Exploring the Apoptotic-Induced Biochemical Mechanism of Traditional Thai Herb (Kerra™) Extract in HCT116 Cells Using a Label-Free Proteomics Approach.

Background and Objectives: Natural products have proven to be a valuable source for the discovery of new candidate drugs for cancer treatment. This study aims to investigate the potential therapeutic effects of "Kerra™", a natural extract derived from a mixture of nine medicinal plants mentioned in the ancient Thai scripture named the Takxila Scripture, on HCT116 cells. Materials and Methods: In this study, the effect of the Kerra™ extract on cancer cells was assessed through cell viability assays. Apoptotic activity was evaluated by examining the apoptosis characteristic features. A proteomics analysis was conducted to identify proteins and pathways associated with the extract's mechanism of action. The expression levels of apoptotic protein markers were measured to validate the extract's efficacy. Results: The Kerra™ extract demonstrated a dose-dependent inhibitory effect on the cells, with higher concentrations leading to decreased cell viability. Treatment with the extract for 72 h induced characteristic features of early and late apoptosis, as well as cell death. An LC-MS/MS analysis identified a total of 3406 proteins. The pathway analysis revealed that the Kerra™ extract stimulated apoptosis and cell death in colorectal cancer cell lines and suppressed cell proliferation in adenocarcinoma cell lines through the EIF2 signaling pathway. Upstream regulatory proteins, including cyclin-dependent kinase inhibitor 1A (CDKN1A) and MYC proto-oncogene, bHLH transcription factor (MYC), were identified. The expressions of caspase-8 and caspase-9 were significantly elevated by the Kerra™ extract compared to the chemotherapy drug Doxorubicin (Dox). Conclusions: These findings provide strong evidence for the ability of the Kerra™ extract to induce apoptosis in HCT116 colon cancer cells. The extract's efficacy was demonstrated by its dose-dependent inhibitory effect, induction of apoptotic activity, and modulation of key proteins involved in cell death and proliferation pathways. This study highlights the potential of Kerra™ as a promising therapeutic agent in cancer treatment.

Molecular Networking-Guided Isolation of New Etzionin-Type Diketopiperazine Hydroxamates from the Persian Gulf Sponge Cliona celata.

The Persian Gulf is a unique and biologically diverse marine environment dominated by invertebrates. In continuation of our research interest in the chemistry and biological activity of marine sponges from the Persian Gulf, we selected the excavating sponge Cliona celata for detailed metabolome analyses, in vitro bioactivity screening, and chemical isolation studies. A UPLC-MS/MS (MS2) molecular-networking-based dereplication strategy allowed annotation and structural prediction of various diketopiperazines (DKPs) and etzionin-type diketopiperazine hydroxamates (DKPHs) in the crude sponge extract. The molecular-networking-guided isolation approach applied to the crude extract afforded the DKPH etzionin (1) and its two new derivatives, clioetzionin A (2) and clioetzionin B (3). Another new modified DKP (4) was identified by MS/MS analyses but could not be isolated in sufficient quantities to confirm its structure. The chemical characterization of the purified DKPHs 1-3 was performed by a combination of 1D and 2D NMR spectroscopy, HRMS, HRMS/MS, and [α]D analyses. Compounds 1 and 2 exhibited broad antibacterial, antifungal, and anticancer activities, with IC50 values ranging from 19.6 to 159.1 µM. This is the first study investigating the chemical constituents of a C. celata specimen from the Persian Gulf. It is also the first report of full spectroscopic data of etzionin based on extensive spectroscopic analyses.

Berberine inhibits cancer cells growth by suppressing fatty acid synthesis and biogenesis of extracellular vesicles.

