii) damage in the seminiferous tubules and (iii) apoptotic cells in the germinal epithelium. Results showed that mice from the conventional farming site bioaccumulated higher Pb hepatic loads, while mice from the organic farming site tend to bioaccumulate higher Cd hepatic loads. In general, for the analyzed testicular damage related parameters, mice from the organic farming site showed a similar performance than mice from the reference site. Mice from the conventional farming site stood out not only by underperforming in most studied parameters, while displaying an association between Pb hepatic loads and the observed testicular structural and functional disruption, but also by the increased stress index (Integrated Biomarker Response value). This study highlights the potential damaging effects of conventional farming practices on testicular structure and function, under natural conditions, raising concern about ensuing fertility risks for farmers.

Cadmium induces NLRP3 inflammasome-dependent pyroptosis in vascular endothelial cells

Cadmium (Cd) is an important and common environmental pollutant that has been linked to cardiovascular diseases, such as atherosclerosis and hypertension. Increasing evidence demonstrates that Cd impairs the cardiovascular system by targeting vascular endothelial cells, but the underlying mechanisms remain obscure. In human umbilical vein endothelial cells (HUVECs), we observed that Cd treatment led to cell death and the generation of inflammatory cytokines. The Cd-induced cell death was identified as pyroptosis, a novel pro-inflammatory form of cell death depending on caspase-1 activation. In addition, exposure of HUVECs to Cd resulted in NLRP3 inflammasome activation as evidenced by cleavage of caspase-1 and downstream interleukin (IL)-1β production. Moreover, knockdown of NLRP3 by small interfering RNA efficiently suppressed Cd-induced caspase-1 cleavage, IL-1β production and pyroptosis in HUVECs. Additional experiments demonstrated that treatment with Cd significantly increased the levels of mitochondrial reactive oxygen species (mtROS) and intracellular ROS in HUVECs. Accordingly, pre-treatment with mtROS scavenger or total ROS scavenger reduced Cd-induced activation of NLRP3 inflammasome and pyroptotic cell death. Taken together, our data suggest that NLRP3 inflammasome, activated by the generation of mtROS, mediates Cd-induced pyroptosis in HUVECs. Our results provide novel insights into Cd-induced cytotoxicity and the underlying mechanism by which Cd induces endothelial injury.

Acute Cadmium Exposure Reduces the Local Angiotensin I Converting Enzyme Activity and Increases the Tissue Metal Content

Cadmium exposure causes health problems that may result from increased oxidative stress and from changes in enzyme metalloproteases activities as angiotensin-converting enzyme (ACE). In fact, cadmium produces inhibition of serum ACE but is not known how cadmium acts on tissue ACE activity and whether following acute exposure tissue cadmium content is increased. In order to elucidate these issues, a cadmium bolus was injected intravenously in Wistar rats, and the cadmium content and the ACE activity were measured in the serum, lungs, aorta and kidneys. Moreover, in order to clarify if the cadmium affects directly tissue ACE activity, acute metal exposure in vitro was performed. Our results demonstrated that 120 min following cadmium administration, blood and organ cadmium content were both increased. Serum and lung ACE activity were reduced following acute cadmium exposure, but aortic and kidney ACE activities were not affected. The inhibitory effects induced by cadmium on ACE activity were also observed in the serum, as well as the lungs and the aorta, but not in the kidneys following in vitro exposure. Moreover, the inhibitory effects induced by cadmium on ACE activity were partially restored in vitro by zinc supplementation, suggesting a possible interaction or competition between cadmium and zinc by at the active site of ACE. Summarising, our results suggest that acute cadmium exposure promotes an increase in the tissue metal content that was accompanied by direct inhibition of serum, aorta and lung ACE activity, an effect that is cadmium concentration-dependent and is partially reversed by zinc.

Heavy metals contamination in lipsticks and their associated health risks to lipstick consumers

This study aimed to determine the heavy metals (lead, cadmium, and chromium) concentration in lipsticks of different price categories sold in the Malaysian market and evaluate the potential health risks due to daily ingestion of heavy metals in lipsticks. A total of 374 questionnaires were distributed to the female staff in a public university in Malaysia in order to obtain information such as brand and price of the lipsticks, body weight, and frequency and duration of wearing lipstick. This information was important for the calculation of hazard quotient (HQ) in health risk assessment. The samples were extracted using a microwave digester and analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The concentrations of lead, cadmium, and chromium in lipsticks ranged from 0.77 to 15.44 mg kg(-1), 0.06-0.33 mg kg(-1), and 0.48-2.50 mg kg(-1), respectively. There was a significant difference of lead content in the lipsticks of different price categories. There was no significant non-carcinogenic health risk due to the exposure of these heavy metals through lipstick consumption for the prolonged exposure of 35 years (HQ < 1).

Urinary cadmium and mortality from all causes, cancer and cardiovascular disease in the general population: systematic review and meta-analysis of cohort studies

BACKGROUND

Cadmium is a toxic heavy metal distributed in the environment. We conducted a systematic review and meta-analysis to examine the association between urinary cadmium concentration and mortality from all causes, cancer and cardiovascular disease (CVD) in the general population.

METHODS

Studies were identified by searching PubMed and Embase (to 30 March 2015) and the reference lists of retrieved articles. We included prospective studies that reported hazard ratios (HR) with 95% confidence intervals (CI) for the association between urinary cadmium concentration and all-cause, cancer or CVD mortality. A random-effects model was used to combine study-specific results.

