Cadmium, lead and phytochemicals

Delineating the protective action of cordycepin against cadmium induced oxidative stress and gut inflammation through downregulation of NF-κB pathway

Cadmium (Cd) exposure is known to cause gut inflammation. In this study, we investigated the protective effects of cordycepin, a natural compound with pharmacological properties, against gut inflammation induced by Cd exposure. Using zebrafish larvae and colon cell line models, we examined the impact of cordycepin on Cd-induced toxicity and inflammation. Zebrafish larvae were exposed to Cd (2 µg/mL) and treated with different concentrations of cordycepin (12.5, 25 and 50 µg/mL). Cordycepin treatment significantly reduced Cd-induced embryotoxicity in zebrafish larvae. It also alleviated Cd-induced oxidative stress by reducing reactive oxygen species (ROS), lipid peroxidation and apoptosis. Furthermore, cordycepin treatment normalized the levels of liver-related biomarkers affected due to Cd exposure. Additionally, cordycepin (50 µg/mL) demonstrated a significant reduction in Cd bioaccumulation and downregulated the expression of inflammatory genes in both zebrafish larval gut and colon cell lines. These findings suggest that cordycepin could be an effective agent against Cd-induced gut inflammation.

Human supplementation with Pediococcus acidilactici GR-1 decreases heavy metals levels through modifying the gut microbiota and metabolome

Exposure to heavy metals (HMs) is a threat to human health. Although probiotics can detoxify HMs in animals, their effectiveness and mechanism of action in humans have not been studied well. Therefore, we conducted this randomized, double-blind, controlled trial on 152 occupational workers from the metal industry, an at-risk human population, to explore the effectiveness of probiotic yogurt in reducing HM levels. Participants were randomly assigned to two groups: one consumed probiotic yogurt containing the HM-resistant strain Pediococcus acidilactici GR-1 and the other consumed conventional yogurt for 12 weeks. Analysis of metal contents in the blood revealed that the consumption of probiotic yogurt resulted in a higher and faster decrease in copper (34.45%) and nickel (38.34%) levels in the blood than the consumption of conventional yogurt (16.41% and 27.57%, respectively). Metagenomic and metabolomic studies identified a close correlation between gut microbiota (GM) and host metabolism. Significantly enriched members of Blautia and Bifidobacterium correlated positively with the antioxidant capacities of GM and host. Further murine experiments confirmed the essential role of GM and protective effect of GR-1 on the antioxidative role of the intestine against copper. Thus, the use of probiotic yogurt may be an effective and affordable approach for combating toxic metal exposure through the protection of indigenous GM in humans.

ClinicalTrials.gov identifier: ChiCTR2100053222

Modulation of the gut microbiota by a galactooligosaccharide protects against heavy metal lead accumulation in mice

The heavy metal lead (Pb) is a toxic contaminant that induces a range of adverse effects in humans. The present study demonstrated for the first time that dietary supplementation with a galactooligosaccharide (GOS) promotes fecal Pb excretion and reduces Pb accumulation in the blood and tissues of mice. The effects against Pb exposure were also observed in mice that received the fecal microbiota from donors treated with GOS, but were diminished in gut microbiota-depleted mice that received antibiotic pre-treatment, indicating that the protection by GOS administration was dependent on the modulation of the gut microbiota. We also provide evidence that the protective mechanism of GOS supplementation was related to the enhanced abundance of intestinal bacteria with good Pb-binding ability, recovery of the gut barrier function, modulation of bile acid metabolism, and improved essential metal utilization. These results indicate that GOS can be considered a potentially protective prebiotic against Pb toxicity.

The uptake and bioaccumulation of heavy metals by food plants, their effects on plants nutrients, and associated health risk: a review

Heavy metal contamination is a globally recognized environmental issue, threatening human life very seriously. Increasing population and high demand for food resulted in release of various contaminants into environment that finally contaminate the food chain. Edible plants are the major source of diet, and their contamination with toxic metals may result in catastrophic health hazards. Heavy metals affect the human health directly and/or indirectly; one of the indirect effects is the change in plant nutritional values. Previously, a number of review papers have been published on different aspects of heavy metal contamination. However, no related information is available about the effects of heavy metals on the nutritional status of food plants. This review paper is focused upon heavy metal sources, accumulation, transfer, health risk, and effects on protein, amino acids, carbohydrates, fats, and vitamins in plants. The literature about heavy metals in food plants shows that both leafy and nonleafy vegetables are good accumulators of heavy metals. In nonleafy vegetables, the bioaccumulation pattern was leaf > root ≈ stem > tuber. Heavy metals have strong influence on nutritional values; therefore, plants grown on metal-contaminated soil were nutrient deficient and consumption of such vegetables may lead to nutritional deficiency in the population particularly living in developing countries which are already facing the malnutrition problems.

