Human Colon Tumor Cell Lines Research Articles

Evaluating the pharmacological activities of Aloe perryi-Silver nanoparticles induced apoptosis against colon cancer cells (HCT-116).

Aloe perryi has been studied and possesses several activities, including antibacterial, antiparasitic, and anticancer properties. In this study, A. perryi was used as a reducing agent of silver ions into silver nanoparticles. Aloe perryi-silver nanoparticles (APS-NPs) were characterized and evaluated using characterization techniques. However, the antioxidative, antibacterial, and anticancer assays were studied to evaluate the pharmacological activities of APS-NPs. APS-NPs were developed and changed to dark brown and the maximum absorption was 442 nm. SEM (5-583 nm), TEM (4-110 nm), XRD (21.84 nm), and zeta potential analysis (63.39 nm) revealed that the APS-NPs were nano-sized, and the APS-NPs had a cubic crystalline structure, according to the XRD results. FTIR analysis suggested that functional groups of A. perryi metabolites were involved in forming APS-NPs. The zeta potential indicated that the APS-NPs were negatively charged (-32 mV), suggesting good stability. APS-NPs showed significant antioxidative stress activity by reducing DPPH-free radicles in a dose-dependent manner. APS-NPs-induced antibacterial effect against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Acinetobacter baumannii (A. baumannii). APS-NPs reduced the cell viability and cell migration of the human colon tumor cell line (HCT 116) compared with controls, indicating that APS-NPs could play a role in reducing metastasis and inducing cell apoptosis against colon cancer. In conclusion, the nanoparticle synthesis from A. perryi extract demonstrated excellent antioxidant, antibacterial, and anticancer activities, thus suggesting that our APS-NPs have the potential to be used as antioxidative and antibacterial in food and pharmaceutical industries.

Molecular Targets of the 5-Amido-Carboxamide Bumped Kinase Inhibitor BKI-1748 in Cryptosporidium parvum and HCT-8 Host Cells.

Cryptosporidium parvum is an apicomplexan parasite causing persistent diarrhea in humans and animals. Issuing from target-based drug development, calcium-dependent protein kinase 1 inhibitors, collectively named bumped kinase inhibitors (BKIs), with excellent efficacies in vitro and in vivo have been generated. Some BKIs including BKI-1748 share a core structure with similarities to the first-generation antiprotozoal drug quinine, which is known to exert notorious side effects. Unlike quinine, BKI-1748 rapidly interfered with C. parvum proliferation in the human colon tumor (HCT) cell line HCT-8 cells and caused dramatic effects on the parasite ultrastructure. To identify putative BKI targets in C. parvum and in host cells, we performed differential affinity chromatography with cell-free extracts from non-infected and infected HCT-8 cells using BKI-1748 and quinine epoxy-activated sepharose columns followed by mass spectrometry. C. parvum proteins of interest were identified in eluates from columns coupled to BKI-1748, or in eluates from both BKI-1748 and quinine columns. However, no C. parvum proteins could be identified binding exclusively to BKI-1748. In contrast, 25 BKI-1748-specific binding proteins originating from HCT-8 cells were detected. Moreover, 29 C. parvum and 224 host cell proteins were identified in both BKI-1748 as well as in quinine eluates. In both C. parvum and host cells, the largest subset of binding proteins was involved in RNA binding and modification, with a focus on ribosomal proteins and proteins involved in RNA splicing. These findings extend previous results, showing that BKI-1748 interacts with putative targets involved in common, essential pathways such as translation and RNA processing.

Discovery of a synthetic taiwaniaquinoid with potent in vitro and in vivo antitumor activity against breast cancer cells

Taiwaniaquinoids are a unique family of diterpenoids predominantly isolated from Taiwania cryptomerioides Hayata. Previously, we evaluated the antiproliferative effect of several synthetic taiwaniaquinoids against human lung (A-549), colon (T-84), and breast (MCF-7) tumor cell lines. Herein, we report the in vitro and in vivo antitumor activity of the most potent compounds. Their cytotoxic activity against healthy peripheral blood mononuclear cells (PBMCs) has also been examined. We underscore the limited toxicity of compound C36 in PBMCs and demonstrate that it exerts its antitumor effect in MCF-7 cells (IC50 = 1.8 µM) by triggering an increase in reactive oxygen species, increasing the cell population in the sub-G1 phase of the cell cycle (90 %), and ultimately activating apoptotic (49.6 %) rather than autophagic processes. Western blot results suggested that the underlying mechanism of the C36 apoptotic effects was linked to caspase 9 activation and a rise in the Bax/Bcl-2 ratio. In vivo analyses showed normal behavior and hematological parameters in C57BL/6 mice post C36 treatment. Moreover, no significant impact was observed on the biochemical parameters of these animals, indicating that C36 did not induce liver toxicity. Furthermore, C36 demonstrated a significant reduction in tumor growth in immune-competent C57BL/6 mice implanted with E0771 mouse mammary tumor cells, effectively improving survival rates. These findings position taiwaniaquinoids, particularly compound C36, as promising therapeutic candidates for human breast cancer.

