In the present study we investigated the effects of panduratin A, isolated from Boesenbergia rotunda, on proliferation and apoptosis in A549 human non-small cell lung cancer cells. Cell proliferation and induction of apoptosis was determined by the real-time cellular analyzer (RTCA), MTT assay and High Content Screening (HCS). The RTCA assay indicated that panduratin A exhibited cytotoxicity, with an IC₅₀ value of 4.4 µg/mL (10.8 µM). Panduratin A arrested cancer cells labeled with bromodeoxyuridine (BrdU) and phospho-Histone H3 in the mitotic phase. The cytotoxic effects of panduratin A were found to be accompanied by a dose-dependent induction of apoptosis, as assessed by DNA condensation, nuclear morphology and intensity, cell permeability, mitochondrial mass/ potential, F-actin and cytochrome c. In addition, treatment with an apoptosis-inducing concentration of panduratin A resulted in significant inhibition of Nuclear Factor-kappa Beta (NF-κB) translocation from cytoplasm to nuclei activated by tumor necrosis factor-alpha (TNF-α), as illustrated by the HCS assay. Our study provides evidence for cell growth inhibition and induction of apoptosis by panduratin A in the A549 cell line, suggesting its therapeutic potential as an NF-κB inhibitor.
Apoptosis is an ordered and orchestrated cellular process that occurs in physiological and pathological conditions. It is also one of the most studied topics among cell biologists. An understanding of the underlying mechanism of apoptosis is important as it plays a pivotal role in the pathogenesis of many diseases. In some, the problem is due to too much apoptosis, such as in the case of degenerative diseases while in others, too little apoptosis is the culprit. Cancer is one of the scenarios where too little apoptosis occurs, resulting in malignant cells that will not die. The mechanism of apoptosis is complex and involves many pathways. Defects can occur at any point along these pathways, leading to malignant transformation of the affected cells, tumour metastasis and resistance to anticancer drugs. Despite being the cause of problem, apoptosis plays an important role in the treatment of cancer as it is a popular target of many treatment strategies. The abundance of literature suggests that targeting apoptosis in cancer is feasible. However, many troubling questions arise with the use of new drugs or treatment strategies that are designed to enhance apoptosis and critical tests must be passed before they can be used safely in human subjects.
Dengue virus type 2 (DENV-2) infection induced apoptotic cellular DNA fragmentation in Vero cells within 8 days of infection. The addition of high concentrations of extracellular Zn(2+) but not Ca(2+), Mg(2+) or Mn(2+) to the cell culture medium hastened the detection of apoptosis to within 4 h after infection. No apoptotic cellular DNA fragmentation was detected in the cell culture treated with Zn(2+) alone or infected with heat- or ultraviolet light-inactivated DENV-2 in the presence of Zn(2+). These results suggest that (i) apoptosis is induced in African green monkey kidney cells infected with live DENV-2 and (ii) the addition of high extracellular Zn(2+) accelerates detection of apoptosis in the DENV-2-infected cells.
Curcumin has poor in vivo absorption and bioavailability, highlighting a need for new curcumin analogues with better characteristics in these aspects. The aim of this study is to determine the anti-cancer properties of four selected curcumin analogues, on the cytotoxicity, proliferative and apoptotic effects on androgen-independent human prostate cancer cells (PC-3 and DU 145). Initial cytotoxicity screening showed MS17 has the highest cell inhibitory effect, with EC50 values of 4.4 ± 0.3 and 4.1 ± 0.8 µM, followed by MS13 (7.5 ± 0.1 and 7.4 ± 2.6 µM), MS49 (14.5 ± 1.2 and 12.3 ± 2.3 µM) and MS40E (28.0 ± 7.8 and 30.3 ± 1.9 µM) for PC-3 and DU 145 cells, respectively. Time-dependent analysis also revealed that MS13 and MS17 displayed a greater anti-proliferative effect than the other compounds. MS17 was chosen based on the high selectivity index value for further analysis on the morphological and biochemical hallmarks of apoptosis. Fluorescence microscopy analysis revealed apoptotic changes in both treated prostate cancer cells. Relative caspase-3 activity increased significantly at 48 h in PC-3 and 12 h in DU 145 cells. Highest enrichment of free nucleosomes was noted at 48 h after treatment with MS17. In conclusion, MS17 demonstrated anti-proliferative effect and induces apoptosis in a time and dose-dependent manner suggesting its potential for development as an anti-cancer agent for androgen-independent prostate cancer.