Essential metals profile of the hair and nails of patients with laryngeal cancer

Trace elements have an impact on numerous physiological processes. The monitoring of their levels in the organism allows you to detect not only their deficiencies, but also several illnesses. The aim of this study was to compare the levels of essential elements (calcium, magnesium, zinc, copper, iron, manganese) in hair, nails and serum of both patients with laryngeal cancer and healthy people. The determination of six metals was performed by an inductively coupled plasma mass spectrometry (ICP-MS) and an inductively coupled plasma optical emission spectrometry (ICP-OES). The concentration of essential elements in hair and nails of the control group was statistically significantly higher than in the group of patients with laryngeal cancer. In the case of serum, differences were found between the patients and controls in respect of the level of three metals. The results of principal component analysis (PCA) revealed the strong and similar clustering behavior of essential elements in hair and nails. The metals did not correlate between two alternative materials. The present study indicated that, using the level of essential elements in hair and nails as a basis, it is possible to distinguish cancer patients from healthy people. The alternative materials are independent of homeostasis and therefore seem to be more useful in the detection of diseases and mineral deficiencies in human than the classical biological materials, such as blood.

In vitro studies on protective effect of Glycyrrhiza glabra root extracts against cadmium-induced genetic and oxidative damage in human lymphocytes

Cadmium is a modern environmental contaminant that is toxic and carcinogenic. Glycyrrhiza glabra is a traditional medicinal herb which grows in the various parts of the World. Recent studies demonstrated that G. glabra has antifungal, antimicrobial, antioxidant, and powerful antiinflammatory features. The purpose of this study was to investigate the genetic safety of extracts from G. glabra and its effects on cadmium (as CdCl2) induced genotoxicity. Therefore we evaluated the capability of G. glabra extract to inhibit the rate of micronucleus (MN), sister chromatid exchange (SCE) formations induced by CdCl2. Moreover, to assess the effects of G. glabra on cell viability and oxidative status, we performed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and total antioxidant capacity (TAC) assays. Our results showed that there were significant increases (P < 0.05) in both SCE and MN frequencies of cultures treated with CdCl2 (5 ppm) as compared to controls. However, co-application of G. glabra extract (5, 10 and 20 ppm) and CdCl2 resulted in decreases of MN and SCE rates as compared to the group treated with CdCl2 alone. Again, the results of MTT and TAC assays clearly indicated dose dependent ameliorative effects of G. glabra extracts against CdCl2 toxicity. In conclusion, this study demonstrated for the first time that G. glabra extracts provided increased resistance of DNA against CdCl2 induced genetic and oxidative damage in human lymphocytes. So, the risk on target tissues of CdCl2 could be reduced and ensured early recovery from its toxicity.

Cytotoxic and genotoxic effects of metal(oid)s bioactivated in rocket leaves (Eruca vesicaria subsp. sativa Miller)

Rocket is an important source of essential elements. However, it may also accumulate toxic elements such as metal(oids). The objectives of the present work were (i) to study the uptake of arsenic, lead, cadmium and zinc in rocket grown in contaminated soils, (ii) to establish the genotoxic and cytotoxic activities of this vegetable material, and (iii) to study the modulator role of the glucosinolate and metal contents in the genotoxic/cytotoxic activities. Lead, cadmium and zinc leaf concentrations in our study were over the concentrations allowed by the statutory limit set for metal(oid) contents in vegetables. The accessions were non genotoxic at the different concentrations studied, although one of the accessions showed the highest mutation rates doubling those of negative control. The cytotoxicity assays with HL60 human leukaemia cells showed that the tumouricide activities of rocket leaves decreased with the increasing of metal(oid) concentrations and also with the decreasing of glucosinolate concentrations in their tissues. An interaction between metal(oid)s and glucosinolate degradation products contained in rocket leaves is suggested as the main modulator agents of the biological activity of the plants grown in metal-contaminated soils.

