Displaying publications 1 - 20 of 166 in total

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  1. Limonoids from the fruits of Chisocheton erythrocarpus and their mosquito larvicidal activities
    Ngadni MA, Chong SL, Hazni H, Asib N, Ishak IH, Mohmad Misnan N, et al.
    Phytochemistry, 2024 Apr 09;222:114092.
    PMID: 38604323 DOI: 10.1016/j.phytochem.2024.114092
    Phytochemical study of the fruits of Chisocheton erythrocarpus (Hiern) allowed the identification of eight undescribed limonoids, namely erythrocarpines O - V (1-6, 7a and 7b), along with seven known compounds. The structures of these compounds were elucidated based on spectroscopic and HRMS data, along with electronic circular dichroism to configure the absolute configuration. Erythrocarpines O and P are γ-hydroxybutenolide analogs of mexicanolide-type limonoids while erythrocarpine Q - V are phragmalin-type limonoids possessing a 1,29-oxymethylene bridge with either benzoyl or cinnamoyl moiety in their structures. Mosquito larvicidal activity revealed that crude DCM extract of C. erythrocarpus possessed a good larvicidal effect against Aedes aegypti larvae in 48 h (LC50 = 153.0 ppm). Subsequent larvicidal activity of isolated compounds indicated that erythrocarpine G (10) and 14-deoxyxyloccensin K (11) were responsible for the enhanced larvicidal effect of the extract, reporting LC50 values of 18.55 ppm and 41.16 ppm, respectively. Moreover, residual activity testing of the crude DCM extract revealed that the duration of its larvicidal effects is up to 14 days, where it maintained a 98 % larval mortality throughout the test period, under laboratory conditions.
  2. Chemodiverse monoterpene indole alkaloids from Kopsia teoi, inhibitory potential against α-amylase, and their molecular docking studies
    Muhammad MT, Beniddir MA, Phongphane L, Abu Bakar MH, Hussin MH, Awang K, et al.
    Fitoterapia, 2024 Apr;174:105873.
    PMID: 38417682 DOI: 10.1016/j.fitote.2024.105873
    Diabetes mellitus stands as a metabolic ailment marked by heightened blood glucose levels due to inadequate insulin secretion. The primary aims of this investigative inquiry encompassed the isolation of phytochemical components from the bark of Kopsia teoi, followed by the assessment of their α-amylase inhibition. The phytochemical composition of the K. teoi culminated in the discovery of a pair of new indole alkaloids; which are 16-epi-deacetylakuammiline N(4)-methylene chloride (akuammiline) (1), and N(1)-methoxycarbonyl-11-methoxy-12-hydroxy-Δ14-17-kopsinine (aspidofractinine) (2), together with five known compounds i.e. kopsiloscine G (aspidofractinine) (3), akuammidine (sarpagine) (4), leuconolam (aspidosperma) (5), N-methoxycarbonyl-12-methoxy-Δ16, 17-kopsinine (aspidofractinine) (6), and kopsininate (aspidofractinine) (7). All compounds were determined via spectroscopic analyses. The in vitro evaluation against α-amylase showed good inhibitory activities for compounds 5-7 with the inhibitory concentration (IC50) values of 21.7 ± 1.2, 34.1 ± 0.1, and 30.0 ± 0.8 μM, respectively compared with the reference acarbose (IC50 = 34.4 ± 0.1 μM). The molecular docking outputs underscored the binding interactions of compounds 5-7 ranging from -8.1 to -8.8 kcal/mol with the binding sites of α-amylase. Consequently, the outcomes highlighted the anti-hyperglycemic attributes of isolates from K. teoi.
  3. The protective effects of Zingiber zerumbet rhizome against fevers in rats
    Mohd Salleh H, Ablat A, Chong SL, Hazni H, Tohar N, Fauzi N, et al.
    Naturwissenschaften, 2024 Apr 01;111(2):20.