Preparation and Properties of Natural Polysaccharide-Based Drug Delivery Nanoparticles.

In recent years, natural polysaccharides have been widely used in the preparation of drug delivery systems. In this paper, novel polysaccharide-based nanoparticles were prepared by layer-by-layer assembly technology using silica as a template. The layers of nanoparticles were constructed based on the electrostatic interaction between a new pectin named NPGP and chitosan (CS). The targeting ability of nanoparticles was formed by grafting the RGD peptide, a tri-peptide motif containing arginine, glycine, and aspartic acid with high affinity to integrin receptors. The layer-by-layer assembly nanoparticles (RGD-(NPGP/CS)3NPGP) exhibited a high encapsulation efficiency (83.23 ± 6.12%), loading capacity (76.51 ± 1.24%), and pH-sensitive release property for doxorubicin. The RGD-(NPGP/CS)3NPGP nanoparticles showed better targeting to HCT-116 cells, the integrin αvβ3 high expression human colonic epithelial tumor cell line with higher uptake efficiency than MCF7 cells, the human breast carcinoma cell line with normal integrin expression. In vitro antitumor activity tests showed that the doxorubicin-loaded nanoparticles could effectively inhibit the proliferation of the HCT-116 cells. In conclusion, RGD-(NPGP/CS)3NPGP nanoparticles have potential as novel anticancer drug carriers because of their good targeting and drug-carrying activity.

Nucleotide Supplements Alter Proliferation and Differentiation of Cultured Human (Caco-2) and Rat (IEC-6) Intestinal Epithelial Cells

The effect of exogenous nucleotides on the proliferation and differentiation of enterocytes was comparatively studied using a human colon tumor cell line (Caco-2) and a normal rat small intestinal crypt cell line (IEC-6). Caco-2 cells exhibited more active endogenous nucleic acid metabolism than did IEC-6 cells, as evidenced by greater cellular pools of nucleotides and their metabolites. To determine the supplemental nutritional effect of nucleotides, a mixture containing equal amounts (10 mg/L) of AMP, CMP, IMP, GMP and UMP was added to the culture medium. The results showed that a nucleotide supplement under normal culture conditions did not affect proliferation and differentiation of Caco-2 cells. In contrast, nucleotide supplements under normal culture conditions promoted proliferation of IEC-6 cells. The addition of nucleotides to the culture medium also enhanced differentiation of IEC-6 cells when grown on an extracellular matrix (Matrigel). Furthermore, when glutamine levels were less than optimal (nutritional stress conditions), nucleotide supplements enhanced growth and maturation of both cell lines. We conclude that the de novo biosynthesis of nucleotides is sufficient to support proliferation of tumor Caco-2 cells but not of the normal crypt IEC-6 cells. Thus, nucleotide supplements may enhance normal enterocyte growth and maturation as well as spare the need for exogenous glutamine in cell maintenance and development.

Theoretical investigation and antineoplastic potential of Zn (II) and Pd (II) complexes of 6-methylpyridine-2-carbaldehyde-N (4)-ethylthiosemicarbazone

