zolkapli bin eshak

Dr. zolkapli bin eshak

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 October 2022 in Antioxidants
Verified
Journal Article
Open access
PDF file
NRNor Shahida Abdul Rahman
Nor Shahida Abdul Rahman
NKNor Ashikin Mohamed Noor Khan
Nor Ashikin Mohamed Noor Khan
ZEzolkapli bin eshak
zolkapli bin eshak
MSMimi Sophia Sarbandi
Mimi Sophia Sarbandi
AKAqila-Akmal Mohammad Kamal
Aqila-Akmal Mohammad Kamal
FOFezah Othman
Fezah Othman
Vitrification is an important tool to store surplus embryos in assisted reproductive technology (ART). However, vitrification increases oxidative damage and results in decreased viability. Studies have reported that L-glutathione (GSH) supplementation improves the preimplantation development of murine embryos. Glutathione constitutes the major non-protein sulphydryl compound in mammalian cells, which confers protection against oxidative damage. However, the effect of GSH supplementation on embryonic vitrification outcomes has yet to be reported. This study aims to determine whether GSH supplementation in culture media improves in vitro culture and vitrification outcomes, as observed through embryo morphology and preimplantation development. Female BALB/c mice aged 6–8 weeks were superovulated through an intraperitoneal injection of 10 IU of pregnant mare serum gonadotrophin (PMSG), followed by 10 IU of human chorionic gonadotrophin (hCG) 48 h later. The mated mice were euthanized by cervical dislocation 48 h after hCG to harvest embryos. Two-cell embryos were randomly assigned to be cultured in either Group 1 (GSH-free medium), Group 2 (GSH-free medium with vitrification), Group 3 (0.01 mM GSH-supplemented medium), or Group 4 (0.01 mM GSH-supplemented medium with vitrification). Non-vitrified (Groups 1 and 3) and vitrified (Groups 2 and 4) embryos were observed for morphological quality and preimplantation development at 24, 48, 72, and 96 h. In the non-vitrified groups, there were significant increases in the number of Grade-1 blastocysts in GSH cultures (p < 0.05). Similarly, in the vitrified groups, GSH supplementation was also seen to significantly increase blastocyst formation. Exogenous GSH supplementation resulted in a significant increase in intracellular GSH, a release of cytochrome c from mitochondria, and a parallel decrease in intracellular reactive oxygen species (ROS) levels in vitrified eight-cell embryos (p < 0.05). GSH supplementation was shown to upregulate Bcl2 expression and downregulate Bax expression in the vitrified preimplantation embryo group. The action of exogenous GSH was concomitant with an increase in the relative abundance of Gpx1 and Sod1. In conclusion, our study demonstrated the novel use and practical applicability of GSH supplementation for improving embryonic cryotolerance via a decrease in ROS levels and the inhibition of apoptotic events by improvement in oxidative status.


31 December 2022 in Journal of Sustainability Science and Management
Verified
Journal Article
Closed access
MAMuhammad Amirul Adli
Muhammad Amirul Adli
RZRozaini Mohd Zohdi
Rozaini Mohd Zohdi
NONurul ‘aQilah Othman
Nurul ‘aQilah Othman
NANur Suhaili Mohamed Amin
Nur Suhaili Mohamed Amin
SMShahida Muhamad Mukhtar
Shahida Muhamad Mukhtar
BEBelantara Sr Enterprise
Belantara Sr Enterprise
This study aims to determine the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of ethanolic extract propolis (EEP) and water extract propolis (WEP) derived from six Malaysian stingless bee species. The TPC and TFC were measured by Folin-Ciocalteu colorimetric and aluminium chloride methods, respectively. The antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. The results indicated that EEP of Geniotrigona thoracica had the highest TPC and TFC at 259.84 ± 4.97 mg/g GAE and 435.00 ± 6.57 mg/g QE, respectively. Similarly, EEP of G. thoracica exhibited the greatest free radical scavenging activity with the percentage of inhibition at 88.00 ± 13.34% and IC50 of 104.20μg/mL. Antioxidant activity was highly correlated with TPC (R2 = -0.744, p < 0.05) whereas no correlation was observed between TFC and antioxidant activity. This study indicates that the antioxidant property of the propolis extract may be influenced by elevated levels of phenolic content. In conclusion, ethanolic extract of G. thoracica is the greatest source of antioxidants among the six tested Malaysian stingless bee propolis and this suggests that the extract may serve as a promising source of antioxidant agent.

