Acute liver injury is a formidable clinical problem. Once that stage is reached, treatment options narrow dramatically, and liver transplantation remains the most effective therapy for severe, irreversible dysfunction. Donor organ shortages, postoperative infection, and graft rejection continue to limit that option, which is why pharmacological strategies that can limit hepatocellular damage before it becomes catastrophic remain a major therapeutic goal.

Hepatocyte apoptosis, a form of programmed cell death, is a central pathological event in several forms of experimental acute liver injury, making it an attractive target for intervention. The Chongqing team, led by Feng Xiang, Shiwen Tong, and Wenwei Yin, used a classic and brutal experimental system: co-injection of lipopolysaccharide, the toxic component of bacterial cell walls, with d-galactosamine, a compound that depletes intracellular uridine nucleotides and thereby sensitizes hepatocytes to inflammatory injury. In this model, lipopolysaccharide is recognized by Toll-like receptor 4 on Kupffer cells, the liver's resident macrophages, triggering the release of pro-inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-6, and interleukin-1beta.

Tumor necrosis factor-alpha is the key executioner: it binds receptors on hepatocytes and can trigger apoptotic signaling through both death-receptor-mediated extrinsic pathways and mitochondria-dependent intrinsic pathways. All untreated mice in the study's survival experiment died within twelve hours of the challenge. Dichloroacetate changed that outcome dramatically.

The drug, an inhibitor of pyruvate dehydrogenase kinase that promotes mitochondrial oxidation of pyruvate, was given by intraperitoneal injection half an hour before the injury was induced. At a dose of 100 milligrams per kilogram, it offered no survival benefit at all. At 200 milligrams per kilogram, forty percent of mice were still alive at the thirty-six-hour endpoint.

At 300 milligrams per kilogram, the survival rate reached eighty percent, a clear dose-dependent effect. The highest dose was therefore selected for all subsequent mechanistic experiments, and the results were consistent across multiple readouts of liver damage. Six hours after the challenge, mice that had received dichloroacetate showed significantly lower serum activities of alanine aminotransferase and aspartate aminotransferase, the standard biochemical markers of hepatocyte destruction.

Histopathological examination told the same story: livers from untreated injured mice displayed severe disruption of hepatic architecture with extensive hemorrhage, while these alterations were markedly attenuated in the drug-treated group. Blinded scoring of the tissue sections, adapted from Suzuki's criteria on a scale of zero to four, confirmed significantly lower injury scores. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, or TUNEL, staining revealed far fewer apoptotic hepatocytes in the treated animals, and Western blotting showed a significant reduction in cleaved caspase-3, the activated form of the enzyme that serves as the hallmark executioner of apoptosis.

What the drug did not do is perhaps the most scientifically interesting part of the study. The researchers used flow cytometry to measure surface Toll-like receptor 4 abundance on Kupffer cells and found it comparable between treated and untreated injured mice. The proportions of Kupffer cells, neutrophils, total T cells, natural killer T cells, natural killer cells, CD4-positive T cells, and CD8-positive T cells in the liver were all unchanged.

Enzyme-linked immunosorbent assays of serum collected two hours after the challenge showed no significant differences in tumor necrosis factor-alpha, interleukin-6, interleukin-1beta, or interleukin-10, and quantitative reverse transcription polymerase chain reaction of liver tissue found no changes in the corresponding messenger RNA levels. The protective effect, in other words, was not accompanied by any measurable dampening of the inflammatory response at the time points examined. To probe whether the drug was acting directly on the apoptotic machinery rather than upstream of it, the team turned to a second model in which liver injury is triggered by injecting recombinant tumor necrosis factor-alpha together with d-galactosamine, bypassing the lipopolysaccharide-sensing step entirely.

Dichloroacetate pretreatment again reduced serum transaminase activities, preserved hepatic architecture, lowered histological injury scores, decreased TUNEL-positive cells, and significantly reduced cleaved caspase-3 expression. This result supports an association between the drug and reduced hepatocyte apoptotic injury even when the inflammatory trigger is removed from the equation, pointing toward hepatocyte-intrinsic mechanisms of protection. The molecular fingerprint of that protection converged on one protein.

In both the lipopolysaccharide and tumor necrosis factor-alpha models, dichloroacetate-treated mice showed significantly higher abundance of A20, also known as TNFAIP3, a downstream regulator of the tumor necrosis factor receptor-1 pathway that inhibits tumor-necrosis-factor-induced cell death. Previous work has shown that mice lacking A20 develop severe inflammation, are hypersensitive to both lipopolysaccharide and tumor necrosis factor, and die prematurely, and that A20 can protect against lipopolysaccharide/d-galactosamine-induced hepatotoxicity. Notably, the expression of other apoptosis-related proteins, including FLIP, XIAP, Bcl-2, and BAX, was not significantly altered by the drug, although the authors caution that unchanged total protein abundance does not rule out post-translational or subcellular regulation of these factors.

The hepatoprotection extended well beyond the endotoxin-driven models. Pretreatment also increased serum glutathione levels, suggesting that maintenance of this critical antioxidant reserve may contribute to the protective effect against acetaminophen toxicity. The drug likewise attenuated injury induced by thioacetamide, another widely used hepatotoxin that acts through oxidative stress and necrosis.

Because these models involve distinct pathogenic mechanisms, the consistent benefit across all of them implies that dichloroacetate may target common pathways of hepatocyte injury and cell death. The authors are careful about what their data do and do not establish. The timing window for delayed treatment appears narrow: when dichloroacetate was given half an hour after acetaminophen, serum alanine aminotransferase showed a marked numerical reduction that nonetheless failed to reach statistical significance after multiple-comparison correction, and treatment at one and a half or twelve hours showed no apparent benefit.

An earlier study in fasted, endotoxin-challenged rats had reported benefits from post-injury administration, but in non-fasted mice the Chongqing team found no significant protection when the drug was given after the lipopolysaccharide challenge, a discrepancy the authors attribute to differences in metabolic status, species, and protocols. Most importantly, the study did not perform A20 loss-of-function experiments, so the causal contribution of A20 to the drug's benefit remains undetermined, and the findings are limited to experimental animal models.

Subject of Research: Protective effects of dichloroacetate in experimental mouse models of acute liver injury

Article Title: Dichloroacetate attenuates experimental acute liver injury and reduces hepatocyte apoptosis

Article References: Xiang, F., Tong, S., & Yin, W. (2026). Dichloroacetate attenuates experimental acute liver injury and reduces hepatocyte apoptosis. Frontiers in Pharmacology, 17, Article 1919667. https://doi.org/10.3389/fphar.2026.1919667

Image Credits: AI Generated

DOI: 10.3389/fphar.2026.1919667

Keywords: dichloroacetate, acute liver injury, hepatocyte apoptosis, A20, TNF-alpha, Kupffer cells, cleaved caspase-3, acetaminophen, thioacetamide, lipopolysaccharide, d-galactosamine, hepatoprotection