AIMS: Berberine is an isoquinoline alkaloid extracted from the root, rhizome and stem bark of Coptidis Rhizoma. Previous studies have revealed the anti-tumor potential of berberine against various types of cancer cells. However, the underlying mechanisms are not yet fully understood. In this study, we focused on the effects of berberine on fatty acid synthesis and extracellular vesicles formation in cancer cells, and revealed the internal mechanism of berberine inhibition on cancer cell proliferation. MATERIALS AND METHODS: Anti-proliferative activity of berberine was determined by cell counting and microscope observation and cell cycle analysis. Activities of AMPK and ACC, expression of extracellular vesicles markers were detected by western blotting. 13C labeling metabolic flux analysis was used for determination of de novo synthesis of fatty acids. The excreted extracellular vesicles in culture mediums were separated by both polyethylene glycol enrichment of extracellular vesicles and differential centrifugation separation. KEY FINDINGS: Among our early experiments, 5-10 µmol/L berberine exhibited the substantial anti-proliferative effect against human colon cancer cell line HCT116, cervical cancer cell line HeLa and other cancer cells. It was also revealed that, through activating AMPK, berberine inhibited ACC activity then suppressed intracellular fatty acid synthesis, finally decreased the biogenesis of extracellular vesicles. Moreover, supplement with citrate acid, palmitic acid, as well as exogenous extracellular vesicles, could rescue the inhibitory effect of berberine on cell proliferation, suggesting that inhibited ACC activity, suppressed fatty acid synthesis and decreased extracellular vesicles production were important mechanisms account for berberine inhibiting cancer cell proliferation. SIGNIFICANCE: Our study indicates that berberine suppresses cancer cell proliferation through inhibiting the synthesis of fatty acids and decreasing biogenesis and secretion of extracellular vesicles, suggests that berberine is a promising candidate for the development of new therapies for cancer.

Identification of a new benzophenone from Psidium guajava L. leaves and its antineoplastic effects on human colon cancer cells.

Psidium guajava L. leaves have a long history of being consumed as herbal teas in many countries. The aim of this study was to identify compounds with anticancer potentials from Psidium guajava L. leaves. Utilizing various extraction and chromatographical techniques, we have isolated one new (2) and two known compounds (1, 3). Structural analyses by the spectroscopic methods of TOF-MS, 1H NMR, 13C NMR, HSQC, and HMBC identified these three compounds as guavinoside E (1), 3,5-dihydroxy-2,4-dimethyl-1-O-(6'-O-galloyl-ß-d-glucopyranosyl)-benzophenone (2), and guavinoside B (3). Cell viability assays showed that compounds 2 and 3 inhibited the growth of HCT116 human colon cancer cells in a dose-dependent manner, where compound 2 was more potent than compound 3. Based on flow cytometry analysis, compound 2 showed stronger activity in inducing cellular apoptosis in cancer cells than compound 3. Furthermore, compounds 2 and 3 modulated expression levels of key proteins involved in cell proliferation and apoptotic signaling. Specifically, compound 2 increased the levels of p53, p-ERK1/2, p-JNK, and cleaved caspases 8 and 9, and compound 3 increased the levels of p53 and cleaved caspase 8. Overall, this study provided identities of three bioactive compounds from P. guajava L. leaves and their anti-cancer effects against human colon cancer cells, which could facilitate the utilization of these compounds and P. guajava L. leaves as potential chemoprevention agents against colon carcinogenesis.

Cytotoxic activity of extract and active fraction of Turbinaria decurrens Bory on colon cancer cell line HCT-116 / Actividad citotóxica del extracto y la fracción activa de Turbinaria decurrens Bory en la línea celular de cáncer de colon HCT-116

Turbinaria deccurrens Bory contains bioactive compound that is beneficial for health. Turbinaria deccurrens Bory is one of many species of brown seaweed that grows in Indonesian marine life and has been known to have cytotoxic activity. The aim of this study is to determine fucoxantin content and the cytotoxic activity of extract and fraction T. decurrens on colon cancer cell lines. Cytotoxic assay of ethanolic extract, n-hexane, ethyl acetate and ethanolic fractions against HCT-116 by MTS assay using Cell Counting Kit-8 (CCK-8). Fucoxantin content in extract and fraction were analyzed using Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) analysis. Extract and fraction of T. decurrens contain fucoxanthin with the highest content of fucoxanthin was in ethyl acetate fraction. CCK-8 assay showed that extract, n-hexane and ethyl acetate fraction inhibited the growth of HCT-116. Brown seaweed Turbinaria decurrens was potential as an anticolon cancer agent.

