The possible crucial role of iron accumulation combined with low tryptophan, zinc and manganese in carcinogenesis

Elements in trace amount with a significant role in human physiology: a tumor pathophysiological and diagnostic aspects

Cancer has a devastating impact globally regardless of gender, age, and community, which continues its severity to the population due to the lack of efficient strategy for the cancer diagnosis and treatment. According to the World Health Organisation report, one out of six people dies due to this deadly cancer and we need effective strategies to regulate it. In this context, trace element has a very hidden and unexplored role and require more attention from investigators. The variation in concentration of trace elements was observed during comparative studies on a cancer patient and a healthy person making them an effective target for cancer regulation. The percentage of trace elements present in the human body depends on environmental exposure, food habits, and habitats and could be instrumental in the early diagnosis of cancer. In this review, we have conducted inclusive analytics on trace elements associated with the various types of cancers and explored the several methods involved in their analysis. Further, intricacies in the correlation of trace elements with prominent cancers like prostate cancer, breast cancer, and leukaemia are represented in this review. This comprehensive information on trace elements proposes their role during cancer and as biomarkers in cancer diagnosis.

Trace elements under the spotlight: A powerful nutritional tool in cancer

Cancer is the second leading cause of death worldwide. Research on the relationships between trace elements (TE) and the development of cancer or its prevention is a field that is gaining increasing relevance. This review provides an evaluation of the effects of TE (As, Al, B, Cd, Cr, Cu, F, I, Pb, Li, Mn, Hg, Mo, Ni, Se, Si, Sn, V and Zn) intake and supplementation in cancer risk and prevention, as well as their interactions with oncology treatments. Advancements in the knowledge of TE, their dietary interactions and their main food sources can provide patients with choices that will help them to improve their quality of life and therapy outcomes. This approach could open new opportunities for treatments based on the integration of conventional therapies (chemotherapy, radiotherapy, and immunotherapy) and dietary interventions that provide advanced personalized treatments.

Serum Levels of Selenium, Zinc, Copper, Manganese, and Iron in Prostate Cancer Patients

Backgrounds

Variations of trace element contents may be associated with several diseases including metabolic disorders, cellular growth disturbance, mutation and tumorigenesis. Prostate cancer is the second most common male cancer worldwide and stand fifth most common male cancer in Saudi Arabia.

Objective

In the present study, Serum levels of selenium, zinc, copper, manganese, and iron were measured in patients with BPH and prostate cancer aiming to explore the association between these elements and prostate cancer.

Patients and Methods

The study included 40 newly diagnosed prostate cancer patients, 22 patients with BPH and 30 healthy male subjects. All participant groups had similar socio-economic levels. Fasting blood samples were collected from all subjects and before any intervention for the patients. Serum PSA concentrations were analyzed by ELIZA and trace elements Se, Zn, Cu, Mn and Fe were measured by ICP-MS.

Results

Serum Se, Zn, and Mn levels of prostate cancer patients were significantly decreased compared to control groups. The levels of serum Cu and Fe were significantly higher in prostate cancer patients than in control groups.

Conclusion

In the present study, an association was noticed between serum trace elements disturbance and prostate cancer. The decreased levels of Se, Zn, and Mn, and increased Cu and Fe levels may play significant roles in the initiation of prostate cancer. However, future prospective studies on the causes of trace elements alteration in prostate cancer patients are needed as well as to illustrate the relation between different prostate cancer stages and trace elements concentrations.

Effects of Physical Activity on Trace Elements and Depression Related Biomarkers in Children and Adolescents

Not much is known about the role of physical activity (PA), obesity related variables, and trace elements as potential risk factors affecting neurotransmitters in schoolchildren with depression. Our objective was to investigate the effect of physical activity (PA) on depressive symptoms in children and adolescents. Also, we aimed to study the association of demographic variables, serum levels of Copper (Cu), Zinc (Zn), serotonin, and salivary cortisol with depression in this population. One hundred and fifty school children (90 boys and 60 girls) aged 7-18 years were recruited for this study. All participants were evaluated for depression using CDI-score analysis. Their physical activity levels were checked using pre-validated questionnaires. The serum levels of Copper (Cu), Zinc (Zn), cortisol, and serotonin were estimated using atomic absorption, and immunoassay techniques. About 48.7 % of the study population had depressive symptoms (CDI-score; ≥13), and were classified into mild, moderate, and severe categories. Older children, especially girls, had higher levels of depression. Participants with moderate and severe depression had significantly lower physical activity, serotonin, and zinc levels, Zn/Cu ratios, and significantly higher copper and cortisol levels. Physically active boys showed significantly lower depressive CDI-scores and improvement in cortisol, serotonin, Cu, and Zn concentrations compared to girls of sedentary life style. CDI- scores correlated positively with BMI, cortisol and Cu, and negatively with PA, serotonin and Zn concentrations. BMI, cortisol, serotonin, Cu and Zn, could explain about 59.3-79 % of the depressive symptoms among schoolchildren, according to stepwise regression analysis. This was especially true in especially older girls. PA and an adequate balance in Zn and Cu levels, plays a positive role in improving CDI-depressive score, BMI, serotonin and cortisol levels among schoolchildren.

