Displaying publications 1 - 20 of 32 in total

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  1. Esa E, Mohamad AS, Hamzah R, Hamid FSA, Aziz NA, Sevaratnam V, et al.
    EJHaem, 2023 Nov;4(4):940-948.
    PMID: 38024609 DOI: 10.1002/jha2.750
    Haemoglobin (Hb) G-Makassar is a rare Hb variant. It presents a diagnostic challenge as it imitates sickle Hb (Hb S) in standard electrophoresis and high-performance liquid chromatography assays requiring DNA analysis to confirm diagnosis. Both have point mutations in codon 6, exon 1 in the β-globin (HBB) gene with different pathogenicities. This study describes the clinical phenotype, haematology and genotype of Hb G-Makassar. Clinical and laboratory data of 38 cases of Hb G-Makassar over 8 years were analysed. Hb G-Makassar was confirmed by a direct sequencing of HBB gene and co-inheritance of α-thalassaemia determined through multiplex gap-PCR and multiplex Amplification Refractory Mutation System polymerase chain reaction. All cases were Malays, predominantly from Terengganu (n = 20, 52.6%). There were 14 (36.8%) males and 24 (63.2%) females with median age of 25 years. Majority (n = 33, 86.8%) had features of thalassaemia trait with mean ± SD for Hb, mean cell volume (MCV) and mean cell haemoglobin (MCH) as 13.21 g/dL ± 1.69, 73.06 ± 4.48 fL and 24.71 ± 1.82 pg, respectively. None had evidence of haemolysis or thromboembolic complications. Six genotypes were identified; ßG-Makassar/ß,αα/αα (n = 19, 50.0%), ßG-Makassar/ßE,αα/αα (n = 4, 10.5%), ßG-Makassar/ßNewYork,αα/αα (n = 1, 2.6%), ßG-Makassar/ß,αα/-α (n = 11, 28.9%), ßG-Makassar/ß,αα/αAdanaα (n = 2, 5.3%) and ßG-Makassar/ß,αα/-SEA (n = 1, 2.6%). The ßG-Makassar/ß,αα/αα showed that features of thalassaemia trait with mean ± SD for Hb, MCV and MCH were 13.74 g/dL ± 2.40, 76.18 ± 6.02 fL and 25.79 ± 2.41 pg, respectively. This is the largest study reporting a significant number of Hb G-Makassar in Malaysia. Although the mutation is similar to Hb S, the phenotype is benign.
  2. Subramaniyan M, Yee A, Hairi FM, Kaai SC, Nordin ASA, Danaee M, et al.
    J Ethn Subst Abuse, 2022 Sep 21.
    PMID: 36129734 DOI: 10.1080/15332640.2022.2123421
    The Malaysian government reinforced smoking restrictions at public venues to protect nonsmokers from secondhand smoke (SHS) exposure. This study examined whether smokers' reports about smoking restrictions and psychosocial beliefs were associated with quit intentions among Malaysian smokers. Data from 1047 cigarette smokers (103 females and 944 males) aged 18 and older from the 2020 International Tobacco Control (ITC) Malaysia Wave 1 Survey were analyzed with bivariate and multivariable logistic regression models. Most Malaysian smokers (85.2%) reported having quit intentions. Smoking was completely restricted in 34.8% of the nighttime venues, 85.3% of air-conditioned (AC) food and beverage (F&B) venues (restaurants, food courts, coffee shops), 87.3% of non-AC F&B, and 69.4% of indoor workplaces. Smokers who visited nighttime entertainment venues where smoking was fully restricted were less likely to have quit intentions. There was no significant association found with quit intentions for smokers who visited AC and non-AC F&B venues and indoor workplaces where smoking was fully restricted. All five psychosocial beliefs assessed, age, and education were positively associated with quit intentions. Malaysian smokers are interested in quitting and psychosocial beliefs were positively associated with quit intentions. There is a need for the Malaysian government to implement and reinforce comprehensive smoking restrictions in all public venues and indoor workplaces to protect nonsmokers from SHS exposure and to encourage smokers to think about quitting, which may influence their quit intentions.
  3. Wai YZ, Ng QX, Adnan TH, Chong YY, Mohamad AS, Goh PP
    Med J Malaysia, 2021 Nov;76(6):884-892.
    PMID: 34806678
    INTRODUCTION: Few studies have reported the impact of preoperative interocular discrepancy in optical biometry (axial length, corneal power, white-to-white, central corneal thickness) on postoperative refractive outcomes. This study aims to investigate any predictive value of preoperative optical biometry differences between eyes on postoperative refractive outcomes.

