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Iodination improves the phototoxicity of an amphiphilic porphyrin

Topkaya D, Ng SY, Bretonnière Y, Lafont D, Chung LY, Lee HB, et al.

Photodiagnosis Photodyn Ther, 2016 Dec;16:12-14.
PMID: 27475243 DOI: 10.1016/j.pdpdt.2016.07.008
Matched MeSH terms: Drug Synergism
Anti-plaque effect of a synergistic combination of green tea and Salvadora persica L. against primary colonizers of dental plaque

Abdulbaqi HR, Himratul-Aznita WH, Baharuddin NA

Arch Oral Biol, 2016 Oct;70:117-124.
PMID: 27343694 DOI: 10.1016/j.archoralbio.2016.06.011

OBJECTIVE: Green tea (Gt), leafs of Camellia sinensis var. assamica, is widely consumed as healthy beverage since thousands of years in Asian countries. Chewing sticks (miswak) of Salvadora persica L. (Sp) are traditionally used as natural brush to ensure oral health in developing countries. Both Gt and Sp extracts were reported to have anti-bacterial activity against many dental plaque bacteria. However, their combination has never been tested to have anti-bacterial and anti-adherence effect against primary dental plaque colonizers, playing an initial role in the dental plaque development, which was investigated in this study.
METHODS: Two-fold serial micro-dilution method was used to measure minimal inhibitory concentration (MIC) of aqueous extracts of Gt, Sp and their combinations. Adsorption to hexadecane was used to determine the cell surface hydrophobicity (CSH) of bacterial cells. Glass beads were used to mimic the hard tissue surfaces, and were coated with saliva to develop experimental pellicles for the adhesion of the primary colonizing bacteria.
RESULTS: Gt aqueous extracts exhibited better anti-plaque effect than Sp aqueous extracts. Their combination, equivalent to 1/4 and 1/2 of MIC values of Gt and Sp extracts respectively, showed synergistic anti-plaque properties with fractional inhibitory concentration (FIC) equal to 0.75. This combination was found to significantly reduce CSH (p<0.05) and lower the adherence ability (p<0.003) towards experimental pellicles.
CONCLUSION: Combination between Gt and Sp aqueous extracts exhibited synergistic anti-plaque activity, and could be used as a useful active agent to produce oral health care products.

Matched MeSH terms: Drug Synergism
Synergistic antifungal indolecarbazoles from Streptomyces sp. CNS-42 associated with traditional Chinese medicine Alisma orientale

Liu M, Huang P, Wang Q, Ren B, Oyeleye A, Liu M, et al.

J Antibiot (Tokyo), 2017 05;70(5):715-717.
PMID: 28074054 DOI: 10.1038/ja.2016.160
Matched MeSH terms: Drug Synergism
Suppression of malaria with monthly administration of combined sulphadoxine and pyrimethamine

Lewis AN, Ponnampalam JT

Ann Trop Med Parasitol, 1975 Mar;69(1):1-12.
PMID: 1092276

A trial of suppression of malaria by administration of combined sulphadoxine-pyrimethamine tablets every 28 days was undertaken in West Malaysia during 1972. One thousand subjects were followed over a 10-month period, including control groups on placebo and on weekly chloroquine. Subjects were examined monthly for parasitaemia, drug reactions, leucopenia, teratogenicity and haemolysis among the subjects deficient in glucose-6-phosphate dehydrogenase. Rates of new infections in the placebo group were 8.0% with Plasmodium falciparum and 6.2% with P. vivax; in the group receiving weekly chloroquine, 5.1% P. falciparum and 0.3% P. vivax; and in the group receiving monthly sulphadoxine-pyrimethamine, 0.3% P. Falciparum and 1.0% P. vivax. The effective rate of cure of new infections with P. falciparum by a single suppressive dose of combined sulphadoxine-pyrimethamine given the following month was 88.7%. No serious side effects were observed.

