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Fulltext Antioxidant, α-Glucosidase, and Nitric Oxide Inhibitory Activities of Six Algerian Traditional Medicinal Plant Extracts and 1H-NMR-Based Metabolomics Study of the Active Extract

Hellal K, Maulidiani M, Ismail IS, Tan CP, Abas F

Molecules, 2020 Mar 10;25(5).
PMID: 32164186 DOI: 10.3390/molecules25051247

Claims of effective therapy against diabetes using plants including Peganum harmala L., Zygophyllum album, Anacyclus valentinus L., Ammodaucus leucotrichus, Lupinus albus, and Marrubium vulgare in Algerian empirical medicine prompted our interest in evaluating their antidiabetic activity by screening their free radical scavenging (DPPH), α-glucosidase, and nitric oxide (NO) inhibitory activities as well as the total phenolic content (TPC). Extracts of the selected plants were prepared using different ratios of ethanol (0, 50, 80, and 100%). In this study, 100%, and 80% ethanol extracts of L. albus were found to be the most potent, in inhibiting α-glucosidase activity with IC50 values of 6.45 and 8.66 μg/mL, respectively. The 100% ethanol extract of A. leucotrichus exhibited the highest free radical scavenging activity with an IC50 value of 26.26 μg/mL. Moreover, the highest TPC of 612.84 μg GAE/mg extract was observed in M. vulgare, extracted with 80% ethanol. Metabolite profiling of the active extract was conducted using 1H-NMR metabolomics. Partial least square analysis (PLS) was used to assess the relationship between the α-glucosidase inhibitory activity of L. albus and the metabolites identified in the extract. Based on the PLS model, isoflavonoids (lupinoisoflavone G, lupisoflavone, lupinoisolone C), amino acids (asparagine and thiamine), and several fatty acids (stearic acid and oleic acid) were identified as metabolites that contributed to the inhibition of α-glucosidase activity. The results of this study have clearly strengthened the traditional claim of the antihyperglycemic effects of L. albus.
1H NMR-Based Metabolomics Approach in Investigating the Chemical Profile, Antioxidant and Anti-Inflammatory Activities of Gynura procumbens and Cleome gynandra

Chandradevan M, Simoh S, Mediani A, Ismail IS, Abas F

Plant Foods Hum Nutr, 2020 Jun;75(2):243-251.
PMID: 32152783 DOI: 10.1007/s11130-020-00805-3

Gynura procumbens and Cleome gynandra are two herbs commonly used in Malaysia to treat various ailments and are also consumed as salads (ulam) and vegetables. The present study aims to evaluate the relationship between the chemical compositions of both herbs and their antioxidant and anti-inflammatory properties using nuclear magnetic resonance (NMR) metabolomics approach, which is being reported for the first time. Different ethanolic extracts of both herbs were tested for DPPH scavenging and inhibition of nitric oxide (NO) via RAW 264.7 macrophage cell induction. Principal component analysis (PCA) revealed a good separation between the extracts and the corresponding metabolites identified via 1H NMR spectroscopy. The 100% ethanolic extract from both herbs and 20% ethanolic extract of C. gynandra were found to have the best antioxidant and anti-inflammatory activities. Kaempferol, quercetin, caffeoylquinic, dicaffeoylquinic acids, gallic acid, mallic acid, citric acid, phenylalanine, and choline are among the metabolites that contributed to bioactivities. The partial least square (PLS) model for both herbs have an overall acceptable goodness of fit and predictive power, which further strengthens the validity of this study. The present study provides a preliminary reference for the selection of optimum extract and will shed some light on the potential use of G. procumbens and C. gynandra as a phytomedicinal preparation.
Synthesis and in-vitro anti-cancer evaluations of multi-methoxylated asymmetrical diarylpentanoids as intrinsic apoptosis inducer against colorectal cancer

Leong SW, Chia SL, Abas F, Yusoff K

Bioorg Med Chem Lett, 2020 04 15;30(8):127065.
PMID: 32127259 DOI: 10.1016/j.bmcl.2020.127065

