Displaying publications 1 - 20 of 152 in total

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  1. Looking for new drugs: what criteria?
    Sévenet T
    J Ethnopharmacol, 1991 Apr;32(1-3):83-90.
    PMID: 1881171
    How to look for new drugs? What guidelines to use? Have we to continue investigations on plant and marine organisms? These questions arise frequently today. A pharmacological effect results from the addition of many effects at a molecular level, i.e. the interaction between a ligand and a receptor. As long as the chemical structure of this receptor remains unknown, studies of Nature's resources will yield the largest reservoir of new drugs. Nature provides our imagination with the pattern of novel biologically active molecules. Criteria classically used in the past to select plants for study were chemotaxonomy, ethnopharmacology or pharmacotaxonomy. Examples will be taken from personal experience, to illustrate work done according to the chemotaxonomical approach (Ochrosia and ellipticines), and the ethnopharmacological approach (antiinflammatory properties of Euphorbiaceae from New Caledonia). Taking into account that one of the major problems we have to face is the unsatisfactory classical pharmacological testing procedure, we have tried to set up a network grouping biologists and chemists. Among many results obtained, one concerns the use of the mammalian hypothalamo-pituitary system to screen effects of alkaloids extracted from Psychotria oleoides, a Rubiaceae collected in New Caledonia. Psycholeine exhibits an intriguing activity on GH release. Another result concerns the influence of a Labiatae extract on the adenylate cyclase system: 9 HODE extracted from Glechoma hederacea stimulates the basal level of enzyme activity in platelets, this activity being possibly involved in the folk uses claimed. Using the tubulin test to screen antimitotic activities of plant extracts, the biological activity of rhazinilam has been demonstrated as responsible for the antitubulin activity of a Malaysian plant, Kopsia singapurensis.(ABSTRACT TRUNCATED AT 250 WORDS)
    Matched MeSH terms: Drug Evaluation, Preclinical
  2. Fulltext In vitro drug susceptibility of Acanthamoeba castellani to chloroquine, ivermectin and fungizon
    Rain AN, Radzan T, Sajiri S, Mak JW
    Southeast Asian J. Trop. Med. Public Health, 1996 Jun;27(2):319-24.
    PMID: 9279996
    In vitro sensitivity of Acanthamoeba castellani was tested to three drugs: Chloroquine, ivermectin and fungizone (amphotericin B). Sensitivity was demonstrated to the latter two compounds but not to chloroquine. Thus ivermectin and amphotericin B show promise as therapeutic agents against this parasite.
    Matched MeSH terms: Drug Evaluation, Preclinical
  3. Isolate resistance of Blastocystis hominis to metronidazole
    Haresh K, Suresh K, Khairul Anus A, Saminathan S
    Trop Med Int Health, 1999 Apr;4(4):274-7.
    PMID: 10357863
    Isolates of Blastocystis hominis from infected immigrant workers from Indonesia, Bangladesh and infected individuals from Singapore and Malaysia were assessed for growth pattern and degree of resistance to different concentrations of metronidazole. Viability of the cells was assessed using eosin-brillian cresyl blue which stained viable cells green and nonviable cells red. The Bangladeshi and Singaporean isolates were nonviable even at the lowest concentration of 0.01 mg/ml, whereas 40% of the initial inoculum of parasites from the Indonesian isolate at day one were still viable in cultures with 1.0 mg/ml metronidazole. The study shows that isolates of B. hominis of different geographical origin have different levels of resistance to metronidazole. The search for more effective drugs to eliminate th parasite appears inevitable, especially since surviving parasites from metronidazole cultures show greater ability to multiply in subcultures than controls.
    Matched MeSH terms: Drug Evaluation, Preclinical
  4. Aphrodisiac evaluation in non-copulator male rats after chronic administration of Eurycoma longifolia Jack
    Ang HH, Ngai TH
    Fundam Clin Pharmacol, 2001 Aug;15(4):265-8.
