Liver and plasma lipid changes induced by cyclic fatty acid monomers from heated vegetable oil in the rat

Abstract

Cyclic fatty acid monomers (CFAM) generated through domestic or industrial heating of vegetable oils may alter liver enzymes and induce hepatomegaly and steatosis, but the underlying mechanisms are not clearly understood. This study aimed to assess the effects of CFAM on liver and plasma lipids and to determine whether these effects are modulated by dietary lipids. Thirty‐six (36) male Wistar rats were fed either of the four isoenergetic diets consisting of canola oil or soybean oil with/without 500 mg/100 g CFAM of total fat for 28 days. Rats fed CFAM had higher liver total lipids (p = 0.03) and triacylglycerols (TAG) (p = 0.02), but less hepatic phosphatidylcholine (p = 0.02) compared to those fed the non‐CFAM diets. CFAM did not alter liver phosphatidylethanolamine N‐methyltransferase (PEMT) activity and CTP: phosphocholine cytidylyltransferase (CT‐α) protein levels. Rats fed CFAM diets had higher levels of plasma total cholesterol (TC), VLDL + LDL cholesterol, higher ratio of TC to HDL cholesterol, and lower levels of HDL cholesterol compared with rats fed non‐CFAM diets (p < 0.05). Plasma alanine transaminase (ALT) was decreased with CFAM, but plasma insulin, glucose, and TAG did not vary among the four diet groups (p < 0.05). Rats fed canola oil and CFAM had higher plasma levels of aspartate transaminase (AST) and AST/ALT ratio compared with the other three diet groups. These results indicate that CFAM may provoke an accumulation of TAG in the liver related to a decrease in phosphatidylcholine (PC) levels, but the effect of CFAM on PC concentrations may not occur through impairment of the two main PC biosynthesis pathways.

Effect of Ginger Extracts on Palm Olein Quality during Frying and Impact of Fried Oils on Some Biological Parameters of Albino Wistar Rats

“…The decrease in serum transaminases in groups fed with oils enriched with plant extracts could be explained by the low rancidity of these oil samples as previously observed with quality indices. Elevated transaminase levels in rats after consumption of fried oils had already been observed in a number of studies (Shastry et al, 2011;Badr El Said et al, 2015;Mboma et al, 2018). These results are also in agreement with Abdulaziz, Fasih, Saada, Khalid & Zarina, (2006), they showed that dietary supplementation with Nigella sativa limits the toxic effect of oxidised corn oil in rats by decreasing serum ALAT/ASAT concentrations.…”

Thermally oxidized sunflower oil diet alters leptin/ghrelin balance and lipid profile in rats: Possible role of reactive aldehydes in dyslipidemia

“…The present study examined changes in hepatic triglyceride and cholesterol levels. Following the administration of heated oil, liver triglyceride levels increased, especially in 120‐TOSO and 240‐TOSO groups probably due to the formation of cyclic fatty acid monomers (CFAM) after thermoxidation of sunflower oil (Mboma et al, 2018). Previous studies indicated that cyclic fatty acid monomers (CFAM) were key factors in inhibiting metabolic enzymes, particularly liver lipase (Mboma et al, 2018; Narayanankutty et al, 2017).…”

“…Following the administration of heated oil, liver triglyceride levels increased, especially in 120‐TOSO and 240‐TOSO groups probably due to the formation of cyclic fatty acid monomers (CFAM) after thermoxidation of sunflower oil (Mboma et al, 2018). Previous studies indicated that cyclic fatty acid monomers (CFAM) were key factors in inhibiting metabolic enzymes, particularly liver lipase (Mboma et al, 2018; Narayanankutty et al, 2017). Following the thermoxidation of sunflower oil, CFMA formation and its inhibitory effects on hepatic lipase enzyme activity can increase serum/liver triglyceride levels (Narayanankutty et al, 2017).…”

“…The present study examined changes in hepatic triglyceride and cholesterol levels. Following the administration of heated oil, liver triglyceride levels increased, especially in 120-TOSO and 240-TOSO groups probably due to the formation of cyclic fatty acid monomers (CFAM) after thermoxidation of sunflower oil (Mboma et al, 2018).…”

Cyclic Fatty Acid Monomers or the Potential Wild Card in Trans Fats

“…Third, a recent animal study (Mboma et al, 2018a(Mboma et al, , 2018b has shown that CFAM from alpha-linolenic acid at 0.05% in no trans-fat diets has affected pro-atherogenic markers in a similar manner to trans fatty acids fed at much higher levels. Individual CFAM isomers in the canola and soybean oils used by Mboma et al ranged from 0.001% to 0.076% of the oil (Table 1), and the content was 10 times lower in the diets.…”