    PMID: 38558027 DOI: 10.1007/s00114-024-01907-7
    The Zingiber zerumbet rhizomes are traditionally used to treat fever, and the in vitro inhibitory effect of ethyl acetate extract from Zingiber zerumbet rhizomes (EAEZZR) against DENV2 NS2B/NS3 (two non-structural proteins, NS2 and NS3 of dengue virus type 2) has been reported earlier. This study was carried out to establish an acute toxicity profile and evaluate the anti-fever (anti-pyretic) activities of EAEZZR in yeast-induced fever in rats. The major compound of EAEZZR, zerumbone, was isolated using chromatographic methods including column chromatography (CC) and preparative thin-layer chromatography (PTLC). Additionally, the structure of zerumbone was elucidated using nuclear magnetic resonance (NMR), liquid chromatography mass spectrometer-ion trap-time of flight (LCMS-IT-TOF), infrared (IR), and ultraviolet (UV) spectroscopy. The toxicity of EAEZZR was evaluated using Organization for Economic Cooperation and Development Test Guideline 425 (OECD tg-425) with minor modifications at concentrations EAEZZR of 2000 mg/kg, 3000 mg/kg, and 5000 mg/kg. Anti-fever effect was determined by yeast-induced fever (pyrexia) in rats. The acute toxicity study showed that EAEZZR is safe at the highest 5000 mg/kg body weight dose in Sprague Dawley rats. Rats treated with EAEZZR at doses of 125, 250, and 500 mg/kg exhibited a significant reduction in rectal temperature (TR) in the first 1 h. EAEZZR at the lower dose of 125 mg/kg showed substantial potency against yeast-induced fever for up to 2 h compared to 0 h in controls. A significant reduction of TR was observed in rats treated with standard drug aspirin in the third through fourth hours. Based on the present findings, ethyl acetate extract of Zingiber zerumbet rhizomes could be considered safe up to the dose of 5000 mg/kg, and the identification of active ingredients of Zingiber zerumbet rhizomes may allow their use in the treatment of fever with dengue virus infection.
  4. Erythrocarpines IN, new limonoids from the barks of Chisocheton erythrocarpus and their neuroprotective effects against hydrogen peroxide in NG108-15 cells
    Ngadni MA, Chong SL, Kamarudin MNA, Hazni H, Litaudon M, Supratman U, et al.
    Fitoterapia, 2024 Mar;173:105765.
    PMID: 38042506 DOI: 10.1016/j.fitote.2023.105765
    A phytochemical study on the bark of Chisocheton erythrocarpus Hiern (Meliaceae) has led to the isolation of six new phragmalin-type limonoids named erythrocarpines I - N (1-6) along with one known limonoid, erythrocarpine F (7). Their structures were fully characterized by spectroscopic methods. The pre-treatment of NG108-15 cells with 1-5, 7 (2 h) demonstrated low to good protective effects against H2O2 exposure; 1 (83.77% ± 1.84 at 12.5 μM), 2 (69.07 ± 2.01 at 12.5 μM), 3 (80.38 ± 2.1 at 12.5 μM), 4 (62.33 ± 1.95 at 25 μM),5 (58.67 ± 1.85 at 50 μM) and 7 (66.07 ± 2.03 at 12.5 μM). Interestingly, 1 and 3 demonstrated comparable protective effects to positive control epigallocatechin gallate (EGCG) with similar cell viability capacity (≈ 80%), having achieved that at lower concentration (12.5 μM) than EGCG (50 μM). Collectively, the results suggested the promising use of 1 and 3 as potential neuroprotective agents against hydrogen peroxide-induced cytotoxicity in neuronal model.
  5. Malabaricones from the fruit of Myristica cinnamomea King as potential agents against Acanthamoeba castellanii
    Ahmed U, Sivasothy Y, Khan KM, Khan NA, Wahab SMA, Awang K, et al.
    Acta Trop, 2023 Dec;248:107033.
