Hawthorn total flavonoids ameliorate ambient fine particulate matter-induced insulin resistance and metabolic abnormalities of lipids in mice.

Recent studies have shown a strong correlation between ambient fine particulate matter (PM _2.5 ) exposure and diabetes risk, including abnormal lipid accumulation and systemic insulin resistance (IR). Hawthorn total flavonoids (HF) are the main groups of active substances in Hawthorn, which showed anti-hyperlipidemic and anti-hyperglycemic effects. Therefore, we hypothesized that HF may attenuate PM _2.5 -induced IR and abnormal lipid accumulation. Female C57BL/6 N mice were randomly assigned to the filtered air exposure (FA) group, concentrated PM _2.5 exposure (PM) group, PM _2.5 exposure maintained on a low-dose HF diet (LHF) group, and PM _2.5 exposure maintained on a high-dose HF diet (HHF) group for an 8-week PM _2.5 exposure using a whole-body exposure device. Body glucose homeostasis, lipid profiles in the liver and serum, and enzymes responsible for hepatic lipid metabolism were measured. We found that exposure to PM _2.5 impaired glucose tolerance and insulin sensitivity. In addition, triacylglycerol (TAG) in serum elevated, whereas hepatic TAG levels were decreased after PM _2.5 exposure, accompanied by inhibited fatty acid uptake, lipogenesis, and lipolysis in the liver. HF administration, on the other hand, balanced the hepatic TAG levels by increasing fatty acid uptake and decreasing lipid export, leading to alleviated systemic IR and hyperlipidemia in PM _2.5 -exposed mice. Therefore, HF administration may be an effective strategy to protect against PM _2.5 -induced IR and metabolic abnormalities of lipids.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022. Published by Elsevier Inc.)