Dryofragin, a phloroglucinol derivative, induces apoptosis in human breast cancer MCF-7 cells through ROS-mediated mitochondrial pathway

Minocycline induced apoptosis and suppressed expression of matrix metalloproteinases 2 and 9 in the breast cancer MCF-7 cells

BACKGROUND

In women, breast cancer is the second most frequent type of cancer. Looking for new and effective cancer-specific therapies with little to no adverse effects on healthy cells is critical.

OBJECTIVE

Minocycline, a second-generation tetracycline, has shown anticancer effects by targeting multiple pathways in various cancers. This study aimed to determine minocycline effects on the cell proliferation, apoptosis, and invasion of the human MCF-7 cells.

METHODS

MTT assay was used to evaluate the cytotoxicity of minocycline on the cells. Flow cytometry was performed to investigate the induction of apoptosis and the cell cycle progression. The expression levels of apoptotic and migration proteins and genes were assessed by western blotting and qRT-PCR. The scratch test was performed to evaluate the anti-migration effect of the drug.

RESULTS

The results indicated that the IC50 value of minocycline for MCF-7 cells was 36.10 µM. Minocycline treatment caused sub-G1 cell accumulation, indicating a significant apoptotic effect on the MCF-7 cells. Annexin-V/PI staining revealed a significant rise in early and late apoptotic cell percentages. Minocycline up-regulated Bax and Caspase-3 expression and down-regulated Bcl-2 and Pro-Cas3. The scratch test revealed significant anti-migration effects for minocycline. Furthermore, it caused down-regulation of MMP-2 and MMP-9 in a concentration-dependent method.

CONCLUSION

These findings further confirmed the anticancer effect of minocycline and highlighted that minocycline maybe considered as potential therapeutic agent for breast cancer treatment.

Configurationally regulated half-sandwich iridium(III)-ferrocene heteronuclear metal complexes: Potential anticancer agents

Half-sandwich iridium(III) (IrIII) complexes and ferrocenyl (Fc) derivatives are becoming the research hotspot in the field of anticancer because of their good bioactivity and unique anticancer mechanism different from platinum-based drugs. Then, a series of half-sandwich IrIII-Fc pyridine complexes have been prepared through the structural regulation in this study. The incorporation of half-sandwich IrIII complex with Fc unit successfully improves their anticancer activity, and the optimal performance (IrFc5) is almost 3-fold higher than that of cisplatin against A549 cells, meanwhile, which also shows better anti-proliferative activity against A549/DDP cells. Complexes can aggregate in the intracellular lysosome of A549 cells and induce lysosomal damage, disrupt the cell cycle, increase the level of intracellular reactive oxygen species, and eventually lead to cell apoptosis. Half-sandwich IrIII-Fc heteronuclear metal complexes possess a different anticancer mechanism from cisplatin, which can serve as a potential alternative to platinum-based drugs and show a good application prospect.

Recent advances in covalent organic frameworks (COFs) for wound healing and antimicrobial applications

Covalent organic frameworks (COFs) are crystal-like organic structures such as cartography buildings prepared from appropriately pre-designed construction block precursors. Moreover, after the expansion of the first COF in 2005, numerous researchers have been developing different materials for versatile applications such as sensing/imaging, cancer theranostics, drug delivery, tissue engineering, wound healing, and antimicrobials. COFs have harmonious pore size, enduring porosity, thermal stability, and low density. In addition, a wide variety of functional groups could be implanted during their construction to provide desired constituents, including antibodies and enzymes. The reticular organic frameworks comprising porous hybrid materials connected via a covalent bond have been studied for improving wound healing and dressing applications due to their long-standing antibacterial properties. Several COF-based systems have been planned for controlled drug delivery with wound healing purposes, targeting drugs to efficiently inhibit the growth of pathogenic microorganisms at the wound spot. In addition, COFs can be deployed for combinational therapy using photodynamic and photothermal antibacterial therapy along with drug delivery for healing chronic wounds and bacterial infections. Herein, the most recent advancements pertaining to the applications of COF-based systems against bacterial infections and for wound healing are considered, concentrating on challenges and future guidelines.

Anticancer application of ferrocene appended configuration-regulated half-sandwich iridium(III) pyridine complexes

Ferrocenyl derivatives and half-sandwich iridium(III) complexes have received extensive attention in the field of anticancer. In this paper, series of configuration-controlled ferrocene-modified half-sandwich iridium(III) pyridine complexes were prepared. The combination of half-sandwich iridium(III) complexes and ferrocenyl unit successfully improved the anticancer activity of these complexes, especially for trans-configurational one towards A549 cells, and the best-performing (FeIr5) was almost 3.5 times more potent than that of cisplatin. In addition, these complexes could inhibit the migration of A549 cells. Complexes can accumulate in intracellular lysosomes (PCC: >0.75), induce lysosomal damage, disturb the cell circle, decrease the mitochondrial membrane potential, improve the intracellular reactive oxygen species (ROS) levels, and eventually lead to apoptosis. Meanwhile, complexes could bind to serum protein following a static quenching mechanism and transport through it. Then, ferrocene-modified half-sandwich iridium(III) pyridine complexes hold the promise as potential organometallic anticancer agents for further investigation.

Synthesis of salicylic acid phenylethyl ester (SAPE) and its implication in immunomodulatory and anticancer roles

Salicylic acid phenylethyl ester (SAPE) was synthesized by Zn(OTf)₂-catalyzed selective esterification of salicylic acid and phenylethyl alcohol and studied for its role as an immunomodulatory and anticancer agent. Low toxicity and favorable physical, Lipinski-type, and solubility properties were elucidated by ADME-tox studies. Molecular docking of SAPE against COX-2 revealed favorable MolDockscore, rerank score, interaction energy, internal pose energy, and hydrogen bonding as compared to ibuprofen and indomethacin. An average RMSD of ~ 0.13 nm for the docked complex with stable dynamic equilibrium condition was noted during the 20 ns MD simulation. A low band gap predicting a strong binding affinity at the enzyme’s active site was further predicted by DFT analysis. The ester caused a reduction in the percentage of erythrocyte hemolysis and was shown to be non-cytotoxic against human lymphocytes, CaCo-2, and HepG-2 cells by the MTT assay. Moreover, it’s in vitro efficacy in inhibiting COX-2 enzyme under both LPS stimulated intestinal cells and direct sequestration assays was found to be higher than salicylic acid and indomethacin. The anticancer activity of SAPE was tested on the breast cancer cell line MCF-7, and potential efficacy was exhibited in terms of decreased cell viability. Flow cytometry analysis exhibited the arrest of the cell cycle at G1/G0 and S phases, during which induction of autophagic vesicle formation and decrease in mitochondrial membrane potential was observed owing to increased ROS production. Furthermore, at these phases, the onset of apoptosis along with DNA damage was also observed. Pre-treatment with SAPE in colitis-induced Wistar rats displayed low disease activity index and reduction in the extent of intestinal tissue disruption and lipid peroxidation. A marked increase of anti-oxidative enzymes viz., catalase, GGT, and GST, and a decrease of pro-inflammatory cytokines IL-6 and TNF-α in the intestinal tissue extracts of the treated groups was noted. The results of this study have sufficient credence to support that the synthesised ester (SAPE) be considered as an anti-oxidative and anti-inflammatory compound with therapeutic potential for the effective management of cancer.

