Chemopreventive effects of a new benzo indole derivative against colon cancer / Fatemeh Hajiaghaalipour

Colorectal cancer is the third most common form of cancer in both genders in the world. A new synthetic compound, 2-(1,1-dimethyl-1H-benzo[e]indol-2-yl)-3-((2-hydroxyphenyl)amino)acrylaldehyde, abbreviated as DBID was screened its anti-proliferation effect against two colorectal cancer cell lines, and its possible mechanism of action was elucidated. In order to investigate the effect of the DBID compound on the azoxymethane-induced colonic aberrant crypt foci in rats, twenty-four adult male rats were injected subcutaneously with 15 mg/kg per body weight azoxymethane (AOM) once a week for two weeks and were then divided randomly into four groups in this experiment. The rats in cancer and treatments groups received two-month treatment with oral administration of 10% Tween 20 as the vehicle (cancer control), 20 and 40 mg/kg of DBID compound (treated groups), and intraperitoneal injection with 35 mg/kg 5-fluorouracil once a week in the reference control group. The normal control group with no AOM injections were orally administered with 10% Tween 20 for two months (non-cancer control or sham group). On the last day of the experiment, the animals were euthanized and the colon tissues were evaluated grossly and histopathologically for aberrant crypt foci (ACF). The colon tissue homogenate was also evaluated for antioxidant enzyme activities, gene and protein expression. The acute toxicity test and subacute toxicity were used to evaluate the safe usage of DBID compound. In vitro antioxidant activities of the compound were investigated. The DBID compound showed high antioxidant activity in ferric reducing antioxidant power (FRAP) and DPPH radical scavenging assays. It inhibited the proliferation of HCT 116 and HT-29 cells with an IC50 of 9.32, and 11.85 μg/ml and significantly increased the levels of caspase -8, -9 and -3/7 in the treated cells compared to untreated cells. Apoptosis features in HCT 116 and HT-29 cells were detected in treated cells by using flow cytometric analysis of Annexin V and AO/PI staining. The apoptotic changes in expression of caspase were confirmed by gene and protein quantification using RT-PCR and western blot analysis, respectively. The acute toxicity and subacute toxicity studies showed no nephrotoxic and no hepatotoxic effects or any serum biochemical changes in rats. Colon tissue evaluation showed that DBID compound diminished azoxymethane-induced aberrant crypt foci formation and pathological changes in the colonic mucosal tissues. Following treatment with the compound, antioxidant enzyme activity was increased compared to carcinogen groups. Moreover, the downregulation of Bcl2 and upregulation of Bax protein and caspase 3 were confirmed by RT-PCR and western blot. This study has shown that the DBID compound has demonstrated chemotherapeutic activity which was evidenced by significant increases in the expression and activation of caspase and exploits the apoptotic signaling pathways to trigger cancer cell death. There was significant inhibition of azoxymethane-induced colonic aberrant crypt foci formation by a new benzo indole derivative compound in rats that might be associated with its potent antioxidant activity and effective activity against free radicals involved in the formation of colorogenic lesions followed by alteration of the expression of apoptotic genes

Ethanolic extract of Brucea javanica inhibit proliferation of HCT-116 colon cancer cells via caspase activation

Brucea javanica (L.) Merr. is a well-known plant in Chinese System of Medicine. Its fruits and seeds have been reported to possess curative properties against various ailments. The chemical constituents and biological activity of this plant have been an interesting area in plant and chemistry medicine. The aim of this study is to evaluate the antiproliferative effects of the B. javanica extract against a colon cancer cell line and identification of the chemical components derived from the extract. An ethanolic extract from B. javanica fruits was prepared by cold maceration method, subjected to LC-MS profiling to elucidate the composition abbreviated as BJEE. The extract was screened for the cytotoxicity effects on HCT-116 colon cancer cells via MTT and LDH methods. Additionally, AO/PI staining verified apoptosis features in HCT-116 cells through microscopic analysis. ROS, caspase activity, and gene expression has been performed to identify its possible mechanism of actions which contribute to apoptosis. Output data from this study showed BJEE inhibited the cell proliferation of HCT-116 colon cancer cells at IC50 value of 8.9 ± 1.32 (μg mL-1) and significantly increased the levels of caspase-8, 9, and 3/7 in treated cells in comparison to untreated. The changes in expression of caspase genes and some apoptosis genes like Bax and Bcl-2 were confirmed using RT-PCR. Phytochemical analysis by LC-MS identified six major active compounds (bruceine D, isobrucein A, quassimarin, C16 sphinganine, phytosphingosine, and enigmol) in BJEE that may play a key role in cell apoptosis. The current study showed BJEE could be a promising agent for colorectal cancer therapy by significant increase in caspase activity level, and up-regulation of the specific apoptotic genes

The apoptotic effects of <em>Brucea javanica</em> fruit extract against HT29 cells associated with p53 upregulation and inhibition of NF-&kappa;B translocation

