Inflammation, oxidative stress and genotoxicity responses to biodiesel emissions in cultured mammalian cells and animals

Abstract

Biodiesel fuels are alternatives to petrodiesel, especially in the transport sector where they have lower carbon footprint. Notwithstanding the environmental benefit, biodiesel fuels may have other toxicological properties than petrodiesel. Particulate matter (PM) from petrodiesel causes cancer in the lung as a consequence of delivery of genotoxic polycyclic aromatic hydrocarbons, oxidative stress and inflammation. We have reviewed articles from 2002 to 2019 (50% of the articles since 2015) that have described toxicological effects in terms of genotoxicity, oxidative stress and inflammation of biodiesel exhaust exposure in humans, animals and cell cultures. The studies have assessed first generation biodiesel from different feedstock (e.g. rapeseed and soy), certain second generation fuels (e.g. waste oil), and hydrogenated vegetable oil. It is not possible to rank the potency of toxicological effects of specific biodiesel fuels. However, exposure to biodiesel exhaust causes oxidative stress, inflammation and genotoxicity in cell cultures. Three studies in animals have not indicated genotoxicity in lung tissue. The database on oxidative stress and inflammation in animal studies is larger (13 studies); ten studies have reported increased levels of oxidative stress biomarkers or inflammation, although the effects have been modest in most studies. The cell culture and animal studies have not consistently shown a different potency in effect between biodiesel and petrodiesel exhausts. Both increased and decreased potency have been reported, which might be due to differences in feedstock or combustion conditions. In conclusion, combustion products from biodiesel and petrodiesel fuel may evoke similar toxicological effects on genotoxicity, oxidative stress and inflammation.

Keywords:

• Biodiesel
• DNA damage
• oxidative stress
• inflammation
• animal models
• in vitro

Acknowledgements

The authors thank the anonymous peer reviewers for constructive criticism and suggested additions. Their comments and suggestions were helpful to us and contributed to the clarity and accuracy of our publication.

Declaration of interest

The employment affiliations of the authors are shown on the cover page. The institutions with which the authors are affiliated are traditional academies. The review, synthesis, and conclusions reported in this paper are the exclusive professional work product of the four authors. The authors are supported by a grant from Laege Sofus Carl Emil Friis og hustru Olga Doris Friis’ legat (project title: “Health effects of exposure to biodiesel combustion particles”). This is a private fund that has no ties to the biodiesel fuel and automobile production industry. The grant supports a controlled human exposure study on biodiesel exhaust and the review was conducted to find knowledge gaps in the literature on mechanisms of action and health effects. There has been no external input into the development of the paper, nor has the private fund or any in-house or outside legal counsel reviewed the paper prior to publication. The authors report no conflict of interest and have not appeared any legal, regulatory or advocacy proceedings related to the contents of the paper.

Author contribution

The author’s affiliation is as shown on the cover page. The authors have sole responsibility for the writing and content of the paper

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