Background: Curcumin is known for its multitude of medicinal properties, including anti-cancer and migrastatic activity. Efforts to overcome poor bioavailability, stability, and side effects associated with the higher dose of curcumin has led to the development of newer derivatives of curcumin. Thus, the focus of this study is to screen novel curcumin derivatives, namely ST03 and ST08, which have not been reported before, for their cytotoxicity and migrastatic property on cancer cells. Methods: Anti-cancer activity of ST03 and ST08 was carried out using standard cytotoxicity assays viz., LDH, MTT, and Trypan blue on both solid and liquid cancer types. Flow cytometric assays and western blotting was used to investigate the cell death mechanisms. Transwell migration assay was carried out to check for migrastatic properties of the compounds. Results: Both the compounds, ST03 and ST08, showed ~ 100 fold higher potency on liquid and solid tumour cell lines compared to its parent compound curcumin. They induced cytotoxicity by activating the intrinsic pathway of apoptosis in the breast (MDA-MB-231) and ovarian cancer cell lines (PA-1) bearing metastatic and stem cell properties, respectively. Moreover, ST08 also showed inhibition on breast cancer cell migration by inhibiting MMP1 (matrix metalloproteinase 1). Conclusion: Both ST03 and ST08 exhibit anti-cancer activity at nanomolar concentration. They induce cell death by activating the intrinsic pathway of apoptosis. Also, they inhibit migration of the cancer cells by inhibiting MMP1 in breast cancer cells.

Aging affects iron homeostasis, as evidenced by tissue iron loading and anemia in the elderly. Iron needs in mammals are met primarily by iron recycling from senescent red blood cells (RBCs), a task chiefly accomplished by splenic red pulp macrophages (RPMs) via erythrophagocytosis. Given that RPMs continuously process iron, their cellular functions might be susceptible to age-dependent decline, a possibility that has been unexplored to date. Here, we found that 10- to 11-month-old female mice exhibit iron loading in RPMs, largely attributable to a drop in iron exporter ferroportin, which diminishes their erythrophagocytosis capacity and lysosomal activity. Furthermore, we identified a loss of RPMs during aging, underlain by the combination of proteotoxic stress and iron-dependent cell death resembling ferroptosis. These impairments lead to the retention of senescent hemolytic RBCs in the spleen, and the formation of undegradable iron- and heme-rich extracellular protein aggregates, likely derived from ferroptotic RPMs. We further found that feeding mice an iron-reduced diet alleviates iron accumulation in RPMs, enhances their ability to clear erythrocytes, and reduces damage. Consequently, this diet ameliorates hemolysis of splenic RBCs and reduces the burden of protein aggregates, mildly increasing serum iron availability in aging mice. Taken together, we identified RPM collapse as an early hallmark of aging and demonstrated that dietary iron reduction improves iron turnover efficacy.

Purpose: Curcumin is known for its anticancer and migrastatic activity in various cancers, including breast cancer. Newer curcumin derivatives are being explored to overcome limitations of curcumin like low bioavailability, stability, and side effects due to its higher dose. In this study, the synthesis of ST09, a novel curcumin derivative, and its antiproliferative, cytotoxic, and migrastatic properties have been explored both in vitro and in vivo. Methods: After ST09 synthesis, anticancer activity was studied by performing standard cytotoxicity assays namely, lactate dehydrogenase (LDH) release assay, 3-(4, 5-dimethylthiazol-2-yl)-2–5-diphenyletrazolium bromide (MTT), and trypan blue exclusion assay. Annexin-FITC, cell cycle analysis using flow cytometry, and Western blotting were performed to elucidate cell death mechanisms. The effect on the inhibition of cell migration was studied by transwell migration assay. An EAC (Ehrlich Ascites carcinoma) induced mouse tumor model was used to study the effect of ST09 on tumor regression. Drug toxicity was measured using aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and flow-cytometry based lymphocyte count. Histological analysis was performed for assessment of any tissue injury post ST09 treatment. Results: ST09 shows an approximate 100-fold higher potency than curcumin, its parent compound, on breast tumor cell lines MCF-7 and MDA-MB231. ST09 arrests the cell cycle in a cell type-specific manner and induces an intrinsic apoptotic pathway both in vitro and in vivo. ST09 inhibits migration by downregulating matrix metalloprotease 1,2 (MMP1,2) and Vimentin. In vivo, ST09 administration led to decreased tumor volume in a mouse allograft model by boosting immunity with no significant drug toxicity. Conclusion: ST09 exhibits antiproliferative and cytotoxic activity at nanomolar concentrations. It induces cell death by activation of the intrinsic pathway of apoptosis both in vitro and in vivo. It also inhibits migration and invasion. This study provides evidence that ST09 can potentially be developed as a novel antitumor drug candidate for highly metastatic and aggressive breast cancer.

