Protective Effect of Cow Placenta Extract on Liver of D-Galactose-Induced Aging Mice

Ethnopharmacological relevance: Placenta is a kind of traditional Chinese medicine, known as “Ziheche”, which has the function of tonifying qi and blood, nourishing liver and kidney. Placenta extract (PE) has been used for delaying organismal aging and treating various liver diseases, including fatty liver, chronic hepatitis, and liver fibrosis. Cow placenta is a rich natural resource with large mass, but it has not been effectively utilized. Its extract (CPE) has the function of antioxidation, skincare, hair growth promotion, and anticancer. However, little is known about the impact of oral CPE on liver conditions.Aim of the studyThis study aims to explore the protective effect of CPE on liver of d-galactose (D-gal) induced aging mice.Materials and methods: Forty-eight 8-week-old SPF Kunming mice were fed adaptively for 1 week and then randomly divided into four groups (n=12): group N (saline + distilled water), group M (D-gal + distilled water), group T (D-gal + CPE) and group P (D-gal + Vit C). Histopathological, transmission electron microscopy (TEM), ELISA, special staining, immunohistochemistry, RT-qPCR and Western-blot were used to detect the changes of liver index, morphological structure, biochemical indexes, oxidative and inflammatory factors, as well as aging-related biomarkers in the liver.Results: The results showed that CPE could increase liver index, restore the normal structure and function of the liver, reduce the levels of AST, ALT and GLOB in serum, downregulate the content of ROS, MDA, IL-1β, IL-6 and TNF-α, and upregulate the content of GSH, SOD, CAT, IL-4 and IL-10 in liver, exhibiting strong hepatoprotective, antioxidant and anti-inflammatory effects. Furthermore, CPE could improve hepatocyte apoptosis and senescence, promote hepatocyte proliferation, and down-regulate the levels of aging markers 8-OHdG and AGEs in the liver, which had a good anti-aging effect. The mechanism involved reducing the expression of p53, p21, p16, BAX, CASP3 and C-CASP3 genes or proteins, and down-regulating the ratio of BAX/BCL-2.Conclusion: CPE could effectively ameliorate the impact of aging on the liver, and its mechanism may be associated to the regulation of apoptosis and proliferation-related factors.