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Fulltext Preliminary phytochemical evaluation and vitamin c content of Tolidus (Hornstedtia havilandii (K. Schum) K. Schum) from Sabah

Nur Syafiqah Martang, Nadia Majitol, Farnidah Jasnie, Lo Chor-Wai

Borneo Akademika, 2020;4(4):15-20.
MyJurnal

Most of the plants in the ginger family Zingeberaceae are well-known for their medicinal properties. However, the genus Hornstedtia found in Sabah is less reported. This research aims to investigate the phytochemical constituent and vitamin C content of a fruit, locally known as the Tolidus fruit in Sabah. The dried fruit sample was extracted using three solvents which were water, ethanol and methanol. The phytochemical constituents were determined using standard Colour Test for the presence of alkaloid, flavonoid, saponin and tannin. Then, the content of Vitamin C was determined using the standard Colorimetric Titration and ascorbic acid as standard. The phytochemical evaluation revealed that all three targeted constituents were present in all extracts except for the alkaloid. The vitamin C content was determined in both dried and fresh sample of fruits, where 52.84 mg was quantified in the fresh fruit aqueous extract and 23.93 mg in the dried fruit aqueous extract respectively. These results are comparable to the content of vitamin C in orange and lime fruits. The phytochemical evaluation and vitamin C content of Tolidus suggested the potential of this underutilised fruit to be the natural and affordable source of vitamin C. Additionally, may protect the body against harmful free radicals. However, further analysis is needed to determine other constructive natural contents and evaluate the efficacy of this fruit as a natural source of antioxidant

Matched MeSH terms: Free Radicals
Fulltext Effect of solvent extraction on antioxidant and antibacterial activities from Quercus infectoria (Manjakani)

Nur Syukriah, A.R., Liza, M.S., Harisun, Y., Fadzillah, A.A.M.

International Food Research Journal, 2014;21(3):1067-1073.
MyJurnal

Bioactive compounds from Quercus Infectoria (manjakani) were extracted with six different types of solvents: 100% methanol, ethanol, acetone, aqueous and 70% methanol and ethanol. High Performance liquid chromatography (HPLC) was used to identify and quantify the active compounds, namely gallic acid and tannic acid. Total phenolics content were determined by Folin-Ciocalteu while antioxidant and antibacterial activity were tested using DPPH free radicals scavenging and disc diffusion assay. The result revealed that aqueous extract contained the highest concentration of bioactive compounds compared to other types of solvents which are 51.14 mg/g sample and 1332.88 mg/g sample of gallic acid and tannic acid respectively.. The highest level of phenolic compound was found in 100% acetone extract (121 mg GAE/g). The results demonstrated that aqueous extract gives the highest antioxidant activity approximately 94.55% while acetone extract gives the largest inhibition zone for disc diffusion assay which is 19.00 mm respectively. The results revealed rich sources of gallic acid and tannic acid in Q. infectoria which might provide a novel source of these natural antioxidant and antibacterial activity.

Matched MeSH terms: Free Radicals
Fulltext Effect of blanching on enzyme and antioxidant activities of rambutan (Nephelium lappaceum) peel

Nurhuda, H.H., Maskat, M.Y., Mamot, S., Afiq, J., Aminah, A.

International Food Research Journal, 2013;20(4):1725-1730.
MyJurnal

Rambutan (Nephelium lappaceum) peel is a potential source of antioxidant. As rambutan is a seasonal fruit, a proper heat treatment prior to storage is necessary. Thus, this study was conducted to determine the effect of water and steam blanchings on browning enzymes and antioxidant activities of rambutan peel extracts. Rambutan from the variety of ‘Anak Sekolah’ were peeled and the peel was blanched in boiling water for 0, 2.5, 5 min and by autoclaving for 0, 5, 10 and 15 min. The residual peroxidase (POD) and polyphenoloxidase (PPO) activities, antioxidant activity (2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity), total polyphenol content (TPC) and peel extract colour were determined. The results showed that both water and steam blanchings significantly reduced (p < 0.05) POD and PPO activities. The results also indicated that the increase in the blanching period did not significantly reduce the enzyme activities further. In terms of antioxidant activity, the thermal pretreatment caused no significant difference in the contents of phenolic compounds, as well as the antioxidant capacity of the final product.