Cancer nanotherapy is progressing rapidly with the introduction of many innovative drug delivery systems to replace conventional therapy. Although the antitumor activity of zerumbone (ZER) has been reported, there has been no information available on the effect of ZER-loaded nanostructured lipid carrier (NLC) (ZER-NLC) on murine leukemia cells. In this study, the in vitro and in vivo effects of ZER-NLC on murine leukemia induced with WEHI-3B cells were investigated. The results from 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, Hoechst 33342, Annexin V, cell cycle, and caspase activity assays showed that the growth of leukemia cells in vitro was inhibited by ZER-NLC. In addition, outcomes of histopathology, transmission electron microscopy, and Tdt-mediated dUTP nick-end labeling analyses revealed that the number of leukemia cells in the spleen of BALB/c leukemia mice significantly decreased after 4 weeks of oral treatment with various doses of ZER-NLC. Western blotting and reverse-transcription quantitative polymerase chain reaction assays confirmed the antileukemia effects of ZER-NLC. In conclusion, ZER-NLC was shown to induce a mitochondrial-dependent apoptotic pathway in murine leukemia. Loading of ZER in NLC did not compromise the anticancer effect of the compound, suggesting ZER-NLC as a promising and effective delivery system for treatment of cancers.
Recent statistics revealed that cancer is one among the main reasons for death throughout the world. Several treatments are available but still there is no cure when it is detected at late stages. One of the treatment modes for cancer is chemotherapy which utilizes anticancer drugs in order to eradicate the cancer cells by apoptosis. Apoptosis is a programmed cell death through which body maintains homeostasis or kills cancer cells by utilizing its cell machinery. Recent researches have concluded that dietary agents have a putative role in instituting apoptosis of cancer cells. Honey, one of the victuals rich in antioxidants, has a long-standing exposure to humans and its role in cancer prevention and treatment is a topic of current interest. Various researchers have been experimenting honey against different cancers and provided valuable insights about the apoptosis induced by the honey. This review will highlight the recent findings of apoptotic mechanism involved in different cancer cells. Further it also reports antitumor activity of honey in some animal models. Hence it is high-time to initiate more preclinical trials as well as clinical experiments which would further add to the knowledge of anticancer nature of honey and also endorse honey as a potential candidate in the war against cancer.
Zerumbone (ZER) is a naturally occurring dietary compound, present in many natural foods consumed today. The compound derived from several plant species of the Zingiberaceae family that has been found to possess multiple biomedical properties, such as antiproliferative, antioxidant, anti-inflammatory, and anticancer activities. However, evidence of efficacy is sparse, pointing to the need for a more systematic review for assessing scientific evidence to support therapeutic claims made for ZER and to identify future research needs. This review provides an updated overview of in vitro and in vivo investigations of ZER, its cancer chemopreventive properties, and mechanisms of action. Therapeutic effects of ZER were found to be scientifically plausible and could be explained partially by in vivo and in vitro pharmacological activities. Much of the research outlined in this paper will serve as a foundation to explain ZER anticancer bioactivity, which will open the door for the development of strategies in the treatment of malignancies using ZER.
Selective Alzheimer Disease Indicator-1 (or Seladin-1) is a multifunctional protein first discovered by downregulation of its expression in Alzheimer's disease. Interestingly, the expression of this protein is upregulated in several cancers, including primary bladder cancer. However, its role in cancer formation has yet to be discovered. Goniothalamin is a natural product that has been demonstrated to induce apoptosis in various cancer cell lines. In this study, we have elucidated the role of Seladin-1 in goniothalamin-induced cytotoxicity towards human urinary bladder cancer cell line RT4.
