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Fulltext Bioassay-guided fractionation of Melastoma malabathricum Linn. leaf solid phase extraction fraction and its anticoagulant activity

Khoo LT, Abdullah JO, Abas F, Tohit ER, Hamid M

Molecules, 2015 Feb 24;20(3):3697-715.
PMID: 25719740 DOI: 10.3390/molecules20033697

The aims of this study were to examine the bioactive component(s) responsible for the anticoagulant activity of M. malabathricum Linn. leaf hot water crude extract via bioassay-guided fractionation and to evaluate the effect of bioactive component(s) on the intrinsic blood coagulation pathway. The active anticoagulant fraction of F3 was subjected to a series of chromatographic separation and spectroscopic analyses. Furthermore, the effect of the bioactive component(s) on the intrinsic blood coagulation pathway was studied through immediate and time incubation mixing studies. Through Activated Partial Thromboplastin Time (APTT) assay-guided fractionation, Subfraction B was considered the most potent anticoagulant fraction. Characterisation of Subfraction B indicated that anticoagulant activity could partly be due to the presence of cinnamic acid and a cinnamic acid derivative. APTT assays for both the immediate and time incubation mixing were corrected back into normal clotting time range (35.4-56.3 s). In conclusion, cinnamic acid and cinnamic acid derivative from Subfraction B were the first such compounds to be discovered from M. malabathricum Linn. leaf hot water crude extract that possess anticoagulant activity. This active anticoagulant Subfraction B prolonged blood clotting time by causing factor(s) deficiency in the intrinsic blood coagulation pathway.
Fulltext Anticoagulant Activity of Polyphenolic-Polysaccharides Isolated from Melastoma malabathricum L

Khoo LT, Abas F, Abdullah JO, Mohd Tohit ER, Hamid M

Evid Based Complement Alternat Med, 2014;2014:614273.
PMID: 24987430 DOI: 10.1155/2014/614273

Melastoma malabathricum Linn. is a perennial traditional medicine plants that grows abundantly throughout Asian countries. In this study, M. malabathricum Linn. leaf hot water crude extract with anticoagulant activity was purified through solid phase extraction cartridge and examined for the bioactive chemical constituents on blood coagulation reaction. The SPE purified fractions were, respectively, designated as F1, F2, F3, and F4, and each was subjected to the activated partial thromboplastin time (APTT) anticoagulant assay. Active anticoagulant fractions (F1, F2, and F3) were subjected to chemical characterisation evaluation. Besides, neutral sugar for carbohydrate part was also examined. F1, F2, and F3 were found to significantly prolong the anticoagulant activities in the following order, F1 > F2 > F3, in a dose dependent manner. In addition, carbohydrate, hexuronic acid, and polyphenolic moiety were measured for the active anticoagulant fractions (F1, F2, and F3). The characterisation of chemical constituents revealed that all these three fractions contained acidic polysaccharides (rhamnogalacturonan, homogalacturonan, and rhamnose hexose-pectic type polysaccharide) and polyphenolics. Hence, it was concluded that the presence of high hexuronic acids and polysaccharides, as well as polyphenolics in traditional medicinal plant, M. malabathricum, played a role in prolonging blood clotting in the intrinsic pathway.
Plasma and urine metabolite profiling reveals the protective effect of Clinacanthus nutans in an ovalbumin-induced anaphylaxis model: 1H-NMR metabolomics approach

Khoo LW, Audrey Kow SF, Maulidiani M, Lee MT, Tan CP, Shaari K, et al.

J Pharm Biomed Anal, 2018 Sep 05;158:438-450.
PMID: 29957507 DOI: 10.1016/j.jpba.2018.06.038