Turbinaria deccurrens Bory contiene compuestos bioactivos que son beneficiosos para la salud. Turbinaria deccurrens Bory es una de muchas especies de algas pardas que crecen en aguas marinas de Indonesia y se ha estudiado su actividad citotóxica. El objetivo de este estudio fue determinar el contenido de fucoxantina y la actividad citotóxica del extracto y la fracción de T. decurrens en líneas celulares de cáncer de colon. Se llevó a cabo un ensayo citotóxico de extracto etanólico, nhexano, acetato de etilo y fracciones etanólicas contra HCT-116 mediante ensayo MTS utilizando Cell Counting Kit-8 (CCK-8). El contenido de fucoxantina en el extracto y la fracción se analizaron usando cromatografía líquida de alta resolución de fase reversa (RP-HPLC). El extracto y la fracción de T. decurrens contienen fucoxantina conmayor contenido de fucoxantina en la fracción de acetato de etilo. El ensayo CCK-8 mostró que la fracción de extracto, n-hexano y acetato de etilo inhibía el crecimiento de HCT-116. El alga marrón Turbinaria decurrens es un agente potencial contra el cáncer de colon.

In vitro antibacterial activity of poly (amidoamine)-G7 dendrimer.

BACKGROUND: Nano-scale dendrimers are synthetic macromolecules that frequently used in medical and health field. Traditional anibiotics are induce bacterial resistence so there is an urgent need for novel antibacterial drug invention. In the present study seventh generation poly (amidoamine) (PAMAM-G7) dendrimer was synthesized and its antibacterial activities were evaluated against representative Gram- negative and Gram-positive bacteria. METHODS: PAMAM-G7 was synthesized with divergent growth method. The structural and surface of PAMAM-G7 were investigated by transmission electron microscopy, scanning electron microscope and fourier transform infrared. Pseudomonas. aeruginosa (n = 15), E. coli (n = 15), Acinetobacter baumanni (n = 15), Shigella dysenteriae (n = 15), Klebsiella pneumoniae (n = 10), Proteus mirabilis (n = 15), Staphylococcus aureus (n = 15) and Bacillus subtilis (n = 10) have been used for antibacterial activity assay. Additionally, representative standard strains for each bacterium were included. Minimum Inhibitory Concentration (MIC) was determined using microdilution method. Subsequently, Minimum Bactericidal Concentration (MBC) was determined by sub-culturing each of the no growth wells onto Mueller Hinton agar medium. The cytotoxicity of PAMAM-G7 dendrimer were evaluated in HCT116 and NIH 3 T3 cells by MTT assay. RESULTS: The average size of each particle was approximately 20 nm. PAMAM-G7 was potentially to inhibit both Gram positive and gram negative growth. The MIC50 and MIC90 values were determined to be 2-4 µg/ml and 4-8 µg/ml, respectively. The MBC50 and MBC90 values were found to be 64-256 µg/ml and 128-256 µg/ml, respectively. The cytotoxity effect of dendrimer on HCT116 and NIH 3 T3 cells is dependent upon exposure time to and concentration of dendrimers. The most reduction (44.63 and 43%) in cell viability for HCT116 and NIH 3 T3 cells was observed at the highest concentration, 0.85 µM after 72 h treatmentm, respectively. CONCLUSIONS: This study we conclude that PAMAM-G7 dendrimer could be a potential candidate as a novel antibacterial agent.

Phenethyl isothiocyanate suppresses cancer stem cell properties in vitro and in a xenograft model.

