On enzyme-based anticancer molecular dietary manipulations

On the toxicity of e-cigarettes consumption: Focus on pathological cellular mechanisms

Tobacco smoking remains without a doubt one of the leading causes of premature death worldwide. In combination with conventional protocols for smoking cessation, e-cigarettes have been proposed as a useful tool to quit smoking. Advertised as almost free of toxic effects, e-cigarettes have rapidly increased their popularity, becoming a sought-after device, especially among young people. Recently some health concerns about e-cigarette consumption are being raised. It is well known that they can release several toxic compounds, some of which are carcinogenic to humans, and emerging results are now outlining the risks related to the onset of respiratory and cardiovascular diseases and even cancer. The present review shows the emerging evidence about the role of technical components of the devices, the e-liquid composition as well as customization by consumers. The primary topics we discuss are the main toxicological aspects associated with e-cigarette consumption, focusing on the molecular pathways involved. Here it will be shown how exposure to e-cigarette aerosol induces stress/mitochondrial toxicity, DNA breaks/fragmentation following the same pathological pathways triggered by tobacco smoke, including the deregulation of molecular signalling axis associated with cancer progression and cell migration. Risk to fertility and pregnancy, as well as cardiovascular risk associated with e-cigarette use, have also been reported.

Co-carcinogenic effects of vitamin E in prostate

A large number of basic researches and observational studies suggested the cancer preventive activity of vitamin E, but large-scale human intervention trials have yielded disappointing results and actually showed a higher incidence of prostate cancer although the mechanisms underlying the increased risk remain largely unknown. Here we show through in vitro and in vivo studies that vitamin E produces a marked inductive effect on carcinogen-bioactivating enzymes and a pro-oxidant status promoting both DNA damage and cell transformation frequency. First, we found that vitamin E in the human prostate epithelial RWPE-1 cell line has the remarkable ability to upregulate the expression of various phase-I activating cytochrome P450 (CYP) enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), giving rise to supraphysiological levels of reactive oxygen species. Furthermore, our rat model confirmed that vitamin E in the prostate has a powerful booster effect on CYP enzymes associated with the generation of oxidative stress, thereby favoring lipid-derived electrophile spread that covalently modifies proteins. We show that vitamin E not only causes DNA damage but also promotes cell transformation frequency induced by the PAH-prototype benzo[a]pyrene. Our findings might explain why dietary supplementation with vitamin E increases the prostate cancer risk among healthy men.

The Customizable E-cigarette Resistance Influences Toxicological Outcomes: Lung Degeneration, Inflammation, and Oxidative Stress-Induced in a Rat Model

Despite the knowledge gap regarding the risk-benefit ratio of the electronic cigarette (e-cig), its use has grown exponentially, even in teenagers. E-cig vapor contains carcinogenic compounds (eg, formaldehyde, acetaldehyde, and acrolein) and free radicals, especially reactive oxygen species (ROS) that cause toxicological effects, including DNA damage. The role of e-cig voltage customization on molecule generation has been reported, but the effects of the resistance on e-cig emissions and toxicity are unknown. Here, we show that the manipulation of e-cig resistance influences the carbonyls production from nonnicotine vapor and the oxidative and inflammatory status in a rat model. Fixing the voltage at the conventional 3.5 V, we observed that the amount of the selected aldehydes increased as the resistance decreased from 1.5 to 0.25 Ω. Under these conditions, we exposed Sprague Dawley rats to e-cig aerosol for 28 days, and we studied the pulmonary inflammation, oxidative stress, tissue damage, and blood homeostasis. We found a perturbation of the antioxidant and phase II enzymes, probably related to the increased ROS levels due to the enhanced xanthine oxidase and P450-linked monooxygenases. Furthermore, frames from scanning electron microscope showed a disorganization of alveolar and bronchial epithelium in 0.25 Ω group. Overall, various toxicological outcomes, widely recognized as smoke-related injuries, can potentially occur in e-cig consumers who use low-voltage and resistance device. Our study suggests that certain “tips for vaping safety” cannot be established, and encourages further independent investigations to help public health agencies in regulating the e-cig use.