Density Functional Theoretical (DFT) and molecular docking studies have been used to elucidate the antineoplastic potential of the ligand 6-Methylpyridine-2-carbaldehyde-N (4)-ethylthiosemicarbazone (MET) and its platinum(II) and zinc(II) complexes. The frontier molecular orbital and the global quantum reactivity parameters were used to study the reactivity and stability of the modeled complexes. The energy gap showed that the complexes have their reactivity in the order Pd[MET] < [MET] < Zn[MET] suggesting a higher reactivity of the Pd complex compared to its Zn(II) congener. NBO indicated Pd(MET)Cl complex to have the highest E(2) energies and exhibiting highest interaction arising from strong coordination of the thiolato sulfur and chloride atoms around the Pd2+ as seen in the σ*S21 -Pd13→ σ*Pd31 – Cl32 transition. QTAIM revealed that highest density of electrons follows the order [Pd(MET)Cl] >[Zn(MET)Cl] > [MET], while computational drug design protocols carried out provided the order of binding affinity as Pd(MET)Cl > Zn(MET)Cl and MET which again presents Pd complex as having greater antineoplastic activity. Our DFT findings are in excellent agreement with previous experimental reports thereby affirming the potential of these complexes as possible candidates for antineoplastic chemotherapeutic treatment against the human colon tumor cell lines (HCT 116) .

Alkaloid Profiling, Anti-Enzymatic and Antiproliferative Activity of the Endemic Chilean Amaryllidaceae Phycella cyrtanthoides

This research aims to identify the alkaloid profile and to evaluate the enzyme inhibitory potential and antiproliferative effects of the Amaryllidaceae plant Phycella cyrtanthoides. The alkaloid extracts from bulbs and leaves were analyzed using ultrahigh performance liquid chromatography orbitrap mass spectrometry (UHPLC-Orbitrap-MS) analysis. A total of 70 alkaloids were detected in the P. cyrtanthoides’ extracts. The enzyme inhibition potential against cholinesterases (AChE: acetylcholinesterase, and BChE butyrylcholinesterase) and tyrosinase were studied. Bulbs displayed the best IC50 values against AChE (4.29 ± 0.03 µg/mL) and BChE (18.32 ± 0.03 µg/mL). These results were consistent with docking experiments with selected major compounds in the active sites of enzymes, while no activity was observed against tyrosinase enzyme. Antiproliferative effects were investigated against human cervical (HeLa), lung (A549, SW1573), colon (WiDr), and breast (HBL-100, T-47D) tumor cell lines. Bulbs and leaves were active in all cell lines (GI50 < 2.5 µg/mL). These findings suggest that the endemic Chilean plant P. cyrtanthoides contains diverse types of bioactive alkaloids with antiproliferative activities and inhibitory effects with potential therapeutic applications for neurodegenerative diseases

Comparison of characteristics and tumor targeting properties of extracellular vesicles derived from primary NK cells or NK-cell lines stimulated with IL-15 or IL-12/15/18

NK cell-based therapies have shown promise for hematological cancer forms, but their use against solid tumors is hampered by their poor ability to infiltrate the tumor. NK cells release extracellular vesicles (EVs) containing cytolytic proteins, indicating that NK-cell derived EVs may have therapeutic potential. In this study, we compared the tumor-targeting potential of EVs derived from either primary NK cells or the NK cell lines NK-92 and KHYG-1 cultured in IL-15 alone or in combination with IL-12 and IL-18. Primary NK cells were also stimulated through the activating receptor CD16. Tumor cell apoptosis was measured using a panel of human colon, melanoma, glioblastoma, prostate, breast, and ovarian tumor cell line spheroids. NK cells or NK-92 cells stimulated with IL-12, IL-15, and IL-18 generated EVs with higher efficiency than EVs from resting cells, although similar amounts of EVs were produced under both conditions. Proteomic analysis indicated similar distribution of cytolytic proteins in EVs from primary NK cells and NK-92, but lower levels in KHYG-1 EVs that translated into poor capacity for KHYG-1 EVs at targeting tumor cell lines. Further, we show that CD16-stimulated NK cells release low amounts of EVs devoid of cytolytic proteins. Importantly, EVs from cytokine-stimulated NK cells penetrate into the spheroid core, and tumor spheroid susceptibility to NK-cell derived EVs was linked to differential expression of the NKG2D ligands MICA/B, which was blocked with an anti-NKG2D antibody. We conclude that EVs from activated primary NK cells or NK-92 cells has the best potential to infiltrate and target solid tumors.

Noninvasive Evaluation of EGFR Expression of Digestive Tumors Using 99mTc-MAG3-Cet-F(ab')2-Based SPECT/CT Imaging.