    PMID: 37783284 DOI: 10.1016/j.actatropica.2023.107033
    Acanthamoeba castellanii is an opportunistic free-living amoeba (FLA) pathogen which can cause fatal central nervous system (CNS) infection, granulomatous amoebic encephalitis (GAE) and potentially blinding ocular infection, Acanthamoeba keratitis (AK). Acanthamoeba species remain a challenging protist to treat due to the unavailability of safe and effective therapeutic drugs and their ability to protect themselves in the cyst stage. Natural products and their secondary metabolites play a pivotal role in drug discovery against various pathogenic microorganisms. In the present study, the ethyl acetate extract of Myristica cinnamomea King fruit was evaluated against A. castellanii (ATCC 50492), showing an IC50 of 45.102 ± 4.62 µg/mL. Previously, the bio-guided fractionation of the extract resulted in the identification of three active compounds, namely Malabaricones (A-C). The isolated and thoroughly characterized acylphenols were evaluated for their anti-amoebic activity against A. castellanii for the first time. Among tested compounds, Malabaricone B (IC50 of 101.31 ± 17.41 µM) and Malabaricone C (IC50 of 49.95 ± 6.33 µM) showed potent anti-amoebic activity against A. castellanii trophozoites and reduced their viability up-to 75 and 80 %, respectively. Moreover, both extract and Malabaricones also significantly (p < 0.05) inhibit the encystation and excystation of A. castellanii, while showed minimal toxicity against human keratinocyte cells (HaCaT cells) at lower tested concentrations. Following that, the explanation of the possible mechanism of action of purified compounds were assessed by detection of the state of chromatin. Hoechst/PI 33342 double staining showed that necrotic cell death occurred in A. castellanii trophozoites after 8 h treatment of Malabaricones (A-C). These findings demonstrate that Malabaricones B and C could serve as promising therapeutic options against A. castellanii infections.
  6. 13C NMR-based dereplication using MixONat software to decipher potent anti-cholinesterase compounds in Mesua lepidota bark
    Leong ST, Liew SY, Khaw KY, Ahmad Hassali H, Richomme P, Derbré S, et al.
    Bioorg Chem, 2023 Dec;141:106859.
    PMID: 37742494 DOI: 10.1016/j.bioorg.2023.106859
    A bio-assay guided fractionation strategy based on cholinesterase assay combined with 13C NMR-based dereplication was used to identify active metabolites from the bark of Mesua lepidota. Eight compounds were identified with the aid of the 13C NMR-based dereplication software, MixONat, i.e., sitosterol (1), stigmasterol (2), α-amyrin (3), friedelin (6), 3β-friedelinol (7), betulinic acid (9), lepidotol A (10) and lepidotol B (11). Further bio-assay guided isolation of active compounds afforded one xanthone, pyranojacareubin (12) and six coumarins; lepidotol A (10), lepidotol B (11), lepidotol E (13), lepidotin A (14), and lepidotin B (15), including a new Mammea coumarin, lepidotin C (16). All the metabolites showed strong to moderate butyrylcholinesterase (BChE) inhibition. Lepidotin B (15) exhibited the most potent inhibition towards BChE with a mix-mode inhibition profile and a Ki value of 1.03 µM. Molecular docking and molecular dynamics simulations have revealed that lepidotin B (15) forms stable interactions with key residues within five critical regions of BChE. These regions encompass residues Asp70 and Tyr332, the acyl hydrophobic pocket marked by Leu286, the catalytic triad represented by Ser198 and His438, the oxyanion hole (OH) constituted by Gly116 and Gly117, and the choline binding site featuring Trp82. To gauge the binding strength of lepidotin B (15) and to pinpoint pivotal residues at the binding interface, free energy calculations were conducted using the Molecular Mechanics Generalized Born Surface Area (MM-GBSA) approach. This analysis not only predicted a favourable binding affinity for lepidotin B (15) but also facilitated the identification of significant residues crucial for the binding interaction.
