Differentiation therapy is an alternative strategy used to induce the differentiation of blast cells toward mature cells and to inhibit tumor cell proliferation for cancer treatment. Nobiletin (NOB), a polymethoxyflavone phytochemical, is present abundantly in citrus peels and has been reported to possess anti-cancer activity. In this study, we investigated the anti-leukemic effects of NOB on cell differentiation and its underlying mechanisms in human chronic myeloid leukemia (CML) K562 cells. NOB (100 μM) treatment for 24 and 48 h significantly decreased viability of K562 cells to 54.4 ± 5.3% and 46.2 ± 9.9%, respectively. NOB (10–100 μM) significantly inhibited cell growth in K562 cells. Flow cytometry analysis and immunoblotting data showed that NOB (40 and 80 μM) could modulate the cell cycle regulators including p21, p27, and cyclin D2, and induce G1 phase arrest. NOB also increased the messenger RNA (mRNA) and protein expression of megakaryocytic differentiation markers, such as CD61, CD41, and CD42 as well as the formation of large cells with multi-lobulated nuclei in K562 cells. These results suggested that NOB facilitated K562 cells toward megakaryocytic differentiation. Furthermore, microarray analysis showed that expression of EGR1, a gene associated with promotion of megakaryocytic differentiation, was markedly elevated in NOB-treated K562 cells. The knockdown of EGR1 expression by small interference RNA (siRNA) could significantly attenuate NOB-mediated cell differentiation. We further elucidated that NOB induced EGR1 expression and CD61 expression through increases in MAPK/ERK phosphorylation in K562 cells. These results indicate that NOB promotes megakaryocytic differentiation through the MAPK/ERK pathway-dependent EGR1 expression in human CML cells. In addition, NOB when combined with imatinib could synergistically reduce the viability of K562 cells. Our findings suggest that NOB may serve as a beneficial anti-leukemic agent for differentiation therapy.

Epigenetic therapy has been demonstrated to be a viable strategy for breast cancer treatment. In this study, we report the anti-tumor activity of a hydroxamate-based histone deacetylase (HDAC)8-selective inhibitor, HMC, in breast cancer cells. MTT assays showed that HMC inhibited cell viability of MCF-7 and MDA-MB-231 cells with IC₅₀ values of 7.7 μM and 9.5 μM, respectively. HMC induced caspase-dependent apoptosis in MCF-7 cells, which was associated with its ability to modulate a series of cell survival-related signaling effectors, including Akt, mTOR, Bax, Mcl-1, and Bcl-2. Additionally, HMC was capable of activating PPARγ, which was accompanied by reduced expression of PPARγ target gene products, such as cyclin D1 and CDK6. HMC increased the production of ROS in MCF-7 cells, which could be partially reversed by the cotreatment with a ROS scavenger (N-acetylcysteine or glutathione). Furthermore, HMC induced autophagy, as characterized by the formation of acidic vesicular organelles and autophagic biomarkers including LC3B-II and Atg5. Notably, pharmacological blockade of autophagy by 3-MA or CQ could attenuate HMC-induced apoptosis, suggesting that autophagy played a self-protective role in HMC-induced cell death. Together, these data suggest the translational potential of HMC to be developed into a potential therapeutic agent for breast cancer therapy.

Proper growth and patterning of blood vessels are critical for embryogenesis. Chemicals or environmental hormones may interfere with vascular growth and cause developmental defects. Nitrobenzoate-based compounds have been demonstrated to have a wide range of biological and pharmacological functions, leading to the development of numerous 4-nitrobenzoate derivatives for clinical application. In this study, we tested a novel nitrobenzoate-derived compound, X8, and investigated its effects on vascular development using zebrafish as a model organism. We first determined the survival rate of embryos after the addition of exogenous X8 (0.5, 1, 3, 5, and 10 μM) to the fish medium and determined a sublethal dose of 3 μM for use in further assays. We used transgenic fish to examine the effects of X8 treatment on vascular development. At 25–32 h postfertilization (hpf), X8 treatment impaired the growth of intersegmental vessels (ISVs) and caudal vein plexuses (CVPs). Moreover, X8-treated embryos exhibited pericardial edema and circulatory defects at 60–72 hpf, suggesting the effects of X8 in vasculature. Apoptosis tests showed that the vascular defects were likely caused by the inhibition of proliferation and migration. To investigate the molecular impacts underlying the defects in the vasculature of X8-treated fish, the expression levels of vascular markers, including ephrinb2, mrc1, and stabilin, were assessed, and the decreased expression of those genes was detected, indicating that X8 inhibited the expression of vascular genes. Finally, we showed that X8 treatment disrupted exogenous GS4012-induced angiogenesis in Tg(flk:egfp) zebrafish embryos. In addition, vascular defects were enhanced during cotreatment with X8 and the VEGFR2 inhibitor SU5416, suggesting that X8 treatment causes vascular defects mediated by disruption of VEGF/VEGFR2 signaling. Collectively, our findings indicate that X8 could be developed as a novel antiangiogenic agent.