The present study sought to identify the key biomarkers and pathways involved in the induction of allergic sensitization to ovalbumin and to elucidate the potential anti-anaphylaxis property of Clinacanthus nutans (Burm. f.) Lindau water leaf extract, a Southeast Asia herb in an in vivo ovalbumin-induced active systemic anaphylaxis model evaluated by 1H-NMR metabolomics. The results revealed that carbohydrate metabolism (glucose, myo-inositol, galactarate) and lipid metabolism (glycerol, choline, sn-glycero-3-phosphocholine) are the key requisites for the induction of anaphylaxis reaction. Sensitized rats treated with 2000 mg/kg bw C. nutans extract before ovalbumin challenge showed a positive correlation with the normal group and was negatively related to the induced group. Further 1H-NMR analysis in complement with Kyoto Encyclopedia of Genes and Genomes (KEGG) reveals the protective effect of C. nutans extract against ovalbumin-induced anaphylaxis through the down-regulation of lipid metabolism (choline, sn-glycero-3-phosphocholine), carbohydrate and signal transduction system (glucose, myo-inositol, galactarate) and up-regulation of citrate cycle intermediates (citrate, 2-oxoglutarate, succinate), propanoate metabolism (1,2-propanediol), amino acid metabolism (betaine, N,N-dimethylglycine, methylguanidine, valine) and nucleotide metabolism (malonate, allantoin). In summary, this study reports for the first time, C. nutans water extract is a potential anti-anaphylactic agent and 1H-NMR metabolomics is a great alternative analytical tool to explicate the mechanism of action of anaphylaxis.
1 H-NMR metabolomics for evaluating the protective effect of Clinacanthus nutans (Burm. f) Lindau water extract against nitric oxide production in LPS-IFN-γ activated RAW 264.7 macrophages

Khoo LW, Kow ASF, Maulidiani M, Ang MY, Chew WY, Lee MT, et al.

Phytochem Anal, 2019 Jan;30(1):46-61.
PMID: 30183131 DOI: 10.1002/pca.2789

INTRODUCTION: Clinacanthus nutans, a small shrub that is native to Southeast Asia, is commonly used in traditional herbal medicine and as a food source. Its anti-inflammation properties is influenced by the metabolites composition, which can be determined by different binary extraction solvent ratio and extraction methods used during plant post-harvesting stage.
OBJECTIVE: Evaluate the relationship between the chemical composition of C. nutans and its anti-inflammatory properties using nuclear magnetic resonance (NMR) metabolomics approach.
METHODOLOGY: The anti-inflammatory effect of C. nutans air-dried leaves extracted using five different binary extraction solvent ratio and two extraction methods was determined based on their nitric oxide (NO) inhibition effect in lipopolysaccharide-interferon-gamma (LPS-IFN-γ) activated RAW 264.7 macrophages. The relationship between extract bioactivity and metabolite profiles and quantifications were established using 1 H-NMR metabolomics and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The possible metabolite biosynthesis pathway was constructed to further strengthen the findings.
RESULTS: Water and sonication prepared air-dried leaves possessed the highest NO inhibition activity (IC50 = 190.43 ± 12.26 μg/mL, P
Fulltext Hematological, Biochemical, Histopathological and ¹H-NMR Metabolomics Application in Acute Toxicity Evaluation of Clinacanthus nutans Water Leaf Extract

Khoo LW, Foong Kow AS, Maulidiani M, Lee MT, Tan CP, Shaari K, et al.

Molecules, 2018 Aug 29;23(9).
PMID: 30158427 DOI: 10.3390/molecules23092172

The present study aims for the first time to provide the in vivo acute toxicological profile of the highest dose of Clinacanthus nutans (Burm. f.) Lindau water leaf extract according to the Organization for economic co-operation and development (OECD) 423 guidelines through conventional toxicity and advanced proton nuclear magnetic resonance (¹H-NMR) serum and urinary metabolomics evaluation methods. A single dose of 5000 mg/kg bw of C. nutans water extract was administered to Sprague Dawley rats, and they were observed for 14 days. Conventional toxicity evaluation methods (physical observation, body and organ weight, food and water consumption, hematology, biochemical testing and histopathological analysis) suggested no abnormal toxicity signs. Serum ¹H-NMR metabolome revealed no significant metabolic difference between untreated and treated groups. Urinary ¹H-NMR analysis, on the other hand, revealed alteration in carbohydrate metabolism, energy metabolism and amino acid metabolism in extract-treated rats after 2 h of extract administration, but the metabolic expression collected after 24 h and at Day 5, Day 10 and Day 15 indicated that the extract-treated rats did not accumulate any toxicity biomarkers. Importantly, the outcomes further suggest that single oral administration of up to 5000 mg/kg bw of C. nutans water leaf extract is safe for consumption.
Fulltext A Comprehensive Review on Phytochemistry and Pharmacological Activities of Clinacanthus nutans (Burm.f.) Lindau

Khoo LW, Audrey Kow S, Lee MT, Tan CP, Shaari K, Tham CL, et al.