  7. Phytoconstituents of Endiandra kingiana; antidiabetic effects and molecular docking studies on alpha-amylase and alpha-glucosidase
    Tanazi NNH, Aziz AN, Azmi MN, Abu Bakar MH, Hassim MFN, Wahab NHA, et al.
    Nat Prod Res, 2023 Nov 27.
    PMID: 38009213 DOI: 10.1080/14786419.2023.2283759
    Phytochemical investigation on the bark of E. kingiana plant afforded ten compounds, including six polyketides namely kingianin A 1, kingianin B 2, kingianin E 3, kingianin F 4, kingianin K 5 and kingianin L 6, three endiandric acids; kingianic acid A 7, tsangibeilin B 8 and endiandric acid M 9, and one sesquiterpene; daibuoxide 10. All compounds were separated as racemic mixture by recycling high-performance liquid chromatography (RHPLC), except for daibuoxide. Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. This is the first report on the presence of the sesquiterpene; daibuoxide in Endiandra genus. In vitro enzymatic bio-evaluation of the isolated compounds against α-amylase and α-glucosidase showed that 4 demonstrated the best α-amylase and α-glucosidase inhibitory activity with IC50 values of 181.54 ± 6.27 µg/mL and 237.87 ± 0.07 µg/mL, respectively. In addition, molecular docking analysis confirmed the α-amylase and α-glucosidase inhibitory activities demonstrated by 4.
  8. Fulltext N-Methyl Costaricine and Costaricine, Two Potent Butyrylcholinesterase Inhibitors from Alseodaphne pendulifolia Gamb
    Husna Hasnan MH, Sivasothy Y, Khaw KY, Nafiah MA, Hazni H, Litaudon M, et al.
    Int J Mol Sci, 2023 Jun 27;24(13).
    PMID: 37445877 DOI: 10.3390/ijms241310699
    Studies have been conducted over the last decade to identify secondary metabolites from plants, in particular those from the class of alkaloids, for the development of new anti-Alzheimer's disease (AD) drugs. The genus Alseodaphne, comprising a wide range of alkaloids, is a promising source for the discovery of new cholinesterase inhibitors, the first-line treatment for AD. With regard to this, a phytochemical investigation of the dichloromethane extract of the bark of A. pendulifolia Gamb. was conducted. Repeated column chromatography and preparative thin-layer chromatography led to the isolation of a new bisbenzylisoquinoline alkaloid, N-methyl costaricine (1), together with costaricine (2), hernagine (3), N-methyl hernagine (4), corydine (5), and oxohernagine (6). Their structures were elucidated by the 1D- and 2D-NMR techniques and LCMS-IT-TOF analysis. Compounds 1 and 2 were more-potent BChE inhibitors than galantamine with IC50 values of 3.51 ± 0.80 µM and 2.90 ± 0.56 µM, respectively. The Lineweaver-Burk plots of compounds 1 and 2 indicated they were mixed-mode inhibitors. Compounds 1 and 2 have the potential to be employed as lead compounds for the development of new drugs or medicinal supplements to treat AD.
  9. Fulltext α-Amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory effects of Melicope latifolia bark extracts and identification of bioactive constituents using in vitro and in silico approaches
    Quek A, Kassim NK, Lim PC, Tan DC, Mohammad Latif MA, Ismail A, et al.
    Pharm Biol, 2021 Dec;59(1):964-973.
    PMID: 34347568 DOI: 10.1080/13880209.2021.1948065
    CONTEXT: Melicope latifolia (DC.) T. G. Hartley (Rutaceae) was reported to contain various phytochemicals including coumarins, flavonoids, and acetophenones.

    OBJECTIVE: This study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.

    MATERIALS AND METHODS: Melicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078-10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.

    RESULTS: Melicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC50: 1464.32 μg/mL; DPP-4 IC50: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF1-CF4) whereby CF3 showed the highest antidiabetic activity (α-amylase IC50: 397.68 μg/mL; DPP-4 IC50: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2-4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC50: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC50: 911.44 μM).