    PMID: 11564133 DOI: 10.1046/j.1472-8206.2001.00038.x
    The aphrodisiac effect of Eurycoma longifolia Jack (0.5 g/kg) was evaluated in noncopulator male rats using an electrical cage. Fractions of E. longifolia Jack decreased the hesitation time of noncopulator male rats, throughout the investigation period. Furthermore, it possessed a transient increase in the percentage of the male rats responding to the right choice, more than 50% of the male rats scored "right choice" after 3 weeks post-treatment and the effect became more prominent after 8 weeks post-treatment (only 40-50% of the control male rats responded to the right choice) using the electrical copulation cage. Hence, this study lends further support to the use of the plant by indigenous populations as a traditional medicine for its aphrodisiac property.
    Matched MeSH terms: Drug Evaluation, Preclinical/methods
  5. The screening of extracts from Goniothalamus scortechinii, Aralidium pinnatifidum and Andrographis paniculata for anti-malarial activity using the lactate dehydrogenase assay
    Siti Najila MJ, Noor Rain A, Mohamad Kamel AG, Syed Zahir SI, Khozirah S, Lokman Hakim S, et al.
    J Ethnopharmacol, 2002 Oct;82(2-3):239-42.
    PMID: 12242001
    Goniothalamus scortechinii, Andrographis paniculata and Aralidium pinnatifidum were selected for the study based on their ethnomedicinal values. They were screened for anti-malarial activity towards Plasmodium falciparum in vitro using the lactate dehydrogenase (LDH) assay. The crude extract of G. scortechinii exhibited the most potent schizonticidal activity compared to the other extracts. It is effective against both the chloroquine resistant isolate, Gombak A and the sensitive strain, D10 of Plasmodium falciparum. Furthermore a better IC(50) value was obtained against the resistant strain, (9 microg/ml) compared to the sensitive strain, 40 microg/ml. When the crude extract was fractionated into 3 fractions, the chloroform fraction yielded the best activity, exhibiting equipotency against both strains of parasite used; IC(50) of 23.53 microg/ml against Gombak A and 21.06 microg/ml against D10.
    Matched MeSH terms: Drug Evaluation, Preclinical/methods
  6. Screening for antihyperglycaemic activity in several local herbs of Malaysia
    Husen R, Pihie AH, Nallappan M
    J Ethnopharmacol, 2004 Dec;95(2-3):205-8.
    PMID: 15507337 DOI: 10.1016/j.jep.2004.07.004
    Screening of aqueous extract of Phyllantus niruri (PL), Zingiber zerumbet (ZG), Eurycoma longifolia (TA-a and TA-b) and Andrographis paniculata (AP) to determine their blood glucose lowering effect were conducted in normoglycaemic and Streptozotocin-induced hyperglycaemic rats. Significant reduction in blood glucose level at 52.90% was shown when hyperglycaemic rats were treated with 50 mg/kg body weight (BW) aqueous extract of AP. This effect is enhanced when freeze-dried material was used, where 6.25 mg/kg BW gave 61.81% reduction in blood glucose level. In the administration of TA-a and TA-b, positive results in hyperglyacaemic rats were only obtained when 150 mg/kg BW of the aqueous extract was used. No significant reduction in blood glucose level were shown in hyperglycaemic rats treated with PL and ZG at all concentrations used (50, 100 and 150 mg/kg BW). In normoglycaemic rats, no significant reduction was noted when all the same extracts were used.
    Matched MeSH terms: Drug Evaluation, Preclinical/methods
  7. The effect of Malaysian cocoa extract on glucose levels and lipid profiles in diabetic rats
    Ruzaidi A, Amin I, Nawalyah AG, Hamid M, Faizul HA
    J Ethnopharmacol, 2005 Apr 8;98(1-2):55-60.
    PMID: 15763363
    The present study aims to investigate the effect of cocoa extract on serum glucose levels and lipid profiles in streptozotocin-diabetic rats. Cocoa extract (contained 285.6 mg total polyphenol per gram extract) was prepared from fermented and roasted (140 degrees C, 20 min) beans by extracting using 80% ethanol in the ratio of 1-10. The extract of three dosages (1, 2, and 3%) was fed to normal and diabetic rats for a period of 4 weeks. In hyperglycaemic group, cocoa extract (1 and 3%) diets were found to significantly lower (p<0.05) the serum glucose levels compared to the control. Furthermore, supplementation of 1 and 3% cocoa extract had significantly reduced (p<0.05) the level of total cholesterol in diabetic rats. In addition, 1, 2, and 3% cocoa extract diets had significantly lowered (p<0.05) the total triglycerides. Interestingly, this study found that serum HDL-cholesterol had increased significantly (p<0.05) in diabetic rats fed with 2% cocoa extract, while the LDL-cholesterol had decreased significantly (p<0.05) in the 1% treated group. These results indicate that cocoa extract may possess potential hypoglycaemic and hypocholestrolemic effects on serum glucose levels and lipid profiles, respectively. The results also found that the effect of cocoa extract was dose-dependent.
