Dietary α -lactalbumin induced fatty liver by enhancing nuclear liver X receptor αβ /sterol regulatory element-binding protein-1c/PPAR γ expression and minimising PPAR α /carnitine palmitoyltransferase-1 expression and AMP-activated protein kinase α phosphorylation associated with atherogenic dyslipidaemia, insulin resistance and oxidative stress in Balb/c mice

Diet, oxidative stress and MAFLD: a mini review

Globally, metabolic dysfunction-associated fatty liver disease (MAFLD), also known as non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD), is a common chronic liver disease. The progression of MAFLD leads to a vicious cycle in which oxidative stress results from the disease that is augmenting de-novo lipid levels and increases steatosis. Most non-enzymatic antioxidants are present in food. Therefore, the present review summarizes the findings of studies on food-derived antioxidants and presents an oxidative stress-related regulatory network in MAFLD, offering new ideas for MAFLD prevention and treatment.

Dietary chenodeoxycholic acid attenuates high-fat diet-induced growth retardation, lipid accumulation and bile acid metabolism disorder in the liver of yellow catfish Pelteobagrus fulvidraco

This experiment was conducted to investigate whether dietary chenodeoxycholic acid (CDCA) could attenuate high-fat (HF) diet-induced growth retardation, lipid accumulation and bile acid (BA) metabolism disorder in the liver of yellow catfish Pelteobagrus fulvidraco. Yellow catfish (initial weight: 4·40 (sem 0·08) g) were fed four diets: the control (105·8 g/kg lipid), HF diet (HF group, 159·6 g/kg lipid), the control supplemented with 0·9 g/kg CDCA (CDCA group) and HF diet supplemented with 0·9 g/kg CDCA (HF + CDCA group). CDCA supplemented in the HF diet significantly improved growth performance and feed utilisation of yellow catfish (P < 0·05). CDCA alleviated HF-induced increment of hepatic lipid and cholesterol contents by down-regulating the expressions of lipogenesis-related genes and proteins and up-regulating the expressions of lipololysis-related genes and proteins. Compared with the control group, CDCA group significantly reduced cholesterol level (P < 0·05). CDCA significantly inhibited BA biosynthesis and changed BA profile by activating farnesoid X receptor (P < 0·05). The contents of CDCA, taurochenodeoxycholic acid and glycochenodeoxycholic acid were significantly increased with the supplementation of CDCA (P < 0·05). HF-induced elevation of cholic acid content was significantly attenuated by the supplementation of CDCA (P < 0·05). Supplementation of CDCA in the control and HF groups could improve the liver antioxidant capacity. This study proved that CDCA could improve growth retardation, lipid accumulation and BA metabolism disorder induced by HF diet, which provided new insight into understanding the physiological functions of BA in fish.

[Conjugated linoleic acid improves glucose and lipid metabolism in diabetic mice]

OBJECTIVE

To analyze the effect of conjugated linoleic acid (CLA) on glucose and lipid metabolism in obese diabetic (db/db) mice.

METHODS

db/db mice were randomized for treatment with saline or CLA mixture administered intragastrically. The changes in body weight, dietary intake, water intake, oral glucose tolerance, triglyceride and total cholesterol were recorded after the treatments. HE staining and oil red O staining were used to assess liver pathologies and fatty acid content. The expression levels of PPARα, PPARγ, CD36, CHREBP and SREBP-1c were detected using real-time PCR and Western blotting. HepG2 cells were treated with CLA and linoleic acid and the expressions of PPARα, ACC, P-ACC, and CD36 were detected; the level of acetyl-CoA in the cell supernatant was detected using ELISA.

RESULTS

CLA treatment obviously reduced the dietary and water intake of db/db mice, effectively reduced the body weight and decreased serum triglyceride and cholesterol levels (P &lt; 0.05). CLA significantly reduced fasting blood glucose, increased glucose tolerance, reduced the accumulation of lipid droplets in the liver and improved lipid metabolism in db/db mice. The mice showed significantly increased expression of PPARα (P &lt; 0.05) and lowered CD36 expression (P &lt; 0.001) in the liver after CLA treatment. Cellular experiments showed that CLA significantly up-regulated PPARα (P &lt; 0.001) and P-ACC and decreased the expression of CD36 (P &lt; 0.01). ELISA showed that acetyl-CoA was significantly up-regulated in the cells after CLA treatment (P &lt; 0.01).

CONCLUSIONS

The mixture of two conjugated linoleic acid isomers can reduce fasting blood glucose, increase glucose tolerance and improve glycolipid metabolism in db/db mice by enhancing the expression of PPARα, increasing P-ACC and inhibiting CD36 expression.

Chronic treatment with the modified Longdan Xiegan Tang attenuates olanzapine-induced fatty liver in rats by regulating hepatic de novo lipogenesis and fatty acid beta-oxidation-associated gene expression mediated by SREBP-1c, PPAR-alpha and AMPK-alpha

ETHNOPHARMACOLOGICAL RELEVANCE

The modified Longdan Xiegan Tang (mLXT) has been used clinically for various neuropsychiatric disorders and liver diseases. The use of antipsychotics is associated with nonalcoholic fatty liver disease.

AIM OF THE STUDY

To investigate the effect and underlying mechanisms of mLXT on antipsychotic-induced fatty liver.

MATERIALS AND METHODS

The representative active components in the formula were identified and quantified by a HPLC method. Fatty liver in male rats was induced by olanzapine (5 mg/kg) (p.o., × 8 weeks), and the rats were co-treated with mLXT extract (50 and 500 mg/kg). Blood and liver variables were determined enzymatically or histologically. Gene/protein expression was analyzed by real-time PCR and Western blot.

RESULTS

Treatment of rats with mLXT decreased olanzapine-induced increases in hepatic triglyceride content, cell vacuolar degeneration and Oil Red O-stained area, accompanied by suppression of olanzapine-stimulated hepatic mRNA and/or protein overexpression of sterol regulatory element-binding protein (SREBP)-1c, and its downstream lipogenic enzymes for de novo lipogenesis. Besides, mLXT also activated hepatic expression of peroxisome proliferator-activated receptor-alpha and its target genes associated with fatty acid beta-oxidation, phosphorylated Thr¹⁷² in AMP-activated protein kinase (AMPK)-alpha (the upstream enzyme of SREBP-1c and PPAR-alpha), and its ratio to total AMPK-alpha.

CONCLUSIONS

The present results suggest that chronic treatment with mLXT ameliorates olanzapine-induced fatty liver by regulating hepatic de novo lipogenesis- and fatty acid beta-oxidation-associated gene expression mediated by SREBP-1c and PPAR-alpha, respectively, through activation of AMPK-alpha. Our findings provide the evidence that supports clinical use of the formula for antipsychotic medication-induced fatty liver.