    DISCUSSION AND CONCLUSIONS: The in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.

  10. Cytotoxic triterpenoids from the stem bark of Aglaia angustifolia
    Hutagaol RP, Harneti D, Safari A, Hidayat AT, Supratman U, Awang K, et al.
    J Asian Nat Prod Res, 2021 Aug;23(8):781-788.
    PMID: 32536210 DOI: 10.1080/10286020.2020.1776704
    A seco-apotirucallane-type triterpenoid, namely angustifolianin (1), along with three dammarane-type triterpenoids, (20S, 24S)-epoxy-dammarane-3β,25-diol (2), 3-epi-cabraleahydroxylactone (3), and cabralealactone (4), were isolated from the stem bark of Aglaia angustifolia Miq. The Chemical structure of the new compounds was elucidated on the basis of spectroscopic data. All of the compounds were evaluated for their cytotoxic effects against MCF-7 breast cancer cells. Among those compounds, angustifolianin (1) showed strongest cytotoxic activity with an IC50 value of 50.5 μg/ml.
  11. Natural DENV-2 NS2B/NS3 protease inhibitors from Myristica cinnamomea King
    Sivasothy Y, Liew SY, Othman MA, Abdul Wahab SM, Hariono M, Mohd Nawi MS, et al.
    Trop Biomed, 2021 Jun 01;38(2):79-84.
    PMID: 33973577 DOI: 10.47665/tb.38.2.044
    The NS2B/NS3 protease is crucial for the pathogenesis of the DENV. Therefore, the inhibition of this protease is considered to be the key strategy for the development of new antiviral drugs. In the present study, malabaricones C (3) and E (4), acylphenols from the fruits of Myristica cinnamomea King, have been respectively identified as moderate (27.33 ± 5.45 μM) and potent (7.55 ± 1.64 μM) DENV-2 NS2B/NS3 protease inhibitors, thus making this the first report on the DENV-2 NS2B/NS3 protease inhibitory activity of acylphenols. Based on the molecular docking studies, compounds 3 and 4 both have π-π interactions with Tyr161. While compound 3 has hydrogen bonding interactions with Gly151, Gly153 and Tyr161, compound 4 however, forms hydrogen bonds with Ser135, Asp129, Phe130 and Ile86 instead. The results from the present study suggests that malabaricones C (3) and E (4) could be employed as lead compounds for the development of new dengue antivirals from natural origin.
  12. Fulltext Alkyl-Resorcinol Derivatives as Inhibitors of GDP-Mannose Pyrophosphorylase with Antileishmanial Activities
    Levaique H, Pamlard O, Apel C, Bignon J, Arriola M, Kuhner R, et al.
    Molecules, 2021 Mar 11;26(6).
    PMID: 33799883 DOI: 10.3390/molecules26061551
    Leishmaniasis is a vector-borne disease caused by the protozoan parasite Leishmania found in tropical and sub-tropical areas, affecting 12 million people around the world. Only few treatments are available against this disease and all of them present issues of toxicity and/or resistance. In this context, the development of new antileishmanial drugs specifically directed against a therapeutic target appears to be a promising strategy. The GDP-Mannose Pyrophosphorylase (GDP-MP) has been previously shown to be an attractive therapeutic target in Leishmania. In this study, a chemical library of 5000 compounds was screened on both L. infantum (LiGDP-MP) and human (hGDP-MP) GDP-MPs. From this screening, oncostemonol D was found to be active on both GDP-MPs at the micromolar level. Ten alkyl-resorcinol derivatives, of which oncostemonols E and J (2 and 3) were described for the first time from nature, were then evaluated on both enzymes as well as on L. infantum axenic and intramacrophage amastigotes. From this evaluation, compounds 1 and 3 inhibited both GDP-MPs at the micromolar level, and compound 9 displayed a three-times lower IC50 on LiGDP-MP, at 11 µM, than on hGDP-MP. As they displayed mild activities on the parasite, these compounds need to be further pharmacomodulated in order to improve their affinity and specificity to the target as well as their antileishmanial activity.
