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  1. Bahari AN, Saari N, Salim N, Ashari SE
    Molecules, 2020 Jun 08;25(11).
    PMID: 32521731 DOI: 10.3390/molecules25112663
    Actinopyga lecanora (A. lecanora) is classified among the edible species of sea cucumber, known to be rich in protein. Its hydrolysates were reported to contain relatively high antioxidant activity. Antioxidants are one of the essential properties in cosmeceutical products especially to alleviate skin aging. In the present study, pH, reaction temperature, reaction time and enzyme/substrate ratio (E/S) have been identified as the parameters in the papain enzymatic hydrolysis of A. lecanora. The degree of hydrolysis (DH) with antioxidant activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays were used as the responses in the optimization. Analysis of variance (ANOVA), normal plot of residuals and 3D contour plots were evaluated to study the effects and interactions between parameters. The best conditions selected from the optimization were at pH 5.00, 70 °C of reaction temperature, 9 h of hydrolysis time and 1.00% enzyme/substrate (E/S) ratio, with the hydrolysates having 51.90% of DH, 42.70% of DPPH activity and 109.90 Fe2+μg/mL of FRAP activity. The A. lecanora hydrolysates (ALH) showed a high amount of hydrophobic amino acids (286.40 mg/g sample) that might be responsible for antioxidant and antityrosinase activities. Scanning electron microscopy (SEM) image of ALH shows smooth structures with pores. Antityrosinase activity of ALH exhibited inhibition of 31.50% for L-tyrosine substrate and 25.40% for L-DOPA substrate. This condition suggests that the optimized ALH acquired has the potential to be used as a bioactive ingredient for cosmeceutical applications.
    Matched MeSH terms: Antioxidants/pharmacology*; Enzyme Inhibitors/pharmacology*; Protein Hydrolysates/pharmacology*
  2. Subramaniam G, Achike FI, Mustafa MR
    J Cardiovasc Pharmacol, 2009 Apr;53(4):333-40.
    PMID: 19295443 DOI: 10.1097/FJC.0b013e31819fd4a7
    The mechanism by which insulin causes vasodilatation remains unclear, so we explored this in aortic rings from normal Wistar Kyoto and streptozotocin-induced diabetic rats. Insulin-induced relaxation of phenylephrine-contracted [endothelium (ED) intact or denuded] aortic rings was recorded in the presence or absence of various drug probes. Insulin relaxant effect was more in ED-intact than in-denuded tissues from normal or diabetic rats. l-NAME or methylene blue partially inhibited insulin effect in ED-intact but not the ED-denuded tissues, whereas indomethacin (cyclooxygenase inhibitor) had no effect on any of the tissues, indicating that insulin induces relaxation by ED-dependent and -independent mechanisms, the former via the NOS-cyclic guanosine monophosphate but not the cyclooxygenase pathway. The voltage-dependent K channel (KV) blocker (4-aminopyridine) inhibited insulin action in all the tissues (normal or diabetic, with or without ED), whereas the selective BKCa blocker, tetraethylammonium, inhibited it in normal (ED intact or denuded) but not in diabetic tissues, indicating that KV mediates insulin action in normal and diabetic tissues, whereas the BKCa mediates it only in normal tissues, with possible pathophysiologic absence in diabetic tissues. The inward rectifier K channel (Kir) blocker (barium chloride) significantly inhibited insulin effect only in ED-intact or -denuded diabetic tissues, whereas the KATP channel blocker, glibenclamide, inhibited it only in the ED-denuded diabetic tissues, suggesting that Kir channels mediate insulin-induced relaxation in ED-intact or -denuded diabetic tissues, whereas the KATP channel mediates it in ED-denuded diabetic tissues. All the agents combined did not abolish insulin action, suggestive of a direct vasodilatory effect. In conclusion, insulin causes vasodilatation in normal and diabetic tissues via ED-dependent and -independent mechanisms differentially modulated by K channels, some of which functions are altered in diabetes and thus are potential therapeutic targets.
    Matched MeSH terms: Insulin/pharmacology*; Streptozocin/pharmacology; Vasodilator Agents/pharmacology*
  3. Kam TS, Sim KM, Koyano T, Toyoshima M, Hayashi M, Komiyama K
    Bioorg Med Chem Lett, 1998 Jul 07;8(13):1693-6.
    PMID: 9873417
    Four new bisindoles of the vobasine-iboga type, conodiparines A-D were obtained from Tabernaemontana corymbosa which showed appreciable activity in reversing resistance in vincristine-resistant KB cells.
    Matched MeSH terms: Antineoplastic Agents, Phytogenic/pharmacology*; Indoles/pharmacology; Vincristine/pharmacology*
  4. Salleh WMNHW, Khamis S
    Z Naturforsch C J Biosci, 2020 Nov 26;75(11-12):467-471.
    PMID: 32469335 DOI: 10.1515/znc-2020-0075
    Chemical composition and anticholinesterase activity of the essential oil of Pavetta graciliflora Wall. ex Ridl. (Rubiaceae) was examined for the first time. The essential oil was obtained by hydrodistillation and was fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 20 components were identified in the essential oil, which made up 92.85% of the total oil. The essential oil is composed mainly of β-caryophyllene (42.52%), caryophyllene oxide (25.33%), β-pinene (8.67%), and α-pinene (6.52%). The essential oil showed weak inhibitory activity against acetylcholinesterase (AChE) (I%: 62.5%) and butyrylcholinesterase (BChE) (I%: 65.4%) assays. Our findings were shown to be very useful for the characterization, pharmaceutical, and therapeutic applications of the essential oil from P. graciliflora.
    Matched MeSH terms: Antioxidants/pharmacology; Cholinesterase Inhibitors/pharmacology*; Oils, Volatile/pharmacology
  5. Awaluddin R, Nugrahaningsih DAA, Solikhah EN
    Med J Malaysia, 2020 05;75(Suppl 1):10-13.
    PMID: 32471963
    INTRODUCTION: Diabetes mellitus is known as one of the risk factors for Idiopathic Pulmonary Fibrosis (IPF) development. Recently, metformin, the commonly used antidiabetic medication, is reported to have a therapeutic effect in IPF. However, the benefit of metformin therapy in IPF is still controversial. The study aims to investigate the metformin effect on the fibroblast and macrophage co-culture under lipopolysaccharides (LPS) and high glucose treatment.