Matched MeSH terms: Free Radicals
Fulltext Phytochemistry, pharmacology and toxicology properties of Strobilanthes crispus

Nurraihana, H., Norfarizan-Hanoon, N.A.

International Food Research Journal, 2013;20(5):2045-2056.
MyJurnal

Strobilanthes crispus (S. crispus) is an herbal medicine plant which is native to countries from Madagascar to Indonesia. The plants contained high amount of mineral content and vitamin C, B1 and B2. This plant are used in medicinal and to treat a variety of ailments in the various traditional systems of medicine. Phytochemical investigations have revealed that the plant contain polyphenols, flavonoids, catechins, alkaloids, caffeine, tannins, compounds known to possess multiple health beneficial effects. Preclinical studies have shown that the plant possess antioxidant, free radical scavenging, anticancer, antidiabetic, antimicrobial, wound healing and antiulcerogenic activities. This review presents the comprehensive overview of phytochemical constituents, pharmacological and toxicological properties of S. crispus and to provide preliminary information for future research and for commercial exploitation.

Matched MeSH terms: Free Radicals
Fulltext Cerebral protection: a review of current techniques

Palur, Ravikant

Medical Health Reviews, 2009;2009(1):15-42.
MyJurnal

The brain is considered the most eloquent organ in the human body as its activities impacts on all other systems. Though protected physically (in a bony covering), physiologically through the blood-CSF barrier (from invading organisms and toxins) and hemodynamically through the phenomenon of cerebral autoregulation; the brain is open to insults of various kinds which can critically damage this structure. Intracellular Ca++ accumulation, excessive activation of excitatory amino acid receptors, lipid peroxidation and free radical releaserelated damage are but a few of the pathological processes that occur at the neuronal level leading to damage. The mechanism by which the brain can be provided protection when it is in a compromised state or likely to be compromised is known as cerebral protection. There are various modalities of pharmacologic (use of barbiturates, etomidate, isoflurane, steroids, Ca++, corticosteroids etc) and non-pharmacologic therapies (hypothermia, hyperventilation, induced hypotension, electrophysiologic monitoring, endovascular management etc) available for cerebral protection which finds place in the armamentarium of clinicians managing the critically injured brain. Our knowledge of the functioning of the brain at the molecular level and the various biochemico-pathological processes that are set into motion during critical states continues to evolve. This review article attempts to explain present understanding of the biochemical and pathological processes involved in neuronal damage while also looking at current available therapies (pharmacologic & nonpharmacologic) being utilized in different clinical settings.

Matched MeSH terms: Free Radicals
Molecularly imprinted polymer synthesis using RAFT polymerisation

Peter A.G. Cormack, Faizatul Shimal Mehamod

Sains Malaysiana, 2013;42:529-535.

In this paper, the synthesis and characterisation of caffeine-imprinted polymers are described. The polymers were prepared in monolithic form via both reversible addition-fragmentation chain-transfer (RAFT) polymerisation and conventional free radical polymerisation, using methacrylic acid and ethylene glycol dimethacrylate as the functional monomer and crosslinking agent, respectively. The potential benefits in applying RAFT polymerisation techniques towards the synthesis of molecularly imprinted polymers (MIPs) are explored and elucidated. The pore structures of the polymers produced were characterised by nitrogen sorption porosimetry and the molecular recognition properties of representative products were evaluated in high-performance liquid chromatography (HPLC) mode. Molecular imprinting effects were confirmed by analysing the relative retentions of analytes on imprinted and non-imprinted HPLC
stationary phases. It was found that a caffeine-imprinted polymer synthesised by RAFT polymerisation was superior to a polymer prepared using a conventional synthetic approach; the imprinting factor and column efficiency were found to be higher for the former material.

Matched MeSH terms: Free Radicals
Fulltext Antioxidative and acetylcholinesterase inhibitor potential of selected honey of Sabah, Malaysian Borneo

Philip, Y., Mohd Fadzelly, A. B.