Effect ofBacillus velezensis JC-K3 on Endophytic Bacterial and Fungal Diversity in Wheat Under Salt Stress

Plant growth-promoting bacteria (PGPB) can effectively reduce salt damage in plants. Currently, there are many studies on the effects of PGPB on the microbial community structure of rhizosphere soil under salt stress, but fewer studies on the community structure of endophytic bacteria and fungi. We propose that inoculation of endophytic bacteria into the rhizosphere of plants can significantly affect the microbial community structure of the plant's above-ground and underground parts, which may be the cause of the plant's "Induced Systemic Tolerance." The isolated endophytes were re-inoculated into the rhizosphere under salinity stress. We found that, compared with the control group, inoculation with endophytic Bacillus velezensis JC-K3 not only increased the accumulation of wheat biomass, but also increased the content of soluble sugar and chlorophyll in wheat, and reduced the absorption of Na in wheat shoots and leaves. The abundance of bacterial communities in shoots and leaves increased and the abundance of fungal communities decreased after inoculation with JC-K3. The fungal community richness of wheat rhizosphere soil was significantly increased. The diversity of bacterial communities in shoots and leaves increased, and the richness of fungal communities decreased. JC-K3 strain improved wheat's biomass accumulation ability, osmotic adjustment ability, and ion selective absorption ability. In addition, JC-K3 significantly altered the diversity and abundance of endophytic and rhizosphere microorganisms in wheat. PGPB can effectively reduce plant salt damage. At present, there are many studies on the effect of PGPB on the microbial community structure in rhizosphere soil under salt stress, but there are few studies on the community structure changes of endophytic bacteria and fungi in plants.

Gigantol inhibits proliferation and enhanced oxidative stress-mediated apoptosis through modulating of Wnt/β-catenin signaling pathway in HeLa cells

Cervical cancer is one of the leading malignant cancers that is the fourth prominent cause of malignancy-related mortality in women globally. There is a predominant validation to a beneficial target in Wnt/β-catenin signaling in cervical carcinogenesis as they are very much deregulated in cancer. Previous studies reported Gigantol (GG) showed suppressive properties on the Wnt/β-catenin pathway in other tumor cells, but no evidence is available regarding GG suppressing Wnt/β-catenin signaling cervical tumor cells. Hence, the current research was planned to examine the suppressive effects of GG on HeLa cells and investigate the mechanism of action. HeLa cells were treated by GG in various doses and then appraising cell viability, oxidant/antioxidant levels, ∆ѰM status, reactive oxygen species (ROS) generation, apoptosis, and cell proliferation via Wnt/β-catenin signaling. We observed that GG noticeably inhibits cell proliferation, increased ROS generation, lipid peroxidation, mitochondrial membrane depolarization (∆ѰM), and increased apoptotic morphological changes of nuclear fragmentation and condensation. Moreover, GG effectively enhances proapoptotic, decreased ∆ѰM and antioxidant amounts, and mitigated Wnt/β-catenin signaling. Concisely, these findings proved that activating apoptosis and suppression of cell proliferation in GG treated HeLa cells was documented by the alleviation of Wnt/β-catenin signaling. Therefore, this study suggested that GG might develop a therapeutic effect against cervical carcinogenesis.

PTP1B inhibition studies of biological active phloroglucinols from the rhizomes of Dryopteris crassirhizoma: Kinetic properties and molecular docking simulation

By various chromatographic methods, 30 phloroglucinols (1-30) were isolated from a methanol extract of Dryopteris crassirhizoma, including two new dimeric phloroglucinols (13 and 25). The structures of the isolates were confirmed by HR-MS, 1D, and 2D NMR as well as by comparison with the literature. The protein tyrosine phosphatase 1B (PTP1B) effects of the isolated compounds (1-30) were evaluated using sodium orthovanadate and ursolic acid as a positive control. Among them, trimeric phloroglucinols 26-28 significantly exhibited the PTP1B inhibitory effects with the IC₅₀ values of 1.19 ± 0.13, 1.00 ± 0.04, 1.23 ± 0.05 μM, respectively. In addition, the kinetic analysis revealed compounds 26-28 acted as competitive inhibitors against PTP1B enzyme with K_i values of 0.63, 0.61, 1.57 μM, respectively. Molecular docking simulations were performed to demonstrate that these active compounds can bind with the catalytic sites of PTP1B with negative binding energies and the results are in accordance with that of the kinetic studies. In vitro and in silico results suggest that D. crassirhizoma rhizomes together with compounds 26-28 are potential candidates for treating type 2 diabetes.

Acridine-Based Covalent Organic Framework Photosensitizer with Broad-Spectrum Light Absorption for Antibacterial Photocatalytic Therapy

Antibiotic resistance is considered as one of the serious public health issues. Antibacterial photocatalytic therapy, a clinically proven antibacterial therapy, is gaining increasing attention in recent years owing to its high efficacy. Here, an acridine-based covalent organic framework (COF) photosensitizer, named TPDA, with multiple active sites is synthesized via Schiff base condensation between 2,4,6-triformylphloroglucinol (TFP) and 3,6-diaminoacridine (DAA). Owing to the increased conjugation effect of the COF skeleton and outstanding light harvesting ability of DAA, TPDA exhibits a narrow optical band gap (1.6 eV), enhancing light energy transformation and conferring a wide optical absorption spectrum (intensity arbitrary unit > 0.8) ranging from the UV to near-infrared region. Moreover, TPDA shows high antibacterial activities against both gram-negative and gram-positive bacteria within a short time (10 min) of light irradiation and is found to efficiently protect fish from skin infections. Molecular dynamics simulation data show that the introduction of DAA and TFP facilitates the interaction between TPDA and bacteria and is conducive to reactive oxygen species migration, which further improves the antimicrobial performance. These findings indicate the potential of TPDA as a novel photosensitive material for photodynamic therapy.

Preparation and the anticancer mechanism of configuration-controlled Fe(II)-Ir(III) heteronuclear metal complexes

A series of configuration-controlled Fe(ii)-Ir(iii) heteronuclear metal complexes, including ferrocene and half-sandwich like iridium(iii) complex units, have been designed and prepared. These complexes show better anticancer activity than cisplatin under the same conditions, especially cis-configurational ones. Laser confocal microscopy analysis confirms that the complexes follow a non-energy-dependent cellular uptake mechanism, accumulate in lysosomes (pearson co-localization coefficient: ∼0.7), lead to lysosomal damage, and eventually induce apoptosis. These complexes can reduce the mitochondrial membrane potential, disturb the cell circle, catalyze the oxidation of nicotinamide-adenine dinucleotide (NADH) and increase the levels of intracellular reactive oxygen species (ROS), following an anticancer mechanism of oxidation. In addition, the complexes could bind to serum protein, and transport through it. Above all, the Fe(ii)-Ir(iii) heteronuclear metal complexes hold promise as potential anticancer agents for further study.

Wnt/β-catenin Antagonists: Exploring New Avenues to Trigger Old Drugs in Alleviating Glioblastoma Multiforme

BACKGROUND

Glioblastoma multiforme is one of the most heterogenous primary brain tumor with high mortality. Nevertheless, of the current therapeutic approaches, survival rate remains poor with 12 to 15 months following preliminary diagnosis, this warrants the need for effective treatment modality. Wnt/β-catenin pathway is presumably the most noteworthy pathway up-regulated in almost 80% GBM cases contributing to tumor-initiation, progression and survival. Therefore, therapeutic strategies targeting key components of Wnt/β-catenin cascade using established genotoxic agents like temozolomide and pharmacological inhibitors would be an effective approach to modulate Wnt/β-catenin pathway. Recently, drug repurposing by means of effective combination therapy has gained importance in various solid tumors including GBM, by targeting two or more proteins in a single pathway, thereby possessing the ability to overcome the hurdle implicated by chemo-resistance in GBM.