Evid Based Complement Alternat Med, 2018;2018:9276260.
PMID: 30105077 DOI: 10.1155/2018/9276260

Clinacanthus nutans (Burm.f.) Lindau (Acanthaceae), commonly known as Sabah snake grass, is a vegetable and a well-known herb that is considered an alternative medicine for insect bites, skin rashes, herpes infection, inflammation, and cancer and for health benefits. Current review aims to provide a well-tabulated repository of the phytochemical screening, identification and quantification, and the pharmacological information of C. nutans according to the experimental design and the plant preparation methods which make it outstanding compared to existing reviews. This review has documented valuable data obtained from all accessible library databases and electronic searches. For the first time we analyzed the presence of flavonoids, triterpenoids, steroids, phytosterols, and glycosides in C. nutans based on the results from phytochemical screening which are then further confirmed by conventional phytochemical isolation methods and advanced spectroscopic techniques. Phytochemical quantification further illustrated that C. nutans is a good source of phenolics and flavonoids. Pharmacological studies on C. nutans revealed that its polar extract could be a promising anti-inflammation, antiviral, anticancer, immune and neuromodulating, and plasmid DNA protective agent; that its semipolar extract could be a promising antiviral, anticancer, and wound healing agent; and that its nonpolar extract could be an excellent anticancer agent.
Evaluation of quality parameters for fresh, used and recycled palm olein

Khor YP, Sim BI, Abas F, Lai OM, Wang Y, Nehdi IA, et al.

J Sci Food Agric, 2019 Dec;99(15):6989-6997.
PMID: 31414493 DOI: 10.1002/jsfa.9989

BACKGROUND: Recycled oil has emerged as a significant food safety issue and poses a major threat to public health. To date, very limited studies have been conducted aiming to detect the adulteration of used and recycled palm olein in refined, bleached and deodorized palm olein (RBDPO). In the present study, oil samples that underwent controlled heating and deep-frying studies were refined using the common oil refining procedure to simulate the production of recycled oil. Polymerized triacylglycerol (PTG), oxidized monomeric triacylglycerols (oxTAGs), such as epoxy, keto and hydroxy acids, and caprylic acid have been proposed as potential indicators for tracking the adulteration of recycled oil.
RESULTS: For PTG, triacylglycerol oligomers and dimers showed a significant increase (P
Fulltext Oxidation and Polymerization of Triacylglycerols: In-Depth Investigations towards the Impact of Heating Profiles

Khor YP, Hew KS, Abas F, Lai OM, Cheong LZ, Nehdi IA, et al.

Foods, 2019 Oct 11;8(10).
PMID: 31614487 DOI: 10.3390/foods8100475

The stability of refined, bleached, and deodorized palm olein (RBDPO) was studied under controlled heating conditions. RBDPO was heated continuously for 24 h at 160, 170, and 180 °C, with oil sampled at four hour intervals. Thermo-oxidative alterations were measured through various parameters, such as monomeric oxidized triacylglycerols (oxTAG), total polar compounds (TPC), polymerized triacylglycerols (PTG), oxidative stability, and fatty acid composition. After 24 h of heating, the TPC and triacylglycerol oligomers showed a linear increase with heating time at all heating temperatures. At the end of the heating study, more epoxy acids were formed than keto and hydroxy acids. Moreover, caprylic acid, which was not present in fresh oil, was formed in significant amounts. The increase in oxTAG was strongly correlated with the increase in the p-anisidine value and total oxidation value. The decreases in diacylglycerol and free fatty acids were strongly correlated with an increase in PTG.
Fulltext Bioactivities of Phenolic Compounds from Kiwifruit and Persimmon

Kim YM, Abas F, Park YS, Park YK, Ham KS, Kang SG, et al.