RESULTS

Nine cohort studies, including 5600 deaths from all causes, 1332 deaths from cancer and 1715 deaths from CVD, were eligible for inclusion in the meta-analysis. The overall HRs for the highest vs lowest category of urinary cadmium were1.44 (95% CI, 1.25-1.64; I(2 )= 40.5%) for all-cause mortality (six studies), 1.39 (95% CI, 0.96-1.99; I(2 )= 75.9%) for cancer mortality (four studies) and 1.57 (95% CI, 1.27-1.95; I(2 )= 34.0%) for CVD mortality (five studies). In an analysis restricted to six cohort studies conducted in populations with a mean urinary cadmium concentration of ≤1 µg/g creatinine, the HRs were 1.38 (95% CI, 1.17-1.63; I(2 )= 48.3%) for all-cause mortality, 1.56 (95% CI, 0.98-2.47; I(2 )= 81.0%) for cancer mortality and 1.50 (95% CI, 1.18-1.91; I(2 )= 38.2%) for CVD mortality.

CONCLUSIONS

Even at low-level exposure, cadmium appears to be associated with increased mortality. Further large prospective studies of cadmium exposure and mortality are warranted.

Clinically relevant doses of candesartan inhibit growth of prostate tumor xenografts in vivo through modulation of tumor angiogenesis

Angiotensin II receptor type 1 blockers (ARBs), widely used antihypertensive drugs, have also been investigated for their anticancer effects. The effect of ARBs on prostate cancer in experimental models compared with meta-analysis data from clinical trials is conflicting. Whereas this discrepancy might be due to the use of supratherapeutic doses of ARBs in cellular and animal models as compared with the clinical doses used in human trials, further investigation of the effects of clinical doses of ARBs on prostate cancer in experimental models is warranted. In the current study, we sought to determine the effects of candesartan on prostate cancer cellular function in vitro and tumor growth in vivo, and characterize the underlying mechanisms. Our analysis indicated that clinically relevant doses of candesartan significantly inhibited growth of PC3 cell tumor xenografts in mice. Interestingly, the same concentrations of candesartan actually promoted prostate cancer cellular function in vitro, through a modest but significant inhibition in apoptosis. Inhibition of tumor growth by candesartan was associated with a decrease in vascular endothelial growth factor (VEGF) expression in tumors and inhibition of tumor angiogenesis, but normalization of tumor vasculature. Although candesartan did not impair PC3 cell viability, it inhibited endothelial-barrier disruption by tumor-derived factors. Furthermore, candesartan significantly inhibited expression of VEGF in PC3 and DU145 cell lines independent of angiotensin II type 2 receptor, but potentially via angiotensin II type 1 receptor inhibition. Our findings clearly demonstrate the therapeutic potential of candesartan for prostate cancer and establish a link between ARBs, VEGF expression, and prostate tumor angiogenesis.

Environmental endocrine disruption of energy metabolism and cardiovascular risk

Rates of metabolic diseases have increased at an astounding rate in recent decades. Even though poor diet and physical inactivity are central drivers, these lifestyle changes alone fail to fully account for the magnitude and rapidity of the epidemic. Thus, attention has turned to identifying novel risk factors, including the contribution of environmental endocrine disrupting chemicals. Epidemiologic and preclinical data support a role for various contaminants in the pathogenesis of diabetes. In addition to the vascular risk associated with dysglycemia, emerging evidence implicates multiple pollutants in the pathogenesis of atherosclerosis and cardiovascular disease. Reviewed herein are studies linking endocrine disruptors to these key diseases that drive significant individual and societal morbidity and mortality. Identifying chemicals associated with metabolic and cardiovascular disease as well as their mechanisms of action is critical for developing novel treatment strategies and public policy to mitigate the impact of these diseases on human health.

Oxymatrine attenuates diabetes-associated cognitive deficits in rats

AIM

Oxymatrine (OMT) is the major quinolizidine alkaloid extracted from the root of Sophora flavescens Ait (the Chinese herb Kushen) and exhibits diverse pharmacological actions. In this work we investigated the effects of OMT on diabetes-associated cognitive decline (DACD) in a rat model of diabetes and explored the mechanisms of action.

METHODS

Male Wistar rats were injected with streptozotocin (65 mg/kg, ip) once to induce diabetes. The rats were then treated with vehicle or OMT (60 or 120 mg/kg per day, ip) for 7 weeks. Memory function was assessed using Morris water maze test. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), NF-κB p65 unit, TNF-α, IL-1β and caspase-3 in the cerebral cortex and hippocampus were quantified.

RESULTS

The diabetic rats exhibited markedly reduced body weight and increased plasma glucose level. The memory function of the rats assessed using Morris water maze test showed significant reduction in the percentage of time spent in the target quadrant and the number of times crossing the platform, coupled with markedly prolongation of escape latency and mean path length. Moreover, the rats showed oxidative stress (significantly increased MDA, decreased SOD and reduced GSH levels), as well as significant increases of NF-κB p65 unit, TNF-α, IL-1β and caspase-3 levels in the cerebral cortex and hippocampus. Chronic treatment with OMT dose-dependently reversed these behavioral, biochemical and molecular changes in the diabetic rats. However, the swimming speed had no significant difference among the control, diabetic and OMT-treated diabetic rats.

CONCLUSION

Chronic treatment with OMT alleviates diabetes-associated cognitive decline in rats, which is associated with oxidative stress, inflammation and apoptotic cascades.