    METHOD: The NIH 3T3 and RAW 264.7 co-culture were induced with LPS and high glucose before it was treated with metformin in different concentration. After 24 hours of treatment, the media and the cells were collected for further examination. The collagen expression was measured using Sirius red dye in the media. The IL-6 and TGF β mRNA examination were done using real-time PCR.

    RESULT: Our study showed that NIH 3T3 and RAW 264.7 coculture treated with metformin has higher collagen expression, but lower IL-6 mRNA expression compares to those on co-culture without treatment.

    CONCLUSION: Metformin increases fibrosis markers in LPS and high glucose-induced NIH 3T3 and RAW 264.7 coculture despite its ability to improve IL-6 mRNA expression.

    Matched MeSH terms: Glucose/pharmacology*; Hypoglycemic Agents/pharmacology*; Metformin/pharmacology*
  6. Masri A, Abdelnasir S, Anwar A, Iqbal J, Numan A, Jagadish P, et al.
    Appl Microbiol Biotechnol, 2021 Apr;105(8):3315-3325.
    PMID: 33797573 DOI: 10.1007/s00253-021-11221-1
    BACKGROUND: Conducting polymer based nanocomposites are known to be effective against pathogens. Herein, we report the antimicrobial properties of multifunctional polypyrrole-cobalt oxide-silver nanocomposite (PPy-Co3O4-AgNPs) for the first time. Antibacterial activities were tested against multi-drug-resistant Gram-negative Escherichia coli (E. coli) and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) bacteria, while antiamoebic effects were assessed against opportunistic protist Acanthamoeba castellanii (A. castellanii).

