The effect of grape seed polyphenols and delta tocotrienol as supplements in improvement of NASH histopathology in C57BL/J6 mice fed high fat diet
Nonalcoholic Fatty Liver Disease (NAFLD) and Nonalcoholic Steatohepatitis (NASH), which are histologically similar to alcoholic hepatitis are the most common liver conditions in USA. Diets high in fat have been associated with the development of obesity and NASH. Currently there are no therapeutic drugs approved by FDA available as treatment for these diseases; therefore attention has been directed towards the role of bioactive compounds like polyphenols and fat-soluble vitamin E in the treatment of NAFLD/NASH.
The objective of this study was to investigate the effects of dietary grape seed polyphenols (GSP, 1% and 2%) and δ-tocotrienol (δ3T, 0.025% and 0.05%) supplementation alone and in combination, incorporated into a high fat diet (HF) on NASH-like histopathologic features and liver fibrosis in C57BL/6J mice.
Mice were placed on HF diets which were supplemented with two doses of GSP, δ-tocotrienol or their combination. Histopathological changes of the liver were assessed using Hematoxylin and Eosin stain, periodic acid Schiff stain (P.A.S) and Masson's trichrome stain and hepatic fibrosis by immunostaining. The morphometric analysis showed that the NASH-like histologic features increased in HF diet fed group, and reduced both by (i) GSP supplementation alone and (ii) in combination with δ3T. Steatosis was reduced by GSP with reduction of the lipid droplet area (p ≤ .01) (cells/mm2). Overall, the HF diet was found to induce steatosis in the mice. The photomicrographs obtained from the three different histology stains showed the beneficial effects of GSP supplementation with reduction in mice mean liver weight, steatosis and absence of collagen accumulation and reduction in the activation of hepatic stellate cells (HSC) and liver fibrosis. Thus dietary GSP supplementation alone and in combination with δ3T in HF diet may ameliorate the NASH-like histopathological features in C57BL/6J mice.