Displaying publications 1 - 20 of 37 in total

Abstract:
Sort:
  1. Chua LS
    Phytother Res, 2014 Nov;28(11):1589-98.
    PMID: 25043965 DOI: 10.1002/ptr.5193
    Till to date, the advancement of medical science and technology is still unable to provide inclusive treatment to liver inflammation caused by neither microbial invasion nor antibiotics nor environmental toxins. Therefore, this article provides the basic knowledge of liver inflammation up to the cellular level and its current medical treatment for inflammatory symptom suppression. Because of the adverse effects of drug treatment, people start looking for comprehensive alternative nowadays. Herbal medicine is believed to be the best of choice because it is being practiced until now for centuries. Although numerous herbal plants have been reported for their efficacies in liver protection, Andrographis paniculata is the most widely used herb for hepatoprotection, particularly in Ayurveda and traditional Chinese medicine. This review covers the significant observation on the biochemical responses due to the experimental induction of liver damage in vitro and in vivo using the marker compound of the herb, namely andrographolide and its derivatives. The standardized extract of A. paniculata with the right phytochemical composition of diterpenic labdanes is likely to have tremendous potential for the development of hepatoprotective medicine. This standardized herbal medicine may not provide immediate remedy, but it can be considered as a comprehensive therapy for liver inflammation.
  2. Chua LS
    J Ethnopharmacol, 2013 Dec 12;150(3):805-17.
    PMID: 24184193 DOI: 10.1016/j.jep.2013.10.036
    Rutin is a common dietary flavonoid that is widely consumed from plant-derived beverages and foods as traditional and folkloric medicine worldwide. Rutin is believed to exhibit significant pharmacological activities, including anti-oxidation, anti-inflammation, anti-diabetic, anti-adipogenic, neuroprotective and hormone therapy. Till date, over 130 registered therapeutic medicinal preparations are containing rutin in their formulations. This article aims to critically review the extraction methods for plant-based rutin and its pharmacological activities. This review provides comprehensive data on the performance of rutin extraction methods and the extent of its pharmacological activities using various in vitro and in vivo experimental models.
  3. Chua LS
    Plant Physiol Biochem, 2016 Sep;106:16-22.
    PMID: 27135814 DOI: 10.1016/j.plaphy.2016.04.040
    The identification of plant metabolites is very important for the understanding of plant physiology including plant growth, development and defense mechanism, particularly for herbal medicinal plants. The metabolite profile could possibly be used for future drug discovery since the pharmacological activities of the indigenous herbs have been proven for centuries. An untargeted mass spectrometric approach was used to identify metabolites from the leaves and stems of Impatiens balsamina using LC-DAD-MS/MS. The putative compounds are mostly from the groups of phenolic, organic and amino acids which are essential for plant growth and as intermediates for other compounds. Alanine appeared to be the main amino acid in the plant because many alanine derived metabolites were detected. There are also several secondary metabolites from the groups of benzopyrones, benzofuranones, naphthoquinones, alkaloids and flavonoids. The widely reported bioactive components such as kaempferol, quercetin and their glycosylated, lawsone and its derivatives were detected in this study. The results also revealed that aqueous methanol could extract flavonoids better than water, and mostly, flavonoids were detected from the leaf samples. The score plots of component analysis show that there is a minor variance in the metabolite profiles of water and aqueous methanolic extracts with 21.5 and 30.5% of the total variance for the first principal component at the positive and negative ion modes, respectively.
  4. Chua LS, Adnan NA
    Acta Sci Pol Technol Aliment, 2014 Apr-Jun;13(2):169-79.
    PMID: 24876312
    The purpose of this study was to investigate the relationship of biochemical (enzymes) and nutritional components in the selected honey samples from Malaysia. The relationship is important to estimate the quality of honey based on the concentration of these nutritious components. Such a study is limited for honey samples from tropical countries with heavy rainfall throughout the year.
  5. Chua LS, Zukefli SN
    J Integr Med, 2016 11;14(6):415-428.
    PMID: 27854193 DOI: 10.1016/S2095-4964(16)60282-0
    Edible bird's nest (EBN) is currently widely consumed by the Chinese community as tonic food and functional food, which is believed to have many medicinal benefits. Some studies have reported the biochemical compositions of EBN, graded on the basis of colour, nitrate and nitrite contents. Other studies have shown significant biological effects, while ongoing research is in progress to explore potential pharmacological applications. The high demand for EBNs in the global market has forced the local regulatory bodies to monitor swiftlet farming activities, including the EBN cleaning process. Furthermore, numerous techniques have been developed to authenticate EBN; proteomics is likely to be the most promising of these methods. However, there are limited numbers of relevant protein sequences deposited at the database. More research is needed at the molecular level to explore the mechanisms behind the biological functions, such as bone strength improvement, skin rejuvenation, epidermal growth factor activity and cell proliferation.The current and future prospects of EBN and swiftlet farming are critically reviewed in this article.