    MATERIALS AND METHODS: A retrospective cohort study of patients who have undergone optical biometry measurement before unilateral phacoemulsification in the Queen Elizabeth Hospital, Sabah, Malaysia from 2018 to 2020. Biometry data of interest includes axial length (AL), keratometry(K), white-to-white (WTW) and central corneal thickness (CCT). The postoperative outcomes of interest were the patient's preoperative refractive target, postoperative best-corrected visual acuity (BCVA), postoperative refractive outcomes, and optical biometry prediction error.

    RESULTS: The interocular biometry discrepancies which were associated with higher odds of prediction error >0.5D from the refractive target were Interocular Corneal Power Difference (IKD)-average≥0.8 D (Odds Ratio, OR=1.97; 95% Confidence Intervals, 95%CI: 1.06, 3.67) and Interocular WTW Difference ≥1.5 mm (OR=2.77; 95%CI: 1.11, 6.92). In cases with prediction error >1.0D, the measurements were Interocular AL Difference ≥0.4 mm (OR=2.99; 95%CI: 1.11, 8.06), IKD flat≥0.4D (OR=2.76; 95%CI: 1.31, 5.82) and Interocular CCT Difference ≥15μm (OR=3.53; 95%CI: 1.29, 9.64).

    CONCLUSION: Interocular axial length difference ≥0.4mm and interocular central corneal thickness difference ≥15μm are associated with refractive error >1.0D from the pre-operative target. Interocular average corneal power difference ≥0.8D and interocular white-to-white difference ≥1.5mm have higher odds of refractive drift >0.5D from the refractive aim. The above cutoff values help clinicians to identify which patients have a higher risk of refractive shift post-cataract surgery and counsel the patient before cataract operation.

  4. Abu Bakar NA, Sulaiman MR, Lajis N, Akhtar MN, Mohamad AS
    J Pharm Bioallied Sci, 2020 Nov;12(Suppl 2):S711-S717.
    PMID: 33828366 DOI: 10.4103/jpbs.JPBS_344_19
    Introduction: Pain is a major global health issue, where its pharmacotherapy prompts unwanted side effects; hence, the development of effective alternative compounds from natural derivatives with lesser side effects is clinically needed. Chalcone; the precursors of flavonoid, and its derivatives have been widely investigated due to its pharmacological properties.

    Objective: This study addressed the therapeutic effect of 3-(2,5-dimethoxyphenyl)-1-(5-methyl furan-2-yl) prop-2-en-1-one (DMPF-1); synthetic chalcone derivative, on antinociceptive activity in vivo.

    Materials and Methods: The antinociceptive profile was evaluated using acetic-acid-induced abdominal writhing, hot plate, and formalin-induced paw licking test. Capsaicin, phorbol 12-myristate 12 acetate (PMA), and glutamate-induced paw licking test were carried out to evaluate their potential effects toward different targets.

    Results: It was shown that the doses of 0.1, 0.5, 1, and 5 mg/kg of DMPF-1 given via intraperitoneal injection showed significant reduction in writhing responses and increased the latency time in hot-plate test where reduced time spent on licking the injected paw in formalin and dose contingency inhibition was observed. The similar results were observed in capsaicin, PMA, and glutamate-induced paw licking test. In addition, the challenge with nonselective opioid receptor antagonist (naloxone) aimed to evaluate the involvement of the opioidergic system, which showed no reversion in analgesic profile in formalin and hot-plate test.

    Conclusion: Collectively, this study showed that DMPF-1 markedly inhibits both peripheral and central nociception through the mechanism involving an interaction with vanilloid and glutamatergic system regardless of the activation of the opioidergic system.

