A series of new chiral benzisoselenazol-3(2H)-ones substituted on the nitrogen atom with three monoterpene moieties—p-menthane, pinane and carane—was synthesized. The compounds were obtained by the reaction of 2-(chloroseleno)benzoyl chloride with an appropriate terpene amine, first synthesized by a multistep methodology starting from the corresponding alcohol (p-menthane system) or alkene (pinene and carene systems). Compounds were tested as antioxidants and anticancer agents. The N-isopinocampheyl-1,2-benzisoselenazol-3(2H)-one was the best peroxide scavenger and antiproliferative agent on the human promyelocytic leukemia cell line HL-60. The N-menthyl-1,2-benzisoselenazol-3(2H)-one revealed the highest anticancer potential towards breast cancer line MCF-7. The influence of structure and chirality on the bio-activity of the obtained organoselenium compounds was thoroughly evaluated.

A series of new chiral benzisoselenazol-3(2H)-ones and their corresponding diselenides bearing an o-amido function substituted on the nitrogen atom with various aliphatic and aromatic moieties were synthesized. All derivatives representing pairs of enantiomers or diastereoisomers were obtained to thoroughly evaluate the three-dimensional structure–activity correlation. First, bensisoselenazol-3(2H)-ones were synthesized by reacting 2-(chloroseleno)benzoyl chloride with an appropriate enantiomerically pure amine. Then, the Se–N bond was cleaved by a reduction–oxidation procedure using sodium borohydride and then air oxidation to obtain the corresponding diselenides. All derivatives were tested as antioxidants and anticancer agents. In general, the diselenides were more reactive peroxide scavengers, with the highest activity observed for 2,2′-diselenobis[N-(1S,2S)-(-)-trans-2-hydroksy-1-indanylbezamide]. The most cytotoxic derivative towards human promyelocytic leukemia HL-60 and breast cancer MCF-7 cell lines was N-[(1S,2R)-(-)-cis-2-hydroksy-1-indanyl]-1,2-benzizoselenazol-3(2H)-one. The structure–activity relationship of the obtained organoselenium derivatives was discussed.

Organoselenium compounds are well-known glutathione peroxidase (GPx) mimetics that possess antioxidants/prooxidant properties and are able to modulate the concentration of reactive oxygen species (ROS), preventing oxidative stress in normal cells or inducing ROS formation in cancer cells leading to apoptosis. The purpose of this study was the synthesis of potent GPx mimics with antioxidant and anticancer activity along with improved bioavailability, as a result of good solubility in protic solvents. As a result of our research, glutathione peroxidase (GPx) mimetics in the form of water-soluble benzeneseleninic acid salts were obtained. The procedure was based on the synthesis of 2-(N-alkylcarboxyamido)benzeneselenenic acids, through the oxidation of benzisoselenazol-3(2H)-ones or analogous arenediselenides with an amido group, which were further converted to corresponding potassium salts by the treatment with potassium tert-butanolate. All derivatives were tested as potential antioxidants and anticancer agents. The areneseleninic acid salts were significantly better peroxide scavengers than analogous acids and the well-known organoselenium antioxidant ebselen. The highest activity was observed for the 2-(N-ethylcarboxyamido)benzeneselenenic acid potassium salt. The strongest cytotoxic effect against breast cancer (MCF-7) and human promyelocytic leukemia (HL-60) cell lines was found for 2-(N-cyclohexylcarboxyamido)benzeneselenenic acid potassium salt and the 2-(N-ethylcarboxyamido)benzeneselenenic acid, respectively. The structure–activity correlations, including the differences in reactivity of benzeneseleninic acids and corresponding salts were evaluated.