Molecules, 2021 Jul 21;26(15).
PMID: 34361562 DOI: 10.3390/molecules26154405

Fruit used in the common human diet in general, and kiwifruit and persimmon particularly, displays health properties in the prevention of heart disease. This study describes a combination of bioactivity, multivariate data analyses and fluorescence measurements for the differentiating of kiwifruit and persimmon, their quenching and antioxidant properties. The metabolic differences are shown, as well in the results of bioactivities and antioxidant capacities determined by ABTS, FRAP, CUPRAC and DPPH assays. To complement the bioactivity of these fruits, the quenching properties between extracted polyphenols and human serum proteins were determined by 3D-fluorescence spectroscopy studies. These properties of the extracted polyphenols in interaction with the main serum proteins in the human metabolism (human serum albumin (HSA), α-β-globulin (α-β G) and fibrinogen (Fgn)), showed that kiwifruit was more reactive than persimmon. There was a direct correlation between the quenching properties of the polyphenols of the investigated fruits with serum human proteins, their relative quantification and bioactivity. The results of metabolites and fluorescence quenching show that these fruits possess multiple properties that have a great potential to be used in industry with emphasis on the formulation of functional foods and in the pharmaceutical industry. Based on the quenching properties of human serum proteins with polyphenols and recent reports in vivo on human studies, we hypothesize that HSA, α-β G and Fgn will be predictors of coronary artery disease (CAD).
Fulltext Identification of Soluble Mediators in IgG-Mediated Anaphylaxis via Fcγ Receptor: A Meta-Analysis

Kow ASF, Chik A, Soo KM, Khoo LW, Abas F, Tham CL

Front Immunol, 2019;10:190.
PMID: 30809224 DOI: 10.3389/fimmu.2019.00190

Background: Anaphylaxis is an acute and life-threatening allergic response. Classically and most commonly, it can be mediated by the crosslinking of allergens to immunoglobulin E (IgE)- high affinity IgE receptor (FcεRI) complex found mostly on mast cells. However, there is another pathway of anaphylaxis that is less well-studied. This pathway known as the alternative pathway is mediated by IgG and its Fc gamma receptor (Fcγ). Though it was not documented in human anaphylaxis, a few studies have found that IgG-mediated anaphylaxis can happen as demonstrated in rodent models of anaphylaxis. In these studies, a variety of soluble mediators were being evaluated and they differ from each study which causes confusion in the suitability, and reliability of choice of soluble mediators to be analyzed for diagnosis or therapeutic purposes. Hence, the objective of this meta-analysis is to identify the potential soluble mediators that are involved in an IgG-mediated anaphylaxis reaction. Methods: Studies related to IgG-mediated anaphylaxis were sourced from five search engines namely PubMed, Scopus, Ovid, Cochrane Library, and Center for Agricultural Bioscience International (CABI) regardless of publication year. Relevant studies were then reviewed based on specific inclusion factors. The means and standard deviations of each soluble mediator studied were then extracted using ImageJ or Get Data Graph Digitiser software and the data were subjected to meta-analysis. Results: From our findings, we found that histamine, serotonin, platelet activating factor (PAF), β-hexosaminidase, leukotriene C4 (LTC4), mucosal mast cell protease-1 (MMCP-1), interleukins (IL)-4,-6, and-13; tumor necrosis factor alpha (TNF-α), and macrophage inflammatory protein-1α (MIP-1α) were often being analyzed. Out of these soluble mediators, histamine, PAF, β-hexosaminidase, IL-6, and-13, MIP-1α and TNF-α were more significant with positive effect size and p < 0.001. As study effect was relatively small, we performed publication bias and found that there was publication bias and this could be due to the small sample size studied. Conclusion: As such, we proposed that through meta-analysis, the potential soluble mediators involved in rodent IgG-mediated anaphylaxis to be histamine, PAF, β-hexosaminidase, IL-6 and-13 and MIP-1α, and TNF-α but will require further studies with larger sample size.
Clinacanthus nutans aqueous leaves extract exerts anti-allergic activity in preclinical anaphylactic models via alternative IgG pathway

Kow ASF, Khoo LW, Tan JW, Abas F, Lee MT, Israf DA, et al.