Purpose This study is aimed at investigating the feasibility of cetuximab (Cet) F(ab′)2 fragment- (Cet-F(ab′)2-) based single photon emission tomography/computed tomography (SPECT/CT) for assessing the epidermal growth factor receptor (EGFR) expression in digestive tumor mouse models. Methods Cet-F(ab′)2 was synthesized using immunoglobulin G-degrading enzyme of Streptococcus pyogenes (IdeS) protease and purified with protein A beads. The product and its in vitro stability in normal saline and 1% bovine serum albumin were analyzed with sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The EGFR expression in the human colon tumor cell line HT29 and the human stomach tumor cell line MGC803 were verified using western blotting and immunocytochemistry. Cet-F(ab′)2 was conjugated with 5(6)-carboxytetramethylrhodamine succinimidyl ester to demonstrate its binding ability to the MGC803 and HT29 cells. Cet-F(ab′)2 was conjugated with NHS-MAG3 for 99mTc radiolabeling. The best imaging time was determined using a biodistribution assay at 1, 4, 16, and 24 h after injection of the 99mTc-MAG3-Cet-F(ab′)2 tracer. Furthermore, 99mTc-MAG3-Cet-F(ab′)2 SPECT/CT was performed on MGC803 and HT29 tumor-bearing nude mice. Results HT29 cells had low EGFR expression while MGC803 cell exhibited the high EGFR expression. Cet-F(ab′)2 and intact cetuximab showed similar high binding ability to MGC803 cells but not to HT29 cells. Cet-F(ab′)2 and 99mTc-MAG3-Cet-F(ab′)2 showed excellent in vitro stability. The biodistribution assay showed that the target to nontarget ratio was the highest at 16 h (17.29 ± 5.72, n = 4) after tracer injection. The 99mTc-MAG3-Cet-F(ab′)2-based SPECT/CT imaging revealed rapid and sustained tracer uptake in MGC803 tumors rather than in HT29 tumors with high image contrast, which was consistent with the results in vitro. Conclusion SPECT/CT imaging using 99mTc-MAG3-Cet-F(ab′)2 enables the evaluation of the EGFR expression in murine EGFR-positive tumors, indicating the potential utility for noninvasive evaluation of the EGFR expression in tumors.

Synthesis, crystal structure, DFT and anticancer study of dihydroartermisinin-paracetamol hybrids

A pair of C-10 epimers of dihydroartermisinin-paracetamol hybrids (A and B) were prepared in this work, and both of which were characterized by MS, 1H NMR, 13C NMR, IR and ECD spectra as well as by a single crystal X-ray structural analysis. Subsequently, the structures of the two compounds were analyzed with DFT-based approaches. The analytical results on conformations indicated that the DFT-optimized molecular structures were consistent with the crystal structures confirmed by X-ray diffraction. The packing of the molecules in the solid state was stabilized by hydrogen bonds. The signs of the experimental IR and ECD spectra was also efficiently simulated by the DFT methods. A primary evaluation on anticancer effects of A and B was conducted towards human breast tumor cell line MCF-7 and human colon tumor cell line HCT116, the results demonstrated that 10-α-O-(4-acetylamino) phenyl dihydroartemisinin (A) was slightly less potent than its 10-β counterpart (B) in both tested cell lines.

Antiproliferative Activity of Stokesia laevis Ethanolic Extract in Combination with Several Food-Related Bioactive Compounds; In Vitro (Caco-2) and In Silico Docking (TNKS1 and TNKS2) Studies

This study evaluates in vitro cytotoxic and antiproliferative activity on human colon tumor cell line Caco-2 (ATCC-HTB-37) of a standardized (5 mg GAE/mL) ethanolic extract from Stokesia laevis (Slae26), of five polyphenols compounds (reference substances, ref.), namely luteolin-7-O-glucoside, luteolin-8-C-glucoside, caffeic acid, gentisic acid, and p-aminobenzoic acid (PABA), as well as of Slae26 combinations with the five reference substances, 1:1 mass rate (GAE, ref.). Cell viability studies (MTS test) have revealed IC50 values of 36 μg GAE/mL in the case of Slae26 ethanolic extract, while Slae26 combinations with the five phenolics indicated IC50 values around 5 μg GAE/mL. In silico docking studies on the molecular targets human tankyrase 1 (TNKS1) and human tankyrase 2 (TNKS2) in complex with their native ligands, Co-crystallized 3J5A and Co-crystallized FLN, indicated score values of −104.15 and −76.97, respectively; in the series of the reference compounds studied, luteolin-7-O-glucoside was revealed with the best score values on both molecular targets (−80.49 and −85.17), together signifying real antiproliferative potential against human colon cancer of Slae26, of luteolin-7-O-glucoside, and of Slae26 combinations with all food-related bioactive compounds tested.