    Matched MeSH terms: Drug Evaluation, Preclinical/methods
  8. Probucol modulates iron nitrilotriacetate (Fe-NTA)-dependent renal carcinogenesis and hyperproliferative response: diminution of oxidative stress
    Iqbal M, Okazaki Y, Okada S
    Mol Cell Biochem, 2007 Oct;304(1-2):61-9.
    PMID: 17487455
    Probucol is a clinically used cholesterol-lowering drug, with pronounced antioxidant properties. We have reported previously, that dietary supplementation of probucol enhances NAD(P)H:quinone reductase (Iqbal M, Okada S (2003) Pharmacol Toxicol 93:259-263) and inhibits Fe-NTA induced lipid peroxidation and DNA damage in vitro (Iqbal M, Sharma SD, Oakada (2004) Redox Rep 9:167-172). Further to this, in the present study, we evaluated the modulatory effect of probucol on iron nitrilotriacetae (Fe-NTA) dependent renal carcinogenesis, hyperproliferative response and oxidative stress. In Fe-NTA alone treated group, a 20% renal cell tumor incidence was recorded whereas, in N-diethylnitrosamine (DEN)-initiated and Fe-NTA promoted animals, the percentage tumor incidence was increased to 70% as compared with untreated controls. No tumor incidence was recorded in DEN-initiated, nonpromoted group. Diet supplemented with 1.0% probucol fed prior to, during and after Fe-NTA treatment in DEN-initiated animals afforded >65% protection in renal cell tumor incidence. Probucol fed diet pretreatment also resulted a significant and dose dependent inhibition of Fe-NTA induced renal ornithine decarboxylase (ODC) activity. In oxidative stress studies, Fe-NTA alone treatment enhanced lipid peroxidation, accompanied by a decrease in the level of GSH, activities of antioxidants and phase II metabolizing enzymes in kidney concomitant with histolopathological changes. These changes were significantly and dose-dependently alleviated by probucol fed diet. From this data, it can be concluded that probucol can modulates toxic and tumor promoting effects of Fe-NTA and can serve as a potent chemopreventive agent to suppress oxidant induced tissue injury and carcinogenesis, in addition to being a cholesterol lowering and anti-atherogenic drug.
    Matched MeSH terms: Drug Evaluation, Preclinical
  9. Fulltext In vitro alpha-glucosidase and alpha-amylase enzyme inhibitory effects of Andrographis paniculata extract and andrographolide
    Subramanian R, Asmawi MZ, Sadikun A
    Acta Biochim. Pol., 2008;55(2):391-8.
    PMID: 18511986
    There has been an enormous interest in the development of alternative medicines for type 2 diabetes, specifically screening for phytochemicals with the ability to delay or prevent glucose absorption. The goal of the present study was to provide in vitro evidence for potential inhibition of alpha-glucosidase and alpha-amylase enzymes, followed by a confirmatory in vivo study on rats to generate a stronger biochemical rationale for further studies on the ethanolic extract of Andrographis paniculata and andrographolide. The extract showed appreciable alpha-glucosidase inhibitory effect in a concentration-dependent manner (IC(50)=17.2+/-0.15 mg/ml) and a weak alpha-amylase inhibitory activity (IC(50)=50.9+/-0.17 mg/ml). Andrographolide demonstrated a similar (IC(50)=11.0+/-0.28 mg/ml) alpha-glucosidase and alpha-amylase inhibitory activity (IC(50)=11.3+/-0.29 mg/ml). The positive in vitro enzyme inhibition tests paved way for confirmatory in vivo studies. The in vivo studies demonstrated that A. paniculata extract significantly (P<0.05) reduced peak blood glucose and area under curve in diabetic rats when challenged with oral administration of starch and sucrose. Further, andrographolide also caused a significant (P<0.05) reduction in peak blood glucose and area under the curve in diabetic rats. Hence alpha-glucosidase inhibition may possibly be one of the mechanisms for the A. paniculata extract to exert antidiabetic activity and indicates that AP extract can be considered as a potential candidate for the management of type 2 diabetes mellitus.
