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Displaying publications 41 - 49 of 49 in total

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Fulltext Protective Effect of Palm Oil-Derived Tocotrienol-Rich Fraction Against Retinal Neurodegenerative Changes in Rats with Streptozotocin-Induced Diabetic Retinopathy

Sadikan MZ, Nasir NAA, Agarwal R, Ismail NM

Biomolecules, 2020 04 05;10(4).
PMID: 32260544 DOI: 10.3390/biom10040556

: Oxidative stress plays an important role in retinal neurodegeneration and angiogenesis associated with diabetes. In this study, we investigated the effect of the tocotrienol-rich fraction (TRF), a potent antioxidant, against diabetes-induced changes in retinal layer thickness (RLT), retinal cell count (RCC), retinal cell apoptosis, and retinal expression of vascular endothelial growth factor (VEGF) in rats. Additionally, the efficacy of TRF after administration by two different routes was compared. The diabetes was induced in Sprague-Dawley rats by intraperitoneal injection of streptozotocin. Subsequently, diabetic rats received either oral or topical treatment with vehicle or TRF. Additionally, a group of non-diabetic rats was included with either oral or topical treatment with a vehicle. After 12 weeks of the treatment period, rats were euthanized, and retinas were collected for measurement of RLT, RCC, retinal cell apoptosis, and VEGF expression. RLT and RCC in the ganglion cell layer were reduced in all diabetic groups compared to control groups (p < 0.01). However, at the end of the experimental period, oral TRF-treated rats showed a significantly greater RLT compared to topical TRF-treated rats. A similar observation was made for retinal cell apoptosis and VEGF expression. In conclusion, oral TRF supplementation protects against retinal degenerative changes and an increase in VEGF expression in rats with streptozotocin-induced diabetic retinopathy. Similar effects were not observed after topical administration of TRF.
Magnesium acetyltaurate protects against endothelin-1 induced RGC loss by reducing neuroinflammation in Sprague dawley rats

Nor Arfuzir NN, Agarwal R, Iezhitsa I, Agarwal P, Ismail NM

Exp Eye Res, 2020 05;194:107996.
PMID: 32156652 DOI: 10.1016/j.exer.2020.107996

Endothelin-1 (ET-1), a potent vasoconstrictor, plays a significant role in the pathophysiology of ocular conditions like glaucoma. Glaucoma is characterized by apoptotic loss of retinal ganglion cells (RGCs) and loss of visual fields and is a leading cause of irreversible blindness. In glaucomatous eyes, retinal ischemia causes release of pro-inflammatory mediators such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α and promotes activation of transcription factors such as nuclear factor kappa B (NFKB) and c-Jun. Magnesium acetyltaurate (MgAT) has previously been shown to protect against ET-1 induced retinal and optic nerve damage. Current study investigated the mechanisms underlying these effects of MgAT, which so far remain unknown. Sprague dawley rats were intravitreally injected with ET-1 with or without pretreatment with MgAT. Seven days post-injection, retinal expression of IL-1β, IL-6, TNF-α, NFKB and c-Jun protein and genes was determined using multiplex assay, Western blot and PCR. Animals were subjected to retrograde labeling of RGCs to determine the extent of RGC survival. RGC survival was also examined using Brn3A staining. Furthermore, visual functions of rats were determined using Morris water maze. It was observed that pre-treatment with MgAT protects against ET-1 induced increase in the retinal expression of IL-1β, IL-6 and TNF-α proteins and genes. It also protected against ET-1 induced activation of NFKB and c-Jun. These effects of MgAT were associated with greater RGC survival and preservation of visual functions in rats. In conclusion, MgAT prevents ET-1 induced RGC loss and loss of visual functions by suppressing neuroinflammatory reaction in rat retinas.
Neuroprotective effect of poly(lactic-co-glycolic acid) nanoparticle-bound brain-derived neurotrophic factor in a permanent middle cerebral artery occlusion model of ischemia in rats

Kamarudin SN, Iezhitsa I, Tripathy M, Alyautdin R, Ismail NM

Acta Neurobiol Exp (Wars), 2020;80(1):1-18.
PMID: 32214270

Poly (lactide‑co‑glycolide) (PLGA) nanoparticles (NPs) are biodegradable carriers that participate in the transport of neuroprotective drugs across the blood brain barrier (BBB). Targeted brain‑derived neurotrophic factor (BDNF) delivery across the BBB could provide neuroprotection in brain injury. We tested the neuroprotective effect of PLGA nanoparticle‑bound BDNF in a permanent middle cerebral artery occlusion (pMCAO) model of ischemia in rats. Sprague‑Dawley rats were subjected to pMCAO. Four hours after pMCAO, two groups were intravenously treated with BDNF and NP‑BDNF, respectively. Functional outcome was assessed at 2 and 24 h after pMCAO, using the modified neurologic severity score (mNSS) and rotarod performance tests. Following functional assessments, rats were euthanized blood was taken to assess levels of the neurobiomarkers neuron‑specific enolase and S100 calcium‑binding protein β (S100β), and the brain was evaluated to measure the infarct volume. The NP‑BDNF‑treated group showed significant improvement in mNSS compared with pMCAO and BDNF‑treated groups and showed improved rotarod performance. The infarct volume in rats treated with NP‑BDNFs was also significantly smaller. These results were further corroborated by correlating differences in estimated NSE and S100β. NP‑BDNFs exhibit a significant neuroprotective effect in the pMCAO model of ischemia in rats.
Fulltext Optical Properties and Conductivity of PVA-H3PO4 (Polyvinyl Alcohol-Phosphoric Acid) Film Blend Irradiated by γ-Rays

Susilawati S, Prayogi S, Arif MF, Ismail NM, Bilad MR, Asy'ari M

Polymers (Basel), 2021 Mar 28;13(7).
PMID: 33800592 DOI: 10.3390/polym13071065

This study assesses the optical properties and conductivity of PVA-H3PO4 (polyvinyl alcohol-phosphoric acid) polymer film blend irradiated by gamma (γ) rays. The PVA-H3PO4 polymer film blend was prepared by the solvent-casting method at H3PO4 concentrations of 75 v% and 85 v%, and then irradiated up to 25 kGy using γ-rays from the Cobalt-60 isotope source. The optical absorption spectrum was measured using an ultraviolet-visible spectrophotometer over a wavelength range of 200 to 700 nm. It was found that the absorption peaks are in three regions, namely two peaks in the ultraviolet region (310 and 350 nm) and one peak in the visible region (550 nm). The presence of an absorption peak after being exposed to hυ energy indicates a transition of electrons from HOMO to LUMO within the polymer chain. The study of optical absorption shows that the energy band gap (energy gap) depends on the radiation dose and the concentration of H3PO4 in the polymer film blend. The optical absorption, absorption edge, and energy gap decrease with increasing H3PO4 concentration and radiation dose. The interaction between PVA and H3PO4 blend led to an increase in the conductivity of the resulting polymer blend film.
Fulltext Magnesium acetyltaurate prevents retinal damage and visual impairment in rats through suppression of NMDA-induced upregulation of NF-κB, p53 and AP-1 (c-Jun/c-Fos)

Lambuk L, Iezhitsa I, Agarwal R, Agarwal P, Peresypkina A, Pobeda A, et al.

Neural Regen Res, 2021 Nov;16(11):2330-2344.
PMID: 33818520 DOI: 10.4103/1673-5374.310691

Magnesium acetyltaurate (MgAT) has been shown to have a protective effect against N-methyl-D-aspartate (NMDA)-induced retinal cell apoptosis. The current study investigated the involvement of nuclear factor kappa-B (NF-κB), p53 and AP-1 family members (c-Jun/c-Fos) in neuroprotection by MgAT against NMDA-induced retinal damage. In this study, Sprague-Dawley rats were randomized to undergo intravitreal injection of vehicle, NMDA or MgAT as pre-treatment to NMDA. Seven days after injections, retinal ganglion cells survival was detected using retrograde labelling with fluorogold and BRN3A immunostaining. Functional outcome of retinal damage was assessed using electroretinography, and the mechanisms underlying antiapoptotic effect of MgAT were investigated through assessment of retinal gene expression of NF-κB, p53 and AP-1 family members (c-Jun/c-Fos) using reverse transcription-polymerase chain reaction. Retinal phospho-NF-κB, phospho-p53 and AP-1 levels were evaluated using western blot assay. Rat visual functions were evaluated using visual object recognition tests. Both retrograde labelling and BRN3A immunostaining revealed a significant increase in the number of retinal ganglion cells in rats receiving intravitreal injection of MgAT compared with the rats receiving intravitreal injection of NMDA. Electroretinography indicated that pre-treatment with MgAT partially preserved the functional activity of NMDA-exposed retinas. MgAT abolished NMDA-induced increase of retinal phospho-NF-κB, phospho-p53 and AP-1 expression and suppressed NMDA-induced transcriptional activity of NF-κB, p53 and AP-1 family members (c-Jun/c-Fos). Visual object recognition tests showed that MgAT reduced difficulties in recognizing the visual cues (i.e. objects with different shapes) after NMDA exposure, suggesting that visual functions of rats were relatively preserved by pre-treatment with MgAT. In conclusion, pre-treatment with MgAT prevents NMDA induced retinal injury by inhibiting NMDA-induced neuronal apoptosis via downregulation of transcriptional activity of NF-κB, p53 and AP-1-mediated c-Jun/c-Fos. The experiments were approved by the Animal Ethics Committee of Universiti Teknologi MARA (UiTM), Malaysia, UiTM CARE No 118/2015 on December 4, 2015 and UiTM CARE No 220/7/2017 on December 8, 2017 and Ethics Committee of Belgorod State National Research University, Russia, No 02/20 on January 10, 2020.
Fulltext Improvement of Properties and Performances of Polyethersulfone Ultrafiltration Membrane by Blending with Bio-Based Dragonbloodin Resin

Ambarita AC, Mulyati S, Arahman N, Bilad MR, Shamsuddin N, Ismail NM

Polymers (Basel), 2021 Dec 17;13(24).
PMID: 34960986 DOI: 10.3390/polym13244436

Polyethersulfone (PES) is the most commonly used polymer for membrane ultrafiltration because of its superior properties. However, it is hydrophobic, as such susceptible to fouling and low permeation rate. This study proposes a novel bio-based additive of dragonbloodin resin (DBR) for improving the properties and performance of PES-based membranes. Four flat sheet membranes were prepared by varying the concentration of DBR (0-3%) in the dope solutions using the phase inversion method. After fabrication, the membranes were thoroughly characterized and were tested for filtration of humic acid solution to investigate the effect of DBR loading. Results showed that the hydrophilicity, porosity, and water uptake increased along with the DBR loadings. The presence of DBR in the dope solution fastened the phase inversion, leading to a more porous microstructure, resulted in membranes with higher number and larger pore sizes. Those properties led to more superior hydraulic performances. The PES membranes loaded with DBR reached a clean water flux of 246.79 L/(m2·h), 25-folds higher than the pristine PES membrane at a loading of 3%. The flux of humic acid solution reached 154.5 ± 6.6 L/(m2·h), 30-folds higher than the pristine PES membrane with a slight decrease in rejection (71% vs. 60%). Moreover, DBR loaded membranes (2% and 3%) showed an almost complete flux recovery ratio over five cleaning cycles, demonstrating their excellent antifouling property. The hydraulic performance could possibly be enhanced by leaching the entrapped DBR to create more voids and pores for water permeation.
Fulltext Fabrication of Polyvinylidene Difluoride Membrane with Enhanced Pore and Filtration Properties by Using Tannic Acid as an Additive

Mulyati S, Aprilia S, Muchtar S, Syamsuddin Y, Rosnelly CM, Bilad MR, et al.