Tumor-specific overexpression of histone gene, H3C14 in gastric cancer is mediated through EGFR-FOXC1 axis

Incorporation of different H3 histone isoforms/variants have been reported to differentially regulate gene expression via alteration in chromatin organization during diverse cellular processes. However, the differential expression of highly conserved histone H3.2 genes, H3C14 and H3C13 in human cancer has not been delineated. In this study, we investigated the expression of H3.2 genes in primary human gastric, brain, breast, colon, liver, and head and neck cancer tissues and tumor cell lines. The data showed overexpression of H3.2 transcripts in tumor samples and cell lines with respect to normal counterparts. Furthermore, TCGA data of individual and TCGA PANCAN cohort also showed significant up-regulation of H3.2 genes. Further, overexpressed H3C14 gene coding for H3.2 protein was regulated by FOXC1 transcription factor and G4-cassette in gastric cancer cell lines. Elevated expression of FOXC1 protein and transcripts were also observed in human gastric cancer samples and cell lines. Further, FOXC1 protein was predominantly localized in the nuclei of neoplastic gastric cells compared to normal counterpart. In continuation, studies with EGF induction, FOXC1 knockdown, and ChIP-qPCR for the first time identified a novel axis, EGFR-FOXC1-H3C14 for regulation of H3C14 gene overexpression in gastric cancer. Therefore, the changes the epigenomic landscape due to incorporation of differential expression H3 variant contributes to change in gene expression pattern and thereby contributing to pathogenesis of cancer.

Biogenic synthesis of silver nanoparticles using Paenibacillus sp. in-vitro and their antibacterial, anticancer activity assessment against human colon tumour cell line

Aim: To evaluate the antibacterial and anticancer activities of silver nanoparticles (AgNPs) synthesized from aqueous extract of Paenibacillus sp. strain NS-36. Methodology: The green synthesized AgNPs were characterized by UV-Vis. spectroscopy, Fourier Transform Infrared Spectroscopy, Atomic Force Microscopy, X-Ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, and Transmission Electron Microscopy. Antibacterial activity was assessed against pathogenic bacteria by using agar well diffusion method and the anticancer activity was evaluated against Human Colon Tumour-116 cell line using 96 well plate cell proliferation assay. Results: The synthesized AgNPs showed UV-Vis absorbance peak at 416 nm. The characterization analyses revealed the shape as spherical and size ranging from 17.49 to 52.85 nm and the presence of different functional groups and elements that involved in the stabilization and capping. The antibacterial activity revealed that AgNPs have good inhibitory action on pathogens, whereas the results of anticancerous assessment indicated that AgNPs have a dose-dependent activity on the Human Colon Tumour-116 cancer cells and the IC50 value was found to be 81.45 μg ml-1. Interpretation: The AgNPs exhibited considerable antibacterial activity against bacterial pathogens by rupturing and damaging the cell membrane. The AgNPs release silver ions into the cell once they attached to the cell membrane and disrupt the bacterial DNA replication. The AgNPs are toxic to tumour cells and induce intracellular reactive oxygen species which damage cells. Along with ROS, the rounding and shrinkage of tumour cells caused by AgNPs reduced the % viability of cancer cells. Key words: Antimicrobial activity, Cytotoxicity, Paenibacillus sp, Silver nanoparticles, Tumour cells

PLA-PEG nanospheres decorated with phage display selected peptides as biomarkers for detection of human colorectal adenocarcinoma.

Peptide-mediated targeting to colorectal cancer can increase selectivity and specificity of this cancer diagnosis acting as biomarkers. The present work aimed to select peptides using the phage display technique and associate the peptides with polymeric nanospheres in order to evaluate their cytotoxicity and selectivity during cell interaction with Caco-2 human colon tumor cell line. Two peptides identified by phage display (peptide-1 and peptide-2) were synthesized and exhibited purityhigher than 84%. Poly(lactic acid)-block-polyethylene glycol nanospheres were prepared by nanoprecipitation and double emulsion methods in order to load the two peptides. Nanoparticles ranged in size from 114 to 150nm and peptide encapsulation efficiency varied from 16 to 32%, depending on the methodology. No cytotoxic activity was observed towards Caco-2 tumor cell line, either free or loaded peptides in concentrations up to 3μM at incubation times of 6 and 24h, indicating safety as biomarkers. Fluorescein isothiocyanate-labeled peptides allowed evaluating selective interactions with Caco-2 cells, where peptide-1 entrapped in nanospheres showed greater intensity of co-localized cell fluorescence, in comparison to peptide-2. Peptide-1 loaded in nanospheres revealed promising to be investigated in further studies of selectivity with other human colon rectal cells as a potential biomarker.Graphical abstract.