Matched MeSH terms: Drug Synergism
The synergistic effects of IL-6/IL-17A promote osteogenic differentiation by improving OPG/RANKL ratio and adhesion of MC3T3-E1 cells on hydroxyapatite

Sritharan S, Kannan TP, Norazmi MN, Nurul AA

J Craniomaxillofac Surg, 2018 Aug;46(8):1361-1367.
PMID: 29805067 DOI: 10.1016/j.jcms.2018.05.002

OBJECTIVE: In this study, we evaluated the potential role of IL-6 and/or IL-17A in regulating the OPG/RANKL (osteoprotegerin/receptor activator of nuclear factor kappa b ligand) system of murine osteoblast cell line (MC3T3-E1) cultured on hydroxyapatite (HA).
METHODS: MC3T3-E1 cells were seeded on HA and treated with recombinant IL-6 or rIL-17A or combination of the two cytokines. Cell proliferation and differentiation activity were measured by MTS and alkaline phosphatase assays respectively. Observation of cell adhesion and proliferation was examined by scanning electron microscopy. Gene and protein expressions were performed on RANKL and OPG using qPCR, Western blot and ELISA.
RESULTS: We demonstrated that treatment with recombinant IL-17A (rIL-17A) and the combination rIL-6/rIL-17A promoted better adhesion and higher proliferation of cells on HA. Cells treated with rIL-17A and the combination cytokines showed a significant increase in differentiation activity on day 7, 10 and 14 as indicated by ALP activity (p

Matched MeSH terms: Drug Synergism
Synergistic effect of non-steroidal anti-inflammatory drugs (NSAIDs) on antibacterial activity of cefuroxime and chloramphenicol against methicillin-resistant Staphylococcus aureus

Chan EWL, Yee ZY, Raja I, Yap JKY

J Glob Antimicrob Resist, 2017 09;10:70-74.
PMID: 28673701 DOI: 10.1016/j.jgar.2017.03.012

OBJECTIVES: Currently, only a few antibiotics are available to treat methicillin-resistant Staphylococcus aureus (MRSA). One alternative approach includes adjuvants to antibiotic therapy. Non-steroidal anti-inflammatory drugs (NSAIDs) are non-antibiotic drugs reported to exhibit antibacterial activity. The objective of this study was to investigate the interaction between NSAIDs with selected antibiotics (cefuroxime and chloramphenicol) against strains of S. aureus.
METHODS: The antibacterial activity of four NSAIDs (aspirin, ibuprofen, diclofenac and mefenamic acid) were tested against ten pathogenic bacterial strains using the microdilution broth method. The interaction between NSAIDs and antibiotics (cefuroxime/chloramphenicol) was estimated by calculating the fractional inhibitory concentration (FICI) of the combination.
RESULTS: Aspirin, ibuprofen and diclofenac exhibited antibacterial activity against the selected pathogenic bacteria. The interaction between ibuprofen/aspirin with cefuroxime was demonstrated to be synergistic against methicillin-sensitive S. aureus (MSSA) and the MRSA reference strain, whereas for MRSA clinical strains additive effects were observed for both NSAIDs and cefuroxime combinations. The combination of chloramphenicol with ibuprofen/aspirin was synergistic against all of the tested MRSA strains and displayed an additive effect against MSSA. A 4-8192-fold reduction in the cefuroxime minimum inhibitory concentration (MIC) and a 4-64-fold reduction of the chloramphenicol MIC were documented.
CONCLUSIONS: Overall, the NSAIDs ibuprofen and aspirin showed antibacterial activity against strains of S. aureus. Although individually less potent than common antibiotics, these NSAIDs are synergistic in action with cefuroxime and chloramphenicol and could potentially be used as adjuvants in combating multidrug-resistant MRSA.

Matched MeSH terms: Drug Synergism
Fulltext Cationic chitosan-propolis nanoparticles alter the zeta potential of S. epidermidis, inhibit biofilm formation by modulating gene expression and exhibit synergism with antibiotics

