BACKGROUND: Curcuma purpurascens BI. (Zingiberaceae) commonly known as 'Koneng Tinggang' and 'Temu Tis' is a Javanese medicinal plant which has been used for numerous ailments and diseases in rural Javanese communities. In the present study, the apoptogenic activity of dichloromethane extract of Curcuma purpurascens BI. rhizome (DECPR) was investigated against HT-29 human colon cancer cells.
METHODS: Acute toxicity study of DECPR was performed in Sprague-Dawley rats. Compounds of DECPR were analyzed by the gas chromatography-mass spectrometry-time of flight (GC-MS-TOF) analysis. Cytotoxic effect of DECPR on HT-29 cells was analyzed by MTT and lactate dehydrogenase (LDH) assays. Effects of DECPR on reactive oxygen species (ROS) formation and mitochondrial-initiated events were investigated using a high content screening system. The activities of the caspases were also measured using a fluorometric assay. The quantitative PCR analysis was carried out to examine the gene expression of Bax, Bcl-2 and Bcl-xl proteins.
RESULTS: The in vivo acute toxicity study of DECPR on rats showed the safety of this extract at the highest dose of 5 g/kg. The GC-MS-TOF analysis of DECPR detected turmerone as the major compound in dichloromethane extract. IC50 value of DECPR towards HT-29 cells after 24 h treatment was found to be 7.79 ± 0.54 μg/mL. In addition, DECPR induced LDH release and ROS generation in HT-29 cells through a mechanism involving nuclear fragmentation and cytoskeletal rearrangement. The mitochondrial-initiated events, including collapse in mitochondrial membrane potential and cytochrome c leakage was also triggered by DECPR treatment. Initiator caspase-9 and executioner caspase-3 was dose-dependently activated by DECPR. The quantitative PCR analysis on the mRNA expression of Bcl-2 family of proteins showed a significant up-regulation of Bax associated with down-regulation in Bcl-2 and Bcl-xl mRNA expression.
CONCLUSIONS: The findings presented in the current study showed that DECP suppressed the proliferation of HT-29 colon cancer cells and triggered the induction of apoptosis through mitochondrial-dependent pathway.
para‑Phenylenediamine (p‑PD) is a potential carcinogen, and widely used in marketed hair dye formulations. In the present study, the role of the protein tyrosine kinase (PTK)/Ras/Raf/c‑Jun N‑terminal kinase (JNK) and phosphoinositide 3‑kinase (PI3k)/protein kinase B (Akt) pathways on the growth of NRK‑52E cells was investigated. The results demonstrated that p‑PD reduced cell viability in a dose‑dependent manner. The cell death due to apoptosis was confirmed by cell cycle analysis and an Annexin‑V‑fluorescein isothiocyanate binding assay. Subsequent to staining with 2',7'‑dichlorofluorescin diacetate, the treated cells demonstrated a significant increase in reactive oxygen species (ROS) generation compared with the controls. The effects of p‑PD on the signalling pathways were analysed by western blotting. p‑PD‑treated cells exhibited an upregulated phospho‑stress‑activated protein kinase/JNK protein expression level and downregulated Ras and Raf protein expression levels; however, Akt, Bcl‑2, Bcl‑XL and Bad protein expression levels were not significantly altered compared with the control. In conclusion, p‑PD induced apoptosis by a PTK/Ras/Raf/JNK‑dependent pathway and was independent of the PI3K/Akt pathway in NRK‑52E cells.
The development of metal-based agents has had a tremendous role in the present progress in cancer chemotherapy. One well-known example of metal-based agents is Schiff based metal complexes, which hold great promise for cancer therapy. Based on the potential of Schiff based complexes for the induction of apoptosis, this study aimed to examine the cytotoxic and apoptotic activity of a CdCl2(C14H21N3O2) complex on HT-29 cells. The complex exerted a potent suppressive effect on HT-29 cells with an IC50 value of 2.57 ± 0.39 after 72 h of treatment. The collapse of the mitochondrial membrane potential and the elevated release of cytochrome c from the mitochondria to the cytosol indicate the involvement of the intrinsic pathway in the induction of apoptosis. The role of the mitochondria-dependent apoptotic pathway was further proved by the significant activation of the initiator caspase-9 and the executioner caspases-3 and -7. In addition, the activation of caspase-8, which is associated with the suppression of NF-κB translocation to the nucleus, also revealed the involvement of the extrinsic pathway in the induced apoptosis. The results suggest that the CdCl2(C14H21N3O2) complex is able to induce the apoptosis of colon cancer cells and is a potential candidate for future cancer studies.
