Displaying all 9 publications

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  1. Jaswir, I., Noviendri, D., Salleh, H.M., Taher, M., Mohamed, F., Octavianti, F., et al.
    MyJurnal
    Supercritical carbon dioxide (SC-CO2) extraction of fucoxanthin is more advantageous over conventional solvent extraction as it is less toxic, less hazardous to the environment and preserves the bioactivity of fucoxanthin. A face-centered central composite design (FCCCD) based on response surface methodology (RSM) was employed for SC-CO2 extraction of oils and fucoxanthin from the brown seaweed Sargassum binderi, with ethanol as a co- solvent. Three independent parameters namely, extraction temperature (A: 40, 50, 60oC), pressure (B: 2900, 3625, 4350 psig and particle size (C: 90, 500 and 1000 µm) were investigated to optimize extraction oil yields (EOY) and fucoxanthin yields (FY). A regression model was developed, tested for quality of fit (R2) and expressed in the form of 3D response surface curve and 2D contour. The optimum extraction conditions were obtained at extraction temperature (A) 50oC, pressure (B) 3625 psig and particle size (C) 500 µm. Under these conditions, optimal EOY and FY were 10.04 mg/g and 3188.99 µg/g, respectively. The difference between the lowest and the highest response in EOY and FY were 5.44 – 10.04 mg/g and 2109.10 - 3188.90 µg/g, respectively. The lowest yields were identified at 60oC, 2900 psig and 1000 µm. The regression models generated showing interactions between the variables and EOY and FY response were significant as tested by ANOVA (p < 0.0005 and p < 0.0007, respectively) with high R2 values (0.9848 and 0.9829, respectively). Interactions between the parameters had a strong synergistic effect on EOY and FY values, as indicated by the 3D response surface curve and 2D contour. The experimental results matched the predicted results closely. This indicated the suitability of the models developed and the success of FCCCD under RSM in optimizing the S. binderi extraction conditions.
  2. Su AT, Darus A, Bulgiba A, Maeda S, Miyashita K
    J Occup Health, 2012;54(5):349-60.
    PMID: 22863899
    The internationally accepted limit values and the health effects of hand-transmitted vibration exposure have been described extensively in the literature from temperate climate countries but not from a tropical climate environment.

    OBJECTIVES: We conducted a systematic review of the health effects of hand-transmitted vibration exposure in tropical countries to determine the characteristics of hand-arm vibration syndrome in a warm environment and compared the findings with the results of the systematic reviews published by the US NIOSH.

    METHODS: We searched major medical databases including MEDLINE, PubMed, Embase, CINAHL, Ovid and Cochrane based on the terms "hand arm vibration syndrome," "hand transmitted vibration," "vibration white finger" and "Raynaud" up to January 2011. Only studies conducted in a tropical or subtropical environment were selected for the review. The quality of the selected papers was assessed independently by two investigators using predefined criteria. A standard set of information was abstracted from the papers for review.

    RESULTS: Only six papers from tropical countries and three papers from subtropical countries were available in the literature. No vibration white finger was reported in the tropical countries. Neurological symptoms were prevalent in the vibration-exposed workers. Finger coldness seems to be an important surrogate for vascular disorder in a tropical environment. Meta-analysis could not be performed due to inadequacy of the information reported in these papers.

    CONCLUSIONS: The current dose-response relationship in ISO5349-1 for hand-transmitted vibration exposure is not applicable to a tropical environment. Further studies on hand-arm vibration syndromes in tropical countries are needed.