Breast cancer presents significant global challenges, necessitating effective treatments to combat drug resistance and minimize chemotherapy side effects. This study evaluated the cytotoxic effects of U-359, Oxaliplatin (Ox), and 5-Fluorouracil (5-FU) in MCF-7 and MCF-10A cells using MTT and RealTime-GLO assays. Morphological changes were assessed by light microscopy following Wright–Giemsa staining. Apoptosis induction was studied using qPCR for apoptotic markers, the RealTime-Glo™ Annexin V assay, and the cleaved PARP1 ELISA assay. Caspase 8 and 9 activities, ABCB1, ABCG2, and NF-κB protein levels were quantified using ELISA. Synergy was analyzed using the Bliss Independence Model. The results indicated that combining U-359 with Ox and 5-FU enhanced cytotoxicity compared to individual treatments. U-359 induced apoptosis-associated morphological changes in MCF-7 cells, which were augmented with the Ox and 5-FU treatment. Apoptosis assays confirmed the up-regulation of pro-apoptotic markers and the down-regulation of anti-apoptotic markers with U-359 alone or in combination. Elevated cleaved PARP1 levels suggested robust apoptosis induction with U-359 and Ox or 5-FU. Caspase activity assays demonstrated a significant activation of caspase 8 and 9, implicating both apoptotic pathways. Furthermore, U-359 down-regulated ABCB1, ABCG2, and NF-κB in MCF-7 cells, which were up-regulated by Ox and 5-FU alone. The Bliss Independence Model revealed strong synergistic interactions (SI < 1) between U-359 and Ox or 5-FU, particularly in reducing ABCB1 and NF-κB levels. U-359 combined with Ox and 5-FU shows potential for overcoming chemotherapy resistance in breast cancer by enhancing apoptosis and modulating drug resistance. Further clinical studies are needed to optimize treatment and improve outcomes.

Background: To identify drug candidates that reduce cellular stress, linear peptides known as endomorphin (EM) analogs containing proline surrogates in position 2 were tested in in vitro injury models induced by corticosterone (CORT). Methods: In this study, neuroblastoma (SH-SY5Y) cells were treated with CORT and synthesized peptides, and then the cell viability and morphology, reactive oxygen species production (ROS), mitochondrial membrane potential (ΔΨm), adenosine triphosphate (ATP), and intracellular calcium ion [Ca²⁺]_i levels were evaluated. We also conducted an in-depth analysis of the apoptosis markers using quantitative real-time PCR (qPCR). Finally, we explore the brain-derived neurotrophic factor (BDNF) expression (qPCR) and protein levels (ELI-SA and Western blot). Results: The strongest neuroprotective effect in the CORT-induced stress model was shown by peptide 3 and peptide 7 (in the following sequence Tyr-Inp-Trp-Phe-NH2 and Tyr-Inp-Phe-Phe-NH2, respectively). These peptides significantly improved cell viability and reduced oxidative stress in CORT-treated cells. Conclusions: Their neuroprotective potential appears linked to anti-apoptotic effects, along with in-creased BDNF expression. Moreover, in the lipopolysaccharide (LPS)- and interferon-γ (IFN-γ)-induced damage model in macrophage RAW 264.7 cells, these two peptides reduced the secretion of inflammatory mediators nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Peptides exhibiting both neuroprotective and anti-inflammatory properties warrant further investigation as potential therapeutic agents.

In the search for new drug candidates, researchers turn to natural substances isolated from plants which may be either used directly or may serve as a source for chemical modifications. An interesting strategy in the design of novel anticancer agents is based on the conjugation of two or more biologically active structural motifs into one hybrid compound. In this study, we investigated the anticancer potential of 4-benzyl-5,7-dimethoxy-4-methyl-3-methylidene-3,4-dihydro-2H-chroman-2-one (DL-247), a new hybrid molecule combining a chroman-2-one skeleton with an exo-methylidene bond conjugated with a carbonyl group, in human myeloid leukemia HL-60 cell line. The cytotoxicity of the new compound was tested using MTT assay. The effect of DL-247 on cell proliferation and apoptosis induction were studied by flow cytometry, fluorometric assay and ELISA analysis. DL-247 displayed high cytotoxic activity (IC₅₀ = 1.15 µM, after 24 h incubation), significantly inhibited cell proliferation and induced apoptosis by both, the intrinsic and extrinsic pathways. A combination of DL-247 with taxol exhibited a strong synergistic effect on DNA damage generation, apoptosis induction and inhibition of cell growth.