    Matched MeSH terms: Drug Evaluation, Preclinical
  10. Similarity-based virtual screening with a bayesian inference network
    Abdo A, Salim N
    ChemMedChem, 2009 Feb;4(2):210-8.
    PMID: 19072820 DOI: 10.1002/cmdc.200800290
    Many methods have been developed to capture the biological similarity between two compounds for use in drug discovery. A variety of similarity metrics have been introduced, the Tanimoto coefficient being the most prominent. Many of the approaches assume that molecular features or descriptors that do not relate to the biological activity carry the same weight as the important aspects in terms of biological similarity. Herein, a novel similarity searching approach using a Bayesian inference network is discussed. Similarity searching is regarded as an inference or evidential reasoning process in which the probability that a given compound has biological similarity with the query is estimated and used as evidence. Our experiments demonstrate that the similarity approach based on Bayesian inference networks is likely to outperform the Tanimoto similarity search and offer a promising alternative to existing similarity search approaches.
    Matched MeSH terms: Drug Evaluation, Preclinical*
  11. Modification of palm oil for anti-inflammatory nutraceutical properties
    Zainal Z, Longman AJ, Hurst S, Duggan K, Hughes CE, Caterson B, et al.
    Lipids, 2009 Jul;44(7):581-92.
    PMID: 19449050 DOI: 10.1007/s11745-009-3304-8
    Palm oil is one of the most important edible oils in the world. Its composition (rich in palmitate and oleate) make it suitable for general food uses but its utility could be increased if its fatty acid quality could be varied. In this study, we have modified a palm olein fraction by transesterification with the n-3 polyunsaturated fatty acids, alpha-linolenate or eicosapentaenoic acid (EPA). Evaluation of the potential nutritional efficacy of the oils was made using chondrocyte culture systems which can be used to mimic many of the degenerative and inflammatory pathways involved in arthritis. On stimulation of such cultures with interleukin-1alpha, they showed increased expression of cyclooxygenase-2, the inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha), IL-1alpha and IL-1beta and the proteinase ADAMTS-4. This increased expression was not affected by challenge of the cultures with palm olein alone but showed concentration-dependent reduction by the modified oil in a manner similar to EPA. These results show clearly that it is possible to modify palm oil conveniently to produce a nutraceutical with effective anti-inflammatory properties.
    Matched MeSH terms: Drug Evaluation, Preclinical
  12. The effect of topical extract of Momordica charantia (bitter gourd) on wound healing in nondiabetic rats and in rats with diabetes induced by streptozotocin
    Teoh SL, Latiff AA, Das S
    Clin Exp Dermatol, 2009 Oct;34(7):815-22.
    PMID: 19508570 DOI: 10.1111/j.1365-2230.2008.03117.x
    Momordica charantia (MC; bitter gourd) is a traditional herb commonly used for its antidiabetic, antioxidant, contraceptive and antibacterial properties. It is also used for the rapid healing of wounds.
    Matched MeSH terms: Drug Evaluation, Preclinical/methods
  13. Fulltext In vitro screening of anti-lice activity of Pongamia pinnata leaves
    Anbu Jeba Sunilson JS, Suraj R, Rejitha G, Anandarajagopal K, Vimala AG, Husain HA
    Korean J Parasitol, 2009 Dec;47(4):377-80.
    PMID: 19967085 DOI: 10.3347/kjp.2009.47.4.377
    Growing patterns of pediculocidal drug resistance towards head louse laid the foundation for research in exploring novel anti-lice agents from medicinal plants. In the present study, various extracts of Pongamia pinnata leaves were tested against the head louse Pediculus humanus capitis. A filter paper diffusion method was conducted for determining the potential pediculocidal and ovicidal activity of chloroform, petroleum ether, methanol, and water extracts of P. pinnata leaves. The findings revealed that petroleum ether extracts possess excellent anti-lice activity with values ranging between 50.3% and 100% where as chloroform and methanol extracts showed moderate pediculocidal effects. The chloroform and methanol extracts were also successful in inhibiting nymph emergence and the petroleum ether extract was the most effective with a complete inhibition of emergence. Water extract was devoid of both pediculocidal and ovicidal activities. All the results were well comparable with benzoyl benzoate (25% w/v). These results showed the prospect of using P. pinnata leave extracts against P. humanus capitis in difficult situations of emergence of resistance to synthetic anti-lice agents.