J Ethnopharmacol, 2023 Mar 01;303:116003.
PMID: 36464074 DOI: 10.1016/j.jep.2022.116003

ETHNOPHARMACOLOGICAL RELEVANCE: Allergy is mediated by the crosslinking of immunoglobulins (Ig) -E or -G to their respective receptors, which degranulates mast cells, macrophages, basophils, or neutrophils, releasing allergy-causing mediators. The removal of these mediators such as histamine, platelet-activating factor (PAF) and interleukins (ILs) released by effector cells will alleviate allergy. Clinacanthus nutans (C. nutans), an herbal plant in Southeast Asia, is used traditionally to treat skin rash, an allergic symptom. Previously, we have reported that C. nutans aqueous leaves extract (CNAE) was able to suppress the release of β-hexosaminidase and histamine but not interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-α) in the IgE-induced mast cell degranulation model at 5 mg/mL and above. We also found that CNAE could protect rats against ovalbumin-challenged active systemic anaphylaxis (OVA-ASA) through the downregulation and upregulation of certain metabolites using proton nuclear magnetic resonance (1H-NMR) metabolomics approach.
AIM OF THE STUDY: As allergy could be mediated by both IgE and IgG, we further evaluated the anti-allergy potential of CNAE in both in vitro model of IgG-induced macrophage activation and in vivo anaphylaxis models to further dissect the mechanism of action underlying the anti-allergic properties of CNAE.
MATERIAL & METHODS: The anti-allergy potential of CNAE was evaluated in in vivo anaphylaxis models of ovalbumin-challenged active systemic anaphylaxis (OVA-ASA) and IgE-challenged passive systemic anaphylaxis (PSA) using Sprague Dawley rats as well as IgG-challenged passive systemic anaphylaxis (IgG-PSA) using C57BL/6 mice. Meanwhile, in vitro model of IgG-induced macrophage activation model was performed using IC-21 macrophages. The release of soluble mediators from both IgE and IgG-mediated pathways were measured using enzyme-linked immunosorbent assay (ELISA). The signaling molecules targeted by CNAE were identified by performing Western blot.
RESULTS: IgG, platelet-activating factor (PAF) and IL-6 was suppressed by CNAE in OVA-ASA, but not IgE. In addition, CNAE significantly suppressed PAF and IL-6 in IgG-PSA but did not suppress histamine, IL-4 and leukotrienes C4 (LTC4) in IgE-PSA. CNAE also inhibited IL-6 and TNF-α by inhibiting the phosphorylation of ERK1/2 in the IgG-induced macrophage activation model.
CONCLUSION: Overall, our findings supported that CNAE exerts its anti-allergic properties by suppressing the IgG pathway and its mediators by inhibiting ERK1/2 phosphorylation, thus providing scientific evidence supporting its traditional use in managing allergy.
Fulltext Postprandial Metabolome Following a Low Glycaemic Index Meal-Challenge Test: A Narrative Review

Lau ZC, Mohd Yusof BN, Abas F, Abd Wahab N, Wan Zukiman WZH, Ismail A

Malays J Med Sci, 2022 Oct;29(5):5-16.
PMID: 36474545 DOI: 10.21315/mjms2022.29.5.2

The Identifying the dynamic metabolome of the individual in response to a particular stimulus using a metabolomic approach is an emerging research area. Measuring the postprandial metabolite response utilising a meal-challenge test (MCT) provides information beyond the fasting state, which is especially important since human beings spend most of their time in the postprandial state. This is pertinent as an excessive rise in postprandial glycaemia is common in individuals with type 2 diabetes mellitus (T2DM), which puts them at a high risk of developing cardiovascular disease (CVD). While a low glycaemic index (GI) meal improves postprandial glycaemia and insulin levels in MCT studies among individuals with T2DM, its effect on metabolite changes in the postprandial state is unclear. This review summarises the perturbation in postprandial metabolites following a low GI meal in comparison to that following a usual or high GI meal and maps the metabolites in their metabolic pathways. We undertook a literature review using electronic databases, with the Medical Subject Headings (MeSH) terms, to retrieve relevant studies based on specific criteria. A total of seven related studies were documented. For the majority of metabolites studied, it was identified that metabolic regulation following an MCT extends beyond the glucose pathway. Altered metabolic pathways after the consumption of a low GI meal include: i) essential amino acid metabolism by altering the levels of plasma phenylalanine, tyrosine, lysine, leucine, isoleucine and valine; ii) glycolysis and tricarboxylic acid (TCA) metabolism by altering citrate and alanine, and iii) gut microbiota metabolism by altering betaine and acetate. The altered metabolites regulated the pancreatic insulin secretion and related to other dietary factors beyond GI modifications. These metabolomics data need to be interpreted cautiously because the metabolic changes analysed might not be due to the beneficial effects of a low GI meal. Validation of the putative metabolomic biomarkers following a dietary intervention MCT is suggested because researchers need to fully understand the kinetics and metabolism of individuals metabolite before reaching a solid conclusion. Further research characterising the metabotype based on habitual dietary patterns is warranted.
Chemopreventive effects of a curcumin-like diarylpentanoid [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] in cellular targets of rheumatoid arthritis in vitro