  5. Mohamad AS, Hamzah R, Selvaratnam V, Yegapan S, Sathar J
    Hematol Rep, 2018 Sep 05;10(3):7210.
    PMID: 30344984 DOI: 10.4081/hr.2018.7210
    Human hemoglobin of G-Makassar variant has been reported very rarely with Beta Thalassemia. In year 1969 Hb GMakassar was first identified in Makassar, Sulawesi (Celebes), Republic of Indonesia. The disease was first published in 1969 and 33 years later it has been reported at a family of Thailand origin. We report a 45-yearold Malay man who was investigated for anemia and thrombocytopenia then diagnosed with Hb G-Makassar. This finding describes as a new Hemoglobin GMakassar discovered in Malaysia after 14 years diagnosed in Thailand.
  6. Wai YZ, Fiona Chew LM, Mohamad AS, Ang CL, Chong YY, Adnan TH, et al.
    Int J Ophthalmol, 2018;11(10):1685-1690.
    PMID: 30364221 DOI: 10.18240/ijo.2018.10.17
    AIM: To report the incidence, risk factors and visual outcomes for postoperative endophthalmitis (POE) based on 7-year data from the Malaysian Ministry of Health Cataract Surgery Registry (MOH CSR).

    METHODS: Data was collected from the web-based MOH CSR. All consecutive cataract surgery patients from 1st June 2008 to 31st December 2014 were identified. Exclusion criteria were traumatic cataract or previous ocular surgery. Demographic data, ocular co-morbidities, intraoperative details and postoperative visual acuity (VA) at final ophthalmological follow-up were noted. All eyes were taken for analysis. Subjects with POE were compared against subjects with no POE for risk factor assessment using multiple logistic regressions.

    RESULTS: A total of 163 503 subjects were screened. The incidence of POE was 0.08% (131/163 503). Demographic POE risk factors included male gender (OR: 2.121, 95%CI: 1.464-3.015) and renal disease (OR: 2.867, 95%CI: 1.503-5.467). POE risk increased with secondary causes of cataract (OR: 3.562, 95%CI: 1.740-7.288), uveitis (OR: 11.663, 95%CI: 4.292-31.693) and diabetic retinopathy (OR: 1.720, 95%CI: 1.078-2.744). Intraoperative factors reducing POE were shorter surgical time (OR: 2.114, 95%CI: 1.473-3.032), topical or intracameral anaesthesia (OR: 1.823, 95%CI: 1.278-2.602), posterior chamber intraocular lens (PCIOL; OR: 4.992, 95%CI: 2.689-9.266) and foldable IOL (OR: 2.276, 95%CI: 1.498-3.457). POE risk increased with posterior capsule rupture (OR: 3.773, 95%CI: 1.915-7.432) and vitreous loss (OR: 3.907, 95%CI: 1.720-8.873). Postoperative VA of 6/12 or better was achieved in 15.27% (20/131) subjects with POE.

    CONCLUSION: This study concurs with other studies regarding POE risk factors. Further strengthening of MOH CSR data collection process will enable deeper analysis and optimization of POE treatment.

