Quantitative method of measuring phosphatidylserine externalization during apoptosis using electron paramagnetic resonance (EPR) spectroscopy and annexin-conjugated iron

Novel indole Schiff base β-diiminato compound as an anti-cancer agent against triple-negative breast cancer: In vitro anticancer activity evaluation and in vivo acute toxicity study

Breast cancer is the most prevalent cancer among women globally, with triple-negative breast cancer (TNBC) associated with poor prognosis and low five-year survival rates. Schiff base compounds, known for their extensive pharmacological activities, have garnered significant attention in cancer drug research. This study aimed to evaluate the anticancer potential of a novel β-diiminato compound and elucidate its mechanism of action. The compound's effect on cell viability was assessed using MTT assays in breast cancer cell lines including MCF-7 and MDA-MB-231. Cytotoxic effects were further analyzed using trypan blue exclusion and lactate dehydrogenase (LDH) release assays. In order to assess the mechanism of inhibitory activity and mode of cell death induced by this compound, flow cytometry of cell cycle distribution and apoptosis analysis were carried out. Apoptosis incidence was initially assessed through cell and nuclear morphological changes (Hoechst 33342/Propidium iodide (PI) staining) and further confirmed by Annexin V/PI staining and flow cytometry analysis. In addition, the effect of this compound on the disruption of mitochondrial membrane potential (MMP) and generation of the reactive oxygen species (ROS) was determined using the JC-1 indicator and DCFDA dye, respectively. The results demonstrated that the 24 h treatment with β-diiminato compound significantly suppressed the viability of MDA-MB-231 and MCF-7 cancer cells in a dose-dependent manner with the IC50 value of 2.41 ± 0.29 and 3.51 ± 0.14, respectively. The cytotoxic effect of the compound was further confirmed with a dose-dependent increase in the number of dead cells and enhanced LDH level in the culture medium. This compound exerted its anti-proliferative effect by G2/M phase cell growth arrest in MDA-MB-231 breast cancer cells and induced apoptosis-mediated cell death, which involved characteristic changes in cell and nuclear morphology, phosphatidylserine externalization, mitochondrial membrane depolarization, and increased ROS level. Neither hepatotoxicity nor nephrotoxicity was detected in the biochemical and histopathological analysis confirming the safety characterization of this compound usage. Therefore, the results significantly confirmed the potential anticancer activity of a novel β-diiminato compound, as evidenced by the induction of cell cycle arrest and apoptosis, which might be driven by the ROS‑mediated mitochondrial death pathway. This compound can be a promising candidate for future anticancer drug design and TNBC treatment, and further preclinical and clinical studies are warranted.

Chaperone-Mediated Autophagy of eNOS in Myocardial Ischemia-Reperfusion Injury

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Anticancer activity of Nigerian medicinal plants: a review

Background

Cancer is currently the leading cause of death globally and the number of deaths from cancer is on the rise daily. Medicinal plants have been in continuous use over the years for the management of cancer, particularly, in most developing countries of the world including Nigeria. The use of synthetic drugs for the treatment of cancer is often accompanied by toxic side effects. Thus, the alternative use of readily available and inexpensive medicinal plants is the panacea to the toxic side effects associated with synthetic drugs.

Main body

The present review summarized the anticancer activity of 51 medicinal plants that are widespread in all regions of Nigeria. Furthermore, the proposed anticancer pharmacological actions as well as the anticancer bioactive compounds, the type of cancer cell inhibited, the plant parts responsible for the anticancer activity, and the nature of the extracts used for the studies were discussed in this review. The 51 Nigerian medicinal plants were reported to exhibit anticancer activities of the prostate, cervices, lung, skin, colon, esophagus, blood, ovary, central nervous system/brain, breast, stomach, pancreas, larynx, and kidney. The major classes of bioactive compounds indicated to be responsible for the anticancer activity include the polyphenols, flavonoids, alkaloids, saponins, triterpenes, tannins, and quinones. The major anticancer pharmacological actions of these bioactive compounds were antiproliferative, cytotoxic, cytostatic, antimetastatic, apoptotic, and antioxidative as well as provoked cell cycle arrest, inhibition of angiogenesis and reduction of cancer cell viability.

Conclusion

The Nigerian medicinal plants can be harnessed to provide for readily available and inexpensive anticancer drugs in the future because the plants reported in this review showed promising anticancer activity.

