MyMedR

Displaying all 14 publications

Abstract:

Sort:

Fulltext Preparing patients for travel to high altitude: advice on travel health and chemoprophylaxis

Flaherty GT, Kennedy KM

Br J Gen Pract, 2016 Jan;66(642):e62-4.
PMID: 26719484 DOI: 10.3399/bjgp16X683377
Matched MeSH terms: Chemoprevention/methods*
Moringa oleifera Lam: Targeting Chemoprevention

Karim NA, Ibrahim MD, Kntayya SB, Rukayadi Y, Hamid HA, Razis AF

Asian Pac J Cancer Prev, 2016;17(8):3675-86.
PMID: 27644601

Moringa oleifera Lam, family Moringaceae, is a perennial plant which is called various names, but is locally known in Malaysia as "murungai" or "kelor". Glucomoringin, a glucosinolate with from M. oleifera is a major secondary metabolite compound. The seeds and leaves of the plant are reported to have the highest amount of glucosinolates. M. oleifera is well known for its many uses health and benefits. It is claimed to have nutritional, medicinal and chemopreventive potentials. Chemopreventive effects of M. oleifera are expected due to the existence of glucosinolate which it is reported to have the ability to induce apoptosis in anticancer studies. Furthermore, chemopreventive value of M. oleifera has been demonstrated in studies utilizing its leaf extract to inhibit the growth of human cancer cell lines. This review highlights the advantages of M. oleifera targeting chemoprevention where glucosinolates could help to slow the process of carcinogenesis through several molecular targets. It is also includes inhibition of carcinogen activation and induction of carcinogen detoxification, anti-inflammatory, anti-tumor cell proliferation, induction of apoptosis and inhibition of tumor angiogenesis. Finally, for synergistic effects of M. oleifera with other drugs and safety, essential for chemoprevention, it is important that it safe to be consumed by human body and works well. Although there is promising evidence about M. oleifera in chemoprevention, extensive research needs to be done due to the expected rise of cancer in coming years and to gain more information about the mechanisms involved in M. oleifera influence, which could be a good source to inhibit several major mechanisms involved in cancer development.

Matched MeSH terms: Chemoprevention/methods
Fulltext Chemopreventive Properties and Toxicity of Kelulut Honey in Sprague Dawley Rats Induced with Azoxymethane

Saiful Yazan L, Muhamad Zali MF, Mohd Ali R, Zainal NA, Esa N, Sapuan S, et al.

Biomed Res Int, 2016;2016:4036926.
PMID: 27525267 DOI: 10.1155/2016/4036926

Ethnopharmacological Relevance. Colon cancer has been a major problem worldwide. Kelulut honey (KH) is produced by the stingless bees from Trigona species and has strong antioxidant activities that could be one of the potential chemopreventive agents from natural resources. Aim of This Study. This study investigated the chemopreventive properties and toxicity of KH in Sprague Dawley rats induced with azoxymethane (AOM). Material and Method. Twenty-four male Sprague Dawley rats aged 5 weeks were divided into 4 groups: (G1) untreated group not induced with AOM, (G2) untreated group induced with AOM, (G3) treated group induced with AOM, and (G4) treated group not induced with AOM. Injection of AOM (15 mg/kg) was via intraperitoneal route once a week for two subsequent weeks. The treatment groups were given oral administration of KH (1183 mg/kg body weight) twice daily for 8 weeks. Results. Treatment with KH significantly reduced the total number of aberrant crypt foci (ACF) and aberrant crypts (AC) and crypt multiplicity. KH was not toxic to the animals since the level of blood profile parameters, liver enzymes, and kidney functions was in normal range. Conclusions. The current finding shows that KH has chemopreventive properties in rats induced with colorectal cancer and also was found not toxic towards the animals.

Matched MeSH terms: Chemoprevention/methods*
Travel medicine physician adherence to guidelines for the emergency self treatment of malaria

Flaherty GT, Walden LM, Townend M

J Travel Med, 2016 May;23(5).
PMID: 27279126 DOI: 10.1093/jtm/taw036

Few studies have examined emergency self treatment (EST) antimalarial prescribing patterns. 110 physician-members of the Travel Medicine Society of Ireland and British Global and Travel Health Association participated in this study. There was a trend towards the prescription of EST for travel to remote low-risk malaria areas; for long-term residents living in low-risk areas; and for frequent travellers to low-risk areas. This study provides insights into the use of EST in travellers' malaria.