Serum Levels of Trace Elements in Patients with Testicular Cancers

INTRODUCTION

Trace elements are primary components of biological structures; however, they can be toxic when their concentrations are higher than those needed for biological functions.

MATERIALS AND METHODS

In the present study serum levels of trace elements were measured in 30 patients (mean age was 26.9±11.2 years) newly diagnosed with germ cell testicular cancer and 32 healthy volunteers (mean age: 27.4±10.8) by using furnace atomic absorption spectrophotometer. Serum samples were stored at-20ºC until assays.

RESULTS

In patients with germ cell testicular cancer, the diagnosis was seminoma in 15, mix germ cell tumor in 7, embryonal carcinoma in 4, yolk sac tumor in 2 and teratoma in 2 patients. There was stage I testicular tumor in 19 patients (63.3%) while stage II in 6 patients (20.0%), stage IIIA in 4 patients (13.3%) and stage IIIC in one patient (3.4%). It was found that serum Co, Cu, Mg and Pb levels were increased (p<0.05), whereas Fe, Mn, and Zn levels were decreased in patients with testicular cancer (p<0.05).

CONCLUSIONS

These alterations may be important in the pathogenesis of testicular cancers; however, further prospective studies are needed to identify the relationship between testicular cancer and trace elements.

Inhibitory effect of aqueous extract of different parts of unripe pawpaw (Carica papaya) fruit on Fe²⁺-induced oxidative stress in rat pancreas in vitro

CONTEXT

Carica papaya L. (Caricaceae) is widespread throughout tropical Africa; it is cultivated for its fruits and it is eaten in various ways.

OBJECTIVE

This study sought to investigate the inhibitory effect of the aqueous extract of different parts of unripe pawpaw fruit on Fe²⁺-induced lipid peroxidation in rat's pancreas in vitro.

MATERIALS AND METHODS

The aqueous extract of the unripe pawpaw fruit parts; peel (PG), seed (SG), flesh (FG), flesh with peel (FPG) and a combination of equal amount of all parts (CG) were prepared, the total phenolic content and the antioxidant activities of the extracts were then evaluated using various spectrophotometric methods.

RESULT

PG had the highest total phenol content (1.24 mg GAE/g), flavonoid content (0.63 mg QUE/g), reducing power (7.07 mg AAE/g) and Fe²⁺ chelating ability while the SG had the highest 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability. Furthermore, all the extracts caused a significant decrease (p < 0.05) in the malondialdehyde contents in the pancreas with SG (IC₅₀ = 4.25 mg/mL) having the highest inhibitory effect on Fe²⁺-induced lipid peroxidation.

DISCUSSION AND CONCLUSION

This protective effect of the extracts on Fe²⁺-induced lipid peroxidation in rat pancreas could be attributed to their phenolic compounds and, the possible mechanism may be through their antioxidant activities. However, the effect of combination of different parts of unripe pawpaw fruit in equal amount (w/w) on the inhibition of Fe²⁺-induced lipid peroxidation in rat pancreas exhibited additive properties.