  6. Chua LS, Yap KC, Jaganath IB
    Nat Prod Commun, 2013 Dec;8(12):1725-9.
    PMID: 24555283
    The total phenolic content and radical scavenging activity of Andrographis paniculata has been investigated to estimate the amount of phenolic compounds and diterpene lactones, respectively in the plant extracts. The stem extracts exhibited higher total phenolic content and scavenging activity than those of the leaf extracts from both young and mature plants. A range of 19.6-47.8 mg extract of A. paniculata from different parts of the plant is equivalent to the scavenging activity exhibited by one mg of standard Trolox. HPLC-ESI-MS/MS was also used to identify simultaneously the phytochemicals from the leaves and stems of both young and mature plant samples. Of the identified compounds, seven of the sixteen diterpene lactones, three of the six flavonoids, five of the six phenolic acids and two cyclic acids are reported here for the first time for this species. Multivariate statistical approaches such as Hierarchiral Component Analysis (HCA) and Principle Component Analysis (PCA) have clustered the plant extracts into the leaf and stem groups, regardless of plant age. Further classification based on the phytochemical profiles revealed that mostly phenolic acids and flavonoids were from the young leaf extracts, and diterpenoids and their glycosides from the mature leaf extracts. However, the phytochemical profiles for the stems of both young and mature plants were not significantly different as presented in the dendrogram of HCA and the score plot of PCA. The marker for mature plants might be the m/z 557 ion (dihydroxyl dimethyl 19-[(beta-D-glucopyranosyl)oxy]-19-oxo-ent-labda-8(17),13-dien-16,15-olide), whereas the m/z 521 ion (propyl neoandrographolide) could be the marker for leaf extracts.
  7. Chua LS, Lee JY, Chan GF
    Anal Bioanal Chem, 2013 Apr;405(10):3063-74.
    PMID: 23292042 DOI: 10.1007/s00216-012-6630-2
    There are relatively limited studies on the protein of honey samples mainly because of the low amount of protein in honey (0.1-0.5 %), the difficulty in extracting honey protein from the sugar-rich environment, and the hindrance of protein characterization by conventional approaches. Several protein extraction methods such as mechanical (ultrafiltration and ultracentrifugation) and chemical (precipitation) techniques have been applied to different types of honey samples. Most of these studies reported the quantity and molecular size of honey protein from gel electrophoresis, but were unable to identify and characterize the protein. This limitation might be due to the low capacity of analytical equipment in those days. Although different precipitants have also been used, not all them are compatible with mass spectrometric methods during downstream analysis. As a result, the sample preparation step is essential in order to confidently characterize the low and varied amount of honey protein. Nowadays, honey protein is getting attention from researchers because of its potential activity in pharmacological applications. Therefore, honey protein extraction and determination by mass spectrometry are critically reviewed in order to stimulate further honey protein research.
  8. Ngo YL, Lau CH, Chua LS
    Food Chem Toxicol, 2018 Nov;121:687-700.
    PMID: 30273632 DOI: 10.1016/j.fct.2018.09.064
    Rosmarinic acid is a bioactive phytochemical that can be found in many herbs as ethnomedicines. It possesses remarkable pharmacological activities, and thus leading to its exploration as a therapeutic drug in diabetes treatment recently. This article reviews the extraction and fractionation techniques for plant-based natural rosmarinic acid and its anti-diabetic potential based on literature data published in journals, books, and patents from 1958 to 2017. Factors affecting the performance of rosmarinic acid extraction and fractionation such as operating temperature, time, solvent to sample ratio and eluent system are compiled and discussed in detail. The inhibitory action of rosmarinic acid against sugar digestive enzymes, and protective action towards pancreatic β-cell dysfunction and glucolipotoxicity mediated oxidative stress are also critically reviewed. The optimal parameters are largely dependent on the applied extraction and fractionation techniques, as well as the nature of plant samples. Previous studies have proven the potent role of rosmarinic acid to control plasma glucose level and increase insulin sensitivity in hyperglycemia. Although rosmarinic acid is readily absorbed by human body, its mechanism after consumption is remained unclear. Intensive studies should be well planned to determine the dosage and toxicity level of rosmarinic acid for efficacy and safe consumption.
  9. Chua LS, Segaran A, Wong HJ
    J Chromatogr Sci, 2021 Jun 21;59(7):659-669.