OBJECTIVE

In this context, by employing computational tools, an attempt has been carried out to speculate the novel combinations against Wnt/β-catenin signaling pathway.

METHODS

We have explored the binding interactions of three conventional drugs namely temozolomide, metformin, chloroquine along with three natural compounds viz., epigallocatechin gallate, naringenin and phloroglucinol on the major receptors of Wnt/β-catenin signaling.

RESULTS

It was noted that all the experimental compounds possessed profound interaction with the two major receptors of Wnt/β-catenin pathway.

CONCLUSION

To the best of our knowledge, this study is the first of its kind to characterize the combined interactions of the afore-mentioned drugs on Wnt/β-catenin signaling in silico and this will putatively open up new avenues for combination therapies in GBM treatment.

Encapsulating Halofuginone Hydrobromide in TPGS Polymeric Micelles Enhances Efficacy Against Triple-Negative Breast Cancer Cells

BACKGROUND

Halofuginone hydrobromide (HF) is a synthetic analogue of the naturally occurring quinazolinone alkaloid febrifugine, which has potential therapeutic effects against breast cancer, however, its poor water solubility greatly limits its pharmaceutical application. D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) is a water-soluble derivative of vitamin E, which can self-assemble to form polymeric micelles (PMs) for encapsulating insoluble anti-tumor drugs, thereby effectively enhancing their anti-cancer effects.

METHODS

HF-loaded TPGS PMs (HTPMs) were manufactured using a thin-film hydration technique, followed by a series of characterizations, including the hydrodynamic diameter (HD), zeta potential (ZP), stability, drug loading (DL), encapsulation efficiency (EE), and in vitro drug release. The anti-cancer effects and potential mechanism of HTPMs were investigated in the breast cell lines MDA-MB-231 and MCF-7, and normal breast epithelial cell line Eph-ev. The breast cancer-bearing BALB/c nude mouse model was successfully established by subcutaneous injection of MDA-MB-231 cells and used to evaluate the in vivo therapeutic effect and safety of the HTPMs.

RESULTS

The optimized HTPMs had an HD of 17.8±0.5 nm and ZP of 14.40±0.1 mV. These PMs exhibited DL of 12.94 ± 0.46% and EE of 90.6 ± 0.85%, along with excellent storage stability, dilution tolerance and sustained drug release in pH-dependent manner within 24 h compared to free HF. Additionally, the HTPMs had stronger inhibitory effects than free HF and paclitaxel against MDA-MB-231 triple-negative breast cancer cells, and little toxicity in normal breast epithelial Eph-ev cells. The HTPMs induced cell cycle arrest and apoptosis of MDA-MB-231 by disrupting the mitochondrial membrane potential and enhancing reactive oxygen species formation. Evaluation of in vivo anti-tumor efficacy demonstrated that HTPMs exerted a stronger tumor inhibition rate (68.17%) than free HF, and exhibited excellent biocompatibility.

CONCLUSION

The findings from this study indicate that HTPMs holds great clinical potential for treating triple-negative breast cancer.

Effects of Enterobacter cloacae HG-1 on the Nitrogen-Fixing Community Structure of Wheat Rhizosphere Soil and on Salt Tolerance

The present study investigated the physiological and biochemical characteristics of Enterobacter cloacae HG-1 isolated from saline-alkali soil. We further studied the effect of this strain on the salt tolerance of wheat and on the community structure of nitrogen-fixing bacteria in rhizosphere soil. We determined that the investigated strain had high nitrogen fixation activity and produced iron carriers, 1-aminocyclopropane-1-carboxylic acid deaminase, and plant hormones. The metabolites of this strain contained 2,3-butanediol, [R-(R*, R*)], 2-heptanone, and other growth-promoting and antibacterial substances. The strain was also highly salt-tolerant (10% NaCl). After the inoculation of wheat with the HG-1 strain, we recorded increases in root length, plant height, fresh weight, and dry weight of 19.15%, 18.83%, 16.67%, and 17.96%, respectively, compared with uninoculated plants (P < 0.05). Compared with the leaves of uninoculated plants, the proline concentration in the leaves of inoculated plants increased by 12.43% (P < 0.05), the malondialdehyde level decreased by 27.26% (P < 0.05), K+ increased by 20.69%, Ca2+ increased by 57.53% and Na+ decreased by 31.43% (all P<0.05). Furthermore, we detected that inoculation with the HG-1 strain did not affect the species composition of nitrogen-fixing bacteria in wheat rhizosphere soil at the phylum level. However, the average relative abundance of Proteobacteria was significantly increased, whereas the abundance of Verrucomiorobia was significantly decreased compared with uninoculated plants. At the genus level, we detected 32 genera in control samples and 27 genera in inoculated samples, and the species diversity and relative abundance of samples inoculated with the HG-1 strain decreased compared with uninoculated plants. Inoculated samples had lower abundances of Azospirillum, Rhodomicrobium, and Anabaena. Our study demonstrated that the inoculation of wheat with E. cloacae HG-1 could promote the growth of wheat under salt stress and increase salt stress tolerance. The results of this study investigating the interaction among soil, plants, and microorganisms supplement agricultural microbial databases and could provide a reference for the development of microbial-based saline soil improvement programs.

Proapoptotic effects of novel thiazole derivative on human glioma cells

The aim of the present study was to investigate the antiproliferative and proapoptotic actions of N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide derivative (compound 5) in glioma cells in comparison with the actions of temozolomide (TMZ) and doxorubicin (Dox), used as positive controls. The antiproliferative activity of the compound 5, TMZ, and Dox on human glioblastoma U251 and human glioblastoma multiform T98G cells was measured using the MTT test. Western blot analysis, fluorescent microscopy, agarose gel retardation assay, flow cytometric analysis, and the DNA comet assay under alkaline conditions were carried out to study the effect of compound 5 on U251 cells. This compound showed ~20 times higher cytotoxicity toward U251 and T98G cells compared with the effects of TMZ and approximately two times higher activity than that of the Dox. Compound 5 induced apoptosis in U251 cells by PARP1 and caspase 3 cleavage mechanisms, also inducing an increase in the level of Bax and Bim proapoptotic proteins and a decrease in the level of phosho-ERK1/2 kinase. The cytotoxicity of compound 5 was associated with an increase in the production of the hydrogen peroxide and the formation of DNA single-strand breaks. This compound 5 did not intercalate into a DNA molecule. Thus, the novel thiazole derivative (compound 5) proved to be a potential antiglioma drug that showed much higher cytotoxic action on human glioma cells compared with the effects of TMZ and Dox. Its cytotoxicity is associated with apoptosis induction, production of the reactive oxygen species, and formation of DNA single-strand breaks without significant DNA intercalation.