Background: Targeted multidrug-loaded delivery systems have emerged as an advanced strategy for cancer treatment. In this context, antibodies, hormones, and small peptides have been coupled to the surface of drug carriers, such as liposomes, polymeric and metallic nanoparticles loaded with drugs, as tumor-specific ligands. In the present study, we have grafted a natural macrophage stimulating peptide, tuftsin, on the surface of the liposomes (LPs) that were loaded with doxorubicin (DOX) and/or curcumin (CUR), by attaching to its C-terminus a palmitoyl residue (Thr-Lys-Pro-Arg-CO-NH-(CH₂)₂-NH-COC₁₅H₃₁, P.Tuft) to enable its grafting within the liposome’s bilayer. Methods: The prepared drug-loaded liposomes (DOX LPs, CUR LPs, DOX-CUR LPs, P.Tuft-LPs, P.Tuft-DOX LPs, P.Tuft-CUR LPs, P.Tuft-DOX-CUR LPs) were thoroughly characterised in terms of particle size, drug content, encapsulation efficiency and structural properties using UV–visible spectroscopy, dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR). The anti-cancer activity and drug toxicity of the liposomal formulations were examined on Ehrlich ascites carcinoma (EAC) tumor-induced mice model. Results: A significant reduction in the tumor weight and volume was observed upon treating the tumor-bearing mice with palmitoyl tuftsin-grafted dual drug-loaded liposomes (P.Tuft-DOX-CUR LPs), as compared to the single drug/peptide-loaded formulation (DOX LPs, CUR LPs, DOX-CUR LPs, P.Tuft- LPs, P.Tuft-DOX LPs, P.Tuft-CUR LPs). Western blot analysis revealed that the tumor inhibition was associated with p53-mediated apoptotic pathway. Further, the biochemical and histological analysis revealed that the various liposomal preparation used in this study were non-toxic to the animals at the specified dose (10mg/kg). Conclusion: In conclusion, we have developed a targeted liposomal formulation of P.Tuftsin-bearing liposomes co-encapsulated with effective anti-cancer drugs such as doxorubicin and curcumin. In experimental animals, tumor inhibition by P.Tuft-DOX-CUR LPs indicates the synergistic therapeutic effect of the peptide and the dual drug.

Mild rupture of aged erythrocytes occurs in the spleen, resulting in hemoglobin (Hb) release, whereas pathological hemolysis characterizes several diseases. Hb detoxification is attributed to macrophages, but other routes of Hb clearance remain elusive. Here, we uncover that Hb uptake is chiefly executed by liver sinusoidal endothelial cells (LSECs) via macropinocytosis. Consistently, LSECs display proteomic signatures indicative of heme catabolism, ferritin iron storage, antioxidant defense, and macropinocytic capacity, alongside high iron content and expression of the iron exporter ferroportin. Erythrocyte/Hb transfusion assays demonstrate that splenic macrophages excel in erythrophagocytosis, while LSECs and Kupffer cells scavenge the spleen-borne hemolysis products Hb and erythrocyte membranes, respectively. High Hb doses result in transient hepatic iron retention, LSEC-specific induction of heme-catabolizing Hmox1 , along with the iron-sensing Bmp6 -hepcidin axis culminating in hypoferremia. Transcriptional induction of Bmp6 in LSECs is phenocopied by erythrocyte lysis upon phenylhydrazine and elicits a distinct transcriptional signature compared to iron. Collectively, we identify LSECs as key Hb scavengers, a function that establishes the spleen-to-liver axis for iron recycling and contributes to heme detoxification during hemolysis.

Curcumin is known for its anticancer properties, but its clinical application is limited due to its poor bioavailability and chemical stability. In this study we report the curcumin derivative, ST03 (1,2-bis[(3E,5E)-3,5-bis[(2-chlorophenyl)methylene]-4-oxo-1-piperidyl]ethane-1,2-dione) exhibits ∼ 14 fold better bioavailability compared to curcumin and is detectable in plasma up to 12 h. ST03 induces ROS, activates the intrinsic apoptotic pathway as evident by disruption of mitochondrial membrane potential, and induction of proapoptotic proteins in ovarian cancer lines PA1 and A2780. ST03 also blocked the migration of ovarian cancer cells. ST03 exerted its antitumor effect in-vivo in the EAC mouse model by activating the intrinsic apoptotic pathway. Our findings demonstrate ST03, a curcumin derivative, with better bioavailability and stability with no discernable toxicity in vivo to be a promising drug candidate for anticancer therapies.