    RESULTS: The ternary nanocomposite containing conducting polymer polypyrrole, cobalt oxide, and silver nanoparticles showed potent antimicrobial effects against these pathogens. The antibacterial assay showed that PPy-Co3O4-AgNPs exhibited significant bactericidal activity against neuropathogenic E. coli K1 at only 8 μg/mL as compared to individual components of the nanocomposite, whereas a 70 % inhibition of A. castellanii viability was observed at 50 μg/mL. Moreover, PPy-Co3O4-AgNPs were found to have minimal cytotoxicity against human keratinocytes HaCaT cells in vitro even at higher concentration (50 μg/mL), and also reduced the microbes-mediated cytopathogenicity against host cells.

    CONCLUSION: These results demonstrate that PPy-Co3O4-AgNPs hold promise in the development of novel antimicrobial nanomaterials for biomedical applications.

    KEY POINTS: •Synthesis of polypyrrole-cobalt oxide-silver (PPy-Co3O4-AgNPs) nanocomposite. •Antimicrobial activity of nanocomposite. •PPy-Co3O4-AgNPs hold promise for biomedical applications.

    Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Pyrroles/pharmacology; Silver/pharmacology
  7. Alamaary MS, Haron AW, Hiew MWH, Ali M
    Vet Med Sci, 2020 11;6(4):666-672.
    PMID: 32602662 DOI: 10.1002/vms3.315
    Present study aimed to investigate the effect of adding antioxidants, cysteine and ascorbic acid on the levels of glutamic oxaloacetic transaminase (GOT), glutamic-pyruvate (GPT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and γ-glutamyl transpeptidase (GGT) enzymes of post-thawed stallion sperm. Ten ejaculates were collected each from four healthy stallions and cryopreserved using HF-20 freezing extender containing either 0 mg/ml cysteine or ascorbic acid, 0.5 mg/ml cysteine and 0.5 mg/ml ascorbic acid. All samples in freezing extender containing cysteine or ascorbic acid or none of them were assessed for sperm motility, viability, plasma membrane integrity, morphology and enzymes concentration. The ALP, LDH and GGT were significantly higher in 0-group compared with cysteine and ascorbic acid groups. The sperm motility of frozen-thawed semen with 0-group was significantly better compared with cysteine and ascorbic acid groups. The variation on viability, sperm membrane integrity and morphology were insignificant between all treated groups. Therefore, these enzymes were reduced when using antioxidants in the freezing extender. Results of the present study suggest that concentration of ALP, LDH and GGT enzymes could be used as parameters for prediction of frozen-thawed stallion semen.
    Matched MeSH terms: Ascorbic Acid/pharmacology*; Cryoprotective Agents/pharmacology*; Cysteine/pharmacology*
  8. Ghazali AR, Muralitharan RV, Soon CK, Salyam T, Ahmad Maulana NN, Mohamed Thaha UAB, et al.
    Asian Pac J Cancer Prev, 2020 Nov 01;21(11):3381-3386.
    PMID: 33247699 DOI: 10.31557/APJCP.2020.21.11.3381
    BACKGROUND: Traditional cooling rice powder (bedak sejuk) is a fermented rice-based cosmetic that is applied topically on one's skin, as an overnight facial mask. According to user testimonies, bedak sejuk beautifies and whitens skin, whereby these benefits could be utilised as a potential melanoma chemopreventive agent.

    OBJECTIVE: Hence, this study aimed to determine the effects of bedak sejuk made from Oryza sativa ssp. indica (Indica) and Oryza sativa ssp. japonica (Japonica) on UVB-induced B164A5 melanoma cells, and also identify the antioxidant capacities of both types of bedak sejuk.

    METHODS: The optimum dose of Indica and Japonica bedak sejuk to treat the cells was determined via the MTT assay. Then, the antioxidant capacities of both types of bedak sejuk were determined using the FRAP assay.

    RESULTS: From the MTT assay, it was found that Indica and Japonica bedak sejuk showed no cytotoxic effects towards the cells. Hence, no IC50 can be obtained and two of the higher doses, 50 and 100 g/L were chosen for treatment. In the FRAP assay, Indica bedak sejuk at 50 and 100 g/L showed FRAP values of 0.003 ± 0.001 μg AA (ascorbic acid)/g of bedak sejuk and 0.004 ± 0.0003 μg AA/g of bedak sejuk. Whereas Japonica bedak sejuk at 50 g/L had the same FRAP value as Indica bedak sejuk at 100 g/L. As for Japonica bedak sejuk at 100 g/L, it showed the highest antioxidant capacity with the FRAP value of 0.01 ± 0.0007 μg AA/g of bedak sejuk which was statistically significant (p < 0.05) when compared to other tested concentrations.