Biosynthesis of gold nanoparticles using Vetex negundo and evaluation of pro-apoptotic effect on human gastric cancer cell lines

Gastric cancer (GC) is mainly widespread gastrointestinal malignancy,which reports for 8% of overallcases in carcinogenesis and 10% of yearly fatality, is 4thprimary cause of cancer associated death global. The plan of the present research was to develop ethanolic extract of Vitex negundo-loaded gold nanoparticles (VN-AuNPs) and to appraise the various characteristic methods likes UV-vis spectroscopy, SAED, FTIR, XRD and HR-TEM. Additionally, the anticancer effect of VN-AuNPs on AGS cells were analysed by cell viability, apoptotic morphological changes by TUNEL, AO/EtBr and Hoechst staining, alterations of mitochondrial membrane potential (MMP) and production reactive oxygen species (ROS). Moreover, the status of apoptosis gene such as caspase-3, Bcl-2, Bcl-XL, Bax and caspase-9 expressions was analysed by using western and RT-PCR techniques. Synthesized AuNPs established by UV absorption peak of the highest at 538 and crystal nature of AuNPs was additionallyverifiedwith SAED and XRD. TEM images were illustrates size and morphological division of NPs. FTIR examinationscompletedalkene, carbodiimide and aliphatic primary amines of biomolecules werepresent in synthesized VN-AuNPs. Additionally, AuNPs were stimulatedapoptosis throughthe cytotoxicity effect,changes of MMP, generation of ROS, nuclear and apoptotic morphological alterationsvia TUNEL, AO/EtBr and Hoechst assay. Furthermore, molecular mechanisms also provoked apoptosis through modulating pro (caspase-3, Bax, Bid, caspase-9) and anti-apoptotic (Bcl-2 and Bcl-XL) mediators by western blotting and gene expression in AGS cells. This production of AuNPs from VN was eco-friendly, large-scaled up and easy.

Assessment of Antioxidant and Cytotoxic Activities of Extracts of Dendrobium crepidatum

Dendrobium crepidatum is an epiphytic orchid found in south Asia including Nepal and China. This orchid species is widely used in traditional Chinese medicine (TCM) for the treatment of cancer, diabetes, cataracts, and fever. The objectives of the present research were to assess the antioxidant and cytotoxic properties of its stem’s extracts with the identification of bioactive secondary metabolites. The antioxidant and cytotoxic activities were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, respectively, and compounds were identified using GC–MS (gas chromatography and mass spectrometry). Ethanol and acetone extracts scavenged 94.69 ± 0.10% and 93.41 ± 0.86% of DPPH free radicals, respectively. They showed 50% inhibition of DPPH free radicals (IC₅₀) at concentrations of 73.90 µg/mL and 99.44 µg/mL, which were found to be statistically similar to that of ascorbic acid (control). Chloroform extract inhibited the growth of 81.49 ± 0.43% of HeLa (human cervical carcinoma) cells and hexane extract inhibited the growth of 76.45 ± 4.26% of U251 (human glioblastoma) cells at 800 µg/mL concentration. These extracts showed 50% inhibition of cell growth (IC₅₀) toward both the HeLa and U251 cell lines at their high concentrations, which were found statistically significantly different from that of cisplatin drug (control). The above extracts showed antioxidant and cytotoxic properties, potentially due to the presence of tetracosane, triacontane, stigmasterol, and some phenol derivatives (2-methoxy-4-vinylphenol, 2-methoxy-5-(1-propenyl)-phenol, p-mesyloxyphenol, and 2,6-dimethoxy-4-(2-propenyl)-phenol). This study explores the potential of this orchid in alternative medicine toward the development of drugs from its medicinally active compounds.

Cytotoxicity of eupatorin in MCF-7 and MDA-MB-231 human breast cancer cells via cell cycle arrest, anti-angiogenesis and induction of apoptosis

Eupatorin has been reported with in vitro cytotoxic effect on several human cancer cells. However, reports on the mode of action and detail mechanism of eupatorin in vitro in breast cancer disease are limited. Hence, eupatorin's effect on the human breast carcinoma cell line MCF-7 and MDA-MB-231 was investigated. MTT assay showed that eupatorin had cytotoxic effects on MCF-7 and MDA-MB-231 cells but was non-toxic to the normal cells of MCF-10a in a time-dose dependent manner. At 24 h, the eupatorin showed mild cytotoxicity on both MCF-7 and MDA-MB-231 cells with IC50 values higher than 20 μg/mL. After 48 h, eupatorin at 5 μg/mL inhibited the proliferation of MCF-7 and MDA-MB-231 cells by 50% while the IC50 of MCF-10a was significantly (p < 0.05) high with 30 μg/mL. The concentration of eupatorin at 5 μg/mL induced apoptosis mainly through intrinsic pathway by facilitating higher fold of caspase 9 compared to caspase 8 at 48 h. The cell cycle profile also showed that eupatorin (5 μg/mL) exerted anti-proliferation activity with the cell cycle arrest of MCF-7 and MDA-MB-231 cells at sub Gθ/G1 in a time-dependent manner. In addition, wound healing assay showed an incomplete wound closure of scratched MDA-MB-231 cells, and more than 60% of the MDA-MB-231 cells were prevented to migrate and invade the membrane in the Boyden chamber after 24 h. Eupatorin also inhibited angiogenic sprouting of new blood vessels in ex vivo mouse aorta ring assay. In gene expression assay, eupatorin up-regulated pro-apoptotic genes such as Bak1, HIF1A, Bax, Bad, cytochrome c and SMAC/Diablo and blocked the Phospho-Akt pathway. In conclusion, eupatorin is a potent candidate to induce apoptosis and concurrently inhibit the invasion, migration and angiogenesis of MDA-MB-231 and MCF-7 cells through inhibition of Phospho-Akt pathway and cell cycle blockade.

Complete chloroplast genome sequence of Dryopteris fragrans (L.) Schott and the repeat structures against the thermal environment

Dryopteris fragrans (L.) Schott is a fern growing on the surface of hot rocks and lava. It is exposed to sunlight directly and bears local hot environment. We sequenced the complete nucleotide sequence of its chloroplast (cp) genome. The cp genome was 151,978 bp in length, consisting of a large single-copy region (85,332 bp), a small single-copy region (31,947 bp) and a pair of inverted repeats (17,314 bp). The cp genome contained 112 genes and 345 RNA editing sites in protein-coding genes. Simple sequence repeats (SSRs) and long repeat structure pairs (30–55 bp) were identified. The number and percent of repeat structures are extremely high in ferns. Thermal denaturation experiments showed its cp genome to have numerous, dispersed and high GC percent repeat structures, which conferred the strongest thermal stability. This repeat-heavy genome may provide the molecular basis of how D. fragrans cp survives its hot environment.

Evaluation of In Vitro Antioxidant and Anticancer Properties of the Aqueous Extract from the Stem Bark of Stryphnodendron adstringens

Stryphnodendron adstringens (Mart.) Coville (Fabaceae) is a tree species native to the Brazilian Cerrado commonly known as barbatimão. In traditional medicine, decoctions or infusions of the stem bark of this plant are used in the treatment of several diseases. The objective of this study was to analyze the chemical composition of Stryphnodendron adstringens aqueous extracts (SAAE) prepared from the stem bark to assess their antioxidant activity and anticancer effects as well as characterize cell death mechanisms against murine B16F10Nex-2 melanoma cells. From the SAAE, gallic acid, gallocatechin, epigallocatechin, dimeric and trimeric proanthocyanidins mainly composed of prodelphinidin units and the isomeric chromones C-hexosyl- and O-pentosyl-5,7-dihydroxychromone were identified. The SAAE showed antioxidant activity through direct free-radical scavenging as well as through oxidative hemolysis and lipid peroxidation inhibition in human erythrocytes. Furthermore, SAAE promoted apoptosis-induced cell death in melanoma cells by increasing intracellular reactive oxygen species (ROS) levels, inducing mitochondrial membrane potential dysfunction and activating caspase-3. Together, these data show the antioxidant and anticancer effects of Stryphnodendron adstringens. These results open new perspectives for studies against other tumor cell lines and in vivo models as well as for the identification and isolation of the chemical constituents responsible for these effects.