Aqueous extracts of two varieties of ginger (Zingiber officinale) inhibit angiotensin I-converting enzyme, iron(II), and sodium nitroprusside-induced lipid peroxidation in the rat heart in vitro

Ginger has reportedly been used in folk medicine for the management and prevention of hypertension and other cardiovascular diseases. Therefore, this study sought to investigate the inhibitory effect of aqueous extracts of two varieties of ginger on a key enzyme linked to hypertension (angiotensin I-converting enzyme [ACE]), and on pro-oxidants [Fe(2+) and sodium nitroprusside (SNP)] which have been shown to induce lipid peroxidation in the rat's isolated heart in vitro. Aqueous extracts (0.05 mg/mL) of red ginger (Zingiber officinale var. Rubra) and white ginger (Zingiber officinale Roscoe) were prepared and the ability of the extracts to inhibit ACE along with Fe(2+)- and SNP-induced lipid peroxidation was determined in rat's heart in vitro. Results revealed that both extracts inhibited ACE in a dose-dependent manner (25-125 μg/mL). However, red ginger extract (EC50=27.5 μg/mL) had a significantly (P<.05) higher inhibitory effect on ACE than white ginger extract (EC50=87.0 μg/mL). Furthermore, incubation of the rat's heart in the presence of Fe(2+) and SNP caused a significant increase (P<.05) in the malondialdehyde (MDA) content of the heart homogenates, while the introduction of the ginger extracts (78-313 μg/mL) caused a dose-dependent decrease in the MDA content of the stressed heart homogenates. This suggests that the possible mechanism through which ginger exerts its antihypertensive properties may be through inhibition of ACE activity and prevention of lipid peroxidation in the heart. Furthermore, red ginger showed stronger inhibition of ACE than white ginger. Additionally, it should be noted that these protective properties of the ginger varieties could be attributed to their polyphenol contents.

Antioxidant and inhibitory effect of red ginger (Zingiber officinale var. Rubra) and white ginger (Zingiber officinale Roscoe) on Fe(2+) induced lipid peroxidation in rat brain in vitro

Neurodegerative diseases have been linked to oxidative stress arising from peroxidation of membrane biomolecules and high levels of Fe have been reported to play an important role in neurodegenerative diseases and other brain disorder. Malondialdehyde (MDA) is the end-product of lipid peroxidation and the production of this aldehyde is used as a biomarker to measure the level of oxidative stress in an organism. The present study compares the protective properties of two varieties of ginger [red ginger (Zingiber officinale var. Rubra) and white ginger (Zingiber officinale Roscoe)] on Fe(2+) induced lipid peroxidation in rat brain in vitro. Incubation of the brain tissue homogenate in the presence of Fe caused a significant increase in the malondialdehyde (MDA) contents of the brain. However, the aqueous extract from both varieties of ginger caused a significant decrease in the MDA contents of the brain in a dose-dependent manner. However, the aqueous extract of red ginger had a significantly higher inhibitory effect on both Fe(2+)-induced lipid peroxidation in the rat brain homogenates than that of white ginger. This higher inhibitory effect of red ginger could be attributed to its significantly higher phytochemical content, Fe(2+) chelating ability, OH scavenging ability and reducing power. However, part of the mechanisms through which the extractable phytochemicals in ginger (red and white) protect the brain may be through their antioxidant activity, Fe(2+) chelating and OH scavenging ability. Therefore, oxidative stress in the brain could be potentially managed/prevented by dietary intake of ginger varieties (red ginger and white ginger rhizomes).

Antioxidant and inhibitory effects of aqueous extracts of Salvia officinalis leaves on pro-oxidant-induced lipid peroxidation in brain and liver in vitro

The present study sought to determine the antioxidant activity and protective ability of water-extractable phytochemicals from Salvia officinalis leaves (strongly aromatic leaves used in flavoring cooked foods) on lipid peroxidation induced by some pro-oxidants in rat brain and liver homogenates in vitro. Aqueous extracts of the leaves were prepared, and the ability of the extract to inhibit 25 microM FeSO(4)- and 7 microM sodium nitroprusside-induced lipid peroxidation in isolated rat brain and liver was determined. Subsequently, the ascorbic acid content, total phenol content, reducing power, Fe(II) chelating, and .OH radical scavenging ability of the extracts were determined as indices of antioxidant activity. The results of the study revealed that the extract inhibited malondialdehyde (MDA) production in basal and pro-oxidant-induced lipid peroxidation in the brain and liver in a dose-dependent manner. The percentage induction of lipid peroxidation by Fe(II) and sodium nitroprusside was higher in the brain than the liver; however, the level of inhibition of MDA production in the brain was significantly (P < .05) higher than the liver. The ascorbic acid (10.3 +/- 2.5 mg/g) and total phenol (7.6 +/- 1.2 mg/g) contents of the leaves were high; likewise, the aqueous extract had high reducing power and Fe(II) chelating ability but low .OH radical scavenging ability. This antioxidant and protective effect of this leaf could be harnessed in the management and prevention of degenerative diseases associated with oxidative stress.