International Food Research Journal, 2015;22(5):1953-1960.
MyJurnal

Honey is a sweet substance that can be obtain from flower nectar and secretes through transformations process by honey bees. The aim of this study was to compare the antioxidant and anti-cholinesterase activities of 4 wild honey (wild honey produced by different species of bees: Apis cerana, Apis andreniformis, Apis koschevnikovi and Apis nuluensis) collected from the secondary forest and 6 commercial (young and old Mangrove, young and old Upper mountain, Tropical, Potiukan) honey of Sabah, Malaysian Borneo. Antioxidant activities were determined using FRAP (Ferric Reducing Antioxidant Power), DPPH free radical scavenging and ABTS decolourization assays. Acetylcholinesterase inhibition effect was determined by enzyme inhibition method. The results of this study showed that wild honey produced by A.cerana collected from the Acacia tree extracted using 80% methanol displayed the highest DPPH free radical scavenging activity and ABTS decolorization assays. Whereas wild honey produced by A.nuluensis collected from the Chestnut tree extracted using 80% methanol displayed the highest FRAP activity. The wild honey produced by A. nuluensis also displayed the highest acetylcholinesterase properties as the antioxidant compounds contributed to the inhibitory properties of the enzyme. Manuka honey (produced from tea tree) found to be higher in antioxidant and acetylcholinesterase properties as compared to all other samples. The same trend of bioactivity was also observed in absolute methanol extracts. Strong positive correlation was found between antioxidant and acetylcholinesterase activity. Therefore, honey has the potential as natural antioxidant and acetylcholinesterase inhibition sources with promising potential benefits to human’s health.

Matched MeSH terms: Free Radicals
Evaluation of the Antioxidative and Hypo-cholesterolemic Effects of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), in Ameliorating Cardiovascular Disease

Rahman MA, Abdullah N, Aminudin N

Int J Med Mushrooms, 2018;20(10):961-969.
PMID: 30806268 DOI: 10.1615/IntJMedMushrooms.2018028370

Oxidative stress (OS) and hypercholesterolemia have been linked with a heightened risk of cardiovascular disease (CVD). Because of the numerous drawbacks of synthetic antioxidants and cholesterol-lowering drugs, natural antioxidative and hypocholesterolemic agents are of immense importance. This study was designed to determine both the OS-attenuating and cholesterol-lowering capacities of the hot water extract (HWE) and of five solvent-solvent-partitioned fractions of Ganoderma lucidum. In vitro antioxidative performance of G. lucidum HWE and fractions was measured through DPPH free radical scavenging, Folin-Ciocalteu assay, lipid peroxidation inhibition, and human low-density lipoprotein (LDL) oxidation inhibition. In vivo antioxidative performance of G. lucidum was assessed by measuring the plasma and liver antioxidative enzymatic activities (catalase, glutathione peroxidase, and superoxide dismutase) in G. lucidum HWE-fed rats. In the CVD tests, the HWE at 200 mg/kg b.w. lowered plasma levels of total cholesterol, triacylglycerol, and LDL cholesterol and increased high-density lipoprotein cholesterol. The current findings indicate the therapeutic potentiality of G. lucidum as an OS-attenuating and hypocholesterolemic agent en route to withstanding CVD complications.

Matched MeSH terms: Free Radicals
Fulltext Waste Fiber-Based Poly(hydroxamic acid) Ligand for Toxic Metals Removal from Industrial Wastewater

Rahman ML, Wong ZJ, Sarjadi MS, Joseph CG, Arshad SE, Musta B, et al.

Polymers (Basel), 2021 May 06;13(9).
PMID: 34066308 DOI: 10.3390/polym13091486

Toxic metals in the industrial wastewaters have been liable for drastic pollution hence a powerful and economical treatment technology is needed for water purification. For this reason, some pure cellulosic materials were derived from waste fiber to obtain an economical adsorbent for wastewater treatment. Conversion of cellulose into grafting materials such as poly(methyl acrylate)-grafted cellulose was performed by free radical grafting process. Consequently, poly(hydroxamic acid) ligand was produced from the grafted cellulose. The intermediate products and poly(hydroxamic acid) ligand were analyzed by FT-IR, FE-SEM, TEM, EDX, and XPS spectroscopy. The adsorption capacity (qe) of some toxic metals ions by the polymer ligand was found to be excellent, e.g., copper capacity (qe) was 346.7 mg·g-1 at pH 6. On the other hand, several metal ions such as cobalt chromium and nickel also demonstrated noteworthy sorption capacity at pH 6. The adsorption mechanism obeyed the pseudo second-order rate kinetic model due to the satisfactory correlated experimental sorption values (qe). Langmuir model isotherm study showed the significant correlation coefficient with all metal ions (R2 > 0.99), indicating that the single or monolayer adsorption was the dominant mode on the surface of the adsorbent. This polymer ligand showed good properties on reusability. The result shows that the adsorbent may be recycled for 6 cycles without any dropping of starting sorption capabilities. This polymeric ligand showed outstanding toxic metals removal magnitude, up to 90-99% of toxic metal ions can be removed from industrial wastewater.