Two new synthesized and characterized quinazoline Schiff bases 1 and 2 were investigated for anticancer activity against MCF-7 human breast cancer cell line. Compounds 1 and 2 demonstrated a remarkable antiproliferative effect, with an IC50 value of 6.246×10(-6) mol/L and 5.910×10(-6) mol/L, respectively, after 72 hours of treatment. Most apoptosis morphological features in treated MCF-7 cells were observed by AO/PI staining. The results of cell cycle analysis indicate that compounds did not induce S and M phase arrest in cell after 24 hours of treatment. Furthermore, MCF-7 cells treated with 1 and 2 subjected to apoptosis death, as exhibited by perturbation of mitochondrial membrane potential and cytochrome c release as well as increase in ROS formation. We also found activation of caspases-3/7, -8, and -9 in compounds 1 and 2. Moreover, inhibition of NF-κB translocation in MCF-7 cells treated by compound 1 significantly exhibited the association of extrinsic apoptosis pathway. Acute toxicity results demonstrated the nontoxic nature of the compounds in mice. Our results showed significant activity towards MCF-7 cells via either intrinsic or extrinsic mitochondrial pathway and are potential candidate for further in vivo and clinical breast cancer studies.
Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting the senile population with manifestation of motor disability and cognitive impairment. Reactive oxygen species (ROS) is implicated in the progression of oxidative stress-related apoptosis and cell death of the midbrain dopaminergic neurons. Its interplay with mitochondrial functionality constitutes an important aspect of neuronal survival in the perspective of PD. Edible bird's nest (EBN) is an animal-derived natural food product made of saliva secreted by swiftlets from the Aerodamus genus. It contains bioactive compounds which might confer neuroprotective effects to the neurons. Hence this study aims to investigate the neuroprotective effect of EBN extracts in the neurotoxin-induced in vitro PD model.
Cratoxylum arborescens is an equatorial plant belonging to the family Guttiferae. In the current study, α-Mangostin (AM) was isolated and its cell death mechanism was studied. HCS was undertaken to detect the nuclear condensation, mitochondrial membrane potential, cell permeability, and the release of cytochrome c. An investigation for reactive oxygen species formation was conducted using fluorescent analysis. To determine the mechanism of cell death, human apoptosis proteome profiler assay was conducted. In addition, using immunofluorescence and immunoblotting, the levels of Bcl-2-associated X protein (Bax) and B-cell lymphoma (Bcl)-2 proteins were also tested. Caspaces such as 3/7, 8, and 9 were assessed during treatment. Using HCS and Western blot, the contribution of nuclear factor kappa-B (NF-κB) was investigated. AM had showed a selective cytotoxicity toward the cancer cells with no toxicity toward the normal cells even at 30 μg/mL, thereby indicating that AM has the attributes to induce cell death in tumor cells. The treatment of MCF-7 cells with AM prompted apoptosis with cell death-transducing signals. This regulated the mitochondrial membrane potential by down-regulation of Bcl-2 and up-regulation of Bax, thereby causing the release of cytochrome c from the mitochondria into the cytosol. The liberation of cytochrome c activated caspace-9, which, in turn, activated the downstream executioner caspace-3/7 with the cleaved poly (ADP-ribose) polymerase protein, thereby leading to apoptotic alterations. Increase of caspace 8 had showed the involvement of an extrinsic pathway. This type of apoptosis was suggested to occur through both extrinsic and intrinsic pathways and prevention of translocation of NF-κB from the cytoplasm to the nucleus. Our results revealed AM prompt apoptosis of MCF-7 cells through NF-κB, Bax/Bcl-2 and heat shock protein 70 modulation with the contribution of caspaces. Moreover, ingestion of AM at (30 and 60 mg/kg) significantly reduced tumor size in an animal model of breast cancer. Our results suggest that AM is a potentially useful agent for the treatment of breast cancer.