Polymers (Basel), 2022 Jan 03;14(1).
PMID: 35012208 DOI: 10.3390/polym14010186

Potential use of tannic acid (TA) as an additive for fabrication of polyvinylidene difluoride (PVDF) membrane was investigated. The TA was introduced by blending into the dope solution with varying concentrations of 0, 1, 1.5, and 2 wt%. The prepared membranes were characterized and evaluated for filtration of humic acid (HA) solution. The stability of the membrane under harsh treatment was also evaluated by one-week exposure to acid and alkaline conditions. The results show that TA loadings enhanced the resulting membrane properties. It increased the bulk porosity, water uptake, and hydrophilicity, which translated into improved clean water flux from 15.4 L/m2.h for the pristine PVDF membrane up to 3.3× for the TA-modified membranes with the 2 wt% TA loading. The flux recovery ratio (FRR) of the TA-modified membranes (FRRs = 78-83%) was higher than the pristine one (FRR = 58.54%), with suitable chemical stability too. The improved antifouling property for the TA-modified membranes was attributed to their enhanced hydrophilicity thanks to improved morphology and residual TA in the membrane matric.
Fulltext School dental screening programmes for oral health

Arora A, Kumbargere Nagraj S, Khattri S, Ismail NM, Eachempati P

Cochrane Database Syst Rev, 2022 Jul 27;7(7):CD012595.
PMID: 35894680 DOI: 10.1002/14651858.CD012595.pub4