Matched MeSH terms: Chemoprevention/methods
Potential chemoprevention activity of pterostilbene by enhancing the detoxifying enzymes in the HT-29 cell line

Harun Z, Ghazali AR

Asian Pac J Cancer Prev, 2012;13(12):6403-7.
PMID: 23464466

Detoxifying enzymes are present in most epithelial cells of the human gastrointestinal tract where they protect against xenobiotics which may cause cancer. Induction of examples such as glutathione S-transferase (GST) and its thiol conjugate, glutathione (GSH) as well as NAD(P)H: quinoneoxidoreductase (NQO1) facilitate the excretion of carcinogens and thus preventing colon carcinogenesis. Pterostilbene, an analogue of resveratrol, has demonstrated numerous pharmacological activities linked with chemoprevention. This study was conducted to investigate the potential of pterostilbene as a chemopreventive agent using the HT-29 colon cancer cell line to study the modulation of GST and NQO1 activities as well as the GSH level. Initially, our group, established the optimum dose of 24 hours pterostilbene treatment using MTT assays. Then, effects of pterostilbene (0-50 μM) on GST and NQO1 activity and GSH levels were determined using GST, NQO1 and Ellman assays, respectively. MTT assay of pterostilbene (0-100 μM) showed no cytotoxicity toward the HT-29 cell line. Treatment increased GST activity in the cell line significantly (p<0.05) at 12.5 and 25.0 μM. In addition, treatment at 50 μM increased the GSH level significantly (p<0.05). Pterostilbene also enhanced NQO1 activity significantly (p<0.05) at 12.5 μM and 50 μM. Hence, pterostilbene is a potential chemopreventive agent capable of modulation of detoxifiying enzyme levels in HT-29 cells.

Matched MeSH terms: Chemoprevention/methods
Antifungal prophylaxis in lung transplantation

Neoh CF, Snell G, Levvey B, Morrissey CO, Stewart K, Kong DC

Int J Antimicrob Agents, 2014 Sep;44(3):194-202.
PMID: 25123811 DOI: 10.1016/j.ijantimicag.2014.05.013

Lung transplant (LTx) patients have an increased risk of developing invasive fungal infections (IFIs), particularly invasive aspergillosis. Rapid identification of the causative fungal pathogen, to allow for early administration of appropriate initial antifungal therapy, in LTx patients has been challenging due to the limited sensitivity and specificity of the diagnostic tools. Hence, there is increasing emphasis on antifungal prophylaxis in the LTx setting, given the high mortality rates and substantial cost of treating IFIs. Evidence for the optimal antifungal prophylactic approach in this setting, however, remains scant and inconsistent. This review will briefly discuss the epidemiology, risk factors, timing and clinical manifestations of fungal infections in LTx patients and will focus primarily on the available evidence related to the efficacy, safety and practicality of current prophylactic strategies in LTx recipients as well as challenges and gaps for future research.

Matched MeSH terms: Chemoprevention/methods*
Fulltext Prediction of Improved Antimalarial Chemoprevention with Weekly Dosing of Dihydroartemisinin-Piperaquine

Permala J, Tarning J, Nosten F, White NJ, Karlsson MO, Bergstrand M

Antimicrob Agents Chemother, 2017 May;61(5).
PMID: 28242661 DOI: 10.1128/AAC.02491-16

Intermittent preventive treatment (IPT) is used to reduce malaria morbidity and mortality, especially in vulnerable groups such as children and pregnant women. IPT with the fixed dose combination of piperaquine (PQ) and dihydroartemisinin (DHA) is being evaluated as a potential mass treatment to control and eliminate artemisinin-resistant falciparum malaria. This study explored alternative DHA-PQ adult dosing regimens compared to the monthly adult dosing regimen currently being studied in clinical trials. A time-to-event model describing the concentration-effect relationship of preventive DHA-PQ administration was used to explore the potential clinical efficacy of once-weekly adult dosing regimens. Loading dose strategies were evaluated and the advantage of weekly dosing regimen was tested against different degrees of adherence. Assuming perfect adherence, three tablets weekly dosing regimen scenarios maintained malaria incidence of 0.2 to 0.3% per year compared to 2.1 to 2.6% for all monthly dosing regimen scenarios and 52% for the placebo. The three tablets weekly dosing regimen was also more forgiving (i.e., less sensitive to poor adherence), resulting in a predicted ∼4% malaria incidence per year compared to ∼8% for dosing regimen of two tablets weekly and ∼10% for monthly regimens (assuming 60% adherence and 35% interindividual variability). These results suggest that weekly dosing of DHA-PQ for malaria chemoprevention would improve treatment outcomes compared to monthly administration by lowering the incidence of malaria infections, reducing safety concerns about high PQ peak plasma concentrations and being more forgiving. In addition, weekly dosing is expected to reduce the selection pressure for PQ resistance.