Background: Brucea javanica (L.) Merr. is a plant from the genus Brucea, which is used in local traditional medicine to treat various diseases. Recent studies revealed an impressive anticancer efficiency of B. javanica extract in different types of cancer cells. Purpose: In this study, we have investigated the cytotoxic effects of the B. javanica hexane, ethanolic extracts against colon cancer cells. HT29 colon cells were selected as an in vitro cancer model to evaluate the anticancer activity of B. javanica ethanolic extract (BJEE) and the possible mechanisms of action that induced apoptosis. Methods: 3-(4,5-dimethylthiazol-2-yl)-2, 5,-diphenyltetrazolium bromide (MTT), lactate dehydrogenase, acridine orange/propidium iodide, and annexin-V-fluorescein isothiocyanate assays were performed to determine the antiproliferative and apoptosis validation of BJEE on cancer cells. Measurement of reactive oxygen species (ROS) production, caspase activities, nucleus factor-κB activity, and gene expression experiments was done to investigate the potential mechanisms of action in the apoptotic process. Results: The results obtained from this study illustrated the significant antiproliferative effect of BJEE on colorectal cancer cells, with a concentration value that inhibits 50% of the cell growth of 25±3.1 µg/mL after 72 h of treatment. MTT assay demonstrated that the BJEE is selectively toxic to cancer cells, and BJEE induced cell apoptosis via activation of caspase-8 along with modulation of apoptosis-related proteins such as Fas, CD40, tumor necrosis factor-related apoptosis-inducing ligands, and tumor necrosis factor receptors, which confirmed the contribution of extrinsic pathway. Meanwhile, increased ROS production in treated cells subsequently activated caspase-9 production, which triggered the intrinsic pathways. In addition, overexpression of cytochrome-c, Bax, and Bad proteins along with suppression of Bcl-2 illustrated that mitochondrial-dependent pathway also contributed to BJEE-induced cell death. Consistent with the findings from this study, BJEE-induced cancer cell death proceeds via extrinsic and intrinsic mitochondrial-dependent and -independent events. Conclusion: From the evidence obtained from this study, it is concluded that the BJEE is a promising natural extract to combat colorectal cancer cells (HT29 cells) via induction of apoptosis through activation of extrinsic and intrinsic pathways

The Effect of Camellia sinensis on Wound Healing Potential in an Animal Model

Camellia sinensis (tea) is reported to have health benefits, including the building of healthy skin. This study evaluated the effects of topical application of Camellia sinensis extract on the rate of wound closure and the histology of wound area. A uniform area of 2.00 cm in diameter was excised from the neck of adult male Sprague Dawley rats. The animals were topically treated with 0.2 mL of vehicle (CMC), Intrasite gel (positive control), or 200 and 400 mg/mL of extract. Wounds dressed with the extract and Intrasite gel healed significantly earlier than those with vehicle. Histological analysis of the wound area after 10 days showed that wounds dressed with the extract had less scar width when compared to the control. The tissue contained less inflammatory cells and more collagen and angiogenesis, compared to wounds dressed with vehicle. In this study, Camellia sinensis showed high potential in wound healing activity

Molecular grafting can generate bioactivities within the cyclic peptide PDP-23

The stability of cyclic peptides, coupled with their structural diversity and ability to host an extensive range of bioactivities, make them promising leads for the development of new drugs. PawS-Derived Peptide-23 (PDP-23) is a head-to-tail macrocyclic peptide with two disulfide bonds produced in plant seeds. Its unusual fold comprises two -hairpins connected by hinges that allow the structure to adapt to different environments. In water two PDP-23 molecules form a compact intertwined dimer that buries hydrophobic residues, whereas in membrane mimicking conditions it adopts an open monomeric form that expose them. Here we investigate PDP-23 as a novel scaffold for the grafting of bioactive epitopes and conjugation of small molecules. To explore the plasticity of PDP-23 we introduced the bioactive loop of sunflower trypsin inhbitor-1 (SFTI-1) or an integrin binding RGD motif into either of the -hairpins. Solution NMR spectroscopy revealed that although the variants were unable to dimerise, the structural features of both the graft and scaffold were retained. SFTI-1 hybrid variants showed trypsin inhibitory activity. PDP-23 has previously been used as a cell permeable drug scaffold targeting drug-resistant cancer cells by inhibiting the drug efflux pump P-glycoprotein and restoring their sensitivity to chemotherapeutic. Introducing the RGD motif into such PDP-23 conjugates significantly improve their potency, suggesting that the RGD sequence targets the peptide to the membrane of cancer cells and improve cell uptake. In conclusion, this study highlights PDP-23 as a stable and versatile scaffold for molecular grafting of bioactivities and targeted delivery of pharmaceutical payloads

Solution NMR and racemic crystallography provide insights into a novel structural class of cyclic plant peptides

Head-to-tail cyclic and disulfide-rich peptides are natural products with applications in drug design. Among these are the PawS-Derived Peptides (PDPs) produced in seeds of the daisy plant family. PDP-23 is a unique member of this class in that it is twice the typical size and adopts two beta-hairpins separated by a hinge region. The beta-hairpins, both stabilised by a single disulfide bond, fold together into a V-shaped tertiary structure creating a hydrophobic core. In water two PDP-23 molecules merge their hydrophobic cores to form a square prism quaternary structure. Here, we synthesised PDP-23 and its enantiomer comprising d-amino acids and achiral glycine, which allowed us to confirm these solution NMR structural data by racemic crystallography. Furthermore, we discovered the related PDP-24. NMR analysis showed that PDP-24 does not form a dimeric structure and it has poor water solubility, but in less polar solvents adopts near identical secondary and tertiary structure to PDP-23. The natural role of these peptides in plants remains enigmatic, as we did not observe any antimicrobial or insecticidal activity. However, the plasticity of these larger PDPs and their ability to change structure under different conditions make them appealing peptide drug scaffolds