  3. Su AT, Maeda S, Fukumoto J, Miyai N, Isahak M, Yoshioka A, et al.
    Ind Health, 2014;52(4):367-76.
    PMID: 24739764
    This study aimed to explore the clinical characteristics of hand arm vibration syndrome (HAVS) in a group of tree fellers in a tropical environment. We examined all tree fellers and selected control subjects in a logging camp of central Sarawak for vibration exposure and presence of HAVS symptoms utilizing vibrotactile perception threshold test (VPT) and cold water provocation test (CWP). None of the subjects reported white finger. The tree fellers reported significantly higher prevalence of finger coldness as compared to the control subjects (OR=10.32, 95%CI=1.21-87.94). A lower finger skin temperature, longer fingernail capillary return time and higher VPT were observed among the tree fellers as compared to the control subjects in all fingers (effect size >0.5). The VPT following CWP of the tree fellers was significantly higher (repeated measures ANOVA p=0.002, partial η(2)=0.196) than the control subject. The A (8) level was associated with finger tingling, numbness and dullness (effect size=0.983) and finger coldness (effect size=0.524) among the tree fellers. Finger coldness and finger tingling, numbness and dullness are important symptoms for HAVS in tropical environment that may indicate vascular and neurological damage due to hand-transmitted vibration exposure.
  4. Ochiai E, Minaguchi K, Nambiar P, Kakimoto Y, Satoh F, Nakatome M, et al.
    Leg Med (Tokyo), 2016 Sep;22:58-61.
    PMID: 27591541 DOI: 10.1016/j.legalmed.2016.08.001
    The Y chromosomal haplogroup determined from single nucleotide polymorphism (SNP) combinations is a valuable genetic marker to study ancestral male lineage and ethical distribution. Next-generation sequencing has been developed for widely diverse genetics fields. For this study, we demonstrate 34 Y-SNP typing employing the Ion PGM™ system to perform haplogrouping. DNA libraries were constructed using the HID-Ion AmpliSeq™ Identity Panel. Emulsion PCR was performed, then DNA sequences were analyzed on the Ion 314 and 316 Chip Kit v2. Some difficulties became apparent during the analytic processes. No-call was reported at rs2032599 and M479 in six samples, in which the least coverage was observed at M479. A minor misreading occurred at rs2032631 and M479. A real time PCR experiment using other pairs of oligonucleotide primers showed that these events might result from the flanking sequence. Finally, Y haplogroup was determined completely for 81 unrelated males including Japanese (n=59) and Malay (n=22) subjects. The allelic divergence differed between the two populations. In comparison with the conventional Sanger method, next-generation sequencing provides a comprehensive SNP analysis with convenient procedures, but further system improvement is necessary.
  5. Su AT, Fukumoto J, Darus A, Hoe VC, Miyai N, Isahak M, et al.
    J Occup Health, 2013;55(6):468-78.
    PMID: 24162147
    OBJECTIVES: The aim of this study was to investigate the clinical characteristics of HAVS in a tropical environment in comparison with a temperate environment.

    METHODS: We conducted a series medical examinations among the forestry, construction and automobile industry workers in Malaysia adopting the compulsory medical examination procedure used by Wakayama Medical University for Japanese vibratory tools workers. We matched the duration of vibration exposure and compared our results against the Japanese workers. We also compared the results of the Malaysian tree fellers against a group of symptomatic Japanese tree fellers diagnosed with HAVS.

    RESULTS: Malaysian subjects reported a similar prevalence of finger tingling, numbness and dullness (Malaysian=25.0%, Japanese=21.5%, p=0.444) but had a lower finger skin temperature (FST) and higher vibrotactile perception threshold (VPT) values as compared with the Japanese workers. No white finger was reported in Malaysian subjects. The FST and VPT of the Malaysian tree fellers were at least as bad as the Japanese tree fellers despite a shorter duration (mean difference=20.12 years, 95%CI=14.50, 25.40) of vibration exposure.

    CONCLUSIONS: Although the vascular disorder does not manifest clinically in the tropical environment, the severity of HAVS can be as bad as in the temperate environment with predominantly neurological disorder. Hence, it is essential to formulate national legislation for the control of the occupational vibration exposure.