Lung cancer remains to be one of the most common and serious types of cancer worldwide. While treatment is available, the survival rate of this cancer is still critically low due to late stage diagnosis and high frequency of drug resistance, thus highlighting the pressing need for a greater understanding of the molecular mechanisms involved in lung carcinogenesis. Studies in the past years have evidenced that microRNAs (miRNAs) are critical players in the regulation of various biological functions, including apoptosis, which is a process frequently evaded in cancer progression. Recently, miRNAs were demonstrated to possess proapoptotic or antiapoptotic abilities through the targeting of oncogenes or tumor suppressor genes. This review examines the involvement of miRNAs in the apoptotic process of lung cancer and will also touch on the promising evidence supporting the role of miRNAs in regulating sensitivity to anticancer treatment.
A phytochemical investigation of the methanolic extract of the bark of Endiandra kingiana led to the isolation of seven new tetracyclic endiandric acid analogues, kingianic acids A-G (1-7), together with endiandric acid M (8), tsangibeilin B (9) and endiandric acid (10). Their structures were determined by 1D- and 2D-NMR analysis in combination with HRMS experiments. The structure of compounds 9 and 10 were confirmed by single-crystal X-ray diffraction analysis. These compounds were screened for Bcl-xL and Mcl-1 binding affinities and cytotoxic activity on various cancer cell lines. Compound 5 showed moderate cytotoxic activity against human colorectal adeno-carcinoma (HT-29) and lung adenocarcinoma epithelial (A549) cell lines, with IC50 values in the range 15-17 µM, and compounds 3, 6 and 9 exhibited weak binding affinity for the anti-apoptotic protein Mcl-1.
Andrographolide (Andro) is a diterpenoid that is isolated from Andrographis paniculata and reported to be active against several cancer cell lines. However, few in-depth studies have been carried out on its effects on ovarian cancer cell lines alone or in combination with cisplatin (Cis), which is commonly used to treat ovarian cancer. The aim of this study was to determine the anti-proliferative and apoptotic effects of Andro administered alone and in combination with Cis in the ovarian A2780 and A2780(cisR) cancer cell lines using five different sequences of administration (Cis/Andro h): 0/0h, 4/0 h, 0/4 h, 24/0 h and 0/24 h. The results were evaluated in terms of medium-effect dose (Dm) and combination indices (CI) using the CalcuSyn software. Unlike Cis, whose activity was lower in the resistant A2780(cisR) cell line than in the parent A2780 cell line, Andro was found to be three times more active in the A2780(cisR) cell line as compared to that in A2780 cell line. Synergism was observed when Cis and Andro were administered using the sequences 0/4 h and 4/0 h. The percentage of apoptotic cell death was found to be greater for the 0/4 h combination of Andro and Cis as compared to those values from single-drug treatments. The results may be clinically significant if confirmed in vivo.
The present research was designed to evaluate the anticancer properties of Dillenia suffruticosa extract. Our focus was on the mode of cell death and cell cycle arrest induced in breast cancer cells by the active fractions (designated as D/F4, D/F5 and EA/P2) derived from chromatographic fractionation of D. suffruticosa extracts. The results showed that the active fractions are more cytotoxic towards MCF-7 (estrogen positive breast cancer cells) and MDA-MB-231 (estrogen negative breast cancer cells) as compared to other selected cancer cell lines that included HeLa, A459 and CaOV3. The induction of cell death through apoptosis by the active fractions on the breast cancer cells was confirmed by Annexin V-FITC and PI staining. Cell cycle analysis revealed that D/F4 and EA/P2 induced G2/M phase cell cycle arrest in MCF-7 cells. On the other hand, MDA-MB-231 cells treated with D/F4 and D/F5 accumulated in the sub-G1 phase without cell cycle arrest, suggesting the induction of cell death through apoptosis. The data suggest that the active fractions of D. suffruticosa extract eliminated breast cancer cells through induction of apoptosis and cell cycle arrest. The reason why MCF-7 was more sensitive towards the treatment than MDA-MB-231 remains unclear. This warrants further work, especially on the role of hormones in response towards cytotoxic agents. In addition, more studies on the mechanisms underlying the induction of apoptosis and cell cycle arrest by the plant extract also need to be carried out.