Matched MeSH terms: Free Radicals
Ion-Imprinted Polymer for Selective Separation of Cerium(III) Ions from Rare Earth Mixture

Rahman ML, Puah PY, Sarjadi MS, Arshad SE, Musta B, Sarkar SM

J Nanosci Nanotechnol, 2019 09 01;19(9):5796-5802.
PMID: 30961741 DOI: 10.1166/jnn.2019.16538

Ion-imprinting polymers (IIPs) materials draw the great recognition because of the powerful selectivity to the desired metal ions. Therefore, the ion-imprinting polymer (Ce-IIP) was prepared by using cerium metal with amidoxime ligand as the complexing agent, in addition ethylene glycol dimethacrylate (EGDMA) and 2,2-azobisisobutyronitrile (AIBN) are crosslinking agent and free radical initiator, respectively. Aqueous HCl was applied to leach the cerium ions from the imprinted polymer for the creation of cavities of template, which is utilized for further cerium ions adsorption with high selectivity. The Ce-IIP was characterized by using ICP-MS, FE-SEM and also solid state analysis by UV-vis NIR spectroscopy. FT-IR study confirmed the complexation of the Ce-IIP was successful. The optimum pH was found to be 6 and the highest adsorption capacity was estimated about 145 mg g-1. Thus, the prepared Ce-IIP gave very good selectivity to cerium ions in the presence of lanthanide ions and also Ce-IIP can be reused 10 times without a substantial loss in adsorption capacity.

Matched MeSH terms: Free Radicals
Fulltext Effects of osmotic dehydration treatment on volatile compound (Myristicin) content and antioxidants property of nutmeg (Myristica fragrans) pericarp

Rahman N, Xin TB, Kamilah H, Ariffin F

J Food Sci Technol, 2018 Jan;55(1):183-189.
PMID: 29358809 DOI: 10.1007/s13197-017-2883-2

The effects of osmotic dehydration (OD) treatment on volatile compound (myristicin) content and the antioxidant capacity of nutmeg (Myristica fragrans) were studied. Fresh nutmeg pericarps were treated with varying sugar concentrations (60, 70, 80%) with different soaking periods at ambient temperature. The OD-treated nutmeg extracts were analyzed for myristicin content via Gas Chromatography Flame Ionization Detector. The phenolic content and antioxidant capacity were analyzed using Follin-Ciocalteu and a free radical scavenging activity assay. The myristicin content was highest (1.69 mg/100 mg) at 80% sugar concentration after 3 h of soaking. Total phenolic content and free radical scavenging activity were highest at 3 h of 80% sugar solution treatment with values of 76.90% and 1.75 mg GAE/g, respectively. OD treatment at varying sugar concentration levels and durations affects the production of myristicin and antioxidant composition. Treatment of nutmeg with OD at 80% sugar concentration for 3 h is preferable, resulting in an acceptable level of myristicin and high antioxidants.

Matched MeSH terms: Free Radicals
Dietary UKMR-1 roselle supplementation prevents nicotine-induced cardiac injury by inhibiting myocardial oxidative stress

Ramalingam A, Siti Balkis Budin, Lim Yc, Lislivia Si Yn, Satirah Zainalabidin

Sains Malaysiana, 2016;45:1131-1137.