Cytotoxicity-Guided Isolation of Two New Phenolic Derivatives from Dryopteris fragrans (L.) Schott

Dryopteris fragrans is a valuable medicinal plant resource with extensive biological activities including anti-cancer, anti-oxidation, and anti-inflammation activities. This work aims to study further the cytotoxic constituents from Dryopteris fragrans. In this work, two new phenolic derivatives known as dryofragone (1) and dryofracoumarin B (2) with six known compounds (3–8) were isolated from the petroleum ether fraction of the methanol extract of the aerial parts of Dryopteris fragrans (L.) Schott by two round cytotoxicity-guided tracking with the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and cell counting kit-8 (CCK-8) assay. Their structures were elucidated by the extensive spectroscopic analysis (¹H-NMR, ¹³C-NMR, and two dimensions NMR), chemical derivatization, and comparison with data reported in the literature. All the isolates were evaluated for their cytotoxicity against nine cancer cell lines as well as their in vitro immunomodulatory activity. The results showed that compounds have a modest cytotoxicity toward human HeLa cell line with IC₅₀ value below 30 μM and compounds 4 and 5 may modulate immunity to affect the growth of tumor cells.

Antibacterial Activity and Mechanism of Action of Aspidinol Against Multi-Drug-Resistant Methicillin-Resistant Staphylococcus aureus

This study aimed at investigating the antibacterial activity of aspidinol, an extract from Dryopteris fragrans (L.) Schott, against methicillin-resistant Staphylococcus aureus (MRSA). MRSA isolates were treated with aspidinol to determine the differential expression of genes and associated pathways following the drug treatment. Aspidinol displayed significant anti-MRSA activity, both in vivo (minimum inhibitory concentration = 2 μg/mL) and in vitro, and achieved an antibacterial effect comparable to that of vancomycin. In the lethal septicemic mouse study, a dose of 50 mg/kg of either aspidinol or vancomycin provided significant protection from mortality. In the non-lethal septicemic mouse study, aspidinol and vancomycin produced a significant reduction in mean bacterial load in murine organs, including the spleen, lung, and liver. After treatment with aspidinol, we found through RNA-seq and RT-PCR experiments that the inhibition of the formation of ribosomes was the primary S. aureus cell-killing mechanism, and the inhibition of amino acid synthesis and the reduction of virulence factors might play a secondary role.

Covalent Organic Frameworks: From Materials Design to Biomedical Application

Covalent organic frameworks (COFs) are newly emerged crystalline porous polymers with well-defined skeletons and nanopores mainly consisted of light-weight elements (H, B, C, N and O) linked by dynamic covalent bonds. Compared with conventional materials, COFs possess some unique and attractive features, such as large surface area, pre-designable pore geometry, excellent crystallinity, inherent adaptability and high flexibility in structural and functional design, thus exhibiting great potential for various applications. Especially, their large surface area and tunable porosity and π conjugation with unique photoelectric properties will enable COFs to serve as a promising platform for drug delivery, bioimaging, biosensing and theranostic applications. In this review, we trace the evolution of COFs in terms of linkages and highlight the important issues on synthetic method, structural design, morphological control and functionalization. And then we summarize the recent advances of COFs in the biomedical and pharmaceutical sectors and conclude with a discussion of the challenges and opportunities of COFs for biomedical purposes. Although currently still at its infancy stage, COFs as an innovative source have paved a new way to meet future challenges in human healthcare and disease theranostic.

Covalent Organic Framework Material Bearing Phloroglucinol Building Units as a Potent Anticancer Agent

Covalent organic frameworks (COFs) having periodicity in pores of nanoscale dimensions can be suitably designed for the organic building units bearing reactive functional groups at their surfaces. Thus, they are an attractive option as an anticancer agent to overcome the limitations of chemotherapy. Herein, we first report a new porous biodegradable nitrogen containing COF material, EDTFP-1 (ethylenedianiline-triformyl phloroglucinol), synthesized using 4,4'-ethylenedianiline and 2,4,6-triformylphloroglucinol via Schiff base condensation reaction. EDTFP-1 exhibited 3D-hexagonal porous structure with average pores of ca. 1.5 nm dimension. Here, we have explored the anticancer potentiality of EDTFP-1. Result demonstrated an enhanced cytotoxicity was observed against four cancer cells HCT 116, HepG2, A549, and MIA-Paca2 with significant lower IC₅₀ on HCT116 cells. Additionally, EDTFP-1-induced cell death was associated with the characteristic apoptotic changes like cell membrane blebbing, nuclear DNA fragmentation, externalization of phosphatidylserine from the cell membrane followed by a loss of mitochondrial membrane potential as well as modulation of pro and antiapoptotic proteins. Further, the result depicted a direct correlation between the generations of ROS with mitochondrial-dependent apoptosis through the involvement of p53 phosphorylation upon EDTFP-1 induction, suggesting this COF material is a novel chemotherapeutic agent for cancer treatment.

4-Thiazolidinone derivative Les-3833 effectively inhibits viability of human melanoma cells through activating apoptotic mechanisms

Aim

To evaluate cytotoxic action of 4-thiazolidinone derivative Les-3833 and study the mechanisms of its pro-apoptotic action toward human melanoma cells and human tumor cell lines of other tissue origin.

Methods

The effect of Les-3833 or doxorubicin on the viability of 9 cell lines was studied using MTT assay, while human melanoma cells of WM793 line were additionally examined using light and fluorescent microscopies for evaluating cytomorphological changes. The Western-blot and flow cytometric analyses were carried out to study signaling pathways of melanoma cell cycling and death.

Results

Les-3833 was the most efficient against melanoma cells. Its half maximal inhibitory concentration (IC₅₀) was 0.22 μg/mL for WM793 cells and 0.3 μg/mL for SK-Mel-28 melanoma cells. For human lung A549, breast MCF-7, colon HCT116, and ovarian SKOV3 carcinoma cell lines IC₅₀ was in between 2.5 to >5.0 μg/mL. Les-3833 was relatively not toxic (IC₅₀ ˃ 5 μg/mL) for human embryonic kidney HEK293 cells. Results of Annexin V/PI staining of melanoma cells and activation of caspase 3, PARP, MAPK, and EndoG protein suggest apoptosis in Les-3833-treated cells. Les-3833 also induced ROS production in melanoma cells and their arrest in G₀/G₁ phase of cell cycle.

Conclusion

Novel 4-thiazolidinone derivative Les-3833 is effective against human melanoma cells in vitro, and such effect is tumor specific since it is much less pronounced in human carcinoma and leukemia cells. In melanoma cells Les-3833 induces apoptosis (morphological changes and increased pro-apoptotic proteins), ROS production, and arrest in G₀/G₁ phase of cell cycle.

Dryocrassin ABBA Induces Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells Through a Caspase-Dependent Mitochondrial Pathway

BACKGROUND

Biological and pharmacological activities of dryocrassin ABBA, a phloroglucinol derivative extracted from Dryopteris crassirhizoma, have attracted attention. In this study, the apoptotic effect of dryocrassin ABBA on human hepatocellular carcinoma HepG2 cells was investigated.

MATERIALS AND METHODS

We tested the effects of dryocrassin ABBA on HepG2 in vitro by MTT, flow cytometry, real-time PCR, and Western blotting. KM male mice were used to detect the effect of dryocrassin ABBA on H22 cells in vivo.

RESULTS

Dryocrassin ABBA inhibited the growth of HepG2 cells in a concentration-dependent manner. After treatment with 25, 50, and 75 μg/mL dryocrassin ABBA, the cell viability was 68%, 60% and 49%, respectively. Dryocrassin ABBA was able to induce apoptosis, measured by propidium iodide (PI)/annexin V-FITC double staining. The results of real-time PCR and Western ting showed that dryocrassin ABBA up-regulated p53 and Bax expression and inhibited Bcl-2 expression which led to an activation of caspase-3 and caspase-7 in the cytosol, and then induction of cell apoptosis. In vivo experiments also showed that dryocrassin ABBA treatment significantly suppressed tumor growth, without major side effects.