Evaluation of some pollutant levels in bitter orange trees: Implications for human health

Samples of bitter orange (Citrus aurantium L.) fruits (epicarp and mesocarp), leaves and its fruit marmalade from sites in Seville (Andalucia, Spain) with different levels of traffic were analysed for Ba, Cd, Cu, Fe, Mn, Ni, Pb and Zn concentrations by ICP/AES. Comparative values are given from a background area. The effect of washing on metal content in epicarp and leaves was investigated. Results revealed that Ba, Fe and Mn accumulated in leaves > epicarp > mesocarp, Cu and Ni in leaves > epicarp congruent withmesocarp and Zn leaves > mesocarp > epicarp. Washing had no significant effect on epicarp metal content while it removes part of Cu, Fe and Zn deposited on leaves. Bitter orange fruits are used mainly to make marmalade; artificial contamination effects on fruit composition were investigated and the dietary intake of the elements was determined. The citrus fruits sprayed with metal solution showed a significant increase in the studied elements compared to untreated fruits. The levels of all elements studied were lower than provisional tolerable daily intake values indicating that bitter orange marmalade consumption is safe for alimentary use.

CAPSULE

Bitter orange tree exhibit differences in metal content between fruits and leaves and fruits are safe for consumption.

Cadmium blood concentrations in relation to nutrition

Cadmium is a toxic element ubiquitous in the environment, which damages biological systems in various ways. The major source of cadmium exposure is food. High cadmium content in the soil leads to high cadmium concentrations in certain plants such as grains (above all surface layers and germs), oil or non-oil seeds, fruit and vegetables. These food commodities are the crucial components of a vegetarian nutrition. Blood cadmium concentrations were measured in two non-smoking population groups: the vegetarian group (n = 80) and the non-vegetarian (control) group of general population on traditional mixed diet (n = 84). The significantly higher blood cadmium content (1.78 +/- 0.22 vs. 0.45 +/- 0.04 microg/l) was measured in vegetarian group. Healthy risk values > 5 microg/l were found in 6 vegetarians vs. no non-vegetarian. The highest cadmium concentration (3.15 +/- 0.77 microg/l) was measured in vegan subgroup (plant food only, n = 10) and that value decreased with increasing animal food consumption (1.75 +/- 0.36 microg/l, lactovegetarian and lactoovovegetarian subgroup/added dairy products and eggs, n = 41/, 1.34 +/- 0.21 microg/I, semivegetarian subgroup /as a previous subgroup and added white meat, n = 291). Risk vegetarians vs. non-risk vegetarians consume significantly higher amounts of whole grain products, grain sprouts and oil seeds. Blood cadmium content is directly influenced by age (r = 0.32, p < 0.001), by whole grain product intake (r = 0.66, p < 0.001) and by duration of vegetarianism (r = 0.5, p < 0.001). Oxidative stress plays a major role in chronic cadmium induced hepatic and renal toxicity as well as in other consequences of cadmium injuries. Vegetarians have significantly higher plasma concentrations of natural antioxidants. The sufficient antioxidative protection against cadmium induced free radical formation in vegetarians may inhibit the harmful effects of greater cadmium intake from plant food.

Metal speciation, phytochemicals and Helicobacter pylori infection

Helicobacter pylori (HP) acquired in childhood is an important risk factor for gastric carcinoma. Once colonization is established, infection may be carried for life. The relationship between food intake and HP infection, the presence of metals and phytochemicals closely associated with oxidative stress within everyday diet are important topics to be considered. The possible anti-HP effects of phytochemicals, prooxidant effects exerted in the presence of metal species, intimate relations between some metals and HP, bivalent effects of some metal species in cancer, interactions between metal species and phytochemicals in HP infection are the topics, which require further research. Formulas or diets enriched with phytochemicals and metals against HP and, which are devoid of metals known to favour the growth of HP, may be suggested as the supplements to the classical treatment regimens. The importance of collective consideration of HP, metal species and phytochemicals should be emphasized.