The combined effect of Sango sprout juice and caloric restriction on metabolic disorders and gut microbiota composition in an obesity model

The main purpose of this study was to compare the benefits of SSJ supplementation in obese rats with those achieved only by switching the alimentary regimen from high-fat (HFD) to the regular one (RD) in liver, ileum and prostate. Furthermore, changings in caecal chime microbiota were investigated. SSJ was administered to rats in combination with a RD (HFD-RD + SSJ). The switch from HFD to RD led to a weight loss of almost 9.8 g, and the total cholesterol was found to be significantly lower. In the HFD-RD + SSJ group, all values were improved compared with the HFD control, and the weight decrement was higher (-23.29 g) with respect to HFD-RD. HFD led to a widespread increment of oxidative stress (OS) markers in liver, ileum and prostate. SSJ has shown to improve the results achieved by the suspension of HFD and it has proven effective wherever the only switch in diet regimen failed.

Raphanus sativus cv. Sango Sprout Juice Decreases Diet-Induced Obesity in Sprague Dawley Rats and Ameliorates Related Disorders

BACKGROUND

Obesity is recognized as a leading global health problem, correlated with an increased risk for several chronic diseases. One strategy for weight control management includes the use of vegetables rich in bioactive compounds to counteract weight gain, improve the antioxidant status and stimulate lipid catabolism.

AIM OF THE STUDY

The aim of this study was to investigate the role of Raphanus sativus Sango sprout juice (SSJ), a Brassica extraordinarily rich in anthocyanins (AC) and isothiocyanates (ITCs), in a non-genetic model of obesity (high fat diet-HFD induced).

METHODS

Control groups were fed with HFD or regular diet (RD). After a 10-week period, animals were assigned to experimental units and treated by gavage for 28 days as follows: HFD and RD control groups (rats fed HFD or RD and treated with vehicle only) and HFD-treated groups (rats fed HFD and treated with 15, 75 or 150 mg/kg b.w. of SSJ). Body weight and food consumption were recorded and serum lipid profile was measured (total cholesterol, triglycerides, and non-esterified fatty acids). Hepatic phase-I, phase-II as well as antioxidant enzymatic activities were assessed.

RESULTS

SSJ lowered total cholesterol level, food intake and liver weight compared with HFD rodents. SSJ at medium dose proved effective in reducing body-weight (~19 g reduction). SSJ was effective in up-regulating the antioxidant enzymes catalase,

NAD(P)H

quinone reductase, oxidised glutathione reductase and superoxide dismutase, which reached or exceeded RD levels, as well as the phase II metabolic enzyme UDP-glucuronosyl transferase (up to about 43%). HFD up-regulated almost every cytochrome P450 isoform tested, and a mild down-regulation to baseline was observed after SSJ intervention.

CONCLUSION

This work reveals, for the first time, the antioxidant, hypolipidemic and antiobesity potential of SSJ, suggesting its use as an efficient new functional food/nutraceutical product.

Disruption of redox homeostasis and carcinogen metabolizing enzymes changes by administration of vitamin E to rats

AIMS

A large meta-analysis of randomized clinical trials has seriously questioned chemoprevention based on vitamins including vitamin E (VE), and an increased risk for cancer among long-term users was actually seen. However, the mechanism underlying these findings still remain unknown. To clarify the mechanism, in an in vivo model we studied the putative disruption of redox homeostasis and the perturbation of carcinogen metabolizing enzymes determined by VE.

MAIN METHODS

Male Sprague-Dawley rats were treated ip with either 100 or 200mg/kg b.w. daily for 7 or 14 consecutive days. Controls received vehicle only. Cytochrome P450 (CYP) content, CYP-reductase, CYP-linked monooxygenases, as well as phase-II and the antioxidant enzymes catalase and

NAD(P)H

quinone reductase were investigated in both liver and kidney. Free radical species in tissue subcellular preparations were measured by electronic paramagnetic resonance (EPR) spectroscopy coupled to a radical probe technique.

KEY FINDINGS

No substantial changes of hepatic xenobiotic metabolism enzymes were determined by VE. Conversely, a powerful booster effect of various renal phase-I carcinogen bioactivating enzymes at both dosages and observational times was recorded. While no relevant changes of post-oxidative phase-II reactions were found in the liver, a significant inactivating effect was caused by VE in renal tissues. Antioxidant enzymes were found mainly downregulated by the treatment. In the kidney, a marked free radical over-generation linked to CYP induction was observed.

SIGNIFICANCE

This study proved that VE acts as a co-carcinogen and pro-oxidant agent. Such epigenetic mechanisms may contribute to explain the harmful outcomes observed in humans.