This study investigated the hepatoprotective effects of ethanolic Andrographis paniculata leaf extract (ELAP) on thioacetamide-induced hepatotoxicity in rats. An acute toxicity study proved that ELAP is not toxic in rats. To examine the effects of ELAP in vivo, male Sprague Dawley rats were given intraperitoneal injections of vehicle 10% Tween-20, 5 mL/kg (normal control) or 200 mg/kg TAA thioacetamide (to induce liver cirrhosis) three times per week. Three additional groups were treated with thioacetamide plus daily oral silymarin (50 mg/kg) or ELAP (250 or 500 mg/kg). Liver injury was assessed using biochemical tests, macroscopic and microscopic tissue analysis, histopathology, and immunohistochemistry. In addition, HepG2 and WRL-68 cells were treated in vitro with ELAP fractions to test cytotoxicity. Rats treated with ELAP exhibited significantly lower liver/body weight ratios and smoother, more normal liver surfaces compared with the cirrhosis group. Histopathology using Hematoxylin and Eosin along with Masson's Trichrome stain showed minimal disruption of hepatic cellular structure, minor fibrotic septa, a low degree of lymphocyte infiltration, and minimal collagen deposition after ELAP treatment. Immunohistochemistry indicated that ELAP induced down regulation of proliferating cell nuclear antigen. Also, hepatic antioxidant enzymes and oxidative stress parameters in ELAP-treated rats were comparable to silymarin-treated rats. ELAP administration reduced levels of altered serum liver biomarkers. ELAP fractions were non-cytotoxic to WRL-68 cells, but possessed anti-proliferative activity on HepG2 cells, which was confirmed by a significant elevation of lactate dehydrogenase, reactive oxygen species, cell membrane permeability, cytochrome c, and caspase-8,-9, and, -3/7 activity in HepG2 cells. A reduction of mitochondrial membrane potential was also detected in ELAP-treated HepG2 cells. The hepatoprotective effect of 500 mg/kg of ELAP is proposed to result from the reduction of thioacetamide-induced toxicity, normalizing reactive oxygen species levels, inhibiting cellular proliferation, and inducing apoptosis in HepG2 cells.
Photodynamic therapy (PDT) has emerged as a capable therapeutic modality for the treatment of cancer. PDT is a targeted cancer therapy that reportedly leads to tumor cell apoptosis and/or necrosis by facilitating the secretion of certain pro-inflammatory cytokines and expression of multiple apoptotic mediators in the tumor microenvironment. In addition, PDT also triggers oxidative stress that directs tumor cell killing and activation of inflammatory responses. However, the cellular and molecular mechanisms underlying the role of PDT in facilitating tumor cell apoptosis remain ambiguous. Here, we investigated the ability of PDT in association with hypericin (HY) to induce tumor cell apoptosis by facilitating the induction of reactive oxygen species (ROS) and secretion of Th1/Th2/Th17 cytokines in human hepatocellular liver carcinoma cell line (HepG2) cells. To discover if any apoptotic mediators were implicated in the enhancement of cell death of HY-PDT-treated tumor cells, selected gene profiling in response to HY-PDT treatment was implemented. Experimental results showed that interleukin (IL)-6 was significantly increased in all HY-PDT-treated cells, especially in 1 μg/ml HY-PDT, resulting in cell death. In addition, quantitative real-time PCR analysis revealed that the expression of apoptotic genes, such as BH3-interacting-domain death agonist (BID), cytochrome complex (CYT-C) and caspases (CASP3, 6, 7, 8 and 9) was remarkably higher in HY-PDT-treated HepG2 cells than the untreated HepG2 cells, entailing that tumor destruction of immune-mediated cell death occurs only in PDT-treated tumor cells. Hence, we showed that HY-PDT treatment induces apoptosis in HepG2 cells by facilitating cytotoxic ROS, and potentially recruits IL-6 and apoptosis mediators, providing additional hints for the existence of alternative mechanisms of anti-tumor immunity in hepatocellular carcinoma, which contribute to long-term suppression of tumor growth following PDT.