  7. Chia JSM, Omar Farouk AA, Mohamad AS, Sulaiman MR, Perimal EK
    Biomed Pharmacother, 2016 Oct;83:1303-1310.
    PMID: 27570173 DOI: 10.1016/j.biopha.2016.08.052
    Zerumbone, a bioactive sesquiterpene isolated from Zingiber zerumbet (Smith), has shown to exert antiallodynic and antihyperalgesic effects in neuropathic pain mice model in our recent study. The mechanism through which zerumbone alleviates neuropathic pain has yet to be elucidated. Thus, this study aimed to determine whether the serotonergic system, part of the descending pain modulation pathway, contributes to the antineuropathic effect of zerumbone. Participation of the serotonergic system in zerumbone-induced antiallodynia and antihyperalgesia was assessed using Dynamic Plantar Aesthesiometer von Frey test and Hargreaves plantar test respectively in chronic-constriction injury mice model. Administration of ρ-chlorophenylalanine (PCPA, 100mg/kg, i.p.) for four consecutive days to deplete serotonin (5-HT) prior to zerumbone administration blocked the antiallodynic and antihyperalgesic effects of zerumbone. Further investigation with 5-HT receptor antagonists methiothepin (5-HT1/6/7 receptor antagonist, 0.1mg/kg), WAY-100635 (5-HT1A receptor antagonist, 1mg/kg), isamoltane (5-HT1B receptor antagonist, 2.5mg/kg), ketanserin (5-HT2A receptor antagonist, 0.3mg/kg) and ondansetron (5-HT3 receptor antagonist, 0.5mg/kg) managed to significantly attenuate antiallodynic and antihyperalgesic effects of zerumbone (10mg/kg). These findings demonstrate that zerumbone alleviates mechanical allodynia and thermal hyperalgesia through the descending serotonergic system via 5-HT receptors 1A, 1B, 2A, 3, 6 and 7 in chronic constriction injury neuropathic pain mice.
  8. Al-Yahya SN, Baki MM, Saad SM, Azman M, Mohamad AS
    Ann Saudi Med, 2016 8 2;36(4):292-7.
    PMID: 27478916 DOI: 10.5144/0256-4947.2016.292
    A systematic review on laryngopyoceles across Ovid, PubMed, and Google Scholar database was conducted. A total of 61 papers published between 1952 and 2015 were found. Of these, 23 cases written in English, which described the number of cases, surgical approaches, resort to tracheostomy, complications, and outcomes, were shortlisted. Four cases of laryngopyoceles were managed endoscopically using a cold instrument, microdebrider, or laser. Eighteen cases were operated via an external approach, and 1 case applied both approaches. One of 4 endoscopic and 10 of 18 external approaches involved tracheostomy. The present study aimed to report a case of large mixed laryngopyocele that was successfully drained and marsupialized endoscopically using suction diathermy without requiring tracheostomy. Management using suction diathermy for excision and marsupialization of a laryngopyocele has never been reported and can be recommended as a feasible method due to its widespread availability. In the presence of a large laryngopyocele impeding the airway, tracheostomy may be averted in a controlled setting.

    SIMILAR CASES PUBLISHED: None specified.