    Matched MeSH terms: Drug Evaluation, Preclinical
  14. Fulltext Identification and characterisation of a novel anti-viral peptide against avian influenza virus H9N2
    Rajik M, Jahanshiri F, Omar AR, Ideris A, Hassan SS, Yusoff K
    Virol J, 2009;6:74.
    PMID: 19497129 DOI: 10.1186/1743-422X-6-74
    Avian influenza viruses (AIV) cause high morbidity and mortality among the poultry worldwide. Their highly mutative nature often results in the emergence of drug resistant strains, which have the potential of causing a pandemic. The virus has two immunologically important glycoproteins, hemagglutinin (HA), neuraminidase (NA), and one ion channel protein M2 which are the most important targets for drug discovery, on its surface. In order to identify a peptide-based virus inhibitor against any of these surface proteins, a disulfide constrained heptapeptide phage display library was biopanned against purified AIV sub-type H9N2 virus particles.
    Matched MeSH terms: Drug Evaluation, Preclinical
  15. Drug-like and non drug-like pattern classification based on simple topology descriptor using hybrid neural network
    Wan-Mamat WM, Isa NA, Wahab HA, Wan-Mamat WM
    Annu Int Conf IEEE Eng Med Biol Soc, 2009;2009:6424-7.
    PMID: 19964424 DOI: 10.1109/IEMBS.2009.5333747
    An intelligent prediction system has been developed to discriminate drug-like and non drug-like molecules pattern. The system is constructed by using the application of advanced version of standard multilayer perceptron (MLP) neural network called Hybrid Multilayer Perceptron (HMLP) neural network and trained using Modified Recursive Prediction Error (MRPE) training algorithm. In this work, a well understood and easy excess Rule of Five + Veber filter properties are selected as the topological descriptor. The main idea behind the selection of this simple descriptor is to assure that the system could be used widely, beneficial and more advantageous regardless at all user level within a drug discovery organization.
    Matched MeSH terms: Drug Evaluation, Preclinical/methods*
  16. Anti-arthritic potential of the plant Justicia gendarussa Burm F
    Paval J, Kaitheri SK, Potu BK, Govindan S, Kumar RS, Narayanan SN, et al.
    Clinics (Sao Paulo), 2009;64(4):357-62.
    PMID: 19488595
    OBJECTIVE: To evaluate the anti-arthritic potential of the plant Justicia gendarussa using two different rat models.

    MATERIALS AND METHOD: The anti-arthritic potential of the alcoholic extract of the plant Justicia gendarussa was evaluated using the Freund's adjuvant-induced and collagen-induced arthritic rat models. The rats were treated with the ethanolic extract of Justicia gendarussa and with standard aspirin.

    RESULTS: The ethanolic extract of Justicia gendarussa showed significant anti-arthritic activity that was statistically similar to that of aspirin. Our results suggest that the alcoholic extract of Justicia gendarussa exhibits significant anti-arthritic potential.

    Matched MeSH terms: Drug Evaluation, Preclinical
  17. Immunomodulatory effects of zerumbone isolated from roots of Zingiber zerumbet
    Keong YS, Alitheen NB, Mustafa S, Abdul Aziz S, Abdul Rahman M, Ali AM
    Pak J Pharm Sci, 2010 Jan;23(1):75-82.
