Background: Curcumin is a natural polyphenol with anti-inflammatory, chemopreventive and anticancer activity. However, its high hydrophobicity and poor bioavailability limit its medical application. The development of nanocarriers for curcumin delivery is an attractive approach to overcome its low bioavailability and fast metabolism in the liver. We synthesized a blood compatible alginate-curcumin conjugate, AA-Cur, which formed colloidally stable micelles of approximately 200 nm and, as previously shown, exerted strong cytotoxicity against mouse cancer cell lines. Here we analyze in vivo toxicity and antitumor activity of AA-Cur in two different mouse tumor models. Method: Potential toxicity of intravenously injected AA-Cur was evaluated by: i) analyses of blood parameters (morphology and biochemistry), ii) histology, iii) DNA integrity (comet assay), and iv) cytokine profiling (flow cytometry). Antitumor activity of AA-Cur was evaluated by measuring the growth of subcutaneously inoculated colon MC38-CEA- or orthotopically injected breast 4T1 tumor cells in control mice vs mice treated with AA-Cur. Results: Injections of four doses of AA-Cur did not reveal any toxicity of the conjugate, thus indicating the safety of its use. AA-Cur elicited moderate anti-tumor activity toward colon MC38-CEA or breast 4T1 carcinomas. Conclusion: The tested conjugate of alginate and curcumin, AA-Cur, is non-toxic and safe, but exhibits limited anticancer activity.

Abdominal aortic aneurysm (AAA) bears a high risk of rupture and sudden death of the patient. The pathogenic mechanisms of AAA remain elusive, and surgical intervention represents the only treatment option. Heme oxygenase-1 (HO-1), a heme degrading enzyme, is induced in AAA, both in mice and humans. HO-1 was reported to mitigate AAA development in an angiotensin II (AngII)-induced model of AAA in hyperlipidemic ApoE^-/- mice. Since the role of hyperlipidaemia in the pathogenesis of AAA remains controversial, we aimed to evaluate the significance of HO-1 in the development and progression of AAA in normolipidemic animals. The experiments were performed in HO-1-deficient mice and their wild-type counterparts. We demonstrated in non-hypercholesterolemic mice that the high-dose of AngII leads to the efficient formation of AAA, which is attenuated by HO-1 deficiency. Yet, if formed, they are significantly more prone to rupture upon HO-1 shortage. Differential susceptibility to AAA formation does not rely on enhanced inflammatory response or oxidative stress. AAA-resistant mice are characterized by an increase in regulators of aortic remodeling and angiotensin receptor-2 expression, significant medial thickening, and delayed blood pressure elevation in response to AngII. To conclude, we unveil a dual role of HO-1 deficiency in AAA in normolipidemic mice, where it protects against AAA development, but exacerbates the state of formed AAA.

Acute pancreatitis (AP), a severe inflammatory disorder of the pancreas, lacks effective pharmacological treatment. The disease is primarily driven by necrosis of pancreatic acinar cells (PACs), which intensifies inflammation and organ injury. This study explores the potential of BCL2 inhibitors, specifically Navitoclax and Venetoclax, to shift cell death pathways from necrosis to apoptosis and thereby mitigate disease severity. Ex vivo models using cerulein or ethanol/palmitoleic acid (EtOH/POA) showed that both inhibitors significantly reduced necrosis, increased apoptosis, and improved PAC viability and ATP levels. In mouse models of AP, both drugs promoted apoptosis and decreased tissue necrosis, with Venetoclax showing superior efficacy and safety. Venetoclax markedly reduced disease severity in two AP models without affecting healthy tissue or inducing thrombocytopenia. In contrast, Navitoclax caused apoptosis even in healthy tissue and triggered thrombocytopenia. Additionally, both drugs attenuated pathological Ca²⁺ responses in PACs and upregulated the expression of Ca²⁺-binding proteins S100A8/A9 and the chemokine CCL8. The latter may mediate enhanced apoptotic clearance and limit secondary necrosis, supporting the therapeutic shift from necrosis to apoptosis. Proteomic analyses revealed extensive drug-induced remodeling. In the short-term AP model, both inhibitors altered expression of proteins linked to intracellular compartments and extracellular signaling, reflecting cellular adaptation. In CP, Navitoclax upregulated ECM and lysosomal proteins while downregulating ribosomal components—indicating intensified fibrosis and suppressed protein synthesis. Venetoclax had milder effects and did not worsen fibrosis. Despite Navitoclax’s efficacy toward activated pancreatic stellate cells in vitro, it exacerbated fibrosis and tissue atrophy in CP in vivo, likely due to ongoing parenchymal damage and stellate cell activation. Together, these findings demonstrate that selective BCL2 inhibition with Venetoclax promotes apoptosis, reduces necrosis, and improves outcomes in AP, supporting its repurposing as a therapeutic strategy. However, BCL2 inhibition does not benefit CP and may aggravate fibrosis, underscoring the need for context-specific approaches.

Up to date, there is no information on the influence of 2,2,2-tribromoethanol (TBE; Avertin), a commonly used anaesthetic, on mice with impaired antioxidant capacity. We aimed to analyse the effect of a single dose of Avertin on anaesthesia duration time, inflammatory response, oxidative stress and collagen deposition in the large intestine of Nrf2 transcriptional knockout mice (tNrf2^-/-). The studies were performed on six-month-old female mice Nrf2^+/+ and tNrf2^-/- randomly assigned to Avertin (250 mg/kg b.w. single i.p. injection) or vehicle group. We observed a 2-fold increase in anaesthesia time and longer recovery time (p = 0.015) in tNrf2^-/- in comparison to Nrf2^+/+. However, no hepato- or nephrotoxicity was detected. Interestingly, we found severe changes in colon morphology of untreated tNrf2^-/- mice associated with colon shortening (p = 0.02) and thickening (p = 0.015). Avertin treatment caused colon damage manifested with epithelial layer damage and goblet depletion in Nrf2^+/+ mice but not in tNrf2^-/- individuals. Additionally, Avertin did not induce oxidative stress in colon tissue, but it increased leukocyte infiltration in Nrf2^+/+ mice (p = 0.02). Immunofluorescent staining also revealed enhanced deposition of collagen I and collagen III in the colon of untreated tNrf2^-/- mice. Avertin contributed to increased deposition of collagen I in Nrf2^+/+ mice but reduced deposition of collagen I and III in tNrf2^-/- individuals. In conclusion, tNrf2^-/- respond to Avertin with prolonged anaesthesia that is not associated with acute toxicity, inflammatory reaction or enhanced oxidative stress. Avertin does not impair intestine morphology in tNrf2^-/- mice but can normalise the enhanced fibrosis.