MicroRNA-29b inhibits cell growth and promotes sensitivity to oxaliplatin in colon cancer by targeting FOLR1.

The present study was aimed to explore the functional role of microRNA (miR)-29b in colon cancer, as well as underlying mechanisms. Expressions of miR-29b and folate receptor 1 (FOLR1) were measured in both human colon tumor samples and cell lines. Colon cancer cell lines SW480 and SW620 were transfected with miR-29b mimic, antisense oligonucleotides (ASO)-miR-29b, small interfering (siRNA) against FOLR1 (si-FOLR1), or corresponding negative controls (NCs), and then were incubated with or without oxaliplatin (L-OHP). Thereafter, cell viability, cytotoxicity, cell apoptosis, and expression of FOLR1, ATP Binding Cassette Subfamily G Member 2 (ABCG2) and p-glycoprotein (p-gp) were analyzed. We found that miR-29b was significantly decreased, while FOLR1 was statistically elevated in colon cancer samples and cell lines compared to the nontumor samples and nontumourigenic immortalized human colon epithelial cell line FHC. Overexpression of miR-29b markedly inhibited cell viability, promoted sensitivity to L-OHP, stimulated cell apoptosis (all p < .05), and decreased the levels of ABCG2 and p-gp in cancer cells, whereas suppression of miR-29b showed contrary results. Moreover, we observed that FOLR1 was a direct target of miR-29b and was negatively regulated by miR-29b. In addition, the findings revealed that the effects of FOLR1 inhibition on cell viability, sensitivity to L-OHP, cell apoptosis, and the levels of ABCG2 and p-gp were similar to overexpression of miR-29b. Taken together, our study suggests that miR-29b inhibits cell growth and promotes sensitivity to L-OHP in colon cancer by targeting FOLR1.

Cyclocarioside O-Q, three novel seco-dammarane triterpenoid glycosides from the leaves of Cyclocarya paliurus

Three previously undescribed seco-dammarane triterpenoid glycosides O-Q (1-3) along with two known compounds (4 and 5) were isolated and characterized from the leaves of Cyclocarya paliurus. Their structures were determined by comprehensive analysis of 1 D, 2 D NMR and HRESIMS data. Compounds 1-5 were evaluated for their inhibitory effects against human pancreatic tumor (ASPC-1), human gastric carcinoma (SNU5), liver hepatocellular carcinoma (HEPG-2) and human colon tumor (HCT116) cell lines. Among them cyclocarioside P (2) showed somewhat inhibitory activity towards those tumor cells.

Screening and characterization of marine actinomycetes from the northern Oman Sea sediments for cytotoxic and antimicrobial activity.

A total of 168 actinomycete colonies were isolated from 14 sediment samples of the northern parts of the Oman Sea and were screened for cytotoxic and antimicrobial activity. Among four media and two treatments, the glucose arginine agar medium (18%) and heat treatment (28.3%) showed maximum isolation rate of actinomycetes. Preliminary characterization revealed that the members of Streptomycetaceae were widely distributed (66%) in the most of the sampling stations followed by Micromonosporaceae (14%), Nocardiaceae (6%), and Pseudonocardiaceae (4%), respectively. Approximately, 23.8% of the isolates inhibited the growth of at least one of the microbial test strains, while the majority of them belonged to the Streptomycetaceae family. Minimum inhibitory concentrations of the ethyl acetate culture extracts of the five most putative isolates varied from 64μg/mL against Micrococcus luteus and Candida albicans to 1mg/mL against Aspergillus niger. These extracts showed significant cytotoxic activity at18.74-193.5μg/mL on the human breast (MCF7), colon (HCT 116), and liver (HepG2) tumor cell lines while exhibited less or no cytotoxicity on the normal cell line (HUVEC). Interestingly, IFSRI 193 extract selectively inhibited the growth of HCT 116 cell line and gram-positive bacteria. 16S rRNA gene sequencing revealed that the potent isolates have 97 to 99% similarity with S. chartreusis, S. cacaoi, S. sampsonii, S. qinglanensis, and S. diastaticus. These results suggested that the five Streptomyces strains could be considered candidates for discovering the antitumor antibiotics.