    PMID: 20067871
    In this study, the immunomodulatory effects of zerumbone isolated from Zingiber zerumbet were investigated by evaluating the effects of this compound towards the lymphocytes proliferation (mice thymocytes, mice splenocytes and human human peripheral blood mononuclear cells, PBMC), cell cycle progression and cytokine (interleukin 2 and 12) induction. Lymphocyte proliferation assay showed that zerumbone was able to activate mice thymocytes, splenocytes and PBMC at dosage dependent pattern where the best concentration was 7.5 microg/ml. Flow cytometry analysis showed the highest population of PBMC entered into G2/M phase after treatment for 72 h with 7.5 microg/ml zerumbone. The production of human interleukin-2 and human interleukin-12 cytokines in culture supernatant from zerumbone activated lymphocytes was prominently upregulated at 24 hour and decreased from 48 h to 72 h. The above results indicate that zerumbone can be used as immunomodulatory agent which can react toward the immune cell cytokine production in dosage dependent pattern.
    Matched MeSH terms: Drug Evaluation, Preclinical
  18. Screening of microfilaricidal effects of plant extracts against Dirofilaria immitis
    Merawin LT, Arifah AK, Sani RA, Somchit MN, Zuraini A, Ganabadi S, et al.
    Res Vet Sci, 2010 Feb;88(1):142-7.
    PMID: 19500810 DOI: 10.1016/j.rvsc.2009.05.017
    Canine dirofilariasis is a common tropical parasitic disease of companion animals, caused by infestation of Dirofilaria immitis filarids within the pulmonary arteries and extending into the right heart. Increased reports of adverse reactions elicited by current microfilaricidal agents against D. immitis such as neurological disorders, circulatory collapse and potential resistance against these agents, warrant the search for new agents in forms of plant extracts. The use of plant extracts in therapeutic medicine is commonly met with scepticism by the veterinary community, thus the lack of focus on its medical potential. This study evaluated the presence of microfilaricidal activities of the aqueous extracts of Zingiber officinale, Andrographis paniculata and Tinospora crispa Miers on D. immitisin vitro at different concentrations; 10mg/ml, 1mg/ml, 100 microg/ml, 10 microg/ml and 1 microg/ml within 24h, by evaluation of relative microfilarial motility as a measure of microfilaricidal activity. All extracts showed microfilaricidal activity with Z. officinale exhibiting the strongest activity overall, followed by A. paniculata and T. crispa Miers. It is speculated that the microfilaricidal mechanism exhibited by these extracts is via spastic paralysis based upon direct observation of the microfilarial motility.
    Matched MeSH terms: Drug Evaluation, Preclinical
  19. Apoptotic effects of Physalis minima L. chloroform extract in human breast carcinoma T-47D cells mediated by c-myc-, p53-, and caspase-3-dependent pathways
    Ooi KL, Tengku Muhammad TS, Lim CH, Sulaiman SF
    Integr Cancer Ther, 2010 Mar;9(1):73-83.
    PMID: 20150224 DOI: 10.1177/1534735409356443
    The chloroform extract of Physalis minima produced a significant growth inhibition against human T-47D breast carcinoma cells as compared with other extracts with an EC(50) value of 3.8 microg/mL. An analysis of cell death mechanisms indicated that the extract elicited an apoptotic cell death. mRNA expression analysis revealed the coregulation of apoptotic genes, that is, c-myc , p53, and caspase-3. The c-myc was significantly induced by the chloroform extract at the earlier phase of treatment, followed by p53 and caspase-3. Biochemical assay and ultrastructural observation displayed typical apoptotic features in the treated cells, including DNA fragmentation, blebbing and convolution of cell membrane, clumping and margination of chromatin, and production of membrane-bound apoptotic bodies. The presence of different stages of apoptotic cell death and phosphatidylserine externalization were further reconfirmed by annexin V and propidium iodide staining. Thus, the results from this study strongly suggest that the chloroform extract of P. minima induced apoptotic cell death via p53-, caspase-3-, and c-myc-dependent pathways.
    Matched MeSH terms: Drug Evaluation, Preclinical
  20. In vitro and in vivo evaluation of self-microemulsifying drug delivery system of buparvaquone
    Venkatesh G, Majid MI, Mansor SM, Nair NK, Croft SL, Navaratnam V
    Drug Dev Ind Pharm, 2010 Jun;36(6):735-45.
    PMID: 20136493 DOI: 10.3109/03639040903460446
    The aim of this study was to prepare a lipid-based self-microemulsifying drug delivery system (SMEDDS) to increase the solubility and oral bioavailability of a poorly water-soluble compound, buparvaquone (BPQ).
    Matched MeSH terms: Drug Evaluation, Preclinical/methods
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