In the present study, a series of nine stable 3,4,5-methoxylphenyl-containing asymmetrical diarylpentanoids, derivatives of curcuminoids, have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, LoVo and SW620, HT29, RKO and NCI-H508, respectively. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-hydroxyl and adjacent dimethoxyl groups are crucial for enhanced cytotoxicity of diarylpentanoids. Among the evaluated analogs, 8 has been identified as the lead compound due to its highest chemotherapeutic index of 9.9 and nano molar scale cytotoxicity against SW620 and RKO. Colonies formation and cell cycle analyses on 8-treated RKO cells showed that 8 exhibits strong anti-proliferative activity by inducing G2/M-phase cell arrest. Subsequent flow cytometry based annexin-V and DCFHDA studies suggested that 8 could induce apoptosis through intracellular ROS-dependent pathway. Further Western blot studies confirmed that 8 has induced intrinsic apoptosis in RKO cells through the up-regulations of Bad and Bax pro-apoptotic proteins and down-regulations of Bcl-2 and Bcl-xL pro-survival proteins. In all, the present results suggest that 8 could be a potent lead which deserves further modification and investigation in the development of small molecule-based anti-colorectal cancer agents.
Have we found the panacea to COVID-19 with remdesivir, an old but newly packaged drug?

Thalha AMM, Lee YY, Besari A, Omar SFS

J R Coll Physicians Edinb, 2020 06;50(2):159-161.
PMID: 32568289 DOI: 10.4997/JRCPE.2020.217
Fulltext The Curcumin Analogue, MS13 (1,5-Bis(4-hydroxy-3- methoxyphenyl)-1,4-pentadiene-3-one), Inhibits Cell Proliferation and Induces Apoptosis in Primary and Metastatic Human Colon Cancer Cells

Ismail NI, Othman I, Abas F, H Lajis N, Naidu R

Molecules, 2020 Aug 20;25(17).
PMID: 32825505 DOI: 10.3390/molecules25173798

The cytotoxic and apoptotic effects of turmeric (Curcuma longa) on colon cancer have been well documented but specific structural modifications of curcumin have been shown to possess greater growth-suppressive potential on colon cancer than curcumin. Therefore, the aim of this study is to identify the anti-cancer properties of curcumin analogue-MS13, a diarylpentanoid on the cytotoxicity, anti-proliferative and apoptotic activity of primary (SW480) and metastatic (SW620) human colon cancer cells. A cell viability assay showed that MS13 has greater cytotoxicity effect on SW480 (EC50: 7.5 ± 2.8 µM) and SW620 (EC50: 5.7 ± 2.4 µM) compared to curcumin (SW480, EC50: 30.6 ± 1.4 µM) and SW620, EC50: 26.8 ± 2.1 µM). Treatment with MS13 at two different doses 1X EC50 and 2X EC50 suppressed the colon cancer cells growth with lower cytotoxicity against normal cells. A greater anti-proliferative effect was also observed in MS13 treated colon cancer cells compared to curcumin at 48 and 72 h. Subsequent analysis on the induction of apoptosis showed that MS13 treated cells exhibited morphological features associated with apoptosis. The findings are also consistent with cellular apoptotic activities shown by increased caspase-3 activity and decreased Bcl-2 protein level in both colon cancer cell lines. In conclusion, MS13 able to suppress colon cancer cell growth by inhibiting cell proliferation and induce apoptosis in primary and metastatic human colon cancer cells.
Fulltext In-Vitro and In-Silico Evaluations of Heterocyclic-Containing Diarylpentanoids as Bcl-2 Inhibitors Against LoVo Colorectal Cancer Cells

Leong SW, Chia SL, Abas F, Yusoff K

Molecules, 2020 Aug 26;25(17).
PMID: 32858795 DOI: 10.3390/molecules25173877

In the present study, we investigated the in-vitro anti-cancer potential of six diarylpentanoids against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, SW620, LoVo, HT29, NCI-H508, RKO, and LS411N cells. Structure-activity relationship study suggested that the insertions of tetrahydro-4H-thiopyran-4-one and brominated phenyl moieties are essential for better cytotoxicity. Among the evaluated analogs, 2e has been identified as the lead compound due to its low IC50 values of approximately 1 µM across all cancer cell lines and high chemotherapeutic index of 7.1. Anti-proliferative studies on LoVo cells showed that 2e could inhibit cell proliferation and colony formations by inducing G2/M cell cycle arrest. Subsequent cell apoptosis assay confirmed that 2e is a Bcl-2 inhibitor that could induce intrinsic cell apoptosis by creating a cellular redox imbalance through its direct inhibition on the Bcl-2 protein. Further molecular docking studies revealed that the bromophenyl moieties of 2e could interact with the Bcl-2 surface pocket through hydrophobic interaction, while the tetrahydro-4H-thiopyran-4-one fragment could form additional Pi-sulfur and Pi-alkyl interactions in the same binding site. In all, the present results suggest that 2e could be a potent lead that deserves further modification and investigation in the development of a new Bcl-2 inhibitor.
Fulltext Effect of Defatted Dabai Pulp Extract in Urine Metabolomics of Hypercholesterolemic Rats