BACKGROUND: In school dental screening, a dental health professional visually inspects children's oral cavities in a school setting and provides information for parents on their child's current oral health status and treatment needs. Screening at school aims to identify potential problems before symptomatic disease presentation, hence prompting preventive and therapeutic oral health care for the children. This review evaluates the effectiveness of school dental screening for improving oral health status. It is the second update of a review originally published in December 2017 and first updated in August 2019.
OBJECTIVES: To assess the effectiveness of school dental screening programmes on overall oral health status and use of dental services.
SEARCH METHODS: An information specialist searched four bibliographic databases up to 15 October 2021 and used additional search methods to identify published, unpublished and ongoing studies.
SELECTION CRITERIA: We included randomised controlled trials (RCTs; cluster- or individually randomised) that evaluated school dental screening compared with no intervention, or that compared two different types of screening.
DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane.
MAIN RESULTS: The previous version of this review included seven RCTs, and our updated search identified one additional trial. Therefore, this update included eight trials (six cluster-RCTs) with 21,290 children aged 4 to 15 years. Four trials were conducted in the UK, two in India, one in the USA and one in Saudi Arabia. We rated two trials at low risk of bias, three at high risk of bias and three at unclear risk of bias. No trials had long-term follow-up to ascertain the lasting effects of school dental screening. The trials assessed outcomes at 3 to 11 months of follow-up. No trials reported the proportion of children with treated or untreated oral diseases other than caries. Neither did they report on cost-effectiveness or adverse events. Four trials evaluated traditional screening versus no screening. We performed a meta-analysis for the outcome 'dental attendance' and found an inconclusive result with high heterogeneity. The heterogeneity was partly due to study design (three cluster-RCTs and one individually randomised trial). Due to this inconsistency, and unclear risk of bias, we downgraded the evidence to very low certainty, and we are unable to draw conclusions about this comparison. Two cluster-RCTs (both four-arm trials) evaluated criteria-based screening versus no screening, suggesting a possible small benefit (pooled risk ratio (RR) 1.07, 95% confidence interval (CI) 0.99 to 1.16; low-certainty evidence). There was no evidence of a difference when comparing criteria-based screening to traditional screening (RR 1.01, 95% CI 0.94 to 1.08; very low-certainty evidence). One trial compared a specific (personalised) referral letter to a non-specific letter. Results favoured the specific referral letter for increasing attendance at general dentist services (RR 1.39, 95% CI 1.09 to 1.77; very low-certainty evidence) and attendance at specialist orthodontist services (RR 1.90, 95% CI 1.18 to 3.06; very low-certainty evidence). One trial compared screening supplemented with motivation to screening alone. Dental attendance was more likely after screening supplemented with motivation (RR 3.08, 95% CI 2.57 to 3.71; very low-certainty evidence). One trial compared referral to a specific dental treatment facility with advice to attend a dentist. There was no evidence of a difference in dental attendance between these two referrals (RR 0.91, 95% CI 0.34 to 2.47; very low-certainty evidence). Only one trial reported the proportion of children with treated dental caries. This trial evaluated a post-screening referral letter based on the common-sense model of self-regulation (a theoretical framework that explains how people understand and respond to threats to their health), with or without a dental information guide, compared to a standard referral letter. The findings were inconclusive. Due to high risk of bias, indirectness and imprecision, we assessed the evidence as very low certainty.
AUTHORS' CONCLUSIONS: The evidence is insufficient to draw conclusions about whether there is a role for school dental screening in improving dental attendance. We are uncertain whether traditional screening is better than no screening (very low-certainty evidence). Criteria-based screening may improve dental attendance when compared to no screening (low-certainty evidence). However, when compared to traditional screening, there is no evidence of a difference in dental attendance (very low-certainty evidence). For children requiring treatment, personalised or specific referral letters may improve dental attendance when compared to non-specific referral letters (very low-certainty evidence). Screening supplemented with motivation (oral health education and offer of free treatment) may improve dental attendance in comparison to screening alone (very low-certainty evidence). We are uncertain whether a referral letter based on the 'common-sense model of self-regulation' is better than a standard referral letter (very low-certainty evidence) or whether specific referral to a dental treatment facility is better than a generic advice letter to visit the dentist (very low-certainty evidence). The trials included in this review evaluated effects of school dental screening in the short term. None of them evaluated its effectiveness for improving oral health or addressed possible adverse effects or costs.
Fulltext Valorization of discarded face mask for bioactive compound synthesis and photodegradation of dye

Kiong TC, Nordin N, Ahmad Ruslan NAA, Kan SY, Ismail NM, Zakaria Z, et al.

Environ Res, 2022 Oct;213:113737.
PMID: 35752328 DOI: 10.1016/j.envres.2022.113737

To keep COVID-19 at bay, most countries have mandated the use of face masks in public places and imposed heavy penalties for those who fail to do so. This has inadvertently created a huge demand for disposable face masks and worsened the problem of littering, where a large number of used masks are constantly discarded into the environment. As such, an efficient and innovative waste management strategy for the discarded face mask is urgently needed. This study presents the transformation of discarded face mask into catalyst termed 'mask waste ash catalyst (MWAC)' to synthesise bisindolylmethanes (BIMs), alkaloids that possess antibacterial, antioxidant and antiviral properties. Using commercially available aldehydes and indole, an excellent yield of reaction (62-94%) was achieved using the MWAC in the presence of water as the sole solvent. On the other hand, the FT-IR spectrum of MWAC showed the absorption bands at 2337 cm-1, 1415 cm-1 and 871 cm-1, which correspond to the signals of calcium oxide. It is then proposed that the calcium oxides mainly present in MWAC can protonate oxygen atoms in the carbonyl molecule of the aldehyde group, thus facilitating the nucleophile attack by indole which consequently improved the product yield. Moreover, the MWAC is also observed to facilitate the photodegradation of methylene blue with an efficiency of up to 94.55%. Our results showed the potential applications of the MWAC derived from discarded face masks as a sustainable catalyst for bioactive compound synthesis and photodegradation of dye compounds.