  9. Kamaldin MN, Akhtar MN, Mohamad AS, Lajis N, Perimal EK, Akira A, et al.
    Molecules, 2013 Apr 10;18(4):4209-20.
    PMID: 23612473 DOI: 10.3390/molecules18044209
    Previous studies have shown that systemic administration of 6'-hydroxy-2',4'-dimethoxychalcone (flavokawin B, FKB) exerts significant peripheral and central antinociceptive effects in laboratory animals. However, the mechanisms underlying these peripheral and central antinociceptive effects have yet to be elucidated. Therefore, the objective of the present study was to evaluate the participation of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP)/potassium (K+) channels pathway in the peripheral antinociception induced by FKB. It was demonstrated that intraplantar (i.pl.) administration of FKB (150, 250, 375 and 500 µg/paw) resulted in dose-dependent peripheral antinociception against mechanical hyperalgesia in carrageenan-induced hyperalgesia test model in rats. The possibility of FKB having either a central or a systemic effect was excluded since administration of FKB into the right paw did not elicit antinociception in the contralateral paw. Furthermore, peripheral antinociception induced by FKB (500 µg/paw) was significantly reduced when L-arginine (25 µg/paw, i.pl.), Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 50 µg/paw, i.pl.), glibenclamide (300 µg/paw, i.pl.), tetraethylammonium (300 µg/paw, i.pl.) and charybdotoxin (3 µg/paw, i.pl.) were injected before treatment. Taken together, our present data suggest that FKB elicits peripheral antinociception when assessed in the mechanical hyperalgesia induced by carrageenan. In addition, it was also demonstrated that this effect was mediated through interaction of the NO/cGMP/K+ channels signaling pathway.
  10. Ming-Tatt L, Khalivulla SI, Akhtar MN, Mohamad AS, Perimal EK, Khalid MH, et al.
    Basic Clin Pharmacol Toxicol, 2012 Mar;110(3):275-82.
    PMID: 21967232 DOI: 10.1111/j.1742-7843.2011.00804.x
    This study investigated the potential antinociceptive efficacy of a novel synthetic curcuminoid analogue, 2,6-bis-(4-hydroxy-3-methoxybenzylidene)cyclohexanone (BHMC), using chemical- and thermal-induced nociception test models in mice. BHMC (0.03, 0.1, 0.3 and 1.0 mg/kg) administered via intraperitoneal route (i.p.) produced significant dose-related inhibition in the acetic acid-induced abdominal constriction test in mice with an ID(50) of 0.15 (0.13-0.18) mg/kg. It was also demonstrated that BHMC produced significant inhibition in both neurogenic (first phase) and inflammatory phases (second phase) of the formalin-induced paw licking test with an ID(50) of 0.35 (0.27-0.46) mg/kg and 0.07 (0.06-0.08) mg/kg, respectively. Similarly, BHMC also exerted significant increase in the response latency period in the hot-plate test. Moreover, the antinociceptive effect of the BHMC in the formalin-induced paw licking test and the hot-plate test was antagonized by pre-treatment with the non-selective opioid receptor antagonist, naloxone. Together, these results indicate that the compound acts both centrally and peripherally. In addition, administration of BHMC exhibited significant inhibition of the neurogenic nociception induced by intraplantar injections of glutamate and capsaicin with ID(50) of 0.66 (0.41-1.07) mg/kg and 0.42 (0.38-0.51) mg/kg, respectively. Finally, it was also shown that BHMC-induced antinociception was devoid of toxic effects and its antinociceptive effect was associated with neither muscle relaxant nor sedative action. In conclusion, BHMC at all doses investigated did not cause any toxic and sedative effects and produced pronounced central and peripheral antinociceptive activities. The central antinociceptive activity of BHMC was possibly mediated through activation of the opioid system as well as inhibition of the glutamatergic system and TRPV1 receptors, while the peripheral antinociceptive activity was perhaps mediated through inhibition of various inflammatory mediators.
  11. Zakaria ZA, Hussain MK, Mohamad AS, Abdullah FC, Sulaiman MR
    Biol Res Nurs, 2012 Jan;14(1):90-7.
    PMID: 21278166 DOI: 10.1177/1099800410395378
    Ficus deltoidea (Family Moraceae) leaves have been used traditionally by the Malays to treat ailments such as wounds, sores, and rheumatism. The aim of the present study was to determine the anti-inflammatory activity of the aqueous extract of F. deltoidea leaf (FDA) using acute and chronic inflammatory models. FDA, in the doses of 30, 100, and 300 mg/kg, was administered intraperitoneally in rats (n = 6) before the animals were subjected to the carrageenan-induced paw edema test, cotton pellet-induced granuloma test, and formalin test. The first two tests represent acute and chronic models of inflammation, respectively. The first and second phases of the formalin test represent neurogenic pain and inflammatory-mediated pain, respectively; thus, only the second phase was measured in the present study. Results showed that FDA exerted significant (p < .05) anti-inflammatory activity in all assays, with dose-response effects seen in the paw edema and formalin tests. In conclusion, the leaf of F. deltoidea possesses anti-inflammatory activity against acute and chronic inflammatory responses and against pain-associated inflammatory response. These findings justify the traditional uses of F. deltoidea leaves for treatment of inflammatory-mediated ailments.
  12. Zakaria ZA, Mohamad AS, Ahmad MS, Mokhtar AF, Israf DA, Lajis NH, et al.
    Biol Res Nurs, 2011 Oct;13(4):425-32.
    PMID: 21112917 DOI: 10.1177/1099800410386590
    Nonsteroidal anti-inflammatory drugs (NSAIDs) have been widely used for the treatment of inflammation. However, despite their effectiveness, most NSAIDs cause various side effects that negatively affect the management of inflammation and, in part, pain. Thus, there is a need to search for new anti-inflammatory agents with few, or no, side effects. Natural products of plant, animal, or microorganism origin have been good sources of new bioactive compounds. The present study was carried out to evaluate the acute and chronic anti-inflammatory activities of the essential oil of the rhizomes of Zingiber zerumbet (Zingiberaceae) using the carrageenan-induced paw edema and cotton pellet-induced granuloma tests, respectively. The effect of the essential oil on inflammatory- and noninflammatory-mediated pain was also assessed using the formalin test. Essential oil of Z. zerumbet, at doses of 30, 100, and 300 mg/kg, was administered intraperitoneally to rats. The substance exhibited significant anti-inflammatory activity both in acute and chronic animal models. The essential oil also inhibited inflammatory- and noninflammatory-mediated pain when assessed using the formalin test. In conclusion, the essential oil of Z. zerumbet possessed anti-inflammatory activity, in addition to its antinociceptive activity, which may explain its traditional uses to treat inflammatory-related ailments.
  13. Khalid MH, Akhtar MN, Mohamad AS, Perimal EK, Akira A, Israf DA, et al.
    J Ethnopharmacol, 2011 Sep 01;137(1):345-51.
    PMID: 21664960 DOI: 10.1016/j.jep.2011.05.043
    ETHNOPHARMACOLOGICAL RELEVANCE: Zingiber zerumbet (L.) Smith, a wild edible ginger species or locally known as "lempoyang", commonly used in the Malays traditional medicine as an appetizer or to treat stomachache, toothache, muscle sprain and as a cure for swelling sores and cuts.

