Induction of liver fibrosis by CCl4 mediates pathological alterations in the spleen and lymph nodes: The potential therapeutic role of propolis

Saudi J Biol Sci. 2021 Feb;28(2):1272-1282. doi: 10.1016/j.sjbs.2020.11.068. Epub 2020 Nov 26.

Abstract

In an animal models, carbon tetrachloride (CCl4) is a carcinogenic agent that causes liver fibrosis. The current study aims to investigate whether induction in liver-fibrosis by CCl4 in the mouse model could promote the initiation of fibrosis in lymph node and spleen due to sustained increase of inflammatory signals and also aimed to clarify the protective therapeutic effects of propolis. The male mice (BALB/c) were categorized into three experimental sets and each group involved 15 mice. Control group falls into first group; group-II and group-III were injected with CCl4 to induce liver-fibrosis and oral supplementation with propolis was provided in group-III for 4-weeks. A major improvement with hepatic collagen and α-smooth muscle actin (α-SMA) production was aligned with the activation of liver fibrosis from CCl4. Mice treated with CCl4 exhibited collagen deposition towards liver sections, pathological alterations in spleen and lymph node architectures, and a significantly increase the circulation of both T&B cells in secondary lymphoid organs. Mechanically, the secondary lymphoid organs treated with CCl4 in mice exposed a positive growth in α-SMA and collagen expression, increased in proinflammatory cytokine levels and a significant increase in TGF-β, NO and ROS levels. A manifest intensification in the expression of Nrf2, COX-2, and eNOS and upregulation of ASK1 and P38 phosphorylation. Interestingly, addition of propolis-treated CCl4 mice, substantially suppressed deposition of liver collagen, repealed inflammatory signals and resorted CCl4-mediated alterations in signaling cascades, thereby repairing the architectures of the secondary lymphoid organs. Our findings revealed benefits of propolis against fibrotic complications and enhancing secondary lymphoid organ architecture.

Keywords: CCl4; Inflammation; Liver fibrosis; Oxidative stress; Propolis; Secondary lymphoid organs.