Lee KH, Abas F, Mohamed Alitheen NB, Shaari K, Lajis NH, Israf DA, et al.

Int J Rheum Dis, 2015 Jul;18(6):616-27.
PMID: 24832356 DOI: 10.1111/1756-185X.12341

Synovial fibroblast has emerged as a potential cellular target in progressive joint destruction in rheumatoid arthritis development. In this study, BDMC33 (2,6-bis[2,5-dimethoxybenzylidene]cyclohexanone), a curcumin analogue with enhanced anti-inflammatory activity has been synthesized and the potency of BDMC33 on molecular and cellular basis of synovial fibroblasts (SF) were evaluated in vitro.
Fulltext BDMC33, A curcumin derivative suppresses inflammatory responses in macrophage-like cellular system: role of inhibition in NF-κB and MAPK signaling pathways

Lee KH, Chow YL, Sharmili V, Abas F, Alitheen NB, Shaari K, et al.

Int J Mol Sci, 2012;13(3):2985-3008.
PMID: 22489138 DOI: 10.3390/ijms13032985

Our preliminary screening has shown that curcumin derivative BDMC33 [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] exerted promising nitric oxide inhibitory activity in activated macrophages. However, the molecular basis and mechanism for its pharmacological action is yet to be elucidated. The aim of this study was to investigate the anti-inflammatory properties of BDMC33 and elucidate its underlying mechanism action in macrophage cells. Our current study demonstrated that BDMC33 inhibits the secretion of major pro-inflammatory mediators in stimulated macrophages, and includes NO, TNF-α and IL-1β through interference in both nuclear factor kappaB (NF-κB) and mitogen activator protein kinase (MAPK) signaling cascade in IFN-γ/LPS-stimulated macrophages. Moreover, BDMC33 also interrupted LPS signaling through inhibiting the surface expression of CD-14 accessory molecules. In addition, the inhibitory action of BDMC33 not only restricted the macrophages cell (RAW264.7), but also inhibited the secretion of NO and TNF-α in IFN-γ/LPS-challenged microglial cells (BV-2). The experimental data suggests the inflammatory action of BDMC33 on activated macrophage-like cellular systems, which could be used as a future therapeutic agent in the management of chronic inflammatory diseases.
Fulltext A curcumin derivative, 2,6-bis(2,5-dimethoxybenzylidene)-cyclohexanone (BDMC33) attenuates prostaglandin E2 synthesis via selective suppression of cyclooxygenase-2 in IFN-γ/LPS-stimulated macrophages

Lee KH, Abas F, Alitheen NB, Shaari K, Lajis NH, Ahmad S

Molecules, 2011 Nov 23;16(11):9728-38.
PMID: 22113581 DOI: 10.3390/molecules16119728

Our preliminary screening had shown that the curcumin derivative [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] or BDMC33 exhibited improved anti-inflammatory activity by inhibiting nitric oxide synthesis in activated macrophage cells. In this study, we further investigated the anti-inflammatory properties of BDMC33 on PGE(2 )synthesis and cyclooxygenase (COX) expression in IFN-γ/LPS-stimulated macrophages. We found that BDMC33 significantly inhibited PGE(2) synthesis in a concentration-dependent manner albeit at a low inhibition level with an IC(50) value of 47.33 ± 1.00 µM. Interestingly, the PGE(2) inhibitory activity of BDMC33 is not attributed to inhibition of the COX enzyme activities, but rather BDMC33 selectively down-regulated the expression of COX-2. In addition, BDMC33 modulates the COX expression by sustaining the constitutively COX-1 expression in IFN-γ/LPS-treated macrophage cells. Collectively, the experimental data suggest an immunodulatory action of BDMC33 on PGE(2) synthesis and COX expression, making it a possible treatment for inflammatory disorders with minimal gastrointestinal-related side effects.
Synthesis and biological evaluation of curcumin-like diarylpentanoid analogues for anti-inflammatory, antioxidant and anti-tyrosinase activities

Lee KH, Ab Aziz FH, Syahida A, Abas F, Shaari K, Israf DA, et al.

