Influence of zinc-whey protein nanoparticles in fermented milk on oxidative stress and liver function in obese rats

Obesity refers to fat accumulation in patients’ adipose tissue and is widespread globally. It is necessary to develop anti-obesity foods and promote a healthy lifestyle before it reaches epidemic proportions. This study aimed to evaluate the effects of zincwhey protein nanoparticles (Zn-WPNPs), incorporated into fermented milk (FM), on oxidative stress, inflammation, and liver fibrosis in obese rats. Chemical analysis included the determination of total solids, protein, fat, carbohydrates, ash contents, and pH. Zn efficacy was within 91.22–97.12%, with particle size within 41.4–228 nm. Zn-WPNPs demonstrated stability after encapsulation, as confirmed by transmission electron microscopy photographs. Moreover, forty female albino rats were divided into five groups and were orally treated for 30 consecutive days: a control group, high-fat diet (HFD; Ch; 1%), FM alone, FM-Zn, and FM-Zn-WPNPS. Blood and liver samples were then collected for analysis. Highly significant increases in body weight, lipid profile (TG and LDL), and malonaldehyde, along with decreases in the levels of hepatic Ch, HDL, and enzyme activity (AST and ALT) were found in the HFD group. On the other hand, the animals treated with FM-Zn-WPNPs showed reduced levels of all the oxidative stress markers (MDA, CAT, and GSH) to 1.19, 1.89, and 43.25, compared to 2.29, 1.20, and 27.40 in the HFD group, respectively, along with improvements in all the liver measurements. Thus, FM-Zn-WPNPs may serve as an appropriate food for nonalcoholic fatty liver disease (NAFLD) patients to improve their health.