BACKGROUND: Cancer stem cells (CSCs) are a subset of cells within the bulk of a tumor that have the ability to self-renew and differentiate, and are thus associated with cancer invasion, metastasis, and recurrence. Phenethyl isothiocyanate (PEITC) is a natural compound found in cruciferous vegetables such as broccoli and is used as a cancer chemopreventive agent; however, its effects on CSCs are little known. PURPOSE: To evaluate the effect of PEITC on CSCs in this study by examining CSC properties. METHODS: NCCIT human embryonic carcinoma cells were treated with PEITC, and the expression of pluripotency factors Oct4, Sox-2, and Nanog were evaluated by luciferase assay and western blot. Effect of PEITC on self-renewal capacity and clonogenicity were assessed with the sphere formation, soft agar assay, and clonogenic assay in an epithelial cell adhesion molecule (EpCAM)-expressing CSC model derived from HCT116 colon cancer cells using a cell sorting system. The effect of PEITC was also investigated in a mouse xenograft model obtained by injecting nude mice with EpCAM-expressing cells. RESULTS: We found that PEITC treatment suppressed expression of the all three pluripotency factors in the NCCIT cells, in which pluripotency factors are highly expressed. Moreover, PEITC suppressed the self-renewal capacity and clonogenicity in the EpCAM-expressing CSC model. EpCAM was used as a specific CSC marker in this study. Importantly, PEITC markedly suppressed both tumor growth and expression of three pluripotency factors in a mouse xenograft model. CONCLUSION: These results demonstrate that PEITC might be able to slow down or prevent cancer recurrence by suppressing CSC stemness.

Inhibition of human colorectal cancer metastasis by notoginsenoside R1, an important compound from Panax notoginseng.

Panax notoginseng (P. notoginseng) and its components are used as traditional Chinese medicine for cardiovascular disease, although studies concerning the anti-metastatic properties of these compounds are limited. The goal of this study was to investigate the effects of notoginsenoside R1 (NGR1), an important compound derived from P. notoginseng, on the metastasis of human colorectal cancer (CRC). The migratory, invasive, and adhesive abilities of cultured human CRC cells (HCT-116) treated with NGR1 and expression of metastasis­associated regulatory molecules were assessed. The migratory and invasive abilities of the HCT-116 cells were reduced after treatment with 75, 150 or 300 µM NGR1 for 24 h. When HCT-116 cells were incubated with 150 or 300 µM NGR1 for 24 h, matrix metalloproteinase (MMP)-9 expression was reduced compared with that of the control group. In the adhesion reaction assays, treatment with 150 or 300 µM NGR1 led to significantly decreased adhesion of the HCT-116 cells to endothelial cells (EA.hy926 cells). Levels of integrin-1 protein were significantly decreased in the HCT-116 cells following treatment with 75, 150 or 300 µM NGR1, and levels of E-selectin and intercellular adhesion molecule 1 (ICAM-1) proteins were significantly decreased in the EA.hy926 cells treated with 75, 150 or 300 µM NGR1. Scanning electron microscopy examination indicated that HCT-116 cells treated with lipopolysaccharide (LPS) combined with 300 µM NGR1 exhibited a less flattened and retracted shape compared with cells treated with LPS alone, and this change in shape is characteristic of extravasation. Additionally, the transepithelial electrical resistance of the EA.hy926 endothelial cell monolayer increased after incubation with 150 or 300 µM NGR1 for 24 h. Overall, these results demonstrated the anti-metastatic properties of 150 or 300 µM NGR1, a compound that affects CRC metastasis by inhibiting cell migration, invasion, and adhesion and by regulating expression of metastasis-associated signalling molecules.

Dietary peptides from the non-digestible fraction of Phaseolus vulgaris L. decrease angiotensin II-dependent proliferation in HCT116 human colorectal cancer cells through the blockade of the renin-angiotensin system.