  6. Su AT, Maeda S, Fukumoto J, Darus A, Hoe VC, Miyai N, et al.
    Occup Environ Med, 2013 Jul;70(7):498-504.
    PMID: 23645621 DOI: 10.1136/oemed-2012-101321
    The dose-response relationship for hand-transmitted vibration has been investigated extensively in temperate environments. Since the clinical features of hand-arm vibration syndrome (HAVS) differ between the temperate and tropical environment, we conducted this study to investigate the dose-response relationship of HAVS in a tropical environment.
  7. Noviendri D, Jaswir I, Taher M, Mohamed F, Salleh HM, Noorbatcha IA, et al.
    J Oleo Sci, 2016 Jul 15.
    PMID: 27430384
    Microencapsulation is a promising approach in drug delivery to protect the drug from degradation and allow controlled release of the drug in the body. Fucoxanthin-loaded microsphere (F-LM) was fabricated by two step w/o/w double emulsion solvent evaporation method with poly (L-lactic-co-glycolic acid) (PLGA) as carrier. The effect of four types of surfactants (PVA, Tween-20, Span-20 and SDS), homogenization speed, and concentration of PLGA polymer and surfactant (PVA), respectively, on particle size and morphology of F-LM were investigated. Among the surfactants tested, PVA showed the best results with smallest particle size (9.18 µm) and a smooth spherical surface. Increasing the homogenization speed resulted in a smaller mean F-LM particle size [d(0.50)] from 17.12 to 9.18 µm. Best particle size results and good morphology were attained at homogenization speed of 20 500 rpm. Meanwhile, increased PLGA concentration from 1.5 to 11.0 (% w/v) resulted in increased F-LM particle size. The mean particle size [d(0.5)] of F-LM increased from 3.93 to 11.88 µm. At 6.0 (% w/v) PLGA, F-LM showed the best structure and external morphology. Finally, increasing PVA concentration from 0.5 to 3.5 (% w/v) resulted in decreased particle size from 9.18 to 4.86 µm. Fucoxanthin characterization before and after microencapsulation was carried out to assess the success of the microencapsulation procedure. Thermo gravimetry analysis (TGA), glass transition (Tg) temperature of F-LM and fucoxanthin measured using DSC, ATR-FTIR and XRD indicated that fucoxanthin was successfully encapsulated into the PLGA matrix, while maintaining the structural and chemical integrity of fucoxanthin.
  8. Ahda M, Jaswir I, Khatib A, Ahmed QU, Mahfudh N, Ardini YD, et al.
    Sci Rep, 2023 Oct 09;13(1):17012.
    PMID: 37813908 DOI: 10.1038/s41598-023-43251-2
    Ocimum aristatum, commonly known as O. stamineus, has been widely studied for its potential as an herbal medicine candidate. This research aims to compare the efficacy of water and 100% ethanolic extracts of O. stamineus as α-glucosidase inhibitors and antioxidants, as well as toxicity against zebrafish embryos. Based on the study findings, water extract of O. stamineus leaves exhibited superior inhibition activity against α-glucosidase, ABTS, and DPPH, with IC50 values of approximately 43.623 ± 0.039 µg/mL, 27.556 ± 0.125 µg/mL, and 95.047 ± 1.587 µg/mL, respectively. The major active compounds identified in the extract include fatty acid groups and their derivates such as linoleic acid, α-eleostearic acid, stearic acid, oleanolic acid, and corchorifatty acid F. Phenolic groups such as caffeic acid, rosmarinic acid, 3,4-Dihydroxybenzaldehyde, norfenefrine, caftaric acid, and 2-hydroxyphenylalanine and flavonoids and their derivates including 5,7-Dihydroxychromone, 5,7-Dihydroxy-2,6-dimethyl-4H-chromen-4-one, eupatorin, and others were also identified in the extract. Carboxylic acid groups and triterpenoids such as azelaic acid and asiatic acid were also present. This study found that the water extract of O. stamineus is non-toxic to zebrafish embryos and does not affect the development of zebrafish larvae at concentrations lower than 500 µg/mL. These findings highlight the potential of the water extract of O. stamineus as a valuable herbal medicine candidate, particularly for its potent α-glucosidase inhibition and antioxidant properties, and affirm its safety in zebrafish embryos at tested concentrations.
  9. Granato D, Shahidi F, Wrolstad R, Kilmartin P, Melton LD, Hidalgo FJ, et al.
    Food Chem, 2018 Oct 30;264:471-475.
    PMID: 29853403 DOI: 10.1016/j.foodchem.2018.04.012
    As many studies are exploring the association between ingestion of bioactive compounds and decreased risk of non-communicable diseases, the scientific community continues to show considerable interest in these compounds. In addition, as many non-nutrients with putative health benefits are reducing agents, hydrogen donors, singlet oxygen quenchers or metal chelators, measurement of antioxidant activity using in vitro assays has become very popular over recent decades. Measuring concentrations of total phenolics, flavonoids, and other compound (sub)classes using UV/Vis spectrophotometry offers a rapid chemical index, but chromatographic techniques are necessary to establish structure-activity. For bioactive purposes, in vivo models are required or, at the very least, methods that employ distinct mechanisms of action (i.e., single electron transfer, transition metal chelating ability, and hydrogen atom transfer). In this regard, better understanding and application of in vitro screening methods should help design of future research studies on 'bioactive compounds'.
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