Apoptosis induced by a low-carbohydrate and high-protein diet in rat livers

AIM: To determine whether high-protein, high-fat, and low-carbohydrate diets can cause lesions in rat livers.METHODS: We randomly divided 20 female Wistar rats into a control diet group and an experimental diet group. Animals in the control group received an AIN-93 M diet, and animals in the experimental group received an Atkins-based diet(59.46% protein, 31.77% fat, and 8.77% carbohydrate). After 8 wk, the rats were anesthetized and exsanguinated for transaminases analysis, and their livers were removed for flow cytometry, immunohistochemistry, and light microscopy studies. We expressed the data as mean ± standard deviation(sd) assuming unpaired and parametric data; we analyzed differences using the student's t-test. statistical significance was set at P < 0.05.RESULTS: We found that plasma alanine aminotransferase and aspartate aminotransferase levels were significantly higher in the experimental group than in the control group. According to flow cytometry, the percentages of nonviable cells were 11.67% ± 1.12% for early apoptosis, 12.07% ± 1.11% for late apoptosis, and 7.11% ± 0.44% for non-apoptotic death in the experimental diet group and 3.73% ± 0.50% for early apoptosis, 5.67% ± 0.72% for late apoptosis, and 3.82% ± 0.28% for non-apoptotic death in the control diet group. The mean percentage of early apoptosis was higher in the experimental diet group than in the control diet group. Immunohistochemistry for autophagy was negative in both groups. sinusoidal dilation around the central vein and small hepatocytes was only observed in the experimental diet group, and fibrosis was not identified by hematoxylin-eosin or Trichrome Masson staining in either group.CONCLUSION: Eight weeks of an experimental diet resulted in cellular and histopathological lesions in rat livers. Apoptosis was our principal finding; elevated plasma transaminases demonstrate hepatic lesions.

Low-carbohydrate diets lead to greater weight loss and better glucose homeostasis than exercise: a randomized clinical trial

Lifestyle interventions,including dietary adjustments and exercise,are important for obesity management.This study enrolled adults with overweight or obesity to explore whether either low-carbohydrate diet(LCD)or exercise is more effective in metabolism improvement.Forty-five eligible subjects were randomly divided into an LCD group(n=22)and an exercise group(EX,n=23).The subjects either adopted LCD(carbohydrate intake<50 g/day)or performed moderate-to-vigorous exercise(≥30 min/day)for 3 weeks.After the interventions,LCD led to a larger weight loss than EX(−3.56±0.37 kg vs.−1.24±0.39 kg,P<0.001),as well as a larger reduction in fat mass(−2.10±0.18 kg vs.−1.25±0.24 kg,P=0.007)and waist circumference(−5.25±0.52 cm vs.−3.45±0.38 cm,P=0.008).Both interventions reduced visceral and subcutaneous fat and improved liver steatosis and insulin resistance.Triglycerides decreased in both two groups,whereas low-density lipoprotein cholesterol increased in the LCD group but decreased in the EX group.Various glycemic parameters,including serum glycated albumin,mean sensor glucose,coefficient of variability(CV),and largest amplitude of glycemic excursions,substantially declined in the LCD group.Only CV slightly decreased after exercise.This pilot study suggested that the effects of LCD and exercise are similar in alleviating liver steatosis and insulin resistance.Compared with exercise,LCD might be more efficient for weight loss and glucose homeostasis in people with obesity.