Matched MeSH terms: Chemoprevention/methods
Fulltext The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats

Rouhollahi E, Moghadamtousi SZ, Al-Henhena N, Kunasegaran T, Hasanpourghadi M, Looi CY, et al.

Drug Des Devel Ther, 2015;9:3911-22.
PMID: 26251570 DOI: 10.2147/DDDT.S84560

Curcuma purpurascens BI. rhizome, a member of the Zingiberaceae family, is a popular spice in Indonesia that is traditionally used in assorted remedies. Dichloromethane extract of C. purpurascens BI. rhizome (DECPR) has previously been shown to have an apoptosis-inducing effect on colon cancer cells. In the present study, we examined the potential of DECPR to prevent colon cancer development in rats treated with azoxymethane (AOM) (15 mg/kg) by determining the percentage inhibition in incidence of aberrant crypt foci (ACF). Starting from the day immediately after AOM treatment, three groups of rats were orally administered once a day for 2 months either 10% Tween 20 (5 mL/kg, cancer control), DECPR (250 mg/kg, low dose), or DECPR (500 mg/kg, high dose). Meanwhile, the control group was intraperitoneally injected with 5-fluorouracil (35 mg/kg) for 5 consecutive days. After euthanizing the rats, the number of ACF was enumerated in colon tissues. Bax, Bcl-2, and proliferating cell nuclear antigen (PCNA) protein expressions were examined using immunohistochemical and Western blot analyses. Antioxidant enzymatic activity was measured in colon tissue homogenates and associated with malondialdehyde level. The percentage inhibition of ACF was 56.04% and 68.68% in the low- and high-dose DECPR-treated groups, respectively. The ACF inhibition in the treatment control group was 74.17%. Results revealed that DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied by reduced expression of PCNA. Upregulation of Bax and downregulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Taken together, the present data clearly indicate that DECPR significantly inhibits ACF formation in AOM-treated rats and may offer protection against colon cancer development.

Matched MeSH terms: Chemoprevention/methods
Inhibitory effect of phenethyl isothiocyanate against benzo[a] pyrene-induced rise in CYP1A1 mRNA and apoprotein levels as its chemopreventive properties

Abdull Razis AF, Konsue N, Ioannides C

Asian Pac J Cancer Prev, 2015;16(7):2679-83.
PMID: 25854346

BACKGROUND: Phenethyl isothiocyanate (PEITC), the most comprehensively studied aromatic isothiocyanate, has been shown to act as an anti-cancer agent mainly through modulation of biotransformation enzymes responsible for metabolizing carcinogens in the human body. Humans are often exposed to carcinogenic factors, some of which through the diet, such as polycyclic aromatic hydrocarbon benzo[a]pyrene via the consumption of over-cooked meats. Inhibition of the enzymes responsible for the bioactivation of this carcinogen, for example CYP1A1, the major enzyme required for polycyclic aromatic hydrocarbons (PAHs) bioactivation, is recognized as a chemoprevention strategy.
OBJECTIVE: To evaluate the inhibitory effects of PEITC against benzo[a]pyrene-induced rise in rat liver CYP1A1 mRNA and apoprotein levels.
MATERIALS AND METHODS: Precision cut rat liver slices were treated with benzo[a]pyrene at 1 and 5 μM in the presence of PEITC (1-25 μM) for 24 hours, followed by determination of CYP1A1 mRNA and apoprotein levels using quantitative polymerase chain reaction and immunoblotting.
RESULTS: Findings revealed that PEITC inhibited benzo[a]pyrene-induced rise in rat liver CYP1A1 mRNA in a dose-dependent manner as well as the apoprotein levels of CYP1A.
CONCLUSIONS: It was demonstrated that PEITC can directly inhibit the bioactivation of benzo[a]pyrene, indicating chemopreventive potential.

Matched MeSH terms: Chemoprevention/methods*
Fulltext Hepatitis C virus treatment as prevention in an extended network of people who inject drugs in the USA: a modelling study

Zelenev A, Li J, Mazhnaya A, Basu S, Altice FL

Lancet Infect Dis, 2018 02;18(2):215-224.
PMID: 29153265 DOI: 10.1016/S1473-3099(17)30676-X