Ong TH, Chitra E, Ramamurthy S, Ling CCS, Ambu SP, Davamani F

PLoS One, 2019;14(2):e0213079.
PMID: 30818374 DOI: 10.1371/journal.pone.0213079

Staphylococcus epidermidis, is a common microflora of human body that can cause opportunistic infections associated with indwelling devices. It is resistant to multiple antibiotics necessitating the need for naturally occurring antibacterial agents. Malaysian propolis, a natural product obtained from beehives exhibits antimicrobial and antibiofilm properties. Chitosan-propolis nanoparticles (CPNP) were prepared using Malaysian propolis and tested for their effect against S. epidermidis. The cationic nanoparticles depicted a zeta potential of +40 and increased the net electric charge (zeta potential) of S. epidermidis from -17 to -11 mV in a concentration-dependent manner whereas, ethanol (Eth) and ethyl acetate (EA) extracts of propolis further decreased the zeta potential from -17 to -20 mV. Confocal laser scanning microscopy (CLSM) depicted that CPNP effectively disrupted biofilm formation by S. epidermidis and decreased viability to ~25% compared to Eth and EA with viability of ~60-70%. CPNP was more effective in reducing the viability of both planktonic as well as biofilm bacteria compared to Eth and EA. At 100 μg/mL concentration, CPNP decreased the survival of biofilm bacteria by ~70% compared to Eth or EA extracts which decreased viability by only 40%-50%. The morphology of bacterial biofilm examined by scanning electron microscopy depicted partial disruption of biofilm by Eth and EA extracts and significant disruption by CPNP reducing bacterial number in the biofilm by ~90%. Real time quantitative PCR analysis of gene expression in treated bacteria showed that genes involved in intercellular adhesion such as IcaABCD, embp and other related genes were significantly downregulated by CPNP. In addition to having a direct inhibitory effect on the survival of S. epidermidis, CPNP showed synergism with the antibiotics rifampicin, ciprofloxacin, vancomycin and doxycycline suggestive of effective treatment regimens. This would help decrease antibiotic treatment dose by at least 4-fold in combination therapies thereby opening up ways of tackling antibiotic resistance in bacteria.

Matched MeSH terms: Drug Synergism
Dual l-Carnosine/Aloe vera Nanophytosomes with Synergistically Enhanced Protective Effects against Methylglyoxal-Induced Angiogenesis Impairment

Darvishi B, Dinarvand R, Mohammadpour H, Kamarul T, Sharifi AM

Mol Pharm, 2021 09 06;18(9):3302-3325.
PMID: 34297586 DOI: 10.1021/acs.molpharmaceut.1c00248

Microvascular complications are among the major outcomes of patients with type II diabetes mellitus, which are the consequences of impaired physiological functioning of small blood vessels and angiogenic responses in these patients. Overproduction and accumulation of methylglyoxal (MGO), a highly reactive dicarbonyl byproduct of glycolysis pathway, has been acclaimed as the main inducer of impaired angiogenic responses and microvascular dysfunction in diabetic patients with uncontrolled hyperglycemia. Hence, an effective approach to overcome diabetes-associated microvascular complications is to neutralize the deleterious activity of enhanced the concentration of MGO in the body. Owing to the glycation inhibitory activity of Aloe vera whole extract, and capability of l-carnosine, an endogenous dipeptide, in attenuating MGO's destructive activity, we examined whether application of a combination of l-carnosine and A. vera could be an effective way of synergistically weakening this reactive dicarbonyl's impaired angiogenic effects. Additionally, overcoming the poor cellular uptake and internalization of l-carnosine and A. vera, a nanophytosomal formulation of the physical mixture of two compounds was also established. Although l-carnosine and A. vera at whole studied combination ratios could synergistically enhance viability of human umbilical vein endothelial cells (HUVECs) treated with MGO, the 25:1 w/w ratio was the most effective one among the others (27 ± 0.5% compared to 12 ± 0.3 to 18 ± 0.4%; F (4, 15) = 183.9, P < 0.0001). Developing dual nanophytosomes of l-carnosine/A. vera (25:1) combination ratio, we demonstrated superiority of the nanophytosomal formulation in protecting HUVECs against MGO-induced toxicity following a 24-72 h incubation period (17.3, 15.8, and 12.4% respectively). Moreover, 500 μg/mL concentration of dual l-carnosine/A. vera nanophytosomes exhibited a superior free radical scavenging potency (63 ± 4 RFU vs 83 ± 5 RFU; F (5, 12) = 54.81, P < 0.0001) and nitric oxide synthesizing capacity (26.11 ± 0.19 vs 5.1 ± 0.33; F (5, 12) = 2537, P < 0.0001) compared to their physical combination counterpart. Similarly, 500 μg/mL dual l-carnosine/A. vera nanophytosome-treated HUVECs demonstrated a superior tube formation capacity (15 ± 3 vs 2 ± 0.3; F (5, 12) = 30.87, P < 0.001), wound scratch healing capability (4.92 ± 0.3 vs 3.07 ± 0.3 mm/h; F (5, 12) = 39.21, P < 0.0001), and transwell migration (586 ± 32 vs 394 ± 18; F (5, 12) = 231.8, P < 0.001) and invasion (172 ± 9 vs 115 ± 5; F (5, 12) = 581.1, P < 0.0001) activities compared to the physical combination treated ones. Further confirming the proangiogenic activity of the dual l-carnosine/A. vera nanophytosomes, a significant shift toward expression of proangiogenic genes including HIF-1α, VEGFA, bFGF, KDR, and Ang II was reported in treated HUVECs. Overall, dual l-carnosine/A. vera nanophytosomes could be a potential candidate for attenuating type II DM-associated microvascular complications with an impaired angiogenesis background.