    PMID: 33876232 DOI: 10.1093/chromsci/bmab041
    The objective of the study was to fractionate the crude extract of Eurycoma longifolia (E. longifolia) roots and identify the intense peaks using HPLC-PDA-MS/MS, UPLC-MS/MS and H-NMR. Column chromatography was used to fractionate the crude extract into individual fractions using six solvent systems ranged from ethyl acetate, methanol and water in increasing polarity. Two fractions with nearly pure and intense peaks were selected for compound identification. Chromenone (coumarin) and chromone derivatives were putatively identified, besides several previously reported quassinoid glycosides (eurycomanone derived glycoside, 2,3-dehydro-4α-hydroxylongilactone glucoside, eurycomanol glycoside and eurycomanol trimer) in the fraction 11 of 100% methanol. A newly reported compound, namely hydroxyl glyyunanprosapogenin D (838 g/mol) was proposed to be the compound detected in the fraction 11 of 50% ethyl acetate and 50% methanol. This is also the first study to report the identification of chromenones and chromones in E. longifolia extract.
  10. Mohmad Saberi SE, Chua LS
    Life Sci, 2023 Nov 15;333:122170.
    PMID: 37827234 DOI: 10.1016/j.lfs.2023.122170
    Orthosiphon aristatus has been traditionally used as a medicinal herb for various illnesses in Southeast Asia and Europe. The most dominant bioactive compound of the herb is rosmarinic acid (RosA) which has been demonstrated for its remarkable anti-inflammatory properties. This review describes the recent progress of studies on multi-target molecular pathways of RosA in relation to targeted inflammatory-associated diseases. An inclusive literature search was conducted using electronic databases such as Google Scholar, Scopus, Springer Link, PubMed, Medline, Wiley and Science Direct for studies reporting on the anti-inflammatory actions of RosA from 2008 until 2023. The keywords of the search were RosA and anti-inflammatory in relation to hepatoprotective, chondroprotective, cardioprotective, neuroprotective and toxicity. Only publications that are written in English are included in this review. The inhibition and deactivation of pro-inflammatory biomolecules by RosA were explained based on the initial inflammation stimuli and their location in the body. The activation of Nrf2/HO-1 expression to inhibit NF-κB pathway is the key mechanism for hepatoprotection. Besides NF-κB inhibition, RosA activates PPARγ to alleviate ischemia/reperfusion (I/R)-induced myocardial injury for cardioprotection. The regulation of MAPK and T-cell activation is important for chondroprotection, whereas the anti-oxidant property of RosA is the main contributor of neuroprotection. Even though less studies on the anti-inflammation of RosA extracts from O. aristatus, but the effective pharmacological properties of RosA has promoted it as a natural potent lead for further investigation.
  11. Lim JR, Chua LS, Mustaffa AA
    PMID: 38484676 DOI: 10.1016/j.jchromb.2024.124072
    The peroxyl radicals generated by the activity of lipoxygenases (LOX) are mediators to trigger inflammatory diseases. Therefore, it is important to investigate potent LOX inhibitor for modulating the occurrence and resolving inflammatory processes. Artemisa vulgaris, is a herbal plant that is known for flavonoids, potentially inhibiting lipid peroxidation and scavenging radicals. The objectives of the present study were to obtain flavonoids rich extract from A. vulgaris, and determine the inhibitory mode of the extract against LOX. The flavonoids rich extract was optimized in an ultrasound assisted extraction using ionic liquids as extraction solvent. The results found that the optimum conditions; ratio of solid-to-liquid (1:10) and 30 min of extraction time could produce the high yield (10.14 %) and flavonoid content (5.30 mg QE/g). The LOX activity was demonstrated to follow a mixed mode of inhibition in the presence of the flavonoid rich extract as an inhibitor. The Michaelis-Menten constant (Km) was increased from 0.283 µM to 0.435 µM, whereas the maximum velocity was reduced from 0.22 µM/min to 0.058 µM/min in the inhibition. The flavonoids rich extract is likely to be a natural potent non-competitive inhibitor which may bind to free LOX or substrate-bound LOX.
  12. Chua LS, Alitabarimansor M, Lee CT, Mat R
    Enzyme Res, 2012;2012:542589.