Enhancement of Cisplatin Cytotoxicity by Cu(II)-Mn(II) Schiff Base Tetradentate Complex in Human Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (SCC) is one of the most predominant tumors worldwide and the present treatment policies are not enough to provide a specific solution. We aimed to assess the cytotoxic effect of Cu(II)–Mn(II) Schiff base tetradentate complex alone or in combination with cisplatin against squamous cell carcinoma cell line (SCCs) in vitro. Oral-derived gingival mesenchymal stem cells (GMSCs) were used as control. The cell viability was assessed by MTT assay. IC50 values were calculated. Evaluation of apoptosis and DNA damage were performed. In addition, the expression of pro-apoptotic and anti-apoptotic genes and proteins were tested. IC50 values indicated less toxicity of the Schiff base complex on GMSCs compared to cisplatin. Schiff base complex treatment resulted in up-regulation of p53 and Bax genes expression and down-regulation of Bcl2 gene expression in SCCs paralleled with increased protein expression of caspase-3 and Bax and down-regulation of Bcl-2 protein. Annexin V-FITC apoptosis kit showed a higher apoptotic effect induced by a Schiff base complex compared to the cisplatin-treated group. These effects were markedly increased on the combination of Schiff base and cisplatin. The present study established that Cu(II)–Mn(II) Schiff base tetradentate complex might induce a cytotoxic effect on SCCs cells via induction of the apoptotic pathway. Moreover, this Schiff base complex augments the anticancer effect of cisplatin.

Thioredoxin protects mitochondrial structure, function and biogenesis in myocardial ischemia-reperfusion via redox-dependent activation of AKT-CREB- PGC1α pathway in aged mice

Aging is an independent risk factor for cardiovascular diseases, such as myocardial infarction due to ischemia-reperfusion injury (I/R) of the heart. Cytosolic thioredoxin (Trx) is a multifunctional redox protein which has antioxidant and protein disulfide reducing properties. We hypothesized that high levels of Trx will protect against multifactorial disease such as myocardial infarction due to I/R injury in aged mice. Aged mice overexpressing human Trx (Trx-Tg), mice expressing redox-inactive mutant of human Trx (dnTrx-Tg) and non-transgenic litter-mates (NT) were subjected to I/R (60/30 min), and cardiac function, mitochondrial structure and function, and biogenesis involving PGC1α pathway were evaluated in these mice. While aged Trx-Tg mice were protected from I/R-induced reduction in ejection fraction (EF) and fractional shortening (FS), had smaller infarct with decreased apoptosis and preserved mitochondrial function, aged dnTrx-Tg mice showed enhanced myocardial injury and mitochondrial dysfunction. Further, Trx-Tg mice were protected from I/R induced loss of PGC1α, ACO2, MFN1 and MFN2 in the myocardium. The dnTrx-Tg mice were highly sensitive to I/R induced apoptosis. Overall, our study demonstrated that the loss of Trx redox balance in I/R in aged NT or dnTrx-Tg mice resulted in decreased PGC1α expression that decreased mitochondrial gene expression with increased myocardial apoptosis. High levels of Trx, but not mitochondrial thioredoxin (Trx-2) maintained Trx redox balance in I/R resulting in increased PGC1α expression via AKT/CREB activation upregulating mitochondrial gene expression and protection against I/R injury.

Carvacrol Promotes Cell Cycle Arrest and Apoptosis through PI3K/AKT Signaling Pathway in MCF-7 Breast Cancer Cells

OBJECTIVE

To examine the role of carvacrol in modulating PI3K/AKT signaling involved in human breast cancer pathogenesis using in vitro experimental model MCF-7 cells.

METHODS

MTT and lactate dehydrogenase assays were performed with cells treated with different doses of carvacrol (0-250 p mol/L) at different time points (24 and 48 h). The nuclear morphology was assessed in MCF-7 cells with propidium iodide (PI) and acridine orange/ethidium bromide (AO/EB) staining and analyzed by fluorescence microscopy. Events like cell cycle arrest, apoptosis was observed by flow cytometric analysis and expressions of p-Rb, cyclin D1, cyclin-dependent kinase 4 (CDK4), CDK6, Bax, Bcl-2, PI3K/p-AKT was analyzed by immunoblot.

RESULTS

Carvacrol significantly reduced cell viability with the half maximal inhibitory concentration value of 200 µmol/L at 24 and 48 h (P<0.05). importantly, there was a significant increase in the accumulation of the G₀/G₁ phase upon treatment with carvacrol in MCF-7 cells (P<0.05 or P<0.01). A remarkable decrease in protein expressions of p-Rb, cyclin D1, CDK4 and CDK6 denotes cell cycle arrest (P<0.05 or P<0.01). In addition, carvacrol treatment significantly inhibited PI3K/p-AKT protein expressions leading to induction of apoptosis mediated by decreased Bcl2 and increased Bax protein expressions. Further, Annexin V/PI staining by FACS analysis, dual staining by AO/EB and PI staining studies suggests induction of apoptosis by carvacrol through PI3K/Akt signaling pathway in MCF-7 cells.

CONCLUSION

Carvacrol significantly inhibited the breast cancer MCF-7 cell proliferation and induced apoptosis via suppressing PI3/AKT signaling pathway.

The effect of ageing on the resolution of inflammation

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Age-related chronic inflammation (inflammaging) contributes to diseases of ageing.

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Inflammaging suggests age-associated impairment of the resolution of inflammation.

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Human models of inflammation in ageing will be useful in defining these defects.

Ageing is associated with the development of a low-level, systemic, chronic inflammation known as “inflammaging”. This chronic inflammatory state can contribute to diseases of ageing such as sarcopenia and frailty. The presence of inflammaging suggests a failure of the cell clearance mechanisms that ordinarily aid in the resolution of inflammation after pathogen infiltration or tissue injury. This review aims to explore what is known of how the processes involved in the resolution of inflammation might become defective with age.

Cellular effect of styrene substituted biscoumarin caused cellular apoptosis and cell cycle arrest in human breast cancer cells

BACKGROUND

Coumarins occurs naturally across plant kingdoms exhibits significant pharmacological properties and pharmacokinetic activity. The conventional, therapeutic agents are often associated with poor stability, absorption and increased side effects. Therefore, identification of a drug that has little or no-side effect on humans is consequential. Here, we investigated the antiproliferative activity of styrene substituted biscoumarin against various human breast cancer cell lines, such as MCF-7, (ER-) MDA-MB-231 and (AR+) MDA-MB-453. Styrene substituted biscoumarin induced cell death by apoptosis in MDA-MB-231 cell line was analyzed.

METHODS

Antiproliferative activity of Styrene substituted biscoumarin was performed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Styrene substituted biscoumarin induced apoptosis was assessed by Hoechst staining, Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining and flow cytometric analysis. Migratory and proliferating characteristic of breast cancer cell line MDA-MB-231 was also analyzed by wound healing and colony formation assay. Furthermore, mRNA expression of BAX and BCL-2 were quantified using qRT-PCR and protein expression level analyzed by Western blot.

RESULTS

The inhibition concentration (IC₅₀) of styrene substituted biscoumarin was assayed against three breast cancer cell lines. The inhibition concentration (IC₅₀) value of styrene substituted biscoumarin toward MDA-MB-231, MDA-MB-453 and MCF-7 cell lines was 5.63, 7.30 and 10.84μg/ml respectively. Styrene substituted biscoumarin induced apoptosis was detected by Hoechst staining, DAPI/PI analysis and flow-cytometric analysis. The migration and proliferative efficiency of MDA-MB-231 cells were completely arrested upon styrene substituted biscoumarin treatment. Also, mRNA gene expression and protein expression of pro-apoptotic (BAX) and anti-apoptotic (BCL-2) genes were analyzed by qRT-PCR and western blot analysis upon styrene substituted biscoumarin treatment to MDA-MB-231 cells. Our results showed that styrene substituted biscoumarin downregulated BCL-2 gene expression and upregulated BAX gene expression to trigger apoptotic process.

CONCLUSION

Styrene substituted biscoumarin could induce apoptosis through intrinsic mitochondrial pathway in breast cancer cell lines, particularly in MDA-MB-231. Our data suggest that styrene substituted biscoumarin may act as a potential chemotherapeutic agent against breast cancer.

Kelussia odoratissima Mozaff. activates intrinsic pathway of apoptosis in breast cancer cells associated with S phase cell cycle arrest via involvement of p21/p27 in vitro and in vivo

Background

The aim of this study was to evaluate the anticancer potential of Kelussia odoratissima. Several in vitro and in vivo biological assays were applied to explore the direct effect of an extract and bioactive compound of this plant against breast cancer cells and its possible mechanism of action.

Materials and methods

K. odoratissima methanol extract (KME) was prepared, and MTT assay was used to evaluate the cytotoxicity. To identify the cytotoxic compound, a bioassay-guided investigation was performed on methanol extract. 8-Hydroxy-ar-turmerone was isolated as a bioactive compound. In vivo study was performed in the breast cancer rat model. LA7 cell line was used to induce the breast tumor. Histopathological and expression changes of PCNA, Bcl-2, Bax, p27 and p21 and caspase-3 were examined. The induction of apoptosis was tested using Annexin V-fluorescein isothiocyanate (FITC) assay. To confirm the intrinsic pathway of apoptosis, caspase-7 and caspase-9 assays were utilized. In addition, cell cycle arrest was evaluated.