Matched MeSH terms: Drug Synergism
Brain-Eating Amoebae: Silver Nanoparticle Conjugation Enhanced Efficacy of Anti-Amoebic Drugs against Naegleria fowleri

Rajendran K, Anwar A, Khan NA, Siddiqui R

ACS Chem Neurosci, 2017 12 20;8(12):2626-2630.
PMID: 29206032 DOI: 10.1021/acschemneuro.7b00430

The overall aim of this study was to determine whether conjugation with silver nanoparticles enhances effects of available drugs against primary amoebic meningoencephalitis due to Naegleria fowleri. Amphotericin B, Nystatin, and Fluconazole were conjugated with silver nanoparticles, and synthesis was confirmed using UV-visible spectrophotometry. Atomic force microscopy determined their size in range of 20-100 nm. To determine amoebicidal effects, N. fowleri were incubated with drugs-conjugated silver nanoparticles, silver nanoparticles alone, and drugs alone. The findings revealed that silver nanoparticles conjugation significantly enhanced antiamoebic effects of Nystatin and Amphotericin B but not Fluconazole at micromolar concentrations, compared with the drugs alone. For the first time, our findings showed that silver nanoparticle conjugation enhances efficacy of antiamoebic drugs against N. fowleri. Given the rarity of the disease and challenges in developing new drugs, it is hoped that modifying existing drugs to enhance their antiamoebic effects is a useful avenue that holds promise in improving the treatment of brain-eating amoebae infection due to N. fowleri.

Matched MeSH terms: Drug Synergism
Fulltext Antibacterial effects of 18 medicinal plants used by the Khyang tribe in Bangladesh

Hossan MS, Jindal H, Maisha S, Samudi Raju C, Devi Sekaran S, Nissapatorn V, et al.

Pharm Biol, 2018 Dec;56(1):201-208.
PMID: 29529970 DOI: 10.1080/13880209.2018.1446030

CONTEXT: The resistance of bacteria to antibiotics is raising serious concern globally. Asian medicinal plants could improve the current treatment strategies for bacterial infections. The antibacterial properties of medicinal plants used by the Khyang tribe in Bangladesh have not been investigated.
OBJECTIVE: The present study examines the antibacterial properties of 18 medicinal plants used by the Khyang tribe in day-to-day practice against human pathogenic bacteria.
MATERIALS AND METHODS: Leaves, bark, fruits, seeds, roots and rhizomes from collected plants were successively extracted with hexane, ethyl acetate and ethanol. The corresponding 54 extracts were tested against six human pathogenic bacteria by broth microdilution assay. The antibacterial mode of actions of phytoconstituents and their synergistic effect with vancomycin and cefotaxime towards MRSA was determined by time-killing assay and synergistic interaction assay, respectively.
RESULTS AND DISCUSSION: Hexane extract of bark of Cinnamomum cassia (L.) J. Presl. (Lauraceae) inhibited the growth of MRSA, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii with MIC values below 100 µg/mL. From this plant, cinnamaldehyde evoked at 4 × MIC in 1 h an irreversible decrease of MRSA count Log10 (CFU/mL) from 6 to 0, and was synergistic with vancomycin for MRSA with fractional inhibitory concentration index of 0.3.
CONCLUSIONS: Our study provides evidence that the medicinal plants in Bangladesh have high potential to improve the current treatment strategies for bacterial infection.