CONCLUSIONS

Overall, these findings provide evidence that dryocrassin ABBA may induce apoptosis in human hepatocellular carcinoma cells through a caspase-mediated mitochondrial pathway.

A New Human Cancer Cell Proliferation Inhibition Sesquiterpene, Dryofraterpene A, from Medicinal Plant Dryopteris fragrans (L.) Schott

The global burden of cancer continues to increase largely with the aging and growth of the world population. The purpose of the present work was to find new anticancer molecules from a natural source. We utilized chromatographic methods to isolate compounds from medicinal plant Dryopteris fragrans (L.) Schott. The structure of the new compounds was determined by spectroscopic and spectrometric data (1D NMR, 2D NMR, and EMI-MS). Their anti-proliferation effects against five human cancer cell lines including A549, MCF7, HepG2, HeLa, and PC-3 were evaluated by CCK-8 andlactate dehydrogenase (LDH) assay. A new sesquiterpene, (7S, 10S)-2,3-dihydroxy-calamenene-15-carboxylic acid methyl ester (1), and two known compounds (2 and 3) were isolated. The new sesquiterpene was named dryofraterpene A and significantly inhibited cancer cell proliferation without any obvious necrosis below a 10 μM concentration. In conclusion, a novel anticancer sesquiterpene together with two known compounds was isolated, which might be a promising lead compound for the treatment of cancer.

Persian Gulf Jellyfish (Cassiopea andromeda) Venom Fractions Induce Selective Injury and Cytochrome C Release in Mitochondria Obtained from Breast Adenocarcinoma Patients

Objective:

This study was conducted to investigate whether fractions of jellyfish Cassiope andromeda venom, could selectively induce toxicity on mitochondria isolated from cancer tissue of patients with breast adenocarcinomas.

Methods:

Firstly, we extracted two fractions, (f1 and f2) from crude jellyfish venom by gel filtration on Sephadex G-200. Then different dilutions of these extracted fractions were applied to mitochondria isolated from human breast tumoral- and extra-tumoral tissues. Parameters of mitochondrial toxicity including generation of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) collapse, swelling, cytochrome c release, activation of caspase3 and apoptosis were then assayed.

Result:

Our results demonstrate that fraction 2 of Cassiopea andromeda crude venom significantly (P<0.05) decreased mitochondrial succinate dehydrogenase activity, increased mitochondrial ROS production, induced mitochondrial swelling, MMP collapse and cytochrome c release, activated caspase3 and induced apoptosis only in tumoral mitochondria, and not in mitochondria obtained from extra-tumoral tissue (P<0.05).

Conclusion:

In conclusion this study suggested that fraction 2 of Cassiopea andromeda crude venom selectively induces ROS mediated cytotoxicity by directly targeting mitochondria isolated from human breast tumor tissue.

Separation of glycine-rich proteins from sea hare eggs and their anti-cancer activity against U937 leukemia cell line

The present study was designed to investigate the anti-cancer effects of Sea hare eggs (SE) in U937 cells and its major active components. The aqueous extract of SE (ASE), which contained the highest protein content, dose-dependently inhibited the cancer cell's growth (IC₅₀ value, 10.42 ± 0.5 µg/mL). Additionally, ASE markedly caused DNA damage by inducing apoptotic body formation, DNA fragmentation, and accumulation of sub-G₁ DNA contents. ASE induced apoptosis by activating caspase-3 and 9 and poly (ADP-ribose) polymerase (PARP) by regulating the expression of Bcl-2/Bax. Moreover, among its molecular weight fractions, the > 30 kDa fraction showed the highest cell-growth-inhibitory effects, which was inhibited by heat treatment. Furthermore, the > 30 kDa fraction had markedly higher glycine content than the ASE. The presence of two protein bands at around 16 and 32 kDa was identified. In addition, two fractions, F1 and F2, were obtained using anion-exchange chromatography, with the F1 having an improved cell-growth-inhibitory effect than the > 30 kDa fraction. Taken together, these results suggest that the ASE contains glycine-rich proteins, including the active 16 and 32 kDa proteins, which account for its anti-cancer effects by inducing apoptosis via regulation of the mitochondrial pathway.

Inhibitory effects of polyphenol-enriched extract from Ziyang tea against human breast cancer MCF-7 cells through reactive oxygen species-dependent mitochondria molecular mechanism

A polyphenol-enriched extract from selenium-enriched Ziyang green tea (ZTP) was selected to evaluate its antitumor effects against human breast cancer MCF-7 cells. In ZTP, (−)-epigallocatechin gallate (28.2%) was identified as the major catechin, followed by (−)-epigallocatechin (5.7%) and (−)-epicatechin gallate (12.6%). ZTP was shown to inhibit MCF-7 cell proliferation (half maximal inhibitory concentration, IC₅₀ = 172.2 μg/mL) by blocking cell-cycle progression at the G0/G1 phase and inducing apoptotic death. Western blotting assay indicated that ZTP induced cell-cycle arrest by upregulation of p53 and reduced the expression of CDK2 in MCF-7 cells. ZTP-caused cell apoptosis was associated with an increase in Bax/Bcl-2 ratio, and activation of caspase-3 and -9. MCF-7 cells treated with ZTP also showed an overproduction of reactive oxygen species, suggesting that reactive oxygen species played an important role in the induction of apoptosis in MCF-7 cells. This is the first report showing that ZTP is a potential novel dietary agent for cancer chemoprevention or chemotherapy.

Cell cycle arrest and apoptosis induced by aspidin PB through the p53/p21 and mitochondria-dependent pathways in human osteosarcoma cells

Aspidin PB is a natural product extracted from Dryopteris fragrans (L.) Schott, which has been characterized for its various biological activities. We reported that aspidin PB induced cell cycle arrest and apoptosis through the p53/p21 and mitochondria-dependent pathways in human osteosarcoma cells. Aspidin PB inhibited the proliferation of Saos-2, U2OS, and HOS cells in a dose-dependent and time-dependent manner. Aspidin PB induced changes in the cell cycle regulators (cyclin A, pRb, CDK2, p53, and p21), which caused cell cycle arrest in the S phase. We also explored the role of siRNA targeted to p53; it led to a dose-dependent attenuation of aspidin PB-induced apoptosis signaling. Moreover, after treatment with aspidin PB, the p21-silenced cells decreased significantly at the S phase. Aspidin PB increased the percentage of cells with mitochondrial membrane potential disruption. Western blot analysis showed that aspidin PB inhibited Bcl-2 expression and induced Bax expression to disintegrate the outer mitochondrial membrane and caused cytochrome C release. Mitochondrial cytochrome C release was associated with the activation of caspase-9 and caspase-3 cascades. Furthermore, the double-stranded DNA breaks and reactive oxygen species signaling were both involved in aspidin PB-induced DNA damage. In addition, aspidin PB inhibited tumor growth significantly in U2OS xenografts. Above all, we conclude that aspidin PB represents a valuable natural source and may potentially be applicable in osteosarcoma therapy.