Results

Our results demonstrated that K. odoratissima has an obvious effect on the arrest of proliferation of cancer cells. It induced apoptosis, transduced the cell death signals, decreased the threshold of mitochondrial membrane potential (MMP), upregulated Bax and downregulated Bcl-2.

Conclusion

This study demonstrated that K. odoratissima exhibits antitumor activity against breast cancer cells via cell death and cell cycle arrest.

Live-cell imaging to detect phosphatidylserine externalization in brain endothelial cells exposed to ionizing radiation: implications for the treatment of brain arteriovenous malformations

OBJECT Stereotactic radiosurgery (SRS) is an established intervention for brain arteriovenous malformations (AVMs). The processes of AVM vessel occlusion after SRS are poorly understood. To improve SRS efficacy, it is important to understand the cellular response of blood vessels to radiation. The molecular changes on the surface of AVM endothelial cells after irradiation may also be used for vascular targeting. This study investigates radiation-induced externalization of phosphatidylserine (PS) on endothelial cells using live-cell imaging. METHODS An immortalized cell line generated from mouse brain endothelium, bEnd.3 cells, was cultured and irradiated at different radiation doses using a linear accelerator. PS externalization in the cells was subsequently visualized using polarity-sensitive indicator of viability and apoptosis (pSIVA)-IANBD, a polarity-sensitive probe. Live-cell imaging was used to monitor PS externalization in real time. The effects of radiation on the cell cycle of bEnd.3 cells were also examined by flow cytometry. RESULTS Ionizing radiation effects are dose dependent. Reduction in the cell proliferation rate was observed after exposure to 5 Gy radiation, whereas higher radiation doses (15 Gy and 25 Gy) totally inhibited proliferation. In comparison with cells treated with sham radiation, the irradiated cells showed distinct pseudopodial elongation with little or no spreading of the cell body. The percentages of pSIVA-positive cells were significantly higher (p = 0.04) 24 hours after treatment in the cultures that received 25- and 15-Gy doses of radiation. This effect was sustained until the end of the experiment (3 days). Radiation at 5 Gy did not induce significant PS externalization compared with the sham-radiation controls at any time points (p > 0.15). Flow cytometric analysis data indicate that irradiation induced growth arrest of bEnd.3 cells, with cells accumulating in the G2 phase of the cell cycle. CONCLUSIONS Ionizing radiation causes remarkable cellular changes in endothelial cells. Significant PS externalization is induced by radiation at doses of 15 Gy or higher, concomitant with a block in the cell cycle. Radiation-induced markers/targets may have high discriminating power to be harnessed in vascular targeting for AVM treatment.

Tanacetum polycephalum (L.) Schultz-Bip. induces mitochondrial-mediated apoptosis and inhibits migration and invasion in MCF7 cells

Tanacetumpolycephalum (L.) Schultz-Bip (Mokhaleseh) has been traditionally used in the treatment of headaches, migraines, hyperlipidemia and diabetes. The present study aimed to evaluate its anticancer properties and possible mechanism of action using MCF7 as an invitro model. T.polycephalum leaves were extracted using hexane, chloroform and methanol solvents and the cytotoxicity was evaluated using the MTT assay. Detection of the early apoptotic cells was investigated using acridine orange/propidium iodide staining. An Annexin-V-FITC assay was carried out to observe the phosphatidylserine externalization as a marker for apoptotic cells. High content screening was applied to analyze the cell membrane permeability, nuclear condensation, mitochondrial membrane potential (MMP) and cytochrome c release. Apoptosis was confirmed by using caspase-8, caspase-9 and DNA laddering assays. In addition, Bax/Bcl-2 expressions and cell cycle arrest also have been investigated. MTT assay revealed significant cytotoxicity of T.Polycephalum hexane extract (TPHE) on MCF7 cells with the IC₅₀ value of 6.42 ± 0.35 µg/mL. Significant increase in chromatin condensation was also observed via fluorescence analysis. Treatment of MCF7 cells with TPHE encouraged apoptosis through reduction of MMP by down-regulation of Bcl-2 and up-regulation of Bax, triggering the cytochrome c leakage from mitochondria to the cytosol. The treated MCF7 cells significantly arrested at G₁ phase. The chromatographic analysis elicited that the major active compound in this extract is 8β-hydroxy-4β,15-dihydrozaluzanin C. Taken together, the results presented in this study demonstrated that the hexane extract of T.Polycephalum inhibits the proliferation of MCF7 cells, resulting in the cell cycle arrest and apoptosis, which was explained to be through the mitochondrial pathway.