    PMID: 22953055 DOI: 10.1155/2012/542589
    Hydrolysis of virgin coconut oil (VCO) had been carried out by using an immobilised lipase from Mucor miehei (Lipozyme) in a water-jacketed batch reactor. The kinetic of the hydrolysis was investigated by varying the parameters such as VCO concentration, enzyme loading, water content, and reaction temperature. It was found that VCO exhibited substrate inhibition at the concentration more than 40% (v/v). Lipozyme also achieved the highest production of free fatty acids, 4.56 mM at 1% (w/v) of enzyme loading. The optimum water content for VCO hydrolysis was 7% (v/v). A relatively high content of water was required because water was one of the reactants in the hydrolysis. The progress curve and the temperature profile of the enzymatic hydrolysis also showed that Lipozyme could be used for free fatty acid production at the temperature up to 50°C. However, the highest initial reaction rate and the highest yield of free fatty acid production were at 45 and 40°C, respectively. A 100 hours of initial reaction time has to be compensated in order to obtain the highest yield of free fatty acid production at 40°C.
  13. Chua LS, Abdul-Rahaman NL, Sarmidi MR, Aziz R
    Food Chem, 2012 Dec 1;135(3):880-7.
    PMID: 22953800 DOI: 10.1016/j.foodchem.2012.05.106
    The elemental profiles of six honey samples from Malaysia had been constructed using the data obtained from both ICP-AES and ICP-MS. Potassium and sodium were the most abundant minerals covering from 69.3-78.6% and 14.1-28.7%, respectively. The ratio of potassium to sodium was more than one. Even though the minerals and trace elements composition varied dependent on the type of honey samples, there was no statistically significant difference between the analysed honey samples, namely tualang, gelam, acacia and a few forest honeys based on two-factor ANOVA and cluster analysis. The total element content of honey samples were strongly correlated with the electrical conductivity, but only have moderate correlation with the ash content and honey colour based on the regression analysis. PCA result on the available elemental data from worldwide honeys, including honey samples from Malaysia revealed that potassium and sodium were the mineral markers to distinguish honey origin. Both tualang and gelam honey samples from Malaysia have close mineral profile with sesame honeys from Egypt and multifloral honeys from India, whereas forest honeys Malaysia were near to avocado honeys from Spain and multifloral honeys from India.
  14. Chua LS, Lee SY, Abdullah N, Sarmidi MR
    Fitoterapia, 2012 Dec;83(8):1322-35.
    PMID: 22521793 DOI: 10.1016/j.fitote.2012.04.002
    Labisia pumila is a traditional herb widely used as post-partum medication for centuries. Recently, extensive researches have been carried out on the phytochemical identification, biological and toxicological studies for the herb. Phytochemicals found in the herbal extract showed high antioxidant properties, which were essential for various pharmacological activities. The significant findings are anti-estrogenic deficiency and -immunodeficiency diseases. Another finding that has considerable impact on natural product research is the contribution of L. pumila in promoting skin collagen synthesis. The performance of the herb as anti-aging agent due to natural aging process and accelerated by UV radiation was reviewed critically.
  15. Chua LS, Abdul-Rahman N, Rosidi B, Lee CT
    Nat Prod Res, 2013 Mar;27(4-5):314-8.
    PMID: 22468741 DOI: 10.1080/14786419.2012.676552
    A water extraction method has been used to extract plant proteins from the roots of Eurycoma longifolia harvested from Perak and Pahang, Malaysia. On the basis of the spectroscopic Bradford assay, Tongkat Ali Perak and Pahang contained 0.3868 and 0.9573 mg mL(-1) of crude protein, respectively. The crude proteins were separated by one dimensional 15% sodium dodecyl sulphate polyacrylamide gel electrophoresis into two (49.8 and 5.5 kD) and four (49.8, 24.7, 21.1 and 5.5 kD) protein spots for Tongkat Ali Perak and Pahang, respectively. Isoleucine was present in the highest concentration significantly. Both plant samples showed differences in the mineral and trace element profiles, but the minerals calcium, magnesium and potassium were present in the highest concentration. The highly concerned toxic metals such as arsenic and lead were not detected.
  16. Lim LY, Bong CP, Chua LS, Lee CT
    Environ Sci Pollut Res Int, 2015 Dec;22(24):19814-22.
    PMID: 26286798 DOI: 10.1007/s11356-015-5156-5
    This study was carried out to investigate the physicochemical properties of compost from oil palm empty fruit bunches (EFB) inoculated with effective microorganisms (EM∙1™). The duration of microbial-assisted composting was shorter (∼7 days) than control samples (2 months) in a laboratory scale (2 kg) experiment. The temperature profile of EFB compost fluctuated between 26 and 52 °C without the presence of consistent thermophilic phase. The pH of compost changed from weak acidic (pH ∼5) to mild alkaline (pH ∼8) because of the formation of nitrogenous ions such as ammonium (NH4 (+)), nitrite (NO2 (-)), and nitrate (NO3 (-)) from organic substances during mineralization. The pH of the microbial-treated compost was less than 8.5 which is important to prevent the loss of nitrogen as ammonia gas in a strong alkaline condition. Similarly, carbon mineralization could be determined by measuring CO2 emission. The microbial-treated compost could maintain longer period (∼13 days) of high CO2 emission resulted from high microbial activity and reached the threshold value (120 mg CO2-C kg(-1) day(-1)) for compost maturity earlier (7 days). Microbial-treated compost slightly improved the content of minerals such as Mg, K, Ca, and B, as well as key metabolite, 5-aminolevulinic acid for plant growth at the maturity stage of compost. Graphical Abstract Microbial-assisted composting on empty fruit bunches.