BACKGROUND: Chronic infections with hepatitis C virus (HCV) and HIV are highly prevalent in the USA and concentrated in people who inject drugs. Treatment as prevention with highly effective new direct-acting antivirals is a prospective HCV elimination strategy. We used network-based modelling to analyse the effect of this strategy in HCV-infected people who inject drugs in a US city.
METHODS: Five graph models were fit using data from 1574 people who inject drugs in Hartford, CT, USA. We used a degree-corrected stochastic block model, based on goodness-of-fit, to model networks of injection drug users. We simulated transmission of HCV and HIV through this network with varying levels of HCV treatment coverage (0%, 3%, 6%, 12%, or 24%) and varying baseline HCV prevalence in people who inject drugs (30%, 60%, 75%, or 85%). We compared the effectiveness of seven treatment-as-prevention strategies on reducing HCV prevalence over 10 years and 20 years versus no treatment. The strategies consisted of treatment assigned to either a randomly chosen individual who injects drugs or to an individual with the highest number of injection partners. Additional strategies explored the effects of treating either none, half, or all of the injection partners of the selected individual, as well as a strategy based on respondent-driven recruitment into treatment.
FINDINGS: Our model estimates show that at the highest baseline HCV prevalence in people who inject drugs (85%), expansion of treatment coverage does not substantially reduce HCV prevalence for any treatment-as-prevention strategy. However, when baseline HCV prevalence is 60% or lower, treating more than 120 (12%) individuals per 1000 people who inject drugs per year would probably eliminate HCV within 10 years. On average, assigning treatment randomly to individuals who inject drugs is better than targeting individuals with the most injection partners. Treatment-as-prevention strategies that treat additional network members are among the best performing strategies and can enhance less effective strategies that target the degree (ie, the highest number of injection partners) within the network.
INTERPRETATION: Successful HCV treatment as prevention should incorporate the baseline HCV prevalence and will achieve the greatest benefit when coverage is sufficiently expanded.
FUNDING: National Institute on Drug Abuse.

Matched MeSH terms: Chemoprevention/methods*
Fulltext Suppression of Plasmodium berghei parasitemia by LiCl in an animal infection model

Nurul Aiezzah Z, Noor E, Hasidah MS

Trop Biomed, 2010 Dec;27(3):624-31.
PMID: 21399604 MyJurnal

Malaria, caused by the Plasmodium parasite is still a health problem worldwide due to resistance of the pathogen to current anti-malarials. The search for new anti-malarial agents has become more crucial with the emergence of chloroquine-resistant Plasmodium falciparum strains. Protein kinases such as mitogen-activated protein kinase (MAPK), MAPK kinase, cyclin-dependent kinase (CDK) and glycogen synthase kinase- 3(GSK-3) of parasitic protozoa are potential drug targets. GSK-3 is an enzyme that plays a vital role in multiple cellular processes, and has been linked to pathogenesis of several diseases such as type II diabetes and Alzheimer's disease. In the present study, the antiplasmodial property of LiCl, a known GSK-3 inhibitor, was evaluated in vivo for its antimalarial effect against mice infected with Plasmodium berghei. Infected ICR mice were intraperitoneally administered with LiCl for four consecutive days before (prophylactic test) and after (suppressive test) inoculation of P. berghei-parasitised erythrocytes. Results from the suppressive test (post-infection LiCl treatment) showed inhibition of erythrocytic parasitemia development by 62.06%, 85.67% and 85.18% as compared to nontreated controls for the 100 mg/kg, 300 mg/kg and 600 mg/kg dosages respectively. Both 300 mg/kg and 600 mg/kg LiCl showed similar significant (P<0.05) suppressive values to that obtained with chloroquine-treated mice (86% suppression). The prophylactic test indicated a significantly (P<0.05) high protective effect on mice pre-treated with LiCl with suppression levels relatively comparable to chloroquine (84.07% and 86.26% suppression for the 300 mg/kg and 600 mg/kg LiCl dosages respectively versus 92.86% suppression by chloroquine). In both the suppressive and prophylactic tests, LiCl-treated animals survived longer than their non-treated counterparts. Mortality of the non-treated mice was 100% within 6 to 7 days of parasite inoculation whereas mice administered with LiCl survived beyond 9 days. Healthy non-infected mice administered with 600 mg/ kg LiCl for four consecutive days also showed decreased mortality compared to animals receiving lower doses of LiCl; three of the seven mice intraperitoneally injected with the former dose of LiCl did not survive more than 24 h after administration of LiCl whereas animals given the lower LiCl doses survived beyond four days of LiCl administration. To date, no direct evidence of anti-malarial activity in vivo or in vitro has been reported for LiCl. Evidence of anti-plasmodial activity of lithium in a mouse infection model is presented in this study.