  13. A new antiplasmodial sterol from Indonesian marine sponge, Xestospongia sp
    Murtihapsari M, Salam S, Kurnia D, Darwati D, Kadarusman K, Abdullah FF, et al.
    Nat Prod Res, 2021 Mar;35(6):937-944.
    PMID: 31210054 DOI: 10.1080/14786419.2019.1611815
    A new antimalarial sterol, kaimanol (1), along with a known sterol, saringosterol (2) was isolated from the Indonesian Marine sponge, Xestospongia sp. The chemical structure of the new compound was determined on the basis of spectroscopic evidences and by comparison to those related compounds previously reported. Isolated compounds, 1 and 2 were evaluated for their antiplasmodial effect against Plasmodium falciparum 3D7 strains. Compounds 1 and 2 exhibited antiplasmodial activity with IC50 values of 359 and 0.250 nM, respectively.
  14. Fulltext Leaf Anatomy and Micromorphology Characteristics of Ketum [Mitragyna speciosa (Korth.) Havil.] (Rubiaceae)
    Ghazalli MN, Md Sah MS, Mat M, Awang K, Jaafar MA, Mirad R, et al.
    Trop Life Sci Res, 2021 Mar;32(1):107-117.
    PMID: 33936554 DOI: 10.21315/tlsr2021.32.1.7
    Mitragyna speciosa (Korth.) Havil. or locally known as ketum/daun sebiak/biak-biak belongs to Rubiaceae family and generally occurs in secondary forest or disturbed areas in tropical and subtropical region. This research enumerated the characterisation of Mitragyna speciosa leaf anatomy and micromorphology features which is still not well documented. This medium to large sized tree species characterised with opposite arrangement, ovate-acuminate leaf and with 12-17 pairs of veins. Transverse sections of petioles showed that this species has petiole outlines with slightly convex at the middle of the adaxial part and 'U'-shaped on abaxial side. Results also showed that this species has paracytic and hypostomatic stomata, combination of non-glandular (majority) and glandular trichomes (minority), with observation on the secretory cells present in petiole and midrib parenchyma cells. Cuticle on the abaxial and adaxial epidermal surfaces showed the presence granule and wax films with periclinal and anticlinal walls can be differentiated clearly. The results obtained in this study can be used to providing additional systematics information of Mitragyna speciosa with the documentation of the leaf anatomy and micromorphology characters.
  15. Giganteone A and malabaricone C as potential pharmacotherapy for diabetes mellitus
    Sivasothy Y, Leong KH, Loo KY, Adbul Wahab SM, Othman MA, Awang K
    Nat Prod Res, 2021 Feb 16.
    PMID: 33593208 DOI: 10.1080/14786419.2021.1885405
    The use of antidiabetic agents which control glycemic levels in the blood and simultaneously inhibit oxidative stress is an important strategy in the prevention of Diabetes Mellitus and its complications. In our previous study, malabaricone C (3) and its dimer, giganteone A (5) exhibited significant DPPH free radical scavenging activities which were lower than the activity of the positive control, ascorbic acid. These compounds were evaluated for their α-glucosidase inhibitory activities at different concentrations (0.02-2.5 mM) in the present study. Compounds 3 (IC50 59.61 µM) and 5 (IC50 39.52 µM) were identified as active alpha-glucosidase inhibitors, each respectively being 24 and 37 folds more potent than the standard inhibitor, acarbose. Based on the molecular docking studies, compounds 3 and 5 docked into the active site of the α-glucosidase enzyme, forming mainly hydrogen bonds in the active site.
  16. Cytotoxic constituent of Melicope latifolia (DC.) T. G. Hartley
    Lim PC, Ali Z, Khan IA, Khan SI, Kassim NK, Awang K, et al.