    CONCLUSION: In conclusion, Japonica bedak sejuk has a higher antioxidant capacity compared to Indica bedak sejuk despite both being not cytotoxic towards the cells. Regardless, further investigations need to be done before bedak sejuk could be developed as potential melanoma chemoprevention agents.

    Matched MeSH terms: Antineoplastic Agents, Phytogenic/pharmacology*; Antioxidants/pharmacology*; Powders/pharmacology*
  9. Zulkiflee NS, Awang SA, Ming WX, Kamilan MFW, Mariappan MY, Kit TJ
    Curr Comput Aided Drug Des, 2020;16(4):467-472.
    PMID: 31203808 DOI: 10.2174/1573409915666190614113733
    BACKGROUND: Vitamin E is comprised of α, β, γ and δ-tocopherols (Ts) and α, β, γ and δ- tocotrienols (T3s). Vitamin E has neuroprotective antioxidant, anti-cancer, and cholesterol-lowering effects. Intracellular trafficking of these isomers remains largely unknown, except for αT which is selectively transported by αT transfer protein (αTTP).

    OBJECTIVE: This study aimed to determine the binding of vitamin E isomers on transport proteins using in silico docking.

    METHODS: Transport proteins were selected using AmiGo Gene Ontology tool based on the same molecular function annotation as αTTP. Protein structures were obtained from the Protein Data Bank. Ligands structures were obtained from ZINC database. In silico docking was performed using SwissDock.

    RESULTS AND DISCUSSION: A total of 6 transport proteins were found: SEC14-like protein 2, glycolipid transfer protein (GLTP), pleckstrin homology domain-containing family A member 8, collagen type IV alpha-3-binding protein, ceramide-1-phosphate transfer protein and afamin. Compared with other transport proteins, αTTP had the highest affinities for all isomers except βT3. Binding order of vitamin E isomers toward αTTP was γT > βT > αT > δT > αT3 > γT3 > δT3 > βT3. GLTP had a higher affinity for tocotrienols than tocopherols. βT3 bound stronger to GLTP than αTTP.

    CONCLUSION: αTTP remained as the most preferred transport protein for most of the isomers. The binding affinity of αT toward αTTP was not the highest than other isomers suggested that other intracellular trafficking mechanisms of these isomers may exist. GLTP may mediate the intracellular transport of tocotrienols, especially βT3. Improving the bioavailability of these isomers may enhance their beneficial effects to human.