Matched MeSH terms: Drug Synergism
Fulltext Inhibition of euchromatic histone methyltransferase 1 and 2 sensitizes chronic myeloid leukemia cells to interferon treatment

Loh SW, Ng WL, Yeo KS, Lim YY, Ea CK

PLoS One, 2014;9(7):e103915.
PMID: 25079219 DOI: 10.1371/journal.pone.0103915

H3K9 methylation is one of the essential histone post-translational modifications for heterochromatin formation and transcriptional repression. Recently, several studies have demonstrated that H3K9 methylation negatively regulates the type I interferon response.

Matched MeSH terms: Drug Synergism
Fulltext 1'-Acetoxychavicol acetate inhibits growth of human oral carcinoma xenograft in mice and potentiates cisplatin effect via proinflammatory microenvironment alterations

In LL, Arshad NM, Ibrahim H, Azmi MN, Awang K, Nagoor NH

BMC Complement Altern Med, 2012;12:179.
PMID: 23043547 DOI: 10.1186/1472-6882-12-179

Oral cancers although preventable, possess a low five-year survival rate which has remained unchanged over the past three decades. In an attempt to find a more safe, affordable and effective treatment option, we describe here the use of 1'S-1'-acetoxychavicol acetate (ACA), a component of Malaysian ginger traditionally used for various medicinal purposes.

Matched MeSH terms: Drug Synergism
Cation dependence, pH tolerance, and dosage requirement of a bioflocculant produced by Bacillus spp. UPMB13: flocculation performance optimization through kaolin assays

Zulkeflee Z, Aris AZ, Shamsuddin ZH, Yusoff MK

ScientificWorldJournal, 2012;2012:495659.
PMID: 22997497

A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological characteristics identified as Bacillus spp. UPMB13 was found to be a potential bioflocculant-producing bacterium. The effect of cation dependency, pH tolerance and dosage requirement on flocculating ability of the strain was determined by flocculation assay with kaolin as the suspended particle. The flocculating activity was measured as optical density and by flocs formation. A synergistic effect was observed with the addition of monovalent and divalent cations, namely, Na⁺, Ca²⁺, and Mg²⁺, while Fe²⁺ and Al³⁺ produced inhibiting effects on flocculating activity. Divalent cations were conclusively demonstrated as the best cation source to enhance flocculation. The bioflocculant works in a wide pH range, from 4.0 to 8.0 with significantly different performances (P < 0.05), respectively. It best performs at pH 5.0 and pH 6.0 with flocculating performance of above 90%. A much lower or higher pH would inhibit flocculation. Low dosage requirements were needed for both the cation and bioflocculant, with only an input of 50 mL/L for 0.1% (w/v) CaCl₂ and 5 mL/L for culture broth, respectively. These results are comparable to other bioflocculants produced by various microorganisms with higher dosage requirements.

Matched MeSH terms: Drug Synergism
Real-life safety and effectiveness of amlodipine/valsartan combination in the treatment of hypertension

Chazova IE, Dongre N, Vigdorchik AV

Adv Ther, 2011 Feb;28(2):134-49.
PMID: 21240661 DOI: 10.1007/s12325-010-0099-1

The aim of our study was to evaluate the safety and effectiveness of the free combination of amlodipine/valsartan in patients with arterial hypertension in a real-life setting.

Matched MeSH terms: Drug Synergism
Pharmacological mechanisms underlying the vascular activities of Loranthus ferrugineus Roxb. in rat thoracic aorta

Ameer OZ, Salman IM, Siddiqui MJ, Yam MF, Sriramaneni RN, Mohamed AJ, et al.

J Ethnopharmacol, 2010 Jan 8;127(1):19-25.
PMID: 19808083 DOI: 10.1016/j.jep.2009.09.057

The present study was aimed to investigate the pharmacological basis for the use of Loranthus ferrugineus in hypertension.

