Toxicology: Open Access
Open Access

SENCAR mice; Toxicology; Tumor; Toxicology Cigarette

Introduction

The modern American-style blended cigarette filler is made up of a distinctive mixture of heat- and air-cured tobaccos as well as a reconstituted tobacco sheet component. Natural leaf sugars in burley tobacco are lost during the air curing process; these sugars and syrups are then added to the casings as "sauces" to restore the natural leaf sugars to the tobacco. Tobacco friability is managed during high-speed manufacturing by using humectants such glycerol and propylene glycol, which also help to preserve the quality of packed goods. Specialized "top dressing" compositions of natural and artificial flavours, herbs, spices, and essential oils applied at low concentrations to cigarette tobacco contribute to the overall smoking attributes of the tobacco mix and create distinctive, brand-specific flavour notes [1].

By mixing 14C-labeled materials with tobacco, researchers were able to demonstrate this effect for a number of tobacco tastes. They discovered that more than 90% of the radioactivity applied was accounted for in the mainline smoke, sidestream smoke, or the filter. Without pyrolytic degradation, it would be predicted that the parent structure and the method of administration would determine the toxicologic potential of components entrained in the smokestream. When tobacco is smoked, flavourings that are heat labile or have high enough boiling temperatures, however, may breakdown and may rearrange or combine with other smoke elements rather than being transported intact to the smoke. The pyrolysis byproducts of processed tobaccos should therefore be taken into account in a comprehensive toxicologic assessment of cigarette tastes [2].

We have previously reported the results of a series of four 13-week smoke inhalation studies conducted in rats to evaluate the biological effects of 172 ingredients used domestically by the US tobacco industry. Here, we provide the results of four skin painting initiation/promotion bioassays carried out in SENCAR mice to assess the tumor-causing potential of smoke condensate from cigarettes made up of 150 different chemical combinations. Wynder and Hoffmann (1964) employed the mouse skin painting model to explore the tumorigenic potential of cigarette smoke condensates as well as other complex mixes including particle emissions. In the initiation/promotion skin painting test method, the SENCAR mouse has been shown to be a more sensitive model system than the B6C3F1 or Swiss (CD-1) strains. Although it is unknown whether mouse skin cancers are related to any human manifestation of the toxicity of complex combinations, the skin painting model [3].

Controls that are negative, positive, and limited to CSC promotions

The smoke condensate samples used in the current paper were taken from cigarettes that had mixtures of flavours applied to tobacco in a way resembling that employed in commercial manufacture, as opposed to conducting numerous tests with individual flavouring components. This strategy best simulates any possibly important interactions between additives and tobacco pyrolysis products during cigarette combustion. The inclusion rates of the compounds studied here are thought to be representative of, or higher than, those found in modern cigarette designs, despite the fact that the taste formulations employed by different cigarette makers are trade secrets similar to those of food and beverage producers. Six different test cigarette formulations were used in studies that were carried out between 1989 and 1997. The investigation's goal was to contrast the biologic.

The test plan presented in Table 1 was used in four different studies. Mice were weighed for each research and divided into study groups of 30–50 animals each. A single 50 g application of 7,12-dimethylbenz(a) anthracene (DMBA; Sigma Chemical Co., St. Louis, MO) diluted in 0.1 ml of acetone was administered to the mice on the first day of the trial at a region on the dorsal skin that had been shaved and measured 2 to 3 cm in size. The mice were given topical treatments beginning one week later.

In all investigations, acetone- or TPA-treated groups were used as system negative or positive controls, respectively (Table 4). Acetone therapy produced minimal mortality and a very weak tumour response, as was expected. Only two mice that had acetone treatment developed tumours [4, 5].

Topical treatments are the initial line of defence in therapeutic procedures. It is typically treated with phototherapy and conventional systemic medications if the condition is regarded as moderate to severe and the topical treatments are no longer working. The chosen therapeutic strategy should always be reviewed between the doctor and the patient and should be appropriate for the patient's type, the symptoms they exhibit, the presentation and severity of the condition, and other factors. Corticosteroids, vitamin D3 analogues, retinoids, calcineurin inhibitors, and even combinations of two or more drugs are some of the topical medications used to treat psoriasis. Despite the fact that these medications are very effective, there is a problem with their unfavourable side effects [6].

According to each person's propensity for the condition and the aggressivity of the triggers, psoriasis advances differently. A moderate case of psoriasis exists if the afflicted skin area is less than 5%. A more severe type of psoriasis that is frequently accompanied by additional comorbidities is deemed to exist if the afflicted area is greater than 10% and falls between the ranges of 5 and 10%. The appearance and severity of the various kinds of psoriasis differ. Plaque psoriasis, or common psoriasis as it is also known, is the most prevalent variety of psoriasis. Raised, red lesions that vary in size and extent across individuals are its defining characteristics. Any area of the body can be damaged, however the skin is the most severely impacted [7,8].

Discussion

The US Food and Drug Administration and/or the Flavor and Extract Manufacturers Association have designated the vast majority of the flavouring ingredients used in tobacco products as "generally regarded as safe" (GRAS). These ingredients are commonly used spices and flavours in the food and beverage industries. This designation is supported by evidence on animal toxicity and a long history of safe use in food items [9].

Conclusion

The systemic absorption of the existing topical treatments for skin conditions like psoriasis and their low medication penetration can have unfavourable effects. The majority of in vivo tests using nanoformulations revealed increased skin permeability and no or very few instances of irritative or inflammatory effects. One of the most promising technologies is nanotechnology, which has a wide range of applications and a great deal of promise to support cutting-edge treatment options. However, there are still a lot of hazards associated with it and numerous unknown. There is still much to learn about the topical application of nanotechnology as a therapy option for skin illnesses, even though extensive research is ongoing and significant discoveries have been made. Additionally, current research on the causes, symptoms, and treatments of psoriasis [10].

Acknowledgement

The McGill Engineering Doctoral Award (MEDA) and the Natural Sciences and Engineering Research Council of Canada Doctoral Postgraduate Scholarship (NSERC PGS-D) to PKP, the NSERC Postdoctoral and Fonds de Recherche du Québec - Nature et Technologies (FRQNT) Postdoc Fellowships to LSF, the Canada Research Chair in Advanced Cellular Mice (RGPIN-2015-05512 to CM), the FRQNT (Grant #205292).

Potential Conflict of Interest

The authors affirm that they have no known financial or interpersonal conflicts that would have appeared to have an impact on the research presented in this study.

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