This study aimed to determine the ability of peptides present in the non-digestible fraction (NDF) of common beans to decrease angiotensin II (AngII) through the blockade of RAS and its effect on the proliferation of HCT116 human colorectal cancer cells. Pure synthesized peptides GLTSK and GEGSGA and the peptide fractions (PF) of cultivars Azufrado Higuera and Bayo Madero were used. The cells were pretreated with pure peptides, PF or AGT at their IC50 or IC25 values, in comparison with the simultaneous treatment of peptides and AGT. For western blot and microscopy analysis, 100 µM and 0.5 mg mL(-1) were used for pure peptides and PF treatments, respectively. According to the ELISA tests, GLTSK and GEGSGA decreased (p < 0.05) the conversion rate of AGT to angiotensin I (AngI) by 38 and 28%, respectively. All the peptides tested reduced (p < 0.05) the conversion rate of AngI to AngII from 38 to 50%. When the cells were pretreated with both pure peptides and PF before exposure to AGT, the effectiveness inhibiting cell proliferation was higher than the simultaneous treatment suggesting their preventive effects. GLTSK and GEGSGA interacted with the catalytic site of renin, the angiotensin-I converting enzyme, and the AngII receptor, mainly through hydrogen bonds, polar, hydrophobic and cation-π interactions according to molecular docking. Through confocal microscopy, it was determined that GLTSK and GEGSGA caused the decrease (p < 0.05) of AngII-dependent STAT3 nuclear activation in HCT116 cells by 66 and 23%, respectively. The results suggest that peptides present in the common bean NDF could potentially ameliorate the effects of RAS overexpression in colorectal cancer.

Ethanolic Extract of Bark from Salix aegyptiaca Ameliorates 1,2-dimethylhydrazine-induced Colon Carcinogenesis in Mice by Reducing Oxidative Stress.

We have previously shown that ethanolic extract from bark (EEB) of Salix aegyptiaca (Musk Willow) can inhibit proliferation and motility and induce apoptosis in colon cancer cells. Tandem mass spectrometry revealed EEB to be rich in catechin, catechol, and salicin. The present study investigated the chemopreventive effect of HPLC-fingerprinted EEB on 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) formation in mice. DMH (20 mg/kg body weight) was weekly injected subcutaneously to mice for the first 2 weeks. EEB (100 and 400 mg/kg body weight) was provided orally from the 7th to 14th week, after which colon tissues were evaluated histologically and biochemically. DMH treatment induced high number of ACF; EEB significantly reduced the number and multiplicity of ACF, along with a restoration in goblet cells and mucin accumulation. EEB supplementation improved the markers of inflammation (myeloperoxidase and neutrophil infiltration) and oxidative stress. More importantly, EEB amplified apoptosis of neoplastic cells in the colon mucosa of DMH-treated mice. It also lowered levels of markers for early transformation events such as EGFR, nuclear ß-catenin, and COX-2 in colon cancer cell lines HT-29 and HCT-116. The innocuity of EEB (up to 1600 mg/kg) to mice reinforces its potential as a chemopreventive agent.

Study of Malformin C, a Fungal Source Cyclic Pentapeptide, as an Anti-Cancer Drug.

Malformin C, a fungal cyclic pentapeptide, has been claimed to have anti-cancer potential, but no in vivo study was available to substantiate this property. Therefore, we conducted in vitro and in vivo experiments to investigate its anti-cancer effects and toxicity. Our studies showed Malformin C inhibited Colon 38 and HCT 116 cell growth dose-dependently with an IC50 of 0.27±0.07µM and 0.18±0.023µM respectively. This inhibition was explicated by Malformin C's effect on G2/M arrest. Moreover, we observed up-regulated expression of phospho-histone H2A.X, p53, cleaved CASPASE 3 and LC3 after Malformin C treatment, while the apoptosis assay indicated an increased population of necrotic and late apoptotic cells. In vivo, the pathological study exhibited the acute toxicity of Malformin C at lethal dosage in BDF1 mice might be caused by an acute yet subtle inflammatory response, consistent with elevated IL-6 in the plasma cytokine assay. Further anti-tumor and toxicity experiments proved that 0.3mg/kg injected weekly was the best therapeutic dosage of Malformin C in Colon 38 xenografted BDF1 mice, whereas 0.1mg/kg every other day showed no effect with higher resistance, and 0.9mg/kg per week either led to fatal toxicity in seven-week old mice or displayed no advantage over 0.3mg/kg group in nine-week old mice. Overall, we conclude that Malformin C arrests Colon 38 cells in G2/M phase and induces multiple forms of cell death through necrosis, apoptosis and autophagy. Malformin C has potent cell growth inhibition activity, but the therapeutic index is too low to be an anti-cancer drug.