Matched MeSH terms: Drug Synergism
Mechanisms of antihyperuricemic effect of Phyllanthus niruri and its lignan constituents

Murugaiyah V, Chan KL

J Ethnopharmacol, 2009 Jul 15;124(2):233-9.
PMID: 19397979 DOI: 10.1016/j.jep.2009.04.026

ETHNOPHARMACOLOGICAL RELEVANCE: Phyllanthus niruri Linn. (Euphorbiaceae) is used as folk medicine in South America to treat excess uric acid. Our initial study showed that the methanol extract of Phyllanthus niruri and its lignans were able to reverse the plasma uric acid of hyperuricemic animals.
AIM OF THE STUDY: The study was undertaken to investigate the mechanisms of antihyperuricemic effect of Phyllanthus niruri and its lignan constituents.
MATERIAL AND METHODS: The mechanisms were investigated using xanthine oxidase assay and uricosuric studies in potassium oxonate- and uric acid-induced hyperuricemic rats.
RESULTS: Phyllanthus niruri methanol extract exhibited in vitro xanthine oxidase inhibition with an IC50 of 39.39 microg/mL and a moderate in vivo xanthine oxidase inhibitory activity. However, the lignans display poor xanthine oxidase inhibition in vitro and a relatively weak in vivo inhibitory activity at 10mg/kg. On the other hand, intraperitoneal treatment with Phyllanthus niruri methanol extract showed 1.69 folds increase in urinary uric acid excretion when compared to the hyperuricemic control animals. Likewise, the lignans, phyllanthin, hypophyllanthin and phyltetralin exhibited up to 2.51 and 11.0 folds higher in urinary uric acid excretion and clearance, respectively. The co-administration of pyrazinamide with phyllanthin exhibited a significant suppression of phyllanthin's uricosuric activity resembling that of pyrazinamide with benzbromarone.
CONCLUSIONS: The present study showed that the antihyperuricemic effect of Phyllanthus niruri methanol extract may be mainly due to its uricosuric action and partly through xanthine oxidase inhibition, whereas the antihyperuricemic effect of the lignans was attributed to their uricosuric action.

Matched MeSH terms: Drug Synergism
Coadministration of alloxan and nicotinamide in rats produces biochemical changes in blood and pathological alterations comparable to the changes in type II diabetes mellitus

Vattam KK, Raghavendran H, Murali MR, Savatey H, Kamarul T

Hum Exp Toxicol, 2016 Aug;35(8):893-901.
PMID: 26429928 DOI: 10.1177/0960327115608246

In the present study, thirty six male Sprague Dawley rats were randomly divided into six groups and were injected with varying doses of alloxan (Ax) and nicotinamide (NA). The serum levels of glucose, insulin, and adiponectin were measured weekly up to 4 weeks.

Matched MeSH terms: Drug Synergism
Fulltext Scalable Production of Recombinant Membrane Active Peptides and Its Potential as a Complementary Adjunct to Conventional Chemotherapeutics

Rothan HA, Ambikabothy J, Abdulrahman AY, Bahrani H, Golpich M, Amini E, et al.

PLoS One, 2015;10(9):e0139248.
PMID: 26418816 DOI: 10.1371/journal.pone.0139248

The production of short anticancer peptides in recombinant form is an alternative method for costly chemical manufacturing. However, the limitations of host toxicity, bioactivity and column purification have impaired production in mass quantities. In this study, short cationic peptides were produced in aggregated inclusion bodies by double fusion with a central protein that has anti-cancer activity. The anticancer peptides Tachiplicin I (TACH) and Latarcin 1 (LATA) were fused with the N- and C-terminus of the MAP30 protein, respectively. We successfully produced the recombinant TACH-MAP30-LATA protein and MAP30 alone in E. coli that represented 59% and 68% of the inclusion bodies. The purified form of the inclusion bodies was prepared by eliminating host cell proteins through multiple washing steps and semi-solubilization in alkaline buffer. The purified active protein was recovered by inclusive solubilization at pH 12.5 in the presence of 2 M urea and refolded in alkaline buffer containing oxides and reduced glutathione. The peptide-fusion protein showed lower CC50 values against cancer cells (HepG2, 0.35±0.1 μM and MCF-7, 0.58±0.1 μM) compared with normal cells (WRL68, 1.83±0.2 μM and ARPE19, 2.5±0.1 μM) with outstanding activity compared with its individual components. The presence of the short peptides facilitated the entry of the peptide fusion protein into cancer cells (1.8 to 2.2-fold) compared with MAP30 alone through direct interaction with the cell membrane. The cancer chemotherapy agent doxorubicin showed higher efficiency and selectivity against cancer cells in combination with the peptide- fusion protein. This study provides new data on the mass production of short anticancer peptides as inclusion bodies in E. coli by fusion with a central protein that has similar activity. The product was biologically active against cancer cells compared with normal cells and enhanced the activity and selective delivery of an anticancer chemotherapy agent.