    Matched MeSH terms: Antioxidants/pharmacology*; Vitamin E/pharmacology*; Vitamins/pharmacology*
  10. Dang K, Toi CS, Lilly DG, Lee CY, Naylor R, Tawatsin A, et al.
    Pest Manag Sci, 2015 Jul;71(7):1015-20.
    PMID: 25132449 DOI: 10.1002/ps.3880
    Bed bugs [both Cimex hemipterus (F.) and Cimex lectularius L.] are highly resistant to pyrethroids worldwide. An important resistance mechanism known as 'knockdown resistance' (kdr) is caused by genetic point mutations on the voltage-gated sodium channel (VGSC) gene. Previous studies have identified two point mutations (V419L and L925I) on the VGSC gene in C. lectularius that are responsible for kdr-type resistance. However, the kdr mutations in C. hemipterus have not been investigated.
    Matched MeSH terms: Allethrin/pharmacology*; Insecticides/pharmacology*; Pyrethrins/pharmacology*
  11. Neoh KB, Lee CC, Lee CY
    Pest Manag Sci, 2014 Feb;70(2):240-4.
    PMID: 23554339 DOI: 10.1002/ps.3544
    Mutual interactions, including reciprocal food sharing and grooming between chlorantraniliprole- and fipronil-treated, and untreated Asian subterranean termites, Coptotermes gestroi (Wasmann), were examined using rubidium as a tracer. Two questions were addressed in this study: (1) After insecticide treatment, does the mutual interaction between termiticide-treated termites and untreated nestmates increase? (2) Does the nutritional status of both termiticide-treated termites and untreated nestmates affect the mutual interaction?
    Matched MeSH terms: Insecticides/pharmacology*; Pyrazoles/pharmacology; ortho-Aminobenzoates/pharmacology
  12. Kwan TK, Lim YT, Gower DB
    Biochem Soc Trans, 1992 May;20(2):232S.
    PMID: 1397603
    Matched MeSH terms: Aspirin/pharmacology*; Flurbiprofen/pharmacology*; Indomethacin/pharmacology*
  13. Shreaz S, Shiekh RA, Raja V, Wani WA, Behbehani JM
    Chem Biol Interact, 2016 Mar 05;247:64-74.
    PMID: 26806515 DOI: 10.1016/j.cbi.2016.01.015
    In this study, we have used aldehyde function of cinnamaldehyde to synthesize N, N'-Bis (cinnamaldehyde) ethylenediimine [C20H20N2] and Co(II) complex of the type [Co(C40H40N4)Cl2]. The structures of the synthesized compounds were determined on the basis of physiochemical analysis and spectroscopic data ((1)H NMR, FTIR, UV-visible and mass spectra) along with molar conductivity measurements. Anticandidal activity of cinnamaldehyde its ligand [L] and Co(II) complex was investigated by determining MIC80, time-kill kinetics, disc diffusion assay and ergosterol extraction and estimation assay. Ligand [L] and Co(II) complex are found to be 4.55 and 21.0 folds more efficient than cinnamaldehyde in a liquid medium. MIC80 of Co(II) complex correlated well with ergosterol inhibition suggesting ergosterol biosynthesis to be the primary site of action. In comparison to fluconazole, the test compounds showed limited toxicity against H9c2 rat cardiac myoblasts. In confocal microscopy propidium iodide (PI) penetrates the yeast cells when treated with MIC of metal complex, indicating a disruption of cell membrane that results in imbibition of dye. TEM analysis of metal complex treated cells exhibited notable alterations or damage to the cell membrane and the cell wall. The structural disorganization within the cell cytoplasm was noted. It was concluded that fungicidal activity of Co(II) complex originated from loss of membrane integrity and a decrease in ergosterol content is only one consequence of this.
    Matched MeSH terms: Acrolein/pharmacology; Cobalt/pharmacology*; Fungicides, Industrial/pharmacology*
  14. Mustafa MR, Hadi AH
    Toxicon, 1990;28(10):1237-9.
    PMID: 2264070
    Crude glycoside extracts from the plant, Sarcolobus globosus, were tested on the rat phrenic nerve-diaphragm, chick biventer cervicis and frog rectus abdominis preparations. Nerve-stimulated twitches were inhibited by the extract. The muscle paralysis was not similar to that by curare-like blockers as it was not reversed by neostigmine or by a tetanus. Although contractures to acetylcholine or carbachol were not affected by 0.6 mg/ml of the extract, higher concentration of the extracts (3 mg/ml) depressed the log dose-response curve of acetylcholine and carbachol. The results suggest that the neuromuscular blocking effect of the extracts is either dose-dependent or due to a mixture of toxins with presynaptic or postsynaptic actions.
    Matched MeSH terms: Glycosides/pharmacology*; Neuromuscular Blocking Agents/pharmacology*; Plant Extracts/pharmacology*
  15. Ho LY, Zairi J
    Trop Biomed, 2013 Mar;30(1):125-30.
    PMID: 23665718 MyJurnal
