Silybin inhibits interleukin‐1β‐induced production of pro‐inflammatory mediators in canine hepatocyte cultures

Abstract

Hepatocytes are highly susceptible to cytokine stimulation and are fundamental to liver function. We established primary canine hepatocyte cultures to study effects of anti-inflammatory agents with hepatoprotective properties. Hepatocyte cultures were incubated with control media alone, silybin (SB), or the more bioavailable silybin-phosphatidylcholine complex (SPC), followed by activation with interleukin-1 beta (IL-1β; 10 ng/mL). Inflammatory response was measured by prostaglandin E2 (PGE(2) ), interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) production and also nuclear factor-kappa B (NF-κB) translocation. Hepatocyte cultures continued production of the phenotypic marker albumin for more than 7 days in culture. IL-1β exposure increased PGE(2) , IL-8, and MCP-1 production, which was paralleled by NF-κB translocation from the cytoplasm to the nucleus. Pretreatment with SB and SPC significantly inhibited IL-1β-induced production of pro-inflammatory markers and attenuated NF-κB nuclear translocation. We demonstrate for the first time that primary canine hepatocyte cultures can be maintained in culture without phenotypic loss. The observation that hepatocyte cultures respond to pro-inflammatory IL-1β activation indicates hepatocytes as primary cellular targets of extrinsic IL-1β. The ability of SB and SPC to inhibit hepatocyte culture activation by IL-1β reinforces the notion of their hepatoprotective effects. Our primary canine hepatocyte culture model facilitates identification of hepatoprotective agents and their mechanism of action.

Evaluation of potential serum biomarkers of hepatic fibrosis and necroinflammatory activity in dogs with liver disease

“…The chemokine CCL2 is secreted by Kupffer cells, injured hepatocytes, and activated hepatic stellate cells, and leads to monocyte recruitment, macrophage activation, progressive inflammation, and fibrogenesis during liver injury . It has not been studied previously in dogs with liver disease, but CCL2 production by canine hepatocytes was inhibited in vitro by the commercially available liver protectant, silybin . Increased serum CCL2 concentrations also have been found in critically ill dogs, and in those with lymphoma, histiocytic sarcoma, pulmonary fibrosis, congestive heart failure, and immune‐mediated hemolytic anemia .…”

Effect of Silibinin in Reducing Inflammatory Pathways in In Vitro and In Vivo Models of Infection-Induced Preterm Birth

“…Thus, it is possible that silibinin is exerting its anti-inflammatory actions by inhibiting the activity of NF-κB. Indeed, in non-gestational tissues, silibinin has been shown to exert its effects by inhibiting the activity of NF-κB [27], [40], [55].…”

“…Silibinin has been utilised as an effective treatment for hepatic disease [23] and as an adjunctive cancer therapy [24], [25]. Silibinin has been shown to have potent anti-inflammatory and anti-cancer effects (reviewed in [26]); silibinin reduced pro-inflammatory mediators in vitro in canine hepatocytes [27], an HIV viral infection model [28], in vitro and in vivo models of mouse skin inflammation [29], [30], and skin and prostate cancer cells from animal models [24]. In mouse models of allergic inflammation [31] and infection-induced sepsis [32], silibinin decreased inflammation and increased survival rate.…”

Milk Thistle and Its Derivative Compounds: A Review of Opportunities for Treatment of Liver Disease

“…Secondary to lipopolysaccharide (LPS) stimulation, silibinin inhibits inducible nitric‐oxide synthase expression in vitro . Multiple in vitro studies in stellate cells and hepatocytes have demonstrated a reduction in monocyte chemoattractant protein 1 secondary to interleukin (IL) 1β stimulation . IL‐1β and prostaglandin E2 have been decreased in vivo with silibinin administration, which also improved survival in a mouse LPS sepsis model .…”