Three New Isoflavonoid Glycosides from the Mangrove-Derived Actinomycete Micromonospora aurantiaca 110B.

The mangrove ecosystem is a rich resource for the discovery of actinomycetes with potential applications in pharmaceutical science. Besides the genus Streptomyces, Micromonospora is also a source of new bioactive agents. We screened Micromonospora from the rhizosphere soil of mangrove plants in Fujian province, China, and 51 strains were obtained. Among them, the extracts of 12 isolates inhibited the growth of human lung carcinoma A549 cells. Strain 110B exhibited better cytotoxic activity, and its bioactive constituents were investigated. Consequently, three new isoflavonoid glycosides, daidzein-4′-(2-deoxy-α-l-fucopyranoside) (1), daidzein-7-(2-deoxy-α-l-fucopyranoside) (2), and daidzein-4′,7-di-(2-deoxy-α-l-fucopyranoside) (3) were isolated from the fermentation broth of strain 110B. The structures of the new compounds were determined by spectroscopic methods, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESIMS). The result of medium-changing experiments implicated that these new compounds were microbial biotransformation products of strain M. aurantiaca 110B. The three compounds displayed moderate cytotoxic activity to the human lung carcinoma cell line A549, hepatocellular liver carcinoma cell line HepG2, and the human colon tumor cell line HCT116, whereas none of them showed antifungal or antibacterial activities.

Preparation of Sesquiterpene Lactone Derivatives: Cytotoxic Activity and Selectivity of Action.

Cancer is one of the most important causes of death worldwide. Solid tumors represent the great majority of cancers (>90%) and the chemotherapeutic agents used for their treatment are still characterized by variable efficacy and toxicity. Sesquiterpene lactones are a group of naturally occurring compounds that have displayed a diverse range of biological activities including cytotoxic activity. A series of oxygenated and oxy-nitrogenated derivatives (4–15) from the sesquiterpene lactones cumanin (1), helenalin (2), and hymenin (3) were synthesized. The silylated derivatives of helenalin, compounds 13 and 14, were found to be the most active against tumor cell lines, with GI50 values ranging from 0.15 to 0.59 μM. The ditriazolyl cumanin derivative (11) proved to be more active and selective than cumanin in the tested breast, cervix, lung, and colon tumor cell lines. This compound was the least toxic against splenocytes (CC50 = 524.1 µM) and exhibited the greatest selectivity on tumor cell lines. This compound showed a GI50 of 2.3 µM and a SI of 227.9 on WiDr human colon tumor cell lines. Thus, compound 11 can be considered for further studies and is a candidate for the development of new antitumor agents.

Antiproliferative Effect of Amaranth Proteins and Peptides on HT-29 Human Colon Tumor Cell Line.

Antiproliferative effect of Amaranthus mantegazzianus proteins and peptides released after simulated gastrointestinal digestion (DH% 37.8 ± 3.8) was investigated on human colon cancer cell line HT-29. Inhibition of proliferation of HT-29 cells was exhibited after a 24h treatment with different concentrations of amaranth protein isolate (API) and the peptides released after digestion (DGS), presenting IC50 values of 1.35 ± 0.12 and 0.30 ± 0.07mg soluble protein/mL, respectively. Lactate dehydrogenase assay indicated that both samples caused the loss of membrane integrity and cell lysis over HT-29 cells, and DAPI fluorescence microscopies evidenced typical apoptotic features. Moreover, Annexin V-FITC flow cytometry showed a significant increase of early apoptotic and late apoptotic/necrotic HT-29 cells compared to untreated ones, and caspase-3 assay confirmed the apoptosis induction with a 43.0 ± 10.3 and 65.8 ± 12.7% increase of caspase-3 activity produced by a 2mg/mL treatment of API and DGS, respectively. In conclusion, amaranth peptides successfully released after simulated gastrointestinal digestion would exert a potential antiproliferative activity over HT-29 tumor cells. This effect was linked to the induction of cell necrosis and apoptosis, supporting the idea of using amaranth proteins as a potential food alternative ingredient for functional foods.