Electronic nicotine delivery systems first appeared on the market in 2003 and have been promoted as healthier alternatives to conventional tobacco cigarettes. The rapid evolution of technology for these products generated a wide variety of models, and electronic cigarettes have quickly gained worldwide popularity. However, research regarding the effects of both short-term and long-term exposure revealed a wide variety of potential negative effects on human health, and the first system to be affected by these electronic smoking devices is the oral cavity. This review makes an up-to-date extensive presentation of the possible mechanisms that associate electronic cigarette smoking with increased prevalence and progression of oral cancer. Oxidative stress, inflammation response, and DNA damage are the main mechanisms that explain e-cigarettes’ cytotoxicity, but there are still questions to be answered. At present, tens of thousands of e-liquids are available, with distinct compositions, which makes the research even more challenging. Another aspect approached in the present paper is the effect of nicotine on chemotherapy drug resistance. Nicotine activates nicotinic acetylcholine receptors, consecutively inhibiting apoptosis, increasing tumor cells proliferation and survival, and reducing the effects of chemotherapy drugs.

Even in modern times, the popularity level of medicinal plants and herbal medicines in therapy is still high. The World Health Organization estimates that 80% of the population in developing countries uses these types of remedies. Even though herbal medicine products are usually perceived as low risk, their potential health risks should be carefully assessed. Several factors can cause the toxicity of herbal medicine products: plant components or metabolites with a toxic potential, adulteration, environmental pollutants (heavy metals, pesticides), or contamination of microorganisms (toxigenic fungi). Their correct evaluation is essential for the patient’s safety. The toxicity assessment of herbal medicine combines in vitro and in vivo methods, but in the past decades, several new techniques emerged besides conventional methods. The use of omics has become a valuable research tool for prediction and toxicity evaluation, while DNA sequencing can be used successfully to detect contaminants and adulteration. The use of invertebrate models (Danio renio or Galleria mellonella) became popular due to the ethical issues associated with vertebrate models. The aim of the present article is to provide an overview of the current trends and methods used to investigate the toxic potential of herbal medicinal products and the challenges in this research field.

The present review summarizes the literature data regarding the application of Triticum aestivum assay as an alternative method for toxicity assessment of environmental pollutants or potential therapeutic agents. Plant bioassays present several advantages among other biological assays (simplicity, low cost, rapid test activation, a wide array of assessment endpoints). They present a good correlation with animal and human cells models, and are a reliable tool for genotoxicity assessment. Furthermore, in the context of toxicology guidelines that promote the substitution of assays using animal models with other bioassays, genotoxicity assays using higher plants models have gained in popularity. The present review focuses on three major aspects regarding Triticum aestivum assay - its utility in environmental pollution monitoring, its application in genotoxicity assessment studies, and its application in phytotoxicity evaluation of nanomaterials.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

The study aimed at assessing the in vitro digestive bioavailability of heavy metals in the presence of plant extracts under simulated digestive system conditions. The complexing ability of aqueous herbal extracts of Crataegus sp., Tilia spp., Rosa canina, Vaccinium myrtillus, Geranium robertianum, Mentha piperita, Cynara cardunculus subsp. Scolymus, Plantago sp., and Coriandrum sativum was researched on Cu+2, Cd+2, Ni+2, Pb+2 and Hg+2 cations. The quantitative determination of the fraction of free metal left, available for absorption, was achieved by atomic absorption spectroscopy (AAS) or potentiometry using an ion-selective electrode (ISE).

The growing popularity of electronic cigarettes has raised several public health concerns, including the risks associated with heavy metals exposure via e-liquids and vapors. The purpose of this study was to determine, using atomic absorption spectrometry, the concentrations of Pb, Ni, Zn, and Co in some commercially available e-liquid samples from Romania immediately after purchase and after storage in clearomizers. Lead and zinc were found in all investigated samples before storage. The initial concentrations of Pb ranged from 0.13 to 0.26 mg L−1, while Zn concentrations were between 0.04 and 0.07 mg L−1. Traces of nickel appeared in all investigated e-liquids before storage but in very small amounts (0.01–0.02 mg L−1). Co was below the detection limits. We investigated the influence of the storage period (1, 3, and 5 days), storage temperature (22 °C and 40 °C), and type of clearomizer. In most cases, the temperature rise and storage period increase were associated with higher concentrations of heavy metals. This confirms that storage conditions can affect metal transfer and suggests that the temperature of storage is another parameter that can influence this phenomenon.