Eur J Med Chem, 2009 Aug;44(8):3195-200.
PMID: 19359068 DOI: 10.1016/j.ejmech.2009.03.020

A series of 46 curcumin related diarylpentanoid analogues were synthesized and evaluated for their anti-inflammatory, antioxidant and anti-tyrosinase activities. Among these compounds 2, 13 and 33 exhibited potent NO inhibitory effect on IFN-gamma/LPS-activated RAW 264.7 cells as compared to L-NAME and curcumin. However, these series of diarylpentanoid analogues were not significantly inhibiting NO scavenging, total radical scavenging and tyrosinase enzyme activities. The results revealed that the biological activity of these diarylpentanoid analogues is most likely due to their action mainly upon inflammatory mediator, inducible nitric oxide synthase (iNOS). The present results showed that compounds 2, 13 and 33 might serve as a useful starting point for the design of improved anti-inflammatory agents.
Fulltext Antioxidants and α-glucosidase inhibitors from Neptunia oleracea fractions using 1H NMR-based metabolomics approach and UHPLC-MS/MS analysis

Lee SY, Mediani A, Ismail IS, Maulidiani, Abas F

BMC Complement Altern Med, 2019 Jan 07;19(1):7.
PMID: 30616569 DOI: 10.1186/s12906-018-2413-4

BACKGROUND: Neptunia oleracea is a plant cultivated as vegetable in Southeast Asia. Previous works have revealed the potential of this plant as a source of natural antioxidants and α-glucosidase inhibitors. Continuing our interest on this plant, the present work is focused in identification of the bioactive compounds from different polarity fractions of N. oleracea, namely hexane (HF), chloroform (CF), ethyl acetate (EF) and methanol (MF).
METHODS: The N. oleracea fractions were obtained using solid phase extraction (SPE). A metabolomics approach that coupled the use of proton nuclear magnetic resonance (1H NMR) with multivariate data analysis (MVDA) was applied to distinguish the metabolite variations among the N. oleracea fractions, as well as to assess the correlation between metabolite variation and the studied bioactivities (DPPH free radical scavenging and α-glucosidase inhibitory activities). The bioactive fractions were then subjected to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis to profile and identify the potential bioactive constituents.
RESULTS: The principal component analysis (PCA) discriminated EF and MF from the other fractions with the higher distributions of phenolics. Partial least squares (PLS) analysis revealed a strong correlation between the phenolics and the studied bioactivities in the EF and the MF. The UHPLC-MS/MS profiling of EF and MF had tentatively identified the phenolics present. Together with some non-phenolic metabolites, a total of 37 metabolites were tentatively assigned.
CONCLUSIONS: The findings of this work supported that N. oleracea is a rich source of phenolics that can be potential antioxidants and α-glucosidase inhibitors for the management of diabetes. To our knowledge, this study is the first report on the metabolite-bioactivity correlation and UHPLC-MS/MS analysis of N. oleracea fractions.
Comparison of partial least squares and random forests for evaluating relationship between phenolics and bioactivities of Neptunia oleracea

Lee SY, Mediani A, Maulidiani M, Khatib A, Ismail IS, Zawawi N, et al.