20 January 2023 in Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
Verified
Journal Article
Open access
PDF file
ZGZulkifli Abdul Ghaffar
Zulkifli Abdul Ghaffar
SKSalmiah Kasolang
Salmiah Kasolang
AHAhmad Hussein Abdul Hamid
Ahmad Hussein Abdul Hamid
ZEzolkapli bin eshak
zolkapli bin eshak
A swirl atomizer is a widely applied spray-generating device. The swirling motion of a swirl atomizer is induced either by a tangential inlet or a swirl-generating vane. The swirling effect produces a spray with a wide angle which is important in various applications such as gas cooling, diesel engine combustion, and automatic hand sanitizer. An intense swirling mechanism was reported to significantly affect the spray angle. An attempt was made by combining tangential inlet and swirl-generating vane in a single embodiment to create a more intense swirling effect. The experiment was conducted with pipe flow in transition and turbulence regimes. The shadowgraph technique was applied to acquire the spray images. The images were processed using image processing software. It was found that the combined swirling mechanism produces a wider spray angle compared to the individual tangential inlet swirl atomizer. It was also found that the swirling intensity has a bigger effect on the spray angle than the Reynolds number.

30 December 2023 in Malaysian Applied Biology
Verified
Journal Article
Open access
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SKSiti Syafinaz Kamaruzzaman
Siti Syafinaz Kamaruzzaman
CMChe Ku Afina Haida Che Ku Mazuan
Che Ku Afina Haida Che Ku Mazuan
SRShamima Abdul Rahman
Shamima Abdul Rahman
IMImtiaz Khalid Mohamed
Imtiaz Khalid Mohamed
ZEzolkapli bin eshak
zolkapli bin eshak
MMMAHANI MAHADI
MAHANI MAHADI
Neptunia oleracea also known as water mimosa is widely consumed by people worldwide including Malaysia. This plant was claimed able to treat several diseases such as epileptic convulsion, syphilis, jaundice, and bloody diarrhea. Moreover, it has been reported to possess antimicrobial, antioxidant, and anti-ulcer properties that benefit human health. Hence, this study investigates the content of macronutrients, micronutrients, phytochemical constituents, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant properties in the aqueous leaf extract of this plant. The study found that N. oleracea leaves were possessed with high fiber (52%), moisture (23.33%), fat (5.33%), protein (5.25%), carbohydrate (6.42%), ash (7.67%), and mineral content with a sequence of Potassium > Calcium > Sodium > Phosphorus. A positive result of tannins, steroids, phenols, and flavonoids were detected. High values of TPC and TFC which were 136.19 ± 0.62 mg GAE/g and 829.17 ± 19.09 mg GAE/g of dry weight respectively were obtained. Meanwhile, the hydrogen peroxide scavenging activity of the plant extract produced an IC50 of 70.09 µg/mL. The presence of a high content of polyphenolic compounds may reflect the antioxidant properties of this plant. In conclusion, the aqueous extract of N. oleracea leaves showed the presence of various phytochemical constituents and has a high content of TPC and TFC which may be derived from its nutritional content. Hence, consumption of N. oleracea leaves is useful for human health and disease prevention.

12 October 2023 in Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
Verified
Journal Article
Open access
PDF file
ZTZatil Izzah Ahmad Tarmizi
Zatil Izzah Ahmad Tarmizi
RARoshafima Rasit Ali
Roshafima Rasit Ali
Mohamed Mahmoud NasefMohamed Mahmoud Nasef
Mohamed Mahmoud Nasef
ARAfifah Mardhiah Mohamed Radzi
Afifah Mardhiah Mohamed Radzi
AAAbdah Md Akim
Abdah Md Akim
SFSyazwani Mohd Faizo
Syazwani Mohd Faizo
Polyurethane (PU) membranes was prepared using electrospinning followed by modification with 2-hydroxyethyl methacrylate (HEMA) by radiation-induced grafting (RIG) copolymerization method via electron beam. The lack of knowledge of polymer properties of PU-based membrane prepared using RIG method need for dedicated study. Thus, the effect of thermal stability, in vitro degradation, water uptake analysis, and surface morphology after 84 days’ incubation times toward grafted PU-g-poly(HEMA) membrane was evaluated for the first time using thermal gravimetric analysis (TGA), analysis of mass, percentage of water uptake and Scanning Electron Microscope (SEM), respectively. Based on the DTGA curves, the electrospun PU exhibits two-stage of deposition. After grafted with HEMA, the first stage of decomposition was shifted to the lower temperature, and the second stage of decomposition was shifted to a higher temperature. At 500 °C, PU grafted with HEMA leaves residue about 3.526% more elevated in value than original material of PU, which is 1.151%. Degradation test showed that a higher percentage degree of grafting was lowering the percentage of weight loss. SEM images supported the morphology observation shows no noticeable changes such as cracked or eroded has occurred. In conclusion, electrospun PU grafted with HEMA was improved its thermal stability, stable in swelling properties and was found competent to degrade slowly in phosphate buffer saline (PBS). The results show that PU-g-poly(HEMA) exhibits better thermal stability than pure poly(HEMA) and the amorphous regions give the polymer toughness and could be up-and coming candidates for tissue engineering including artificial blood contracting medical devices.