    Nat Prod Res, 2021 Feb 12.
    PMID: 33576269 DOI: 10.1080/14786419.2021.1885031
    An undescribed conjugated sesquiterpene, amelicarin (1), together with nine known compounds (2-10) were isolated for the first time from Melicope latifolia. Their structures were elucidated by extensive NMR spectroscopic and mass spectrometric methods. The conjugated sesquiterpene possesses a unique 6/6/9/4-ring fused tetracyclic skeleton. The proposed biosynthesis pathway of 1 consist of three reactions steps: (1) polyketide formation, (2) cyclisation and (3) addition to form the conjugated sesquiterpenoid as final metabolite. Out of the ten isolated metabolites, amelicarin (1) showed activity against 4 cancerous cell lines namely SK-MEL skin cancer, KB oral cancer, BT-549 breast cancer, and SK-OV-3 ovarian cancer with IC50 values between 15 and 25 µg/mL.
  17. Fulltext The Incidence of Nasopharyngeal Carcinoma in Pahang State of Malaysia from 2012 to 2017
    Ahmad A, Yassin WM, Rahman NAA, Leman WI, Rosla L, Paul M, et al.
    Malays J Med Sci, 2021 Feb;28(1):66-74.
    PMID: 33679222 DOI: 10.21315/mjms2021.28.1.9
    Background: Nasopharyngeal carcinoma (NPC) is the fifth most common cancer among Malaysians. While several studies have reported the trend of NPC in other states in Malaysia, no studies have reported the trend of NPC in Pahang state. This study was designed to report the number and distribution of newly diagnosed NPC cases in Pahang.

    Methods: NPC cases that were diagnosed between 2012 and 2017 in two referral hospitals in Pahang were traced. The crude incidence rate (CR) and age-standardised rate (ASR) were calculated to investigate the NPC incidence.

    Results: There were 143 new cases of NPC reported from the two hospitals. The mean age at diagnosis was 52.0 ± 13.7 years old. The majority of cases involved males (74.1%) with a male to female ratio of 2.9:1. Chinese males were found to have the highest incidence with a mean ASR of 4.7 per 100,000 population. Overall, the mean ASR for Pahang was 2.4 per 100,000 population for males and 0.9 per 100,000 population for females.

    Conclusion: The total number of NPC cases reveals an increasing trend from 2012 to 2014 and then a slightly decreasing trend from 2015 to 2017. The incidence of NPC in Pahang was intermediate in males and low in females.

  18. Fulltext Oxygen radical antioxidant capacity (ORAC) and antibacterial properties of Melicope glabra bark extracts and isolated compounds
    Quek A, Mohd Zaini H, Kassim NK, Sulaiman F, Rukayadi Y, Ismail A, et al.
    PLoS One, 2021;16(5):e0251534.
    PMID: 33970960 DOI: 10.1371/journal.pone.0251534
    Melicope glabra (Blume) T. G. Hartley from the Rutaceae family is one of the richest sources of plant secondary metabolites, including coumarins and flavanoids. This study investigates the free radical scavenging and antibacterial activities of M. glabra and its isolated compounds. M. glabra ethyl acetate and methanol extracts were prepared using the cold maceration technique. The isolation of compounds was performed with column chromatography. The free radical scavenging activity of the extracts and isolated compounds were evaluated based on their oxygen radical absorbance capacity (ORAC) activities. The extracts and compounds were also subjected to antibacterial evaluation using bio-autographic and minimal inhibitory concentration (MIC) techniques against two oral pathogens, Enterococcus faecalis and Streptococcus mutans. Isolation of phytoconstituents from ethyl acetate extract successfully yielded quercetin 3, 5, 3'-trimethyl ether (1) and kumatakenin (2), while the isolation of the methanol extract resulted in scoparone (3), 6, 7, 8-trimethoxycoumarin (4), marmesin (5), glabranin (6), umbelliferone (7), scopoletin (8), and sesamin (9). The study is the first to isolate compound (1) from Rutaceae plants, and also the first to report the isolation of compounds (2-5) from M. glabra. The ORAC evaluation showed that the methanol extract is stronger than the ethyl acetate extract, while umbelliferone (7) exhibited the highest ORAC value of 24 965 μmolTE/g followed by glabranin (6), sesamin (9) and scopoletin (8). Ethyl acetate extract showed stronger antibacterial activity towards E. faecalis and S. mutans than the methanol extract with MIC values of 4166.7 ± 1443.4 μg/ml and 8303.3 ± 360.8 μg/ml respectively. Ethyl acetate extract inhibited E. faecalis growth, as shown by the lowest optical density value of 0.046 at a concentration of 5.0 mg/mL with a percentage inhibition of 95%. Among the isolated compounds tested, umbelliferone (7) and sesamin (9) exhibited promising antibacterial activity against S. mutans with both exhibiting MIC values of 208.3 ± 90.6 μg/ml. Findings from this study suggests M. glabra as a natural source of potent antioxidant and antibacterial agents.