A polyphenolic flavonoid glabridin: Oxidative stress response in multidrug-resistant Staphylococcus aureus

Glabridin a polyphenolic flavonoid from Glycyrrhiza glabra is known to possess several therapeutic properties. In the present study, we report for the first time the in vitro antibacterial activity (MIC values ranging from 3.12 to 25 μg/mL) of glabridin against multidrug-resistant clinical isolates of S. aureus by inducing oxidative stress. Increased levels of H2O2 and NO were observed in a dose-dependent manner after treatment of glabridin that further affected macromolecules such as DNA, lipids, and proteins. Surprisingly, glabridin was found to possess antioxidant properties when used at lower concentrations using three different methods including DPPH, FRAP, and SOD assays. These observations were further validated through the expression analysis of oxidative stress-responsive genes using qRT-PCR wherein glabridin was observed to up- and down-regulate these genes at lower and higher concentrations, respectively. In in vitro combination experiments, glabridin was found to reduce the MIC of different antibiotics such as norfloxacin, oxacillin, and vancomycin by up to 4-fold, while the MIC of glabridin itself was found to be reduced by up to 8-fold in the presence of antibiotics. A synergistic interaction was observed between norfloxacin and glabridin when used in combination against multidrug-resistant clinical isolate SA 4627 of Staphylococcus aureus at much lower concentrations, indicating the suitability of glabridin in combination therapy.

Naphthazarin enhances ionizing radiation-induced cell cycle arrest and apoptosis in human breast cancer cells

Naphthazarin (Naph, DHNQ, 5,8-dihydroxy-l,4-naphthoquinone) is one of the naturally available 1,4-naphthoquinone derivatives that are well-known for their anti-inflammatory, antioxidant, antibacterial and antitumor cytotoxic effects in cancer cells. Herein, we investigated whether Naph has effects on cell cycle arrest and apoptosis in MCF-7 human breast cancer cells exposed to ionizing radiation (IR). Naph reduced the MCF-7 cell viability in a dose-dependent manner. We also found that Naph and/or IR increased the p53-dependent p21 (CIP/WAF1) promoter activity. Noteworthy, our ChIP assay results showed that Naph and IR combined treatment activated the p21 promoter via inhibition of binding of multi-domain proteins, DNMT1, UHRF1 and HDAC1. Apoptosis and cell cycle analyses demonstrated that Naph and IR combined treatment induced cell cycle arrest and apoptosis in MCF-7 cells. Herein, we showed that Naph treatment enhances IR-induced cell cycle arrest and death in MCF-7 human breast cancer cells through the p53-dependent p21 activation mechanism. These results suggest that Naph might sensitize breast cancer cells to radiotherapy by enhancing the p53-p21 mechanism activity.

Glyoxalase I inhibition induces apoptosis in irradiated MCF-7 cells via a novel mechanism involving Hsp27, p53 and NF-κB

BACKGROUND

Glyoxalase I (GI) is a cellular defence enzyme involved in the detoxification of methylglyoxal (MG), a cytotoxic byproduct of glycolysis, and MG-derived advanced glycation end products (AGEs). Argpyrimidine (AP), one of the major AGEs coming from MG modifications of proteins arginines, is a pro-apoptotic agent. Radiotherapy is an important modality widely used in cancer treatment. Exposure of cells to ionising radiation (IR) results in a number of complex biological responses, including apoptosis. The present study was aimed at investigating whether, and through which mechanism, GI was involved in IR-induced apoptosis.

METHODS

Apoptosis, by TUNEL assay, transcript and protein levels or enzymatic activity, by RT-PCR, western blot and spectrophotometric methods, respectively, were evaluated in irradiated MCF-7 breast cancer cells, also in experiments with appropriate inhibitors or using small interfering RNA.

RESULTS

Ionising radiation induced a dramatic reactive oxygen species (ROS)-mediated inhibition of GI, leading to AP-modified Hsp27 protein accumulation that, in a mechanism involving p53 and NF-κB, triggered an apoptotic mitochondrial pathway. Inhibition of GI occurred at both functional and transcriptional levels, the latter occurring via ERK1/2 MAPK and ERα modulation.

CONCLUSIONS

Glyoxalase I is involved in the IR-induced MCF-7 cell mitochondrial apoptotic pathway via a novel mechanism involving Hsp27, p53 and NF-κB.

Transport and killing mechanism of a novel camptothecin-deoxycholic acid derivate on hepatocellular carcinoma cells

Abstract Camptothecin-20(s)-O-glycine ester-[N-(3'α, 12'α-dihydroxy-24'-carbonyl-5'β-cholan)] (A2), 10-(3'α,12'α-dihydroxy-5'β-cholan-24'-carboxyl)-(20 s)-camptothecin (C2), and 10-O-(3-O-(3'α, 12'α-dihydroxy-24'-carbonyl-5'β-cholan)-propyl)-(20S)-camptothecin (D2) are novel camptothecin-deoxycholic acid analogues. MTT assays were performed to assess the anticancer activity of these compounds against hepatocellular carcinoma SMMC-7721, breast carcinoma MCF-7, and colorectal carcinoma HCT-116 cells. A2 had a high killing ability on SMMC-7721 cells selectively, but C2 and D2 did not exhibit selectivity with regard to SMMC-7721 killing. Uptake assays were performed in an effort to elucidate the transport mechanisms of A2 into SMMC-7721 cells. A2 increased the mRNA expression of OATP1B3 (an organic anion-transporting polypeptide) and uptake of A2 was inhibited by rifampin (inhibitor of OATP1B3), which indicated that the transporter-mediated transport of A2 was mediated by OATP1B3. In addition, according to the western blot and apoptosis assays, we found that A2 killed SMMC-7721 cells by inducing cell apoptosis mainly via an AIF (apoptosis-inducing factor) pathway and a caspase-dependent mitochondria apoptosis pathway.

Tetrahydrocurcumin induces G2/M cell cycle arrest and apoptosis involving p38 MAPK activation in human breast cancer cells

Curcumin (CUR) is a major naturally-occurring polyphenol of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. In recent years, it has been reported that CUR exhibits significant anti-tumor activity in vivo. However, the pharmacokinetic features of CUR have indicated poor oral bioavailability, which may be related to its extensive metabolism. The CUR metabolites might be responsible for the antitumor pharmacological effects in vivo. Tetrahydrocurcumin (THC) is one of the major metabolites of CUR. In the present study, we examined the efficacy and associated mechanism of action of THC in human breast cancer MCF-7 cells for the first time. Here, THC exhibited significant cell growth inhibition by inducing MCF-7 cells to undergo mitochondrial apoptosis and G2/M arrest. Moreover, co-treatment of MCF-7 cells with THC and p38 MAPK inhibitor, SB203580, effectively reversed the dissipation in mitochondrial membrane potential (Δψm), and blocked THC-mediated Bax up-regulation, Bcl-2 down-regulation, caspase-3 activation as well as p21 up-regulation, suggesting p38 MAPK might mediate THC-induced apoptosis and G2/M arrest. Taken together, these results indicate THC might be an active antitumor form of CUR in vivo, and it might be selected as a potentially effective agent for treatment of human breast cancer.

EGCG inhibits Cd(2+)-induced apoptosis through scavenging ROS rather than chelating Cd(2+) in HL-7702 cells

CONTEXT AND OBJECTIVE

Epigallocatechin-3-gallat (EGCG), the major catechin in green tea, shows a potential protective effect against heavy metal toxicity to humans. Apoptosis is one of the key events in cadmium (Cd(2+))-induced cytotoxicity. Nevertheless, the study of EGCG on Cd(2+)-induced apoptosis is rarely reported. The objective of this study was to clarify the effect and detailed mechanism of EGCG on Cd(2+)-induced apoptosis.

METHODS

Normal human liver cells (HL-7702) were treated with Cd(2+) for 21 h, and then co-treated with EGCG for 3 h. Cell viability, apoptosis, intracellular reactive oxygen species (ROS), malondialdehyde (MDA), mitochondrial membrane potential (MMP) and caspase-3 activity were detected. On the other hand, the chelation of Cd(2+) with EGCG was tested by UV-Vis spectroscopy analysis and Nuclear Magnetic Resonance ((1)H NMR) spectroscopy under neutral condition (pH 7.2).

RESULTS AND CONCLUSION

Cd(2+) significantly decreased the cell viability and induced apoptosis in HL-7702 cells. Conversely, EGCG co-treatment resulted in significant inhibition of Cd(2+)-induced reduction of cell viability and apoptosis, implying a rescue effect of EGCG against Cd(2+) poisoning. The protective effect most likely arises from scavenging ROS and maintaining redox homeostasis, as the generation of intracellular ROS and MDA is significantly reduced by EGCG, which further prevents MMP collapse and suppresses caspase-3 activity. However, no evidence is observed for the chelation of EGCG with Cd(2+) under neutral condition. Therefore, a clear conclusion from this work can be made that EGCG could inhibit Cd(2+)-induced apoptosis by acting as a ROS scavenger rather than a metal chelating agent.

2,4-dichlorophenol induces apoptosis in primary hepatocytes of grass carp (Ctenopharyngodon idella) through mitochondrial pathway

2,4-Dichlorophenol (2,4-DCP), a major type of chlorophenols, has been widely used to produce some herbicides and pharmaceuticals, yet due to its incomplete degradation and bioaccumulation characteristics, it is toxic to aquatic organisms. Apoptosis is one of the most severe outcomes of cell poisoning and injury. So far, the potential molecular mechanism of 2,4-DCP-induced apoptosis has not been reported. This study showed that 2,4-DCP significantly induced apoptosis in primary hepatocytes of grass carp (Ctenopharyngodon idella). 2,4-DCP exposure upregulated mRNA of caspase-3, reduced the mitochondrial membrane potential (Δψm), increased intracellular reactive oxygen species (ROS) and the Bax/Bcl-2 ratio, while protection of mitochondria with acetyl-l-carnitine hydrochloride (ALC) rescued 2,4-DCP-induced apoptosis, restored the Δψm and reduced the Bax/Bcl-2 ratio. Taken together, this is the first study that has identified that 2,4-DCP exposure induced apoptosis through the mitochondria-dependent pathway in primary hepatocytes of grass carp.

Aspidin BB, a phloroglucinol derivative, induces cell cycle arrest and apoptosis in human ovarian HO-8910 cells

Aspidin BB, an effective phloroglucinol derivative from Dryopteris fragrans (L.) Schott, has been previously reported to exert high biological activities. In this study, we analyzed the underlying mechanisms of aspidin BB on human ovarian cancer cell line, HO-8910. Aspidin BB significantly inhibited HO-8910 cell proliferation in a dose- and time-dependent manner. The IC50 values were 15.02, 25.79 and 68.81μM after 72, 48 and 24h treatment, respectively. Meanwhile, aspidin BB markedly induced apoptosis evidenced by characteristic apoptotic morphological changes, nuclear DNA fragmentation, annexin V-FITC/propidium iodide (PI) double staining and S peak. Western blot analysis showed that aspidin BB suppressed Bcl-2 expression and enhanced Bax expression to desintegrate the outer mitochondrial membrane, then caused cytochrome c release which led to the activation of effector caspase-3, and further cleaved the poly ADP-ribose polymerase (PARP) in the nucleus, finally induced cell apoptosis. Furthermore, aspidin BB provoked S phase arrest in HO-8910 cells with up-regulation of pRb, E2F1, CDK2, cyclin E and cyclin A proteins. Taken together, these findings support the conclusion that aspidin BB exhibits cytotoxicity towards human ovarian cancer HO-8910 cells through induction of apoptosis via mitochondrial pathway and arresting cell cycle progression in S phase.

Hypocrea lixii, novel endophytic fungi producing anticancer agent cajanol, isolated from pigeon pea (Cajanus cajan [L.] Millsp.)

AIMS

The aim was to isolate, identify and characterize endophytes from pigeon pea (Cajanus cajan [L.] Millsp.), as novel producer of cajanol and its in vitro cytotoxicity assay.

METHODS AND RESULTS

Isolation, identification and characterization of novel endophytes producing cajanol from the roots of pigeon pea were investigated. The endophytes were identified as Hypocrea lixii by morphological and molecular methods. Cajanol produced by endophytes were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). R-18 produced the highest levels of cajanol (322·4 ± 10·6 μg l(-1) or 102·8 ± 6·9 μg g(-1) dry weight of mycelium) after incubation for 7 days. The cytotoxicity towards human lung carcinoma cells (A549) of fungal cajanol was investigated in vitro.

CONCLUSIONS

First, a novel endophyte Hypocrea lixii, producing anticancer agent cajanol, was isolated from the host pigeon pea (Cajanus cajan [L.] Millsp.). Fungal cajanol possessed stronger cytotoxicity activity towards A549 cells in time- and dose-dependent manners.

SIGNIFICANCE AND IMPACT OF THE STUDY

This endophyte is a potential handle for scientific and commercial exploitation, and it could provide a promising alterative approach for large-scale production of cajanol to satisfy new anticancer drug development.

Inhibitory effects and molecular mechanisms of selenium-containing tea polysaccharides on human breast cancer MCF-7 cells

Dietary supplementation of selenium-enriched tea is known to have an anticancer health benefit. This study was to investigate the inhibitory effect of selenium-containing tea polysaccharides (Se-GTPs) from a new variety of selenium-enriched Ziyang green tea against human MCF-7 breast cancer cells. Se-GTPs dose-dependently exhibited an effective cell growth inhibition with an IC(50) of 140.1 μg/mL by inducing MCF-7 cancer cells to undergo G2/M phase arrest and apoptosis. The blockade of cell cycle was associated with an up-regulation of p53 expression, but not CDK2. Se-GTPs clearly triggered the mitochondrial apoptotic pathway, as indicated by an increase in Bax/Bcl-2 ratio and subsequent caspase-3 and caspase-9 activation. It was also found that the generation of intracellular ROS is a critical mediator in Se-GTPs-induced cell growth inhibition. These findings suggest that Se-GTPs may serve as a potential novel dietary agent for human breast cancer chemoprevention.

Antiproliferation and induction of apoptosis in Ca9-22 oral cancer cells by ethanolic extract of Gracilaria tenuistipitata

The water extract of Gracilaria tenuistipitata have been found to be protective against oxidative stress-induced cellular DNA damage, but the biological function of the ethanolic extracts of G. tenuistipitata (EEGT) is still unknown. In this study, the effect of EEGT on oral squamous cell cancer (OSCC) Ca9-22 cell line was examined in terms of the cell proliferation and oxidative stress responses. The cell viability of EEGT-treated OSCC cells was significantly reduced in a dose-response manner (p < 0.0001). The annexin V intensity and pan-caspase activity of EEGT-treated OSCC cells were significantly increased in a dose-response manner (p < 0.05 to 0.0001). EEGT significantly increased the reactive oxygen species (ROS) level (p < 0.0001) and decreased the glutathione (GSH) level (p < 0.01) in a dose-response manner. The mitochondrial membrane potential (MMP) of EEGT-treated OSCC cells was significantly decreased in a dose-response manner (p < 0.005). In conclusion, we have demonstrated that EEGT induced the growth inhibition and apoptosis of OSCC cells, which was accompanied by ROS increase, GSH depletion, caspase activation, and mitochondrial depolarization. Therefore, EEGT may have potent antitumor effect against oral cancer cells.