The long-term objective of the present study was to determine the ability of NiZn ferrite nanoparticles to kill cancer cells. NiZn ferrite nanoparticle suspensions were found to have an average hydrodynamic diameter, polydispersity index, and zeta potential of 254.2 ± 29.8 nm, 0.524 ± 0.013, and -60 ± 14 mV, respectively. We showed that NiZn ferrite nanoparticles had selective toxicity towards MCF-7, HepG2, and HT29 cells, with a lesser effect on normal MCF 10A cells. The quantity of Bcl-2, Bax, p53, and cytochrome C in the cell lines mentioned above was determined by colorimetric methods in order to clarify the mechanism of action of NiZn ferrite nanoparticles in the killing of cancer cells. Our results indicate that NiZn ferrite nanoparticles promote apoptosis in cancer cells via caspase-3 and caspase-9, downregulation of Bcl-2, and upregulation of Bax and p53, with cytochrome C translocation. There was a concomitant collapse of the mitochondrial membrane potential in these cancer cells when treated with NiZn ferrite nanoparticles. This study shows that NiZn ferrite nanoparticles induce glutathione depletion in cancer cells, which results in increased production of reactive oxygen species and eventually, death of cancer cells.
Centratherum anthelminticum (L.) Kuntze (scientific synonyms: Vernonia anthelmintica; black cumin) is one of the ingredients of an Ayurvedic preparation, called "Kayakalp", commonly applied to treat skin disorders in India and Southeast Asia. Despite its well known anti-inflammatory property on skin diseases, the anti-cancer effect of C. anthelminticum seeds on skin cancer is less documented. The present study aims to investigate the anti-cancer effect of Centratherum anthelminticum (L.) seeds chloroform fraction (CACF) on human melanoma cells and to elucidate the molecular mechanism involved.
The plant Artocarpus obtusus is a tropical plant that belongs to the family Moraceae. In the present study a xanthone compound Pyranocycloartobiloxanthone A (PA) was isolated from this plant and the apoptosis mechanism was investigated. PA induced cytotoxicity was observed using MTT assay. High content screening (HCS) was used to observe the nuclear condensation, cell permeability, mitochondrial membrane potential (MMP) and cytochrome c release. Reactive oxygen species formation was investigated on treated cells by using fluorescent analysis. Human apoptosis proteome profiler assays were performed to investigate the mechanism of cell death. In addition mRNA levels of Bax and Bcl2 were also checked using RT-PCR. Caspase 3/7, 8 and 9 were measured for their induction while treatment. The involvement of NF-κB was analyzed using HCS assay. The results showed that PA possesses the characteristics of selectively inducing cell death of tumor cells as no inhibition was observed in non-tumorigenic cells even at 30 μg/ml. Treatment of MCF7 cells with PA induced apoptosis with cell death-transducing signals, that regulate the MMP by down-regulation of Bcl2 and up-regulation of Bax, triggering the cytochrome c release from mitochondria to cytosol. The release of cytochrome c triggered the activation of caspases-9, then activates downstream executioner caspase-3/7 and consequently cleaved specific substrates leading to apoptotic changes. This form of apoptosis was found closely associated with the extrinsic pathway caspase (caspase-8) and inhibition of translocation of NF-κB from cytoplasm to nucleus. The results demonstrated that PA induced apoptosis of MCF7 cells through NF-κB and Bcl2/Bax signaling pathways with the involvement of caspases.
The Fau gene (Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV)-associated ubiquitously expressed gene) was identified as a potential tumor suppressor gene using a forward genetics approach. Downregulation of Fau by overexpression of its reverse sequence has been shown to inhibit apoptosis induced by DNA-damaging agents. To address a potential role of Fau in benzene toxicity, we investigated the apoptotic effects of hydroquinone (HQ), a major benzene metabolite, in W7.2 mouse thymoma cells transfected with either a plasmid construct expressing the antisense sequence of Fau (rfau) or the empty vector (pcDNA3.1) as a control. HQ induced apoptosis via increased production of reactive oxygen species and DNA damage, measured using dihydroethidine (HE) staining and alkaline Comet assay, respectively, in W7.2 pcDNA3.1 cells. In contrast, when Fau was downregulated by the antisense sequence in W7.2 rfau cells, HQ treatment did not cause DNA damage and oxidative stress and these cells were markedly more resistant to HQ-induced apoptosis. Further investigation revealed that there was an upregulation of NAD(P)H: quinone oxidoreductase 1 (NQO1), a detoxification enzyme for benzene-derived quinones, in W7.2 rfau cells. Compromising cellular NQO1 by use of a specific mechanism-based inhibitor (MAC 220) and NQO1 siRNA resensitized W7.2 rfau cells to HQ-induced apoptosis. Silencing of Fau in W7.2 wild-type cells resulted in increased levels of NQO1, confirming that downregulation of Fau results in NQO1 upregulation which protects against HQ-induced apoptosis.