UKMR-1, a local variant of mutant Roselle strain (Hibiscus sabdariffa) is enriched with free radical scavenging polyphenols
such as anthocyanin, vitamin C and hydroxycitric acid. However, pharmacological actions of UKMR-1 are not fully known.
This study was conducted to determine whether supplementation of aqueous UKMR-1 calyx extract was able to protect
against nicotine-induced cardiac injury in rats. In this experimental study, healthy male albino rats were randomly
allotted into three groups (n=7 per group): control, nicotine and UKMR-1+Nicotine groups. Nicotine (0.6 mg/kg, i.p.)
was administered to both nicotine and UKMR-1+Nicotine groups for 28 consecutive days. UKMR-1+Nicotine group also
received 100 mg/kg UKMR-1 extract orally via gavage 30 min prior to nicotine injection, daily. UKMR-1+Nicotine group
had significantly (p<0.05) higher lactate dehydrogenase (LDH) activity, as well as lower malondialdehyde content in
heart tissue homogenate than nicotine group, suggesting its cardio protective activity by inhibition of lipid peroxidation.
UKMR-1 also lowered (p<0.05) the blood pressure in nicotine-administered rats. In addition, UKMR-1 significantly (p<0.05)
restored activities of cytosolic superoxide dismutase, glutathione peroxidase and glutathione-S-transferase as well as
redox balance ratio (GSH:GSSG). In conclusion, UKMR-1 was a

Matched MeSH terms: Free Radicals
Cytoprotective Effect of Tocotrienol-Rich Fraction and α-Tocopherol Vitamin E Isoforms Against Glutamate-Induced Cell Death in Neuronal Cells

Rati Selvaraju T, Khaza'ai H, Vidyadaran S, Sokhini Abd Mutalib M, Ramachandran V, Hamdan Y

Int J Vitam Nutr Res, 2014;84(3-4):140-51.
PMID: 26098478 DOI: 10.1024/0300-9831/a000201

Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100-300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76% and 79% in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2%, 95.0%, and 95.6%, respectively (p<0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.

Matched MeSH terms: Free Radicals/antagonists & inhibitors
Antioxidants from tropical herbs

Razab R, Abdul-Aziz A

Nat Prod Commun, 2010 Mar;5(3):441-5.
PMID: 20420325

Plants that contain high amounts of polyphenolic compounds are potential candidates for natural antioxidant sources. Studies are on going in the search for new sources of antioxidants. Not much data are available on the antioxidant capacity of tropical herbs. With this in mind, 19 commonly consumed Malaysian herbs were analyzed for their polyphenolic content and antioxidant activities. A majority of these plants have never been studied before with regards to their polyphenolic content and antioxidant activities. The shoots of Anacardium occidentale, the shoots and fruits of Barringtonia racemosa, Pithecellobium jiringa and Parkia speciosa had high polyphenolic contents (> 150 microg gallic acid equivalents/mg dried plant) and antioxidant activities when measured using the ferric reducing antioxidant power (FRAP) (>1.2 mM) and Trolox equivalent antioxidant capacity (TEAC) assays (>2.4 mM). A strong correlation was observed between the two antioxidant assays (FRAP vs TEAC) implying that the plants could both scavenge free radicals and reduce oxidants. There was also a strong correlation between the antioxidant activities and polyphenolic content suggesting the observed antioxidant activities were contributed mainly by the polyphenolics in the plants.

Matched MeSH terms: Free Radicals
Fulltext Ameliorative Effects of Aquilaria malaccensis Leaves Aqueous Extract on Reproductive Toxicity Induced by Cyclophosphamide in Male Rats

Razak RNHA, Ismail F, Isa MLM, Wahab AYA, Muhammad H, Ramli R, et al.

Malays J Med Sci, 2019 Jan;26(1):44-57.
PMID: 30914892 MyJurnal DOI: 10.21315/mjms2019.26.1.4

Background: Cyclophosphamide (CP) is a widely used anti-neoplastic and immunosuppressive agent that is associated with adverse side effects including reproductive toxicity. Aquilaria malaccensis (AM) is a traditional medicinal plant which was reported to exhibit high anti-oxidant and free radical scavenging properties. The present study was aimed to evaluate the protective effects of AM leaves extract on sperm quality following toxic exposure to CP.
Methods: Forty-eight male Sprague Dawley rats were allocated into eight groups of six rats (n = 6): control, CP only (200 mg kg-1), AM only (100 mg kg-1, 300 mg kg-1 and 500 mg kg-1) and CP + AM (100 mg kg-1, 300 mg kg-1 and 500 mg kg-1). Animals were sacrificed after 63 days of treatment and the sperm from the caudal epididymis was taken for sperm analysis.
Results: The body and the reproductive organs weight, sperm count and motility did not differ between CP and other groups (P > 0.05). A significant increase (P < 0.05) in percentage of the dead and abnormal sperm were seen in the CP alone treated group compared to the control group. Co-administration of AM to the CP exposed rats significantly reduced the (P < 0.05) percentage of abnormal sperm as compared to the CP only group.
Conclusion: Overall, the present results represent the potential of AM to protect against CP induced reproductive toxicity.