  17. Mustafa SM, Chua LS, El-Enshasy HA
    Molecules, 2019 Jun 26;24(13).
    PMID: 31247970 DOI: 10.3390/molecules24132357
    The issues of lactose intolerance and vegetarianism have encouraged the introduction of non-dairy fermented food into the market. Therefore, this study aims to evaluate the effect of agitation speed on the bioactive compounds and functional characteristics of probioticated pomegranate juice. Pomegranate juice was fermented with Lactobacillus casei at different agitation speeds ranging from 0 (microaerophilic) to 150 rpm at 37 °C. The functional properties of probioticated pomegranate juice were evaluated in terms of growth (biomass), lactic acid production, antioxidant activity, total phenolic content, and key metabolites using LC-MS/MS. The growth kinetics of fermentation was monitored at the optimal condition using one factor at a time method. High cell growth (3.58 × 1010 cfu/mL or 7.9 gL-1) was observed for L. casei probioticated pomegranate juice agitated at 0 rpm. The findings of this study reveal the potential of pomegranate juice as a medium for L. casei cultivation without nutrient supplementation. The improvement of antioxidant activity in the probioticated juice could be due to the increment of quercetin-3-glucoside. Therefore, L. casei grew well in pomegranate juice with a high cell viability and antioxidant activity at a non-agitated condition. Probioticated pomegranate juice is a potentially functional drink.
  18. Lim JR, Chua LS, Dawood DAS
    Foods, 2023 Jun 06;12(12).
    PMID: 37372501 DOI: 10.3390/foods12122290
    The aim of the present study was to determine the content of phenolics, flavonoids and tannins, as well as the biological functions of propolis extracts from the stingless bee (Heterotrigona itama). The raw propolis was extracted via maceration with ultrasonic pretreatment in 100% water and 20% ethanol. The yield of ethanolic propolis extracts was about 1% higher than its aqueous counterpart. The colorimetric assays showed that the ethanolic propolis extract had about two times higher phenolics (17.043 mg GAE/g) and tannins (5.411 mg GAE/g), and four times higher flavonoids (0.83 mg QE/g). The higher phenolic content had enhanced the antiradical and antibacterial capacities of the ethanolic extract. The propolis extracts significantly exhibited higher antibacterial activity against gram-positive bacteria (Staphylococcus aureus) than gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). However, aqueous extract was found to have a higher anticancer property based on the viability of lung cancer cells. No cytotoxic effect was observed on normal lung cells as the cell viability was maintained >50%, even the concentration of propolis extracts were increased up to 800 µg/mL. Different chemical compositions of propolis extract would show different bioactivities depending upon the individual applications. The high content of phenolics suggests that the propolis extract could be a natural source of bioactive ingredients for the development of innovative and functional foods.
  19. Chua LS, Abdullah FI, Lim TK, Lin Q
    Food Chem, 2024 Jan 30;432:137261.
    PMID: 37651783 DOI: 10.1016/j.foodchem.2023.137261
    This study was aimed to extract bioactive peptides from the white and purple flower varieties of Orthosiphon aristatus leaves. The herb is well known for its pharmacological importance, possibly attributed to its plant proteins. Phenol based extraction was used to extract plant proteins, and then hydrolysed by proteolytic enzymes such as trypsin (serine protease) and pepsin (aspartic protease). MS/MS analysis revealed that 145 and 125 proteins were detected from the white and purple flower varieties, respectively. Trypsin hydrolysates were showed to have a higher degree of hydrolysis (24-33%), resulting in higher antioxidant and antibacterial activities. The white flower of trypsin hydrolysates showed a higher radical scavenging activity which could be attributed to its higher content of stress proteins (19%). However, trypsin hydrolysates from the purple flower showed higher ferric reducing power and bacterial growth inhibition. The performance of hydrolysates was better than ampicillin in inhibiting Acinetobacter baumanni and Staphylococcus aureus.
Filters
Contact Us

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

External Links