A parasite plant, Loranthus parasiticus (Loranthaceae), which is generally known as benalu teh (in Malay), Sang Ji Sheng (in Chinese), and baso-kisei (in Japan) distributed in south and southwest part of China, has been used as a folk medicine for the treatment of schizophrenia in southwest China. Loranthus parasiticus has various uses in folk and traditional medicines for bone, brain, kidney, liver, expels wind-damp, and prevents miscarriage.
The immunomodulatory activity of Cassia auriculata (CA)-derived polyphenols was tested on aged rats. Rats (24-26 months old) were given CA polyphenols supplementation at doses of 25, 50, and 100 mg/kg for 28 days. Flow cytometry analysis of CA polyphenols-treated aged rats showed increased T and B cells percentage along with enhanced proliferation of splenocytes in both resting and LPS-stimulated cells. Increased percentage of pan T cells is further supported by an elevation of CD4+, CD8+, and CD4+CD25+ regulatory cells. In terms of innate immune cell activity, CA polyphenol supplementation reduced the oxidative burst activity of neutrophils in response to PMA and Escherichia coli activation. Our results collectively show that polyphenols derived from CA boost T cell immunity by increasing the number of T cells and its sensitivity towards stimulants and decreasing ROS production by neutrophils that could potentially harm multiple biological systems in aged individuals.
Some chalcones, such as hydroxychalcones have been reported previously to inhibit major pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E(2) (PGE(2)), tumor necrosis factor-alpha (TNF-alpha) and reactive oxygen species production by suppressing inducible enzyme expression via inhibition of the mitogen-activated protein kinase (MAPK) pathway and nuclear translocation of critical transcription factors. In this report, the effects of cardamonin (2',4'-dihydroxy-6'-methoxychalcone), a chalcone that we have previously isolated from Alpinia rafflesiana, was evaluated upon two cellular systems that are repeatedly used in the analysis of anti-inflammatory bioactive compounds namely RAW 264.7 cells and whole blood. Cardamonin inhibited NO and PGE(2) production from lipopolysaccharide- and interferon-gamma-induced RAW cells and whole blood with IC(50) values of 11.4 microM and 26.8 microM, respectively. Analysis of thromboxane B(2) (TxB(2)) secretion from whole blood either stimulated via the COX-1 or COX-2 pathway revealed that cardamonin inhibits the generation of TxB(2) via both pathways with IC(50) values of 2.9 and 1.1 microM, respectively. Analysis of IC(50) ratios determined that cardamonin was more COX-2 selective in its inhibition of TxB(2) with a ratio of 0.39. Cardamonin also inhibited the generation of intracellular reactive oxygen species and secretion of TNF-alpha from RAW 264.7 cells in a dose responsive manner with IC(50) values of 12.8 microM and 4.6 microM, respectively. However, cardamonin was a moderate inhibitor of lipoxygenase activity when tested in an enzymatic assay system, in which not a single concentration tested was able to cause an inhibition of more than 50%. Our results suggest that cardamonin acts upon major pro-inflammatory mediators in a similar fashion as described by previous work on other closely related synthetic hydroxychalcones and strengthens the conclusion of the importance of the methoxyl moiety substitution on the 4' or 6' locations of the A benzene ring.
Centratherum anthelminticum (L.) seeds (CA) is a well known medicinal herb in Indian sub-continent. We recently reported anti-oxidant property of chloroform fraction of Centratherum anthelminticum (L.) seeds (CACF) by inhibiting tumor necrosis factor-α (TNF-α)-induced growth of human breast cancer cells. However, the active compounds in CACF have not been investigated previously.