Fermented So-Cheong-Ryong-Tang (FCY) induces apoptosis via the activation of caspases and the regulation of MAPK signaling pathways in cancer cells.

BACKGROUND: So-Cheong-Ryong-Tang (CY), a traditional herbal formula, mainly has been shown to possess allergic rhinitis and asthma for hundreds of years in Asian countries. Although this medicine has been attracted Asian scientists with investigating mechanisms of action against inflammatory-related diseases, there is a little available information on the anti-cancer effect of CY, especially on the fermented form (FCY). In this study, we explored the chemopreventive/chemotherapeutic efficacy of FCY against cancer cells and proved the efficacy of FCY through performing in vivo xenograft assay. METHODS: CY was fermented with bacteria and lyophilized. For analysis of the constituents of CY and FCY, high performance liquid chromatography (HPLC)-DAD system was performed. To detect the anti-cancer effect of FCY, cell viability assay, caspase activity assay, cell cycle analysis, and Western blot analysis were performed in AGS human gastric cancer cells. The inhibitory effects of tumor growth by CY and FCY were evaluated in athymic nude mice inoculated with HCT116 human colon cancer cells. RESULTS: As a result of analyzing the 11components present in CY and FCY, the contents of ephedrine HCl, glycyrrhizin, gingerol, schisandrin, and gomisin A were respectively increased by fermentation in FCY. The treatment of CY or FCY inhibited the viability of AGS cells, interestingly, the inhibition of cancer cell growth was enhanced by fermentation of CY. FCY induced the apoptosis through activating the caspase-3, -8, and -9. Additionally, FCY regulated the activation of mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase (ERK), p38, and c-Jun NH2-terminal kinase (JNK). In vivo xenografts, administration of FCY significantly inhibited the tumor formation, and improved the anti-tumor effect compared to that of CY in athymic nude mice. CONCLUSIONS: FCY indicated significant anti-cancer effects, and its efficacy against tumor formation was improved than that of CY, therefore, FCY might be used for applications of traditional medicine against cancer in modern complementary and alternative therapeutics. Graphical Abstract ᅟ.

Lipoic acid inhibits the DNA repair protein O 6-methylguanine-DNA methyltransferase (MGMT) and triggers its depletion in colorectal cancer cells with concomitant autophagy induction.

Alkylating agents are present in food and tobacco smoke, but are also used in cancer chemotherapy, inducing the DNA lesion O (6)-methylguanine. This critical adduct is repaired by O (6)-methylguanine-DNA methyltransferase (MGMT), resulting in MGMT inactivation and degradation. In the present study, we analyzed the effects of the natural disulfide compound lipoic acid (LA) on MGMT in vitro and in colorectal cancer cells. We show that LA, but not its reduced form dihydrolipoic acid, potently inhibits the activity of recombinant MGMT by interfering with its catalytic Cys-145 residue, which was partially reversible by N-acetyl cysteine. Incubation of HCT116 colorectal cancer cells with LA altered their glutathione pool and caused a decline in MGMT activity. This was mirrored by LA-induced depletion of MGMT protein, which was not attributable to changes in MGMT messenger RNA levels. Loss of MGMT protein coincided with LA-induced autophagy, a process resulting in lysosomal degradation of proteins, including presumably MGMT. LA-stimulated autophagy in a p53-independent manner as revealed by the response of isogenic HCT116 cell lines. Knockdown of the crucial autophagy component beclin-1 and chemical inhibitors blocked LA-induced autophagy, but did not abrogate LA-triggered MGMT degradation. Concomitant with MGMT depletion, LA pretreatment resulted in enhanced O (6)-methylguanine levels in DNA. It also increased the cytotoxicity of the alkylating anticancer drug temozolomide in temozolomide-resistant colorectal cancer cells. Taken together, our study showed that the natural compound LA inhibits MGMT and induces autophagy. Furthermore, LA enhanced the cytotoxic effects of temozolomide, which makes it a candidate for a supplement in cancer therapy.