Kadir NAAA, Azlan A, Abas F, Ismail IS

Nutrients, 2020 Nov 14;12(11).
PMID: 33202660 DOI: 10.3390/nu12113511

A source of functional food can be utilized from a source that might otherwise be considered waste. This study investigates the hypocholesterolemic effect of defatted dabai pulp (DDP) from supercritical carbon dioxide extraction and the metabolic alterations associated with the therapeutic effects of DDP using 1H NMR urinary metabolomic analysis. Male-specific pathogen-free Sprague-Dawley rats were fed with a high cholesterol diet for 30 days to induce hypercholesterolemia. Later, the rats were administered with a 2% DDP treatment diet for another 30 days. Supplementation with the 2% DDP treatment diet significantly reduced the level of total cholesterol (TC), triglyceride, low-density lipoprotein (LDL), and inflammatory markers (C-reactive protein (CRP), interleukin 6 (IL6) and tumour necrosis factor-α (α-TNF)) and significantly increased the level of antioxidant profile (total antioxidant status (TAS), superoxide dismutase (SOD), glutathione peroxide (GPX), and catalase (CAT)) compared with the positive control group (PG) group (p < 0.05). The presence of high dietary fibre (28.73 ± 1.82 g/100 g) and phenolic compounds (syringic acid, 4-hydroxybenzoic acid and gallic acid) are potential factors contributing to the beneficial effect. Assessment of 1H NMR urinary metabolomics revealed that supplementation of 2% of DDP can partially recover the dysfunction in the metabolism induced by hypercholesterolemia via choline metabolism. 1H-NMR-based metabolomic analysis of urine from hypercholesterolemic rats in this study uncovered the therapeutic effect of DDP to combat hypercholesterolemia.
The Pattern of Injuries Among Motorcyclists in Fatal Road Traffic Accidents: An Autopsy-Based Study

Mohd Saman SA, Jothee S, Nor FM, Shafie MS

Am J Forensic Med Pathol, 2021 Jun 01;42(2):141-146.
PMID: 33346978 DOI: 10.1097/PAF.0000000000000639

INTRODUCTION: In recent years, there has been a significant increase in mortality among motorcyclists, which warrants a need to analyze the epidemiology and pattern of injuries among road users in Malaysia. Hence, prioritizing road safety in the government policy by implementing targeted actions is justified to reduce injury and fatality.
MATERIALS AND METHODS: Cases of road accident deaths in motorcyclists received by UKM Medical Centre were studied over a period of 10 years, that is, between 2010 and 2019. This study was based on forensic autopsy records database and forensic autopsy.
RESULTS: The most affected age group by road fatalities were young men. The most common injuries were intracranial hemorrhage (74%), thoracic hemorrhage (73%), and lung laceration (85.7%). About 39 (31%) fatally injured riders were positive for illicit drug and/or alcohol.
CONCLUSIONS: This study showed that men in the third decade of life are the major victims of motorcycle fatalities. Hence, urgent measures are necessary to establish road safety policy to reduce such fatalities.
Fulltext Quality of Dabai Pulp Oil Extracted by Supercritical Carbon Dioxide and Supplementation in Hypercholesterolemic Rat-A New Alternative Fat