13‐Acetoxysarcocrassolide (13‐AC) is a marine cembranoid derived from the aquaculture soft coral of Lobophytum crassum. The cytotoxic effect of 13‐AC against leukemia cells was previously reported but its mechanism of action is still unexplored. In the current study, we showed that 13‐AC induced apoptosis of human acute lymphoblastic leukemia Molt4 cells, as evidenced by the cleavage of PARP and caspases, phosphatidylserine externalization, as well as the disruption of mitochondrial membrane potential. The use of N‐acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, attenuated the cytotoxic effect induced by 13‐AC. Molecular docking and thermal shift assay indicated that the cytotoxic mechanism of action of 13‐AC involved the inhibition of heat shock protein 90 (Hsp 90) activity by eliciting the level of Hsp 70 and topoisomerase IIα in Molt4 cells. 13‐AC also exhibited potent antitumor activity by reducing the tumor volume (48.3%) and weight (72.5%) in the in vivo Molt4 xenograft mice model. Our findings suggested that the marine cembranoid, 13‐AC, acted as a dual inhibitor of Hsp 90 and topoisomerase IIα, exerting more potent apoptotic activity via the enhancement of ROS generation.

This study investigates the ethanolic extract of the sea urchin Temnopleurus toreumaticus (test and spine) for its larvicidal efficacy against Aedes aegypti , cytotoxicity, and in silico interactions supporting potential antimalarial and antiviral activities. Zoochemical profiling by Fourier-transform infrared spectroscopy (FT-IR) showed the presence of functional groups, while gas chromatography-mass spectrometry (GC-MS) analysis identified 24 bioactive compounds with insecticidal and enzyme-inhibitory properties. The extract exhibited strong larvicidal (LC₅₀ = 164.18 µg/mL) and pupicidal (LC₅₀ = 209.91 µg/mL) effects on A. aegypti in a concentration‑dependent manner, supported by significant acetylcholinesterase inhibition (IC₅₀ = 151.49 µg/mL). Morphological examinations showed epithelial disorganization and structural damage in treated larvae and pupae. In silico docking confirmed that the identified zoochemicals exhibited binding affinities ranging from –7 to –8 kcal/mol for juvenile hormone binding protein (PDB 5V13), –5 to –6 kcal/mol for acetylcholinesterase (PDB 1DX4), –4 to –5 kcal/mol for Plasmodium falciparum lactate dehydrogenase (PDB 1CEQ), and –4 to –5 kcal/mol for chikungunya nsP2 protease (PDB 3TRK), indicating their multitarget larvicidal, antimalarial, and antiviral potential. Yeast cell-based assays indicated cytotoxic activity (EC₅₀ = 159.27 µg/mL) with a strong dose-response relationship. Overall, the ethanolic extract of T. toreumaticus is a promising lead for next‑generation, environmentally safe biocontrol agents targeting vector‑borne diseases such as malaria and chikungunya, while clearly emphasizing that the antiviral and antimalarial properties are currently supported only by in silico evidence and require further in vitro and in vivo validation.

Hibiscus rosa-sinensis L. flower has been known to contain polyphenolic compounds, so the current study focuses on the isolation, identification, characterization, and biological applications of flavonoid compounds from H. rosa-sinensis flower, with an emphasis on antioxidant and antibacterial activities. Flavonoid was extracted from flower extract in ethyl acetate and characterized using chemical tests, TLC, UV, HPLC, FTIR, ¹ H-NMR, and ¹³ C-NMR. Azaleatin-3,7-di-O-glucoside, a quercetin derivative, was found to effectively scavenge DPPH, ABTS, and Nitric oxide (IC ₅₀ = 24.61, 22.38, and 39.79 μg/mL) and antioxidant activity index (AAI) determined to be 1.015, indicating a strong level of antioxidant activity, while PASS prediction revealed the higher antioxidant (Pa = 0.786). Furthermore, Azaleatin-3,7-di-O-glucoside demonstrated greater antibacterial activity against Staphylococcus aureus, a gram-positive bacteria, than against gram-negative bacteria such as Escherichia coli . The study concluded that flavonoid compounds can be used as antibacterial and antioxidant agents, as well as has powerful free-radical scavenging properties, which may be mediated by their phenolic and flavonoid concentrations, and are an excellent source for the medical and pharmaceutical industries and human society.