Matched MeSH terms: Drug Synergism
SIRT1 inhibition in pancreatic cancer models: contrasting effects in vitro and in vivo

Oon CE, Strell C, Yeong KY, Östman A, Prakash J

Eur J Pharmacol, 2015 Jun 15;757:59-67.
PMID: 25843411 DOI: 10.1016/j.ejphar.2015.03.064

Gemcitabine remains the standard treatment for pancreatic cancer, although most patients acquire resistance to the therapy. Up-regulated in pancreatic cancer, SIRT1 is involved in tumorigenesis and drug resistance. However the mechanism through which SIRT1 regulates drug sensitivity in cancer cells is mainly unknown. We hypothesise that inhibiting SIRT1 activity may increase sensitivity of pancreatic cancer cells to gemcitabine treatment through the regulation of apototic cell death, cell cycle, epithelial-mesenschymal-transition (EMT) and senescence. We demonstrate that gemcitabine or 6-Chloro-2,3,4,9-tetrahydro-1 H-Carbazole-1-carboxamide (EX527) SIRT1 inhibitor reduces PANC-1 cell proliferation in vitro. EX527 enhanced sensitivity of PANC-1 cells to gemcitabine treatment through increased apoptosis. However, EX527 displayed no beneficial effect either as a monotreatment or in combination with gemcitabine in the modulation of cell cycle progression. Combination treatment did not reverse the two phenomena known to affect drug sensitivity, namely EMT and senescence, which are both induced by gemcitabine. Unexpectedly, EX527 promoted PANC-1 xenograft tumour growth in SCID mice compared to control group. Dual tX527 and gemcitabine displayed no synergistic effect compared to gemcitabine alone. The study reveals that SIRT1 is involved in chemoresistance and that inhibiting SIRT1 activity with EX527 sensitised PANC-1 cells to gemcitabine treatment in vitro. Sensitisation of cells is shown to be mainly through induction of micronuclei formation as a result of DNA damage and apoptosis in vitro. However, the absence of positive combinatorial effects in vivo indicates possible effects on cells of the tumor microenvironment and suggests caution regarding the clinical relevance of tissue culture findings with EX527.

Matched MeSH terms: Drug Synergism
Fulltext The synergism of Clinacanthus nutans Lindau extracts with gemcitabine: downregulation of anti-apoptotic markers in squamous pancreatic ductal adenocarcinoma

Hii LW, Lim SE, Leong CO, Chin SY, Tan NP, Lai KS, et al.

BMC Complement Altern Med, 2019 Sep 14;19(1):257.
PMID: 31521140 DOI: 10.1186/s12906-019-2663-9

BACKGROUND: Clinacanthus nutans extracts have been consumed by the cancer patients with the hope that the extracts can kill cancers more effectively than conventional chemotherapies. Our previous study reported its anti-inflammatory effects were caused by inhibiting Toll-like Receptor-4 (TLR-4) activation. However, we are unsure of its anticancer effect, and its interaction with existing chemotherapy.
METHODS: We investigated the anti-proliferative efficacy of polar leaf extracts (LP), non-polar leaf extracts (LN), polar stem extract (SP) and non-polar stem extracts (SN) in human breast, colorectal, lung, endometrial, nasopharyngeal, and pancreatic cancer cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assay. The most potent extracts was tested along with gemcitabine using our established drug combination analysis. The effect of the combinatory treatment in apoptosis were quantified using enzyme-linked immunosorbent assay (ELISA), Annexin V assay, antibody array and immunoblotting. Statistical significance was analysed using one-way analysis of variance (ANOVA) and post hoc Dunnett's test. A p-value of less than 0.05 (p

Matched MeSH terms: Drug Synergism

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