Iron, lipids, and risk of cancer in the Framingham Offspring cohort

Iron and lipids combine to create oxidative stress, and oxidative stress has a role in the development of cancer. The objective was to determine the risk of cancer among persons who had both elevated iron and lipids. The authors conducted an analysis of the cohort available in the Framingham Offspring Study. Adults aged 30 or more years at baseline had serum iron and high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol, and very low density lipoprotein cholesterol (VLDL-C) assessed in 1979-1982 and were followed for development of cancer until 1996-1997 (n = 3,278). Cox regression models were computed while controlling for age, gender, smoking status, and body mass index. In adjusted models, both elevated iron (hazard ratio (HR) = 1.66, 95% confidence interval (CI): 1.11, 2.46; 29 cases) and VLDL-C (HR = 1.54, 95% CI: 1.04, 2.28; 93 cases) had significant independent risks for development of cancer. When elevated iron was combined with elevated VLDL-C, the adjusted relative risk of cancer increased (HR = 2.68, 95% CI: 1.49, 4.83; 18 cases). Elevated iron and low HDL-C also had a significant adjusted relative risk of cancer (HR = 2.82, 95% CI: 1.50, 5.28; 14 cases). The results suggest that elevated serum iron levels coupled with either high VLDL-C or low HDL-C appear to interact to increase cancer risk in this cohort.

Free radicals: key to brain aging and heme oxygenase as a cellular response to oxidative stress

Aging is one of the unique features in all organisms. The impaired functional capacity of many systems characterizes aging. When such impairments occur in the brain, the susceptibility to neurodegenerative diseases amplifies considerably. The free radical theory of aging posits that the functional impairments in brains are due to the attack on critical cellular components by free radicals, reactive oxygen species, and reactive nitrogen species produced during normal metabolism. In this review, we examine this concept based on the parameters of oxidative stress in correlation to aging. The parameters for lipid peroxidation are phospholipid composition, reactive aldehydes, and isoprostanes. The parameters for protein oxidation are protein carbonyl levels, protein 3-nitrotyrosine levels, electron paramagnetic resonance, and oxidative stress-sensitive enzyme activities. We conclude that free radicals are, at least partially, responsible for the functional impairment in aged brains. The aging brain, under oxidative stress, responds by induction of various protective genes, among which is heme oxygenase. The products of the reaction catalyzed by heme oxygenase, carbon monoxide, iron, and biliverdin (later to bilirubin) each have profound effects on neurons. Although there may be other factors contributing to brain aging, free radicals are involved in the damaging processes associated with brain aging, and cellular stress response genes are induced under free radical oxidative stress. Therefore, this review supports the proposition that free radicals are, indeed, a key to brain aging.

Genome-wide analysis of signal transducers and regulators of mitochondrial dysfunction in Saccharomyces cerevisiae

Mitochondrial dysfunction is a hallmark of cancer cells. However, genetic response to mitochondrial dysfunction during carcinogenesis is unknown. To elucidate genetic response to mitochondrial dysfunction we used Saccharomyces cerevisiae as a model system. We analyzed genome-wide expression of nuclear genes involved in signal transduction and transcriptional regulation in a wild-type yeast and a yeast strain lacking the mitochondrial genome (rho(0)). Our analysis revealed that the gene encoding cAMP-dependent protein kinase subunit 3 (PKA3) was upregulated. However, the gene encoding cAMP-dependent protein kinase subunit 2 (PKA2) and the VTC1, PTK2, TFS1, CMK1, and CMK2 genes, involved in signal transduction, were downregulated. Among the known transcriptional factors, OPI1, MIG2, INO2, and ROX1 belonged to the upregulated genes, whereas MSN4, MBR1, ZMS1, ZAP1, TFC3, GAT1, ADR1, CAT8, and YAP4 including RFA1 were downregulated. RFA1 regulates DNA repair genes at the transcriptional level. RFA is also involved directly in DNA recombination, DNA replication, and DNA base excision repair. Downregulation of RFA1 in rho(0) cells is consistent with our finding that mitochondrial dysfunction leads to instability of the nuclear genome. Together, our data suggest that gene(s) involved in mitochondria-to-nucleus communication play a role in mutagenesis and may be implicated in carcinogenesis.