Three new triterpenoids; namely 28,28,30-trihydroxylupeol (1); 3,21,21,26-tetrahydroxy-lanostanoic acid (2) and dehydroxybetulinic acid (3) and seven known compounds; i.e., taraxerone (4); taraxerol (5); ethyl palmitate (6); herniarin (7); stigmasterol (8); ursolic acid (9) and acetyl ursolic acid (10) were isolated from the stem of Ficus aurantiaca Griff. The structures of the compounds were established by spectroscopic techniques. The compounds were evaluated for their inhibitory effects on polymorphonuclear leukocyte (PMN) chemotaxis by using the Boyden chamber technique and on human whole blood and neutrophil reactive oxygen species (ROS) production by using a luminol-based chemiluminescence assay. Among the compounds tested, compounds 1-4, 6 and 9 exhibited strong inhibition of PMN migration towards the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP) with IC50 values of 6.8; 2.8; 2.5; 4.1; 3.7 and 3.6 μM, respectively, comparable to that of the positive control ibuprofen (6.7 μM). Compounds 2-4, 6, 7 and 9 exhibited strong inhibition of ROS production of PMNs with IC50 values of 0.9; 0.9; 1.3; 1.1; 0.5 and 0.8 μM, respectively, which were lower than that of aspirin (9.4 μM). The bioactive compounds might be potential lead molecules for the development of new immunomodulatory agents to modulate the innate immune response of phagocytes.
Oxidised low density lipoprotein (oxLDL) is thought to be a significant contributor to the death of macrophage cells observed in advanced atherosclerotic plaques. Using human-derived U937 cells we have examined the effect of cytotoxic oxLDL on oxidative stress and cellular catabolism. Within 3h of the addition of oxLDL, there was a rapid, concentration dependent rise in cellular reactive oxygen species followed by the loss of cellular GSH, and the enzyme activity of both glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and aconitase. The loss of these catabolic enzymes was accompanied by the loss of cellular ATP and lower lactate generation. Addition of the macrophage antioxidant 7,8-dihydroneopterin inhibited the ROS generation, glutathione loss and catabolic inactivation. NOX was shown to be activated by oxLDL addition while apocynin inhibited the loss of GSH and cell viability. The data suggests that oxLDL triggers an excess of ROS production through NOX activation, and catabolic failure through thiol oxidation resulting in cell death.
The current study investigated the cytotoxic effect of 3-(5-chloro-2-hydroxybenzylideneamino)-2-(5-chloro-2-hydroxyphenyl)-2,3-dihydroquinazolin-41(H)-one (A) and 3-(5-nitro-2-hydroxybenzylideneamino)-2-(5-nitro-2-hydroxyphenyl)-2,3-dihydroquinazolin-4(1H)-one (B) on MCF-7, MDA-MB-231, MCF-10A and WRL-68 cells. The mechanism involved in apoptosis was assessed to evaluate the possible pathways induced by compound A and B. MTT assay results using A and B showed significant inhibition of MCF-7 cell viability, with IC50 values of 3. 27 ± 0.171 and 4.36 ± 0.219 μg/mL, respectively, after a 72 hour treatment period. Compound A and B did not demonstrate significant cytotoxic effects towards MDA-MB-231, WRL-68 and MCF-10A cells. Acute toxicity tests also revealed an absence of toxic effects on mice. Fluorescent microscopic studies confirmed distinct morphological changes (membrane blebbing and chromosome condensation) corresponding to typical apoptotic features in treated MCF-7 cells. Using Cellomics High Content Screening (HCS), we found that compound A and B could trigger the release of cytochrome c from mitochondria to the cytosol. The release of cytochrome c activated the expression of caspases-9 and then stimulated downstream executioner caspase-3/7. In addition, caspase-8 showed remarkable activity, followed by inhibition of NF-κB activation in A-and B-treated MCF-7 cells. The results indicated that A and B could induce apoptosis via a mechanism that involves either extrinsic or intrinsic pathways.
Elephantopus scaber also known as Elephant's foot (Asteraceae family) has a plethora of traditional applications including dysuria, diarrhea, dysentery, leukemia and cancer. This study aimed to investigate the apoptosis inducing effects of E. scaber and the underlying mechanisms in HCT116 colorectal cell line.