    AIM: The present study was conducted to investigate the possible mechanism of actions underlying the systemic antinociception activity of the essential oil of Zingiber zerumbet (EOZZ) in chemical-induced nociception tests in mice.

    MATERIALS AND METHODS: Acetic acid-induced abdominal constriction, capsaicin-, glutamate- and phorbol 12-myristate 13-acetate-induced paw licking tests in mice were employed in the study. In all experiments, EOZZ was administered systemically at the doses of 50, 100, 200 and 300 mg/kg.

    RESULTS: It was shown that EOZZ given to mice via intraperitoneal and oral routes at 50, 100, 200 and 300 mg/kg produced significant dose dependent antinociception when assessed using acetic acid-induced abdominal writing test with calculated mean ID(50) values of 88.84 mg/kg (80.88-97.57 mg/kg) and 118.8 mg/kg (102.5-137.8 mg/kg), respectively. Likewise, intraperitoneal administration of EOZZ at similar doses produced significant dose dependent inhibition of neurogenic pain induced by intraplantar injection of capsaicin (1.6 μg/paw), glutamate (10 μmol/paw) and phorbol 12-myristate 13-acetate (1.6μg/paw) with calculated mean ID(50) of 128.8 mg/kg (118.6-139.9 mg/kg), 124.8 mg/kg (111.4-139.7 mg/kg) and 40.29 (35.39-45.86) mg/kg, respectively. It was also demonstrated that pretreatment with l-arginine (100mg/kg, i.p.), a nitric oxide precursor significantly reversed antinociception produced by EOZZ suggesting the involvement of l-arginine/nitric oxide pathway. In addition, methylene blue (20mg/kg, i.p.) significantly enhanced antinociception produced by EOZZ. Administration of glibenclamide (10mg/kg, i.p.), an ATP-sensitive K(+) channel antagonist significantly reversed antinociceptive activity induced by EOZZ.

    CONCLUSION: Together, the present results suggested that EOZZ-induced antinociceptive activity was possibly related to its ability to inhibit glutamatergic system, TRPV1 receptors as well as through activation of l-arginine/nitric oxide/cGMP/protein kinase C/ATP-sensitive K(+) channel pathway.

  14. Mohamad AS, Akhtar MN, Khalivulla SI, Perimal EK, Khalid MH, Ong HM, et al.
    Basic Clin Pharmacol Toxicol, 2011 Jun;108(6):400-5.
    PMID: 21214864 DOI: 10.1111/j.1742-7843.2010.00670.x
    The possible mechanisms of action in the antinociceptive activity induced by systemic administration (intraperitoneal, i.p.) of flavokawin B (FKB) were analysed using chemical models of nociception in mice. It was demonstrated that i.p. administration of FKB to the mice at 0.3, 1.0, 3.0 and 10 mg/kg produced significant dose-related reduction in the number of abdominal constrictions. The antinociception induced by FKB in the acetic acid test was significantly attenuated by i.p. pre-treatment of mice with L-arginine, the substