Lard oil

Sprague-Dawley (male, 120-130 g initial weight, diet-induced obesity model)^[1]

Component of high-fat diet

p.o.; ad libitum daily; 18 weeks (HL/HL group); p.o.; ad libitum daily; 10 weeks followed by low-fat diet for 8 weeks (HL/LF group)

Exhibited markedly increased abdominal fat accumulation, body fat ratio, serum insulin and HOMA-IR in the HL/HL group relative to low-fat control and soybean oil-based high-fat diet groups.
Showed the maximal hepatic fat vacuolation and triglyceride levels in the HL/HL group among all experimental groups.
Elevated hepatic inflammatory gene and protein expression of TLR4, TLR2, TNF-α and OPN in the HL/HL group, which were significantly higher than those in soybean oil-treated rats.
Increased multiple endoplasmic reticulum stress and lipogenic markers in the HL/HL group, while significantly downregulating GRP78 protein expression.
Reduced fat deposition, serum insulin level and insulin resistance index in the HL/LF group compared with the HL/HL group.
Decreased hepatic lipid accumulation in the HL/LF group relative to the HL/HL group.
Lowered hepatic inflammatory expression levels in the HL/LF group when compared with the HL/HL group.
Attenuated hepatic endoplasmic reticulum stress and lipogenic activation in the HL/LF group versus the HL/HL group.

Wistar Crl(WI)BR rats (male, ~180 g upon arrival, acclimated 1 week until body weight >100% of pre-surgery weight, carotid artery and jugular vein catheter implanted with 4-5 days recovery)^[2]

70 μl/min per kg

i.v.; 4-hour infusion

Elevated plasma free fatty acids and major saturated and monounsaturated fatty acid levels compared with control rats.
Enhanced hepatic UPR, IKKβ phosphorylation, inflammatory gene expression, and MIP1α and Mmp12 protein levels relative to control and soybean oil groups.
Augmented adipose UPR activation, IKKβ phosphorylation, inflammatory expression, and MCP1 and haptoglobin protein levels compared with control and soybean oil groups.
Exhibited no significant changes in plasma glucose and insulin levels versus controls.