    A 14-months survey was carried out to identify the species composition of Anopheles mosquitoes from Kampung Bongor, Grik, Perak. Adding to that, a preliminary one month mosquito population screening was done at Kampung Tepin, Serian, Sarawak. Consequently, the insecticide susceptibility status of a pyrethroid was tested against two selected species of Anopheles collected from these two locations in Malaysia. A total of 4,497 Anopheles from 11 species were identified from collections in Kampung Bongor, whereas 2,654 An. letifer were collected from Kampung Tepin. The An. maculatus of Kampung Bongor and An. letifer of Kampung Tepin were then selected and tested using WHO standard diagnostic test kits and impregnated papers with 0.75% permethrin. The response values of KT50 and KT95 for An. maculatus were recorded at 28.09 minutes and 62.98 minutes respectively. Anopheles letifer recorded much slower response values of KT50 and KT95, which was at 35.09 minutes and 73.03 minutes respectively. Both An. maculatus and An. letifer showed 100% mortality after 24 hours holding period. The results indicate that both species were still susceptible to the tested pyrethroid. For effective vector control and resistance management, accurate and periodic insecticide resistance monitoring should be undertaken especially in rural areas with agricultural usage of insecticides.
    Matched MeSH terms: Insecticides/pharmacology*; Pyrethrins/pharmacology*; Permethrin/pharmacology
  16. Selvi S, Edah MA, Nazni WA, Lee HL, Azahari AH
    Trop Biomed, 2007 Jun;24(1):63-75.
    PMID: 17568379 MyJurnal
    Larvae and adults of Culex quinquefasciatus were used for the test undertaken for malathion resistant strain (F61 - F65) and permethrin resistant strain (F54 - F58). The results showed that the LC50 for both malathion (F61 - F65) and permethrin (F54 - F58) resistant Cx. quinquefasciatus increased steadily throughout the subsequent five generations, indicating a marked development of resistance. The adult female malathion resistant strain have developed a high resistance level to malathion diagnostic dosage with a resistance ratio of 9.3 to 17.9 folds of resistance compared with the susceptible Cx. quinquefasciatus. Permethrin resistance ratio remained as 1.0 folds of resistance at every generation. It was obvious that malathion resistance developed at a higher rate in adult females compared to permethrin. Enzyme-based metabolic mechanisms of insecticide resistance were investigated based on the biochemical assay principle. From the results obtained obviously shows that there is a significant difference (p < 0.05) in esterase level in both malathion and permethrin selected strains. Female malathion selected strain has the higher level of esterase activity compared to the female permethrin selected strain at (0.8 to 1.04) alpha-Na micromol/min/mg protein versus (0.15 to 0.24) alpha-Na micromol/min/mg protein respectively. This indicated increased level of non-specific esterase is playing an important role in resistance mechanism in female malathion selected strain. Permethrin selected strain exhibited non-specific esterase activity at a very low level throughout the different life stages compared to malathion selected strain. This study suggests that life stages play a predominant role in conferring malathion and permethrin resistance in Cx. quinquefasciatus.
    Matched MeSH terms: Insecticides/pharmacology*; Malathion/pharmacology*; Permethrin/pharmacology*
  17. Mohd Masri S, Nazni WA, Lee HL, T Rogayah TA, Subramaniam S
    Trop Biomed, 2005 Dec;22(2):185-9.
    PMID: 16883286 MyJurnal
    Three new techniques of sterilising maggots of Lucilia cuprina for the purpose of debriding intractable wounds were studied. These techniques were utilisation of ultra-violet C (UVC) and maggot sterilisation with disinfectants. The status of sterility was checked on nutrient agar and blood agar and confirmed with staining. The indicators for the effectiveness of the methods were sterility and survival rate of the eggs or larvae. Egg sterilisation with UVC had the lowest hatching rate (16+/-0.00%) while egg sterilisation with disinfectants showed high hatching rate (36.67+/-4.41%) but low maggot survival rate (31.67+/-1.67%). Sterilisation of the maggots was the most suitable, since the survival rate was the highest (88.67+/-0.88%). Complete sterility was achieved in all cases, except that Proteus mirabilis was consistently found. However, the presence of this microorganism was considered beneficial.
    Matched MeSH terms: Alcohols/pharmacology; Chlorhexidine/pharmacology; Disinfectants/pharmacology
  18. Nazni WA, Lee HL, Azahari AH
    Trop Biomed, 2005 Jun;22(1):63-8.
    PMID: 16880755 MyJurnal
