Toxic effects of mineral oil saturated hydrocarbons (MOSH) and relation to accumulation in rat liver

• Published in: Food and chemical toxicology 2019-01, Vol.123, p.431-442
• Main Authors: Nygaard, Unni Cecilie, Vege, Åshild, Rognum, Torleiv, Grob, Koni, Cartier, Christel, Cravedi, Jean-Pierre, Alexander, Jan
• Format: Article
• Language: English
• Subjects: Animals; Female; Granuloma; Granuloma - etiology; Granuloma - metabolism; Humans; Hydrocarbons - chemistry; Hydrocarbons - metabolism; Hydrocarbons - toxicity; Immune function; Life Sciences; Liver - drug effects; Liver - metabolism; Mineral oil; Mineral Oil - chemistry; Mineral Oil - metabolism; Mineral Oil - toxicity; Mineral wax; n-alkane; Rat; Rats; Rats, Inbred F344; Spleen - drug effects; Spleen - metabolism; Toxicology
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2018.11.022

Humans are daily exposed to mineral oil saturated hydrocarbons (MOSH) from the diet. We exposed female Fischer 344 rats to a broad mixture and sub-fractions of MOSH. Chemical characterization of the MOSH mixture used and material accumulated in rat tissues were previously reported. Rats were exposed to feed containing 0–4000 mg/kg broad MOSH mixture for 30, 60, 90 and 120 days; and for 120 days to feed containing different MOSH fractions: i) mainly molecular masses  C25 (L-C25) and iii) the L-C25 fraction mixed with wax largely consisting of n-alkanes > C25 (L-C25W). Treatments related effects were increased liver and spleen weight, as well as vacuolization and granuloma formation with lymphoid cell clusters in the liver, but effects varied strongly between the MOSH fractions tested. We conclude that increased liver and spleen weights were mainly related to accumulated iso-alkanes and substituted cycloalkanes, but also wax n-alkanes. Induction of liver granuloma appeared to be related to n-alkanes > C25 and not to the accumulated amount of MOSH. Immune responses to an injected antigen were not affected. MOSH fractions associated with increased liver and spleen weights were similar to those accumulating in humans. Granuloma formation (in frame) in liver after dietary exposure to MOSH. [Display omitted] •Humans are exposed to dietary MOSH as contaminants, additives and from packaging material.•In rats, dietary MOSH induced hepatic granuloma associated with lymphoid cells.•n-alkanes above C25 appears to be the most potent inducer of granulomas.•Iso-alkanes and substituted cycloalkanes caused increased liver and spleen weights.•MOSH fractions associated with increased liver or spleen weights were similar to that seen in humans.