Synthesis, antimicrobial, anticancer evaluation and QSAR studies of 3/4-bromo benzohydrazide derivatives.

A series 3/4-bromo-N'-(substituted benzylidene/furan-2-ylmethylene/5-oxopentylidene/3- phenylallylidene)benzohydrazides (1-23) was synthesized and characterized by physicochemical and spectral means. The synthesized compounds were screened for their antimicrobial and anticancer potentials. Antimicrobial activity results indicated that compound 12 (pMICam = 1.67 µM/ml) was the most potent antimicrobial agent. The synthesized benzohydrazides were also having good anticancer potential and compound 22 (IC50 = 1.20 µM µM) was found to be the most potent anticancer agent which was more potent than standard drugs, tetrandrine (IC50 = 1.53) and 5- fluorouracil (IC50 = 4.6 µM). QSAR studies indicated that antimicrobial activity of synthesized compounds was best described by electronic parameter, total energy (Te) and topological parameters, valance zero order molecular connectivity index ((0)χ(v)) and Wiener index (W).

Synthesis, antimicrobial, anticancer evaluation of 2-(aryl)-4- thiazolidinone derivatives and their QSAR studies.

A new class of 4-thiazolidinones clubbed with quinozolinone nucleus has been synthesized. The title compounds were screened for their in vitro antimicrobial and anticancer potentials. Results of antimicrobial and anticancer study revealed that compounds 7 (pMICam = 1.69 µM/ml) and 2 (IC50 = 12.83 µM) were found to be the most potent antimicrobial and anticancer agents respectively. QSAR studies indicated that antimicrobial activity of synthesized 4-thiazolidinone derivatives was governed by the electronic parameters, dipole moment (µ), energy of highest occupied molecular orbital (HOMO), lipophilic parameter, log P and topological parameter, valence third order molecular connectivity index ((3)χ(v)).

HIF-prolyl hydroxylase is a potential molecular target for esculetin-mediated anti-colitic effects.

We investigated a potential molecular target for anti-colitic effects of esculetin, 6,7-dihydroxycoumarin. Esculetin administered rectally effectively ameliorated TNBS-induced rat colitis and attenuated the expression of pro-inflammatory mediators in the inflamed colon. In human colon carcinoma HCT116 cells, esculetin induced hypoxia-inducible factor-1α (HIF-1α), leading to secretion of vascular endothelial growth factor, a HIF-1 target gene product involved in ulcer healing of the gastrointestinal mucosa. Esculetin directly inhibited HIF prolyl hydroxylase-2 (HPH-2), an enzyme playing a major role in negatively regulating HIF-1α protein stability. Esculetin inhibition of HPH and consequent induction of HIF-1α were attenuated by escalating dose of either ascorbate or 2-ketoglutarate, the required factors of the enzyme. Structurally, the catechol moiety in esculetin was required for HPH inhibition. Collectively, HPH may be a molecular target for esculetin-mediated anti-colitic effects and the catechol moiety in esculetin is the pharmacophore for HPH inhibition.

Antioxidant activity and cytotoxicity on tumour cells of the essential oil from Cedronella canariensis var. canariensis (L.) Webb & Berthel. (Lamiaceae).

Cedronella canariensis is a lemon-scented species of the family Lamiaceae endemic to the Canary Islands where it is used in the traditional medicine to prepare infusions or inhalations for anti-catarrhal, tonic, diuretic, hypoglycaemiant, hypotensive, anti-inflammatory and decongestant of the respiratory tract. In this work we investigated for the first time the antioxidant activity of the essential oil and its inhibitory effects on tumour cells (A375, MDA-MB-231, HCT 116) proliferation by DPPH, ABTS, FRAP and MTT assays, respectively. The oil, analysed by GC-ionisation flame detector and GC-MS, was characterised by pinocarvone (58.0%) and ß-pinene (10.8%) as the major constituents, being typical of the chemotype 'canariensis'. Noteworthy was the cytotoxic activity of the oil against the tumour cells examined, with IC50 values of 4.3, 7.3 and 11.4 µg/mL on A375, MDA-MB-231 and HCT 116 tumour cells, respectively, as well as the scavenging activity against the ABTS radical (IC50 of 10.5 µg/mL).