Matched MeSH terms: Chemoprevention/methods
Fulltext Protective effects of Mucuna pruriens seed extract pretreatment against cardiovascular and respiratory depressant effects of Calloselasma rhodostoma (Malayan pit viper) venom in rats

Fung SY, Tan NH, Sim SM

Trop Biomed, 2010 Dec;27(3):366-72.
PMID: 21399576 MyJurnal

The protective effects of Mucuna pruriens seed extract (MPE) against the cardio-respiratory depressant and neuromuscular paralytic effects induced by injection of Calloselasma rhodostoma (Malayan pit viper) venom in anaesthetized rats were investigated. While MPE pretreatment did not reverse the inhibitory effect of the venom on the gastrocnemius muscle excitability, it significantly attenuated the venom-induced cardio-respiratory depressant effects (p < 0.05). The protection effects may have an immunological mechanism, as indicated by the presence of several proteins in the venom that are immunoreactive against anti-MPE. However, we cannot rule out the possibility that the pretreatment may exert a direct, non-immunological protective action against the venom.

Matched MeSH terms: Chemoprevention/methods
Curcumin attenuates oxidative damage in animals treated with a renal carcinogen, ferric nitrilotriacetate (Fe-NTA): implications for cancer prevention

Iqbal M, Okazaki Y, Okada S

Mol Cell Biochem, 2009 Apr;324(1-2):157-64.
PMID: 19165575 DOI: 10.1007/s11010-008-9994-z

Curcumin (diferuloylmethane), a biologically active ingredient derived from rhizome of the plant Curcuma longa, has potent anticancer properties as demonstrated in a plethora of human cancer cell lines/animal carcinogenesis model and also acts as a biological response modifier in various disorders. We have reported previously that dietary supplementation of curcumin suppresses renal ornithine decarboxylase (Okazaki et al. Biochim Biophys Acta 1740:357-366, 2005) and enhances activities of antioxidant and phase II metabolizing enzymes in mice (Iqbal et al. Pharmacol Toxicol 92:33-38, 2003) and also inhibits Fe-NTA-induced oxidative injury of lipids and DNA in vitro (Iqbal et al. Teratog Carcinog Mutagen 1:151-160, 2003). This study was designed to examine whether curcumin possess the potential to suppress the oxidative damage caused by kidney-specific carcinogen, Fe-NTA, in animals. In accord with previous report, at 1 h after Fe-NTA treatment (9.0 mg Fe/kg body weight intraperitoneally), a substantial increased formation of 4-hydroxy-2-nonenal (HNE)-modified protein adducts in renal proximal tubules of animals was observed. Likewise, the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and protein reactive carbonyl, an indicator of protein oxidation, were also increased at 1 h after Fe-NTA treatment in the kidneys of animals. The prophylactic feeding of animals with 1.0% curcumin in diet for 4 weeks completely abolished the formation of (i) HNE-modified protein adducts, (ii) 8-OHdG, and (iii) protein reactive carbonyl in the kidneys of Fe-NTA-treated animals. Taken together, our results suggest that curcumin may afford substantial protection against oxidative damage caused by Fe-NTA, and these protective effects may be mediated via its antioxidant properties. These properties of curcumin strongly suggest that it could be used as a cancer chemopreventive agent.

Matched MeSH terms: Chemoprevention/methods*
Fulltext Chemopreventive effects of Strobilanthes crispus leaf extract on azoxymethane-induced aberrant crypt foci in rat colon

Al-Henhena N, Khalifa SA, Ying RP, Hassandarvish P, Rouhollahi E, Al-Wajeeh NS, et al.

Sci Rep, 2015 Aug 26;5:13312.
PMID: 26307342 DOI: 10.1038/srep13312

In this work, microscopic and histological studies suggest that Strobilanthes crispus ethanol extract reduce azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) in rats. S. crispus is considered a traditional medicine and used as an antioxidant. Its leaf contains a large amount of phenolic compounds to which its radical scavenging role is attributed and enhance its ability to eradicate oxidative stress reactions. The study was designed to determine the chemopreventive effect of S. crispus ethanol extract in vivo and in vitro by elucidating the effect of the extract on intermediate biomarkers which can be used as effective predictors of colon cancer. S. crispus was analyzed for DPPH free radical scavenging, nitric oxide (NO) and ferric acid reduction. The results indicated that S. crispus oral administration significantly inhibited colorectal carcinogenesis induced by AOM as revealed by the reduction in the number of ACF. S. crispus down-regulated the expression of PCNA, Bcl2 and β-catenin. Additionally, it exerted a pronounced inhibitory effect on MDA and NO levels and stimulatory effect on CAT and GPx activities. These results demonstrate that S. crispus is a chemopreventive agent for colorectal cancer through the suppression of early and intermediate carcinogenic phases that may be related to its flavonoid content.

Matched MeSH terms: Chemoprevention/methods

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links