4-Chloro-1,2-phenylenediamine (4-Cl-o-PD) is a halogenated aromatic diamine that was used as a precursor for manufacturing permanent hair dyes. Despite its well-documented mutagenic and carcinogenic effects in a number of in vitro and in vivo models, its cytotoxicity and mode of action have not received similar attention. Here, we investigated the effect of 4-Cl-o-PD on Mardin-Darby canine kidney cells. It induced apoptosis and the evidence suggests its initiation by reactive oxygen species (ROS). The results of various assays used show a dose-dependent (i) decrease in cell viability, (ii) increase in cells at sub-G1 phase and the G0/G1 phase arrested in cell cycle, (iii) increase in intracellular ROS accompanied by depletion of glutathione, and (iv) that apoptotic cell death probably involves activation of both intrinsic and extrinsic pathways.
The seeds of Acalypha wilkesiana have been used empirically by traditional healers in Southwest Nigeria together with other plants as a powder mixture to treat patients with breast tumours and inflammation.
A series of 22 stilbene derivatives based on resveratrol were synthesized incorporating acetoxy-, benzyloxy-, carboxy-, chloro-, hydroxy- and methoxy functional groups. We examined the cytotoxicity of these 22 stilbenes in human K562 chronic myelogenous leukemia cells. Only four compounds were cytotoxic namely 4'-hydroxy-3-methoxystilbene (15), 3'-acetoxy-4-chlorostilbene (19), 4'-hydroxy-3,5-dimethoxystilbene or pterostilbene (3) and 3,5-dibenzyloxy-4'-hydroxystilbene (28) with IC(50)s of 78 µM, 38 µM, 67 µM and 19.5 µM respectively. Further apoptosis assessment on the most potent compound, 28, confirmed that the cells underwent apoptosis based on phosphatidylserine externalization and loss of mitochondrial membrane potential. Importantly, we observed a concentration-dependent activation of caspase-9 as early as 2 hr with resultant caspase-3 cleavage in 28-induced apoptosis. Additionally, a structure-activity relationship (SAR) study proposed a possible mechanism of action for compound 28. Taken together, our data suggests that the pro-apoptotic effects of 28 involve the intrinsic mitochondrial pathway characterized by an early activation of caspase-9.
Zerumbone (ZER) is a potential anticancer natural compound, isolated from Zingiber zerumbet Smith. In this investigation, the anticancer properties of ZER were evaluated on cancer cells of T-acute lymphoblastic leukemia, CEM-ss. The results showed that ZER has cytotoxic effect against CEM-ss cells with an IC(50) of 8.4 ± 1.9 μg/ml (coefficient of variation < 30%). Comparatively, 5-fluorouracil (positive control), imposed an inhibitory effect on CEM-ss cells with an IC(50) of 1.94 ± 0.06 μg/ml. Scanning electron microscopy (SEM) results revealed abnormalities such as membrane blebbing, holes and cytoplasmic extrusions, all of which are characteristics of apoptosis. In addition, ZER has increased the number of TUNEL-positive stain and the cellular level of caspase-3, the hallmarks of apoptosis, on treated CEM-ss cells. It could be concluded that, ZER was able to produce apoptosis on T-acute lymphoblastic leukemia, CEM-ss. The current findings suggest that ZER might be helpful for improving the usefulness of anticancer agents in the therapy of leukemia.
Apoptosis and autophagic cell deaths are programmed cell deaths and they play essential roles in cell survival, growth and development and tumorigenesis. The huge increase of publications in both apoptosis and autophagic signaling pathways has contributed to the wealth of knowledge in facilitating the understanding of cancer pathogenesis. Deciphering the molecular pathways and molecules involved in these pathways has helped scientists devise and develop targeted strategies against cancer. Various drugs targeting the apoptotic TRAIL, Bcl-2 and proteasome pathways are already in Phase II/III clinical trials. The first mTOR inhibitor, temsirolimus has already been approved by the FDA, USA for the treatment of advanced renal cell carcinoma and more mTOR inhibitors are expected to be in the market in a few years time. Strategizing against aberrant autophagy activities in various cancers by using either pro-autophagics or autophagy inhibitors are currently been investigated. This review aims to discuss the most recent antitumor strategies targeting the apoptosis and autophagy signaling pathways and the latest outcome of clinical trials of the above drugs.