Matched MeSH terms: Free Radicals
Smart pH-responsive co-polymeric hydrogels for controlled delivery of capecitabine: Fabrication, Optimization and in vivo toxicology screening

Rehman U, Sarfraz RM, Mahmood A, Hussain Z, Thu HE, Zafar N, et al.

Curr Drug Deliv, 2021 Feb 11.
PMID: 33583374 DOI: 10.2174/1567201818666210212085912

BACKGROUND: Despite exhibiting promising anticancer potential, the clinical significance of capecitabine (a potent prodrug of 5-fluorouracil used for treatment of colorectal cancer) is limited owing to its acidic and enzymatic hydrolysis, lower absorption following the oral administration, poor bioavailability, short plasma half-life and poor patient compliance.
OBJECTIVES: The present study was aimed to fabricate the capecitabine as smart pH-responsive hydrogel network to efficiently facilitate its oral delivery while shielding its stability in the gastric media.
METHODS: The smart pH sensitive HP-β-CD/agarose-g-poly(MAA) hydrogel network was developed using an aqueous free radical polymerization technique. The developed hydrogels were characterized for drug-loading efficiency, structural and compositional features, thermal stability, swelling behaviour, morphology, physical form, and release kinetics. The pH-responsive behaviour of developed hydrogels was established by conducting the swelling and release behaviour at different pH values (1.2 and 7.4), demonstrating significantly higher swelling and release at pH 7.4 as compared with pH 1.2. The capecitabine-loaded hydrogels were also screened for acute oral toxicity in animals by analysing the body weight, water and food intake, dermal toxicity, ocular toxicity, biochemical analysis, and histological examination.
RESULTS: The characteristic evaluations revealed that capecitabine (anticancer agent) was successfully loaded into the hydrogel network. Capecitabine loading was ranged from 71.22% to 90.12%. An interesting feature of hydrogel was its pH-responsive behaviour which triggers release at basic pH (94.25%). Optimum swelling (95%) was seen at pH 7.4. Based upon regression coefficient R2 (0.96 - 0.99) best fit model was zero order. The extensive toxicity evaluations evidenced good safety profile with no signs of oral, dermal or ocular toxicities, as well as no variations in blood parameters and histology of vital organs.
CONCLUSION: Our findings conclusively evinced that the developed hydrogel exhibited excellent pharmaceutical and therapeutic potential and thus can be employed as pH-responsive system for controlled delivery of anticancer agents.

Matched MeSH terms: Free Radicals
Fulltext Radiation dose enhancement effects of superparamagnetic iron oxide nanoparticles to the t24 bladder cancer cell lines irradiated with megavoltage photon beam radiotherapy

Rosmazihana Mat Lazim, Raizulnasuha Ab Rashid, Wan Nordiana Rahman, Binh. T.T. Pham, Brian S. Hawkett, Moshi Geso

Jurnal Sains Nuklear Malaysia, 2018;30(2):30-38.
MyJurnal

Therapeutic application of metallic nanoparticles such as gold nanoparticles have been extensively investigated and intriguing finding have been reported. Superparamagnetic iron oxide nanoparticles (SPION) could also potentially have therapeutic properties that can be exploited to enhance radiotherapy outcome. In this study, investigations on the dose enhancement effects inflicted by SPIONs under irradiation with megavoltage photon beam radiotherapy were conducted. T24 human bladder cancer cell lines were pretreated with 1 mMol/L of SPION and irradiated with 6 MV and 10 MV photon beam at different doses.The non-treated cells irradiation was used as a control. Clonogenic assay was performed to determine the cell survival. Linear quadratic (LQ) model are used as fitting curve and does enhancement factors (DEF) were extrapolated from the curves. The cytotoxicity indicated cell growth normally after 72 hours and no long term cytotoxicity effects of SPIONs towards the cells were observed. The dose enhancement effects were observed for both 6 MV and 10 MV photon beam with DEF obtained 1.71 and 2.50, respectively. This reduction of cell colonies growth could be resulted from the interaction that induced free radical and reactive oxygen species (ROS) by megavoltage photon beams. The SPIONs were therefore act as multifunction nanoparticle both in diagnostic agent and radiotherapy as radiation dose enhancer, thus clearly qualified as future theranostic agents.

