Natural Anthraquinone Rufigallol Shields the Spleen From Diabetes-Driven Damage in Rats

A naturally derived plant compound may offer a new line of defense for one of the most overlooked casualties of diabetes: the spleen. In a new study published in the journal 3 Biotech, researchers report that rufigallol, an anthraquinone compound related to the pigments found in madder root, substantially reduced splenic injury in rats rendered diabetic by the drug streptozotocin. The work positions a modest, inexpensive molecule at the intersection of oxidative stress biology, inflammatory signaling, and programmed cell death, the three molecular currents that collectively erode immune organ function in chronic hyperglycemia.

Diabetes mellitus is far more than a disorder of blood sugar. Persistent hyperglycemia triggers a slow, systemic assault on tissues throughout the body, and while the kidneys, nerves, and retina receive most of the attention, the spleen quietly suffers as well. This fist-sized lymphoid organ orchestrates innate and adaptive immunity, filters aged red blood cells from circulation, and serves as a critical reservoir of immune cells. When the spleen falters, the consequences ripple outward: anemia worsens, infection susceptibility climbs, and the delicate balance between pro-inflammatory and anti-inflammatory signaling collapses. Earlier studies have documented splenic shrinkage, lymphoid degeneration, and immune dysregulation in diabetic animals, but effective pharmacological protectants remain scarce.

The research team, led by Asma B. Omer of Princess Nourah bint Abdulrahman University together with collaborators across Saudi Arabia, Oman, and India, chose streptozotocin, or STZ, as their diabetes-inducing agent. STZ is a glucosamine-nitrosourea compound that selectively destroys insulin-producing pancreatic beta cells, producing a model of persistent hyperglycemia that closely mirrors the metabolic and oxidative burden of uncontrolled human diabetes. A single intraperitoneal dose of 50 milligrams per kilogram was sufficient to push the Wistar rats into a diabetic state, setting the stage for eight weeks of treatment with oral rufigallol at two doses, 10 and 20 milligrams per kilogram per day.

The baseline damage inflicted by STZ was comprehensive and sobering. Diabetic animals developed sustained elevation of fasting blood glucose alongside a measurable reduction in spleen weight, signaling tissue atrophy. Their hematological profiles deteriorated in a pattern familiar to clinicians: anemia, elevated white cell counts consistent with chronic inflammatory activation, and falling platelet numbers. Beneath these visible changes, the molecular machinery of the spleen was under coordinated attack. Levels of malondialdehyde, a canonical marker of lipid peroxidation, surged, and nitric oxide production climbed, both signatures of unchecked oxidative assault on cellular membranes and proteins.

Equally telling was the collapse of the spleen’s antioxidant shield. Superoxide dismutase, catalase, and reduced glutathione, the enzymatic and non-enzymatic sentinels that normally neutralize reactive oxygen species, were all significantly depleted in the diabetic animals. With antioxidant defenses eroded, the pro-inflammatory cascade gained momentum. The researchers measured markedly increased concentrations of interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, and interferon-gamma, coupled with suppression of the anti-inflammatory cytokines interleukin-2 and interleukin-4. At the top of this inflammatory hierarchy sat nuclear factor kappa B, NF-κB, the transcription factor that coordinates the expression of dozens of inflammatory genes, and it was strongly activated in the diabetic spleen.

The third prong of the injury was apoptosis, the controlled self-destruction of cells. In the diabetic spleens, the pro-apoptotic protein Bax and the execution enzyme caspase-3 were upregulated, while the anti-apoptotic guardian Bcl-2 was diminished. This shift in the Bax-to-Bcl-2 ratio pushed splenic cells, including the lymphocytes and macrophages that populate the white and red pulp, toward self-elimination. Histopathological examination confirmed the functional data at the tissue level, revealing marked disruption of the normal splenic architecture, with damage to the lymphoid follicles and red pulp structures that underpin the organ’s immune and filtration roles.