The eucalyptus oil ingredient 1,8-cineol induces oxidative DNA damage.

The natural compound 1,8-cineol, also known as eucalyptol, is a major constituent of eucalyptus oil. This epoxy-monoterpene is used as flavor and fragrance in consumer goods as well as medical therapies. Due to its anti-inflammatory properties, 1,8-cineol is also applied to treat upper and lower airway diseases. Despite its widespread use, only little is known about the genotoxicity of 1,8-cineol in mammalian cells. This study investigates the genotoxicity and cytotoxicity of 1,8-cineol in human and hamster cells. First, we observed a significant and concentration-dependent increase in oxidative DNA damage in human colon cancer cells, as detected by the Formamidopyrimidine-DNA glycosylase (Fpg)-modified alkaline comet assay. Pre-treatment of cells with the antioxidant N-acetylcysteine prevented the formation of Fpg-sensitive sites after 1,8-cineol treatment, supporting the notion that 1,8-cineol induces oxidative DNA damage. In the dose range of DNA damage induction, 1,8-cineol did neither reduce the viability of colon cancer cells nor affected their cell cycle distribution, suggesting that cells tolerate 1,8-cineol-induced oxidative DNA damage by engaging DNA repair. To test this hypothesis, hamster cell lines with defects in BRCA2 and Rad51, which are essentials players of homologous recombination (HR)-mediated repair, were treated with 1,8-cineol. The monoterpene induced oxidative DNA damage and subsequent DNA double-strand breaks in the hamster cell lines tested. Intriguingly, we detected a significant concentration-dependent decrease in viability of the HR-defective cells, whereas the corresponding wild-type cell lines with functional HR were not affected. Based on these findings, we conclude that 1,8-cineol is weakly genotoxic, inducing primarily oxidative DNA damage, which is most likely tolerated in DNA repair proficient cells without resulting in cell cycle arrest and cell death. However, cells with deficiency in HR were compromised after 1,8-cineol treatment, suggesting a protective role of HR in response to high doses of 1,8-cineol.

Impact of Phytolacca americana extracts on gene expression of colon cancer cells.

Native Americans have used Phytolacca americana to treat breast ailments, gastrointestinal disorders, rashes, and inflammation. Some anti-cancer and anti-viral research has been reported on this perennial herb, but none has been published concerning the effects of its extracts on cancer cell genes. In this study, changes in gene expression at the transcription level were evaluated in HCT-116 colon cancer cells after exposure to P. americana ethanol extract and its water fraction using the Human Cancer Pathway Finder PCR Array. Of the genes significantly affected in HCT-116 cells exposed to the ethanol extract at 3200 µg/ml, changes in expression of MYC, PLAU, and TEK may benefit the treatment of colon cancer. Exposing the cells to 1600 µg/ml of the water fraction resulted in several gene changes that may also be beneficial in the treatment of colon cancer: NME4, TEK, and THBS1. A few genes on this array that are known to play a specific role in colon cancer had activities changed in a way that may be detrimental in the treatment of colon cancer. Further studies should be performed to understand how these changes would impact colon cancer treatment.

Three new xanthones from the resin of Garcinia hanburyi.

Three new xanthones, 22,23-dihydroxydihydrogambogenic acid (1), 12-hydroxygambogefic acid A (2), and hanburixanthone (3), along with thirteen known compounds were isolated from the resin of Garcinia hanburyi. The structures of the new compounds were determined by detailed analysis of 1D and 2D NMR spectra and by comparison with related model compounds. All compounds were tested for their cytotoxicities against A549, HCT116, and MDA-MB-231, and most of them showed significant effects on the cell lines.