Kadir NAAA, Azlan A, Abas F, Ismail IS

Foods, 2021 Jan 27;10(2).
PMID: 33513823 DOI: 10.3390/foods10020262

Dabai pulp oil (DPO) is new oil extracted from the pulp of Canarium odontophyllum. The quality and efficacy of DPO are needed to promote its potential as a new alternative fat. Therefore, we investigate the quality of DPO, which includes moisture and volatile content (MVC), free fatty acid content (FFA), iodine value (IV), and peroxide value (PV). Furthermore, we evaluate the efficacy of DPO against hypercholesterolemia elicited by a high-cholesterol diet in rats. The MVC of DPO was <0.001 ± 0.00%. Next, the FFA in DPO was 2.57 ± 0.03%, and the IV of DPO was 53.74 ± 0.08 g iodine/100 g oil. Meanwhile, the PV of DPO was 4.97 ± 0.00 mEq/kg. Supplementation of DPO in hypercholesterolemic rats for 30 days revealed the hypocholesterolemic effect (significant reduction of total cholesterol, triglyceride, and 3-hydroxy-3-methylglutaryl-CoA reductase) accompanied by a significant reduction of inflammatory markers (C-reactive protein, interleukin-6 and tumour necrosis factor-α), and lipid peroxidation (MDA). We also observed a significant improvement of lipoprotein lipase (LPL) and antioxidant capacities (total antioxidant status, superoxide dismutase, glutathione peroxidase, and catalase) of the rats. The results on the quality and efficacy of locally made DPO suggest its potential use as a healthy alternative fat in the future.
Uterine torsion in patient with major placenta previa

Wan Adnan WF, Shamsudin F, Mohamad Zon E

Eur J Obstet Gynecol Reprod Biol, 2021 Mar;258:467-469.
PMID: 33483151 DOI: 10.1016/j.ejogrb.2020.12.007
An approach to enrich online medical Problem-Based Learning with tacit healthcare knowledge

Cheah YN, Rashid FA, Abidi SS

Stud Health Technol Inform, 2003;95:744-9.
PMID: 14664077

Existing Problem-Based Learning (PBL) problems, though suitable in their own right for teaching purposes, are limited in their potential to evolve by themselves and to create new knowledge. Presently, they are based on textbook examples of past cases and/or cases that have been transcribed by a clinician. In this paper, we present (a) a tacit healthcare knowledge representation formalism called Healthcare Scenarios, (b) the relevance of healthcare scenarios in PBL in healthcare and medicine, (c) a novel PBL-Scenario-based tacit knowledge explication strategy and (d) an online PBL Problem Composer and Presenter (PBL-Online) to facilitate the acquisition and utilisation of expert-quality tacit healthcare knowledge to enrich online PBL. We employ a confluence of healthcare knowledge management tools and Internet technologies to bring tacit healthcare knowledge-enriched PBL to a global and yet more accessible level.
Relapsed Acute Lymphoblastic Leukemia Presenting as Optic Neuritis

Fadilah SA, Raymond AA, Cheong SK, Faridah A

Hematology, 2001;6(4):267-9.
PMID: 27414846 DOI: 10.1080/10245332.2001.11752124

Leukemic infiltration of the optic nerve is rare [1]. [Camera, A., Piccirillo, G., Tranfa, F., Rosa, N., Frigeri, F., Martinelli, V., Rotoloi, B. (1993) "Optic nerve involvement in acute lymphoblastic leukemia", Leuk. Lymph. 11, 153-155]. Radiotherapy should be given urgently to all patients with optic nerve infiltrate to restore their vision [2]. [Rosenthal, A. (1983) "Ocular manifestation of leukemia", Ophthalmology 90, 899-905]. We report a case of a unilateral optic nerve relapse 7 months after diagnosis of acute lymphoblastic leukemia (ALL) in a 17-year-old boy who had been off treatment for 6 weeks. The ocular symptoms was initially diagnosed as primary optic neuritis and treated with corticosteroids resulting in temporary clinical recovery. Radiation therapy for ocular leukemia that was commenced 2 months after the onset of symptoms failed to reverse the visual loss. The lack of a reliable and effective tool to diagnose ocular leukemia at an early stage has resulted in significant treatment delay and poor visual outcome.
Effects of sonication on the extraction of free-amino acids from moromi and application to the laboratory scale rapid fermentation of soy sauce

Goh KM, Lai OM, Abas F, Tan CP

Food Chem, 2017 Jan 15;215:200-8.
PMID: 27542468 DOI: 10.1016/j.foodchem.2016.07.146

Soy sauce fermentation was simulated in a laboratory and subjected to 10min of sonication. A full factorial design, including different cycles, probe size, and amplitude was used. The composition of 17 free-amino acids (FAAs) was determined by the AccQ-Tag method with fluorescent detection. Main effect plots showed total FAAs extraction was favoured under continuous sonication at 100% amplitude using a 14mm diameter transducer probe, reaching 1214.2±64.3mg/100ml of total FAAs. Moreover, after 7days of fermentation, sonication treatment caused significantly higher levels (p<0.05) of glutamic acids (343.0±22.09mg/100g), total FAAs (1720.0±70.6mg/100g), and essential FAAs (776.3±7.0mg/100g) 3days sooner than the control. Meanwhile, enzymatic and microbial behaviours remained undisturbed. Collectively, the sonication to moromi resulted in maturation 57% faster than the untreated control.
Fulltext Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique

Karthivashan G, Masarudin MJ, Kura AU, Abas F, Fakurazi S

Int J Nanomedicine, 2016;11:3417-34.
PMID: 27555765 DOI: 10.2147/IJN.S112045

This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as "flavonosome". Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA-phosphatidylcholine) through four different methods of synthesis - bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug-carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA-phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of -39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising nanodrug delivery system for loading multiflavonoids in a single entity with sustained activity as an antioxidant, hepatoprotective, and hepatosupplement candidate.
Fulltext Fusarium solani keratitis. First report from Malaysia

Singh H, Jamal F, Marahakim MN, Chin CS

Med J Malaysia, 1981 Jun;36(2):89-91.
PMID: 7343825

The first culture-proven case zn Malaysia of fungal keratitis, due to Fusarium solani, is presented, followed by a brief discussion of mycotic keratitis.
Identification of the compositional changes in Orthosiphon stamineus leaves triggered by different drying techniques using 1 H NMR metabolomics

Pariyani R, Ismail IS, Ahmad Azam A, Abas F, Shaari K

J Sci Food Agric, 2017 Sep;97(12):4169-4179.
PMID: 28233369 DOI: 10.1002/jsfa.8288

BACKGROUND: Java tea is a well-known herbal infusion prepared from the leaves of Orthosiphon stamineus (OS). The biological properties of tea are in direct correlation with the primary and secondary metabolite composition, which in turn largely depends on the choice of drying method. Herein, the impact of three commonly used drying methods, i.e. shade, microwave and freeze drying, on the metabolite composition and antioxidant activity of OS leaves was investigated using proton nuclear magnetic resonance (1 H NMR) spectroscopy combined with multivariate classification and regression analysis tools.
RESULTS: A total of 31 constituents comprising primary and secondary metabolites belonging to the chemical classes of fatty acids, amino acids, sugars, terpenoids and phenolic compounds were identified. Shade-dried leaves were identified to possess the highest concentrations of bioactive secondary metabolites such as chlorogenic acid, caffeic acid, luteolin, orthosiphol and apigenin, followed by microwave-dried samples. Freeze-dried leaves had higher concentrations of choline, amino acids leucine, alanine and glutamine and sugars such as fructose and α-glucose, but contained the lowest levels of secondary metabolites.
CONCLUSION: Metabolite profiling coupled with multivariate analysis identified shade drying as the best method to prepare OS leaves as Java tea or to include in traditional medicine preparation. © 2017 Society of Chemical Industry.
Volatile organic compounds (VOC), formaldehyde and nitrogen dioxide (NO2) in schools in Johor Bahru, Malaysia: Associations with rhinitis, ocular, throat and dermal symptoms, headache and fatigue

Norbäck D, Hashim JH, Hashim Z, Ali F

Sci Total Environ, 2017 Aug 15;592:153-160.
PMID: 28319702 DOI: 10.1016/j.scitotenv.2017.02.215

This paper studied associations between volatile organic compounds (VOC), formaldehyde, nitrogen dioxide (NO2) and carbon dioxide (CO2) in schools in Malaysia and rhinitis, ocular, nasal and dermal symptoms, headache and fatigue among students. Pupils from eight randomly selected junior high schools in Johor Bahru, Malaysia (N=462), participated (96%). VOC, formaldehyde and NO2 were measured by diffusion sampling (one week) and VOC also by pumped air sampling during class. Associations were calculated by multi-level logistic regression adjusting for personal factors, the home environment and microbial compounds in the school dust. The prevalence of weekly rhinitis, ocular, throat and dermal symptoms were 18.8%, 11.6%, 15.6%, and 11.1%, respectively. Totally 20.6% had weekly headache and 22.1% fatigue. Indoor CO2 were low (range 380-690 ppm). Indoor median NO2 and formaldehyde concentrations over one week were 23μg/m3 and 2.0μg/m3, respectively. Median indoor concentration of toluene, ethylbenzene, xylene, and limonene over one week were 12.3, 1.6, 78.4 and 3.4μg/m3, respectively. For benzaldehyde, the mean indoor concentration was 2.0μg/m3 (median<1μg/m3). Median indoor levels during class of benzene and cyclohexane were 4.6 and 3.7μg/m3, respectively. NO2 was associated with ocular symptoms (p<0.001) and fatigue (p=0.01). Formaldehyde was associated with ocular (p=0.004), throat symptoms (p=0.006) and fatigue (p=0.001). Xylene was associated with fatigue (p<0.001) and benzaldehyde was associated with headache (p=0.03). In conclusion, xylene, benzaldehyde, formaldehyde and NO2 in schools can be risk factors for ocular and throat symptoms and fatigue among students in Malaysia. The indoor and outdoor levels of benzene were often higher than the EU standard of 5μg/m3.
Nitrate and Nitrogen Oxides: Sources, Health Effects and Their Remediation