Rufigallol treatment turned this grim molecular picture around in a dose-dependent fashion. The higher dose of 20 milligrams per kilogram consistently outperformed the lower dose across nearly every endpoint. Treated animals showed significantly reduced fasting blood glucose, recovered spleen weight, and improved hematological indices, including corrections in the anemia, leukocytosis, and thrombocytopenia that had accompanied the diabetic state. At the biochemical level, the compound restored the depleted antioxidant arsenal, elevating superoxide dismutase, catalase, and glutathione while simultaneously driving down malondialdehyde and nitric oxide, evidence that it both quenched existing oxidative damage and rebuilt the spleen’s capacity to resist it.

The anti-inflammatory and anti-apoptotic effects were equally striking. Rufigallol suppressed the elevated pro-inflammatory cytokines and restrained NF-κB activation, dampening the transcriptional engine of splenic inflammation. At the same time, it rebalanced the apoptotic threshold: Bax and caspase-3 expression fell while Bcl-2 rose, shifting cells away from self-destruction and toward survival. Microscopic analysis of the treated spleens confirmed that these molecular changes translated into tangible structural recovery, with substantially improved preservation of the lymphoid architecture compared with untreated diabetic controls. The authors conclude that rufigallol protected the spleen by simultaneously targeting oxidative stress, inflammatory signaling, and the apoptotic pathway, three interlocking mechanisms that converge on tissue survival.

The choice of rufigallol is scientifically grounded rather than arbitrary. The compound, formally 1,2,3,5,6-pentahydroxy-9,10-anthraquinone, belongs to the anthraquinone family, a class of polyphenolic plant metabolites with a growing resume in metabolic research. Related anthraquinones such as emodin, rhein, and aloe-emodin have shown anti-diabetic, antioxidant, and immunomodulatory properties in prior preclinical studies, and the hydroxyl-rich structure of rufigallol makes it a potent electron donor capable of neutralizing free radicals directly. The polyphenol’s redox activity, the researchers note, aligns with the broader recognition that dietary and plant-derived polyphenols can modulate redox signaling, bioenergetics, and cell fate decisions in ways that synthetic antioxidants often cannot.

The findings carry meaningful implications for a global diabetes epidemic that now affects hundreds of millions of people and continues to expand. Because splenic dysfunction compounds the immune weakness already characteristic of diabetes, contributing to heightened infection risk and poorer vaccine responses, protecting this organ could have clinical value beyond the laboratory. The authors caution that these results derive from a rodent model, and translation to human therapy will require pharmacokinetic profiling, toxicity evaluation, and ultimately controlled clinical trials. Nevertheless, the study adds rufigallol to the short list of natural compounds with demonstrated, mechanistically resolved protection of lymphoid tissue in diabetes, and it strengthens the case that inexpensive plant-derived anthraquinones deserve closer scrutiny as adjunctive agents against the multi-organ toll of chronic hyperglycemia. The research was supported by Princess Nourah bint Abdulrahman University Researchers Supporting Project number PNURSP2026R854.

Subject of Research: Protective effects of the anthraquinone compound rufigallol against streptozotocin-induced splenic injury in diabetic rats

Article Title: Rufigallol attenuates splenic damage caused by STZ by targeting oxidative stress, inflammation, and the apoptosis pathway

Article References: Omer, A. B., Afzal, M., Rafeeq, M., Murad, H. A. S., Alzarea, S. I., Sayyed, N., Kazmi, I., & Al-Abbasi, F. A. (2026). Rufigallol attenuates splenic damage caused by STZ by targeting oxidative stress, inflammation, and the apoptosis pathway. 3 Biotech, 16(10), Article 419. https://doi.org/10.1007/s13205-026-05047-9

Image Credits: AI Generated

DOI: 10.1007/s13205-026-05047-9

Keywords: rufigallol, diabetes, spleen, streptozotocin, oxidative stress, inflammation, apoptosis, NF-κB, anthraquinone, antioxidant, Bcl-2, caspase-3