  19. Fulltext Targeting MHC Regulation Using Polycyclic Polyprenylated Acylphloroglucinols Isolated from Garcinia bancana
    Coste C, Gérard N, Dinh CP, Bruguière A, Rouger C, Leong ST, et al.
    Biomolecules, 2020 09 02;10(9).
    PMID: 32887413 DOI: 10.3390/biom10091266
    Modulation of major histocompatibility complex (MHC) expression using drugs has been proposed to control immunity. Phytochemical investigations on Garcinia species have allowed the isolation of bioactive compounds such as polycyclic polyprenylated acylphloroglucinols (PPAPs). PPAPs such as guttiferone J (1), display anti-inflammatory and immunoregulatory activities while garcinol (4) is a histone acetyltransferases (HAT) p300 inhibitor. This study reports on the isolation, identification and biological characterization of two other PPAPs, i.e., xanthochymol (2) and guttiferone F (3) from Garcinia bancana, sharing structural analogy with guttiferone J (1) and garcinol (4). We show that PPAPs 1-4 efficiently downregulated the expression of several MHC molecules (HLA-class I, -class II, MICA/B and HLA-E) at the surface of human primary endothelial cells upon inflammation. Mechanistically, PPAPs 1-4 reduce MHC proteins by decreasing the expression and phosphorylation of the transcription factor STAT1 involved in MHC upregulation mediated by IFN-γ. Loss of STAT1 activity results from inhibition of HAT CBP/p300 activity reflected by a hypoacetylation state. The binding interactions to p300 were confirmed through molecular docking. Loss of STAT1 impairs the expression of CIITA and GATA2 but also TAP1 and Tapasin required for peptide loading and transport of MHC. Overall, we identified new PPAPs issued from Garcinia bancana with potential immunoregulatory properties.
  20. Pro-apoptotic carboxamide analogues of natural fislatifolic acid targeting Mcl-1 and Bcl-2
    Gapil Tiamas S, Daressy F, Abou Samra A, Bignon J, Steinmetz V, Litaudon M, et al.
    Bioorg Med Chem Lett, 2020 04 01;30(7):127003.
    PMID: 32035700 DOI: 10.1016/j.bmcl.2020.127003
    A library of 26 novel carboxamides deriving from natural fislatifolic acid has been prepared. The synthetic strategy involved a bio-inspired Diels-Alder cycloaddition, followed by functionalisations of the carbonyl moiety. All the compounds were evaluated on Bcl-xL, Mcl-1 and Bcl-2 proteins. In this series of cyclohexenyl chalcone analogues, six compounds behaved as dual Bcl-xL/Mcl-1 inhibitors in micromolar range and one exhibited sub-micromolar affinities toward Mcl-1 and Bcl-2. The most potent compounds evaluated on A549 and MCF7 cancer cell lines showed moderate cytotoxicities.
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