J Sci Food Agric, 2018 Jan;98(1):240-252.
PMID: 28580581 DOI: 10.1002/jsfa.8462

BACKGROUND: Neptunia oleracea is a plant consumed as a vegetable and which has been used as a folk remedy for several diseases. Herein, two regression models (partial least squares, PLS; and random forest, RF) in a metabolomics approach were compared and applied to the evaluation of the relationship between phenolics and bioactivities of N. oleracea. In addition, the effects of different extraction conditions on the phenolic constituents were assessed by pattern recognition analysis.
RESULTS: Comparison of the PLS and RF showed that RF exhibited poorer generalization and hence poorer predictive performance. Both the regression coefficient of PLS and the variable importance of RF revealed that quercetin and kaempferol derivatives, caffeic acid and vitexin-2-O-rhamnoside were significant towards the tested bioactivities. Furthermore, principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) results showed that sonication and absolute ethanol are the preferable extraction method and ethanol ratio, respectively, to produce N. oleracea extracts with high phenolic levels and therefore high DPPH scavenging and α-glucosidase inhibitory activities.
CONCLUSION: Both PLS and RF are useful regression models in metabolomics studies. This work provides insight into the performance of different multivariate data analysis tools and the effects of different extraction conditions on the extraction of desired phenolics from plants. © 2017 Society of Chemical Industry.
Fulltext Proteomic Analysis on Anti-Proliferative and Apoptosis Effects of Curcumin Analog, 1,5-bis(4-Hydroxy-3-Methyoxyphenyl)-1,4-Pentadiene-3-One-Treated Human Glioblastoma and Neuroblastoma Cells

Lee YQ, Rajadurai P, Abas F, Othman I, Naidu R

Front Mol Biosci, 2021;8:645856.
PMID: 33996900 DOI: 10.3389/fmolb.2021.645856

Curcumin analogs with excellent biological properties have been synthesized to address and overcome the poor pharmacokinetic profiles of curcumin. This study aims to investigate the cytotoxicity, anti-proliferative, and apoptosis-inducing ability of curcumin analog, MS13 on human glioblastoma U-87 MG, and neuroblastoma SH-SY5Y cells, and to examine the global proteome changes in these cells following treatment. Our current findings showed that MS13 induced potent cytotoxicity and anti-proliferative effects on both cells. Increased caspase-3 activity and decreased bcl-2 concentration upon treatment indicate that MS13 induces apoptosis in these cells in a dose- and time-dependent manner. The label-free shotgun proteomic analysis has defined the protein profiles in both glioblastoma and neuroblastoma cells, whereby a total of nine common DEPs, inclusive of glyceraldehyde 3-phosphate dehydrogenase (GAPDH), alpha-enolase (ENO1), heat shock protein HSP 90-alpha (HSP90AA1), Heat shock protein HSP 90-beta (HSP90AB1), Eukaryotic translation initiation factor 5A-1 (EFI5A), heterogenous nuclear ribonucleoprotein K (HNRNPK), tubulin beta chain (TUBB), histone H2AX (H2AFX), and Protein SET were identified. Pathway analysis further elucidated that MS13 may induce its anti-tumor effects in both cells via the common enriched pathways, "Glycolysis" and "Post-translational protein modification." Conclusively, MS13 demonstrates an anti-cancer effect that may indicate its potential use in the management of brain malignancies.
Fulltext Antioxidant and α-glucosidase inhibitory activities of the leaf and stem of selected traditional medicinal plants

Lee, S.Y., Mediani, A., Nur Ashikin, A.H., Abas, F., Azliana, A.B.S.

International Food Research Journal, 2014;21(1):165-172.
MyJurnal

The study was aimed to determine the antioxidant and α-glucosidase inhibition activities of
the stem and leaf of five different traditional medicinal plants. The studied plants exhibited
varied antioxidant and α-glucosidase inhibition activities. The antioxidant activities of the
plants were determined through their free radical scavenging capabilities using DPPH assay.
The most potent antioxidant activity was demonstrated by Neptunia oleracea with an IC50 of
35.45 and 29.72 μg/mL for leaf and stem, respectively. For α-glucosidase inhibition activity,
Neptunia oleracea exhibited potential α-glucosidase inhibition activity with IC50 value of
19.09 and 19.74 μg/mL for leaf and stem, respectively. The highest total phenolic content
(TPC) was also marked in Neptunia oleracea leaf and stem with value of 40.88 and 21.21 mg
GAE/g dry weight, respectively. The results also showed that Strobilanthes crispus collected
from two different locations possessed different levels of phenolic content, antioxidant and
α-glucosidase inhibition activities. The study revealed that phenolic compounds could be the
main contributors to the antioxidant and α-glucosidase inhibition activities with R values of 78.9
and 67.4%, respectively. In addition, antioxidant and α-glucosidase were positively correlated
(R = 81.9%). Neptunia oleracea could be suggested as a potential natural source of antioxidant
and antidiabetic compounds that can be used for the prevention or treatment of diabetes.

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