    The susceptibility of Culex quinquefasciatus to chemical insecticides in two field sites in Kuala Lumpur was evaluated using the WHO standard susceptibility test. Less then 7 days old female mosquitos, reared from wild caught females were exposed to discriminating dosages of insecticides at recommended exposure periods. The larval bioassay were conducted using the multiple concentrations and the LC50 value was determined. The results indicated that cyfluthrin is the most effective among all the insecticides tested with LT50 value of 29.95 min and 28.59 min, for the strain from Ampang Hill and Pantai Dalam, respectively. It was surprisingly to note that both these field strains showed 0% mortality when tested against malathion and DDT. The LC50 value indicated that both strains were highly resistant to malathion with resistance ratio of 17,988 folds and 14,053 folds, respectively. This concludes that resistance at larval stages is extremely high compared to adult stages.
    Matched MeSH terms: DDT/pharmacology; Insecticides/pharmacology*; Malathion/pharmacology
  19. Appalasamy S, Lo KY, Ch'ng SJ, Nornadia K, Othman AS, Chan LK
    Biomed Res Int, 2014;2014:215872.
    PMID: 24575401 DOI: 10.1155/2014/215872
    Artemisia annua L., a medicinal herb, produces secondary metabolites with antimicrobial property. In Malaysia due to the tropical hot climate, A. annua could not be planted for production of artemisinin, the main bioactive compound. In this study, the leaves of three in vitro A. annua L. clones were, extracted and two bioactive compounds, artemisinin and a precursor, were isolated by thin layer chromatography. These compounds were found to be effective in inhibiting the growth of Gram-positive and Gram-negative bacteria but not Candida albicans. Their antimicrobial activity was similar to that of antibactericidal antibiotic streptomycin. They were found to inhibit the growth of the tested microbes at the minimum inhibition concentration of 0.09 mg/mL, and toxicity test using brine shrimp showed that even the low concentration of 0.09 mg/mL was very lethal towards the brine shrimps with 100% mortality rate. This study hence indicated that in vitro cultured plantlets of A. annua can be used as the alternative method for production of artemisinin and its precursor with antimicrobial activities.
    Matched MeSH terms: Anti-Infective Agents/pharmacology*; Plant Extracts/pharmacology; Artemisinins/pharmacology*
  20. Samat N, Ng MF, Ruslan NF, Okuda KS, Tan PJ, Patel V
    Assay Drug Dev Technol, 2018 10;16(7):408-419.
    PMID: 29985634 DOI: 10.1089/adt.2017.833
    Natural products are prolific producers of diverse chemical scaffolds, which have yielded several clinically useful drugs. However, the complex features of natural products present challenges for identifying bioactive molecules using high-throughput screens. For most assays, measured endpoints are either colorimetric or luminescence based. Thus, the presence of the major metabolites, tannins, and chlorophylls, in natural products could potentially interfere with these measurements to give either false-positive or false-negative hits. In this context, zebrafish phenotypic assays provide an alternative approach to bioprospect naturally occurring bioactive compounds. Whether tannins and/or chlorophylls interfere in zebrafish phenotypic assays, is unclear. In this study, we evaluated the interference potential of tannins and chlorophylls against efficacy of known small-molecule inhibitors that are known to cause phenotypic abnormalities in developing zebrafish embryos. First, we fractionated tannin-enriched fraction (TEF) and chlorophyll-enriched fraction (CEF) from Camellia sinensis and cotreated them with PD0325901 [mitogen-activated protein kinase-kinase (MEK) inhibitor] and sunitinib malate (SM; anti-[lymph]angiogenic drug). While TEF and CEF did not interfere with phenotypic or molecular endpoints of PD0325901, TEF at 100 μg/mL partially masked the antiangiogenic effect of SM. On the other hand, CEF (100 μg/mL) was toxic when treated up to 6 dpf. Furthermore, CEF at 100 μg/mL potentially enhanced the activity of γ-secretase inhibitors, resulting in toxicity of treated embryos. Our study provides evidence that the presence of tannin and/or chlorophyll in natural products do interfere with zebrafish phenotype assays used for identifying potential hits. However, this may be target/assay dependent and thus requiring additional optimization steps to assess interference potential of tannins and chlorophylls before performing any screening assay.
    Matched MeSH terms: Benzamides/pharmacology*; Diphenylamine/pharmacology; Angiogenesis Inhibitors/pharmacology*
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