Hakeem KR, Sabir M, Ozturk M, Akhtar MS, Ibrahim FH

Rev Environ Contam Toxicol, 2017;242:183-217.
PMID: 27734212 DOI: 10.1007/398_2016_11

Increased use of nitrogenous (N) fertilizers in agriculture has significantly altered the global N-cycle because they release nitrogenous gases of environmental concerns. The emission of nitrous oxide (N2O) contributes to the global greenhouse gas accumulation and the stratospheric ozone depletion. In addition, it causes nitrate leaching problem deteriorating ground water quality. The nitrate toxicity has been reported in a number of studies showing the health hazards like methemoglobinemia in infants and is a potent cause of cancer. Despite these evident negative environmental as well as health impacts, consumption of N fertilizer cannot be reduced in view of the food security for the teeming growing world population. Various agronomic and genetic modifications have been practiced to tackle this problem. Some agronomic techniques adopted include split application of N, use of slow-release fertilizers, nitrification inhibitors and encouraging the use of organic manure over chemical fertilizers. As a matter of fact, the use of chemical means to remediate nitrate from the environment is very difficult and costly. Particularly, removal of nitrate from water is difficult task because it is chemically non-reactive in dilute aqueous solutions. Hence, the use of biological means for nitrate remediation offers a promising strategy to minimize the ill effects of nitrates and nitrites. One of the important goals to reduce N-fertilizer application can be effectively achieved by choosing N-efficient genotypes. This will ensure the optimum uptake of applied N in a balanced manner and exploring the molecular mechanisms for their uptake as well as metabolism in assimilatory pathways. The objectives of this paper are to evaluate the interrelations which exist in the terrestrial ecosystems between the plant type and characteristics of nutrient uptake and analyze the global consumption and demand for fertilizer nitrogen in relation to cereal production, evaluate the various methods used to determine nitrogen use efficincy (NUE), determine NUE for the major cereals grown across large agroclimatic regions, determine the key factors that control NUE, and finally analyze various strategies available to improve the use efficiency of fertilizer nitrogen.
Comparative study of the antioxidant activities of some lipase-catalyzed alkyl dihydrocaffeates synthesized in ionic liquid

Gholivand S, Lasekan O, Tan CP, Abas F, Wei LS

Food Chem, 2017 Jun 01;224:365-371.
PMID: 28159281 DOI: 10.1016/j.foodchem.2016.12.075

The solubility limitations of phenolic acids in many lipidic environments are now greatly improved by their enzymatic esterification in ionic liquids (ILs). Herein, four different ILs were tested for the esterification of dihydrocaffeic acid with hexanol and the best IL was selected for the synthesis of four other n-alkyl esters with different chain-lengths. The effect of alkyl chain length on the anti-oxidative properties of the resulted purified esters was investigated using β-carotene bleaching (BCB) and free radical scavenging method DPPH and compared with butylated hydroxytoluene (BHT) as reference compound. All four esters (methyl, hexyl, dodecyl and octadecyl dihydrocaffeates) exhibited relatively strong radical scavenging abilities. The scavenging activity of the test compounds was in the following order: methyl ester>hexyl ester⩾dodecyl ester>octadecyl ester>BHT while the order for the BCB anti-oxidative activity was; BHT>octadecyl ester>dodecyl ester>hexyl ester>methyl ester.
Fulltext Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study

Zokti JA, Sham Baharin B, Mohammed AS, Abas F

Molecules, 2016 Jul 26;21(8).
PMID: 27472310 DOI: 10.3390/molecules21080940

Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%-88.04%, 19.32-24.90 (g GAE/100 g), and 29.52%-38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%-5.11%, 0.28-0.36, 3.22%-4.71%, 0.22-0.28 g/cm³ and 40.43-225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%-188.63% and 207.55%-231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35-60, 34-65 and 231-288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.

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