Matched MeSH terms: Free Radicals
A bio-based, facile approach for the preparation of covalently functionalized carbon nanotubes aqueous suspensions and their potential as heat transfer fluids

Sadri R, Hosseini M, Kazi SN, Bagheri S, Zubir N, Solangi KH, et al.

J Colloid Interface Sci, 2017 Oct 15;504:115-123.
PMID: 28531649 DOI: 10.1016/j.jcis.2017.03.051

In this study, we propose an innovative, bio-based, environmentally friendly approach for the covalent functionalization of multi-walled carbon nanotubes using clove buds. This approach is innovative because we do not use toxic and hazardous acids which are typically used in common carbon nanomaterial functionalization procedures. The MWCNTs are functionalized in one pot using a free radical grafting reaction. The clove-functionalized MWCNTs (CMWCNTs) are then dispersed in distilled water (DI water), producing a highly stable CMWCNT aqueous suspension. The CMWCNTs are characterized using Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The electrostatic interactions between the CMWCNT colloidal particles in DI water are verified via zeta potential measurements. UV-vis spectroscopy is also used to examine the stability of the CMWCNTs in the base fluid. The thermo-physical properties of the CMWCNT nano-fluids are examined experimentally and indeed, this nano-fluid shows remarkably improved thermo-physical properties, indicating its superb potential for various thermal applications.

Matched MeSH terms: Free Radicals
The relationship between Helicobacter pylori and oxygen-derived free radicals in the mechanism of duodenal ulceration

Salim AS

Intern. Med., 1993 May;32(5):359-64.
PMID: 8400493

This prospective randomized study investigated the possibility that duodenal ulcer relapse associated with Helicobacter Pylori infection is mediated by oxygen-derived free radicals. To this end, the radical scavengers allopurinol (50 mg 4 times daily) and dimethyl sulphoxide (DMSO, 500 mg 4 times daily) were administered orally. One hundred and forty-six consecutive patients with previous symptomatic endoscopy proven duodenal ulceration, which had been shown endoscopically to have healed in the presence of gastric mucosal infection with Helicobacter Pylori, were randomized to receive for the period of one year either placebo, or cimetidine 400 mg at bedtime, or allopurinol, or DMSO. In one hundred and twenty-six patients evaluable for efficacy, the cumulative relapse at one year was: placebo 47%, cimetidine 24%, allopurinol 6% and DMSO 6%. Cimetidine was significantly effective in preventing the relapse (p < 0.01), however allopurinol and DMSO were superior to cimetidine in this respect (p < 0.05). In the patients who relapsed, ulcer recurrence tended to occur early in those on placebo and cimetidine and to be evenly distributed over the year in those on free radical scavenging therapy. In all groups, ulcer recurrence throughout the maintenance year was more frequently symptomatic than silent. The incidence of infection with Helicobacter Pylori was not influenced by any of the regimens employed and the bacterium was detected with every relapse noted in this study and during the follow-up endoscopy which was carried out at 6 months and at 12 months during the maintenance year. The results suggest that oxygen-derived free radicals are involved in the relapse of duodenal ulceration in patients infected with Helicobacter Pylori.

Matched MeSH terms: Free Radicals/metabolism
Fulltext Oxygen-derived free radical scavengers: a new approach to the problem of refractory peptic ulceration

Salim AS

Med J Malaysia, 1993 Dec;48(4):392-6.
PMID: 8183161

Refractory peptic ulceration refers to ulcers which are slow to heal despite active treatment for at least three months. Oxygen-derived free radicals are cytotoxic and promote tissue injury. Twelve consecutive patients with refractory peptic ulceration (eight with duodenal ulcers and four with solitary pre-pyloric gastric ulcers) were treated using the radical scavengers allopurinol or dimethyl sulphoxide. This treatment was well tolerated by all patients and produced no adverse effects. Endoscopic examination four weeks later demonstrated complete healing (an intact gastric or duodenal mucosa without any breaches) in all patients. The results suggest that oxygen-derived free radicals perpetuate the process of peptic ulceration and exert an adverse effect on healing. Scavengers of these radicals stimulate the healing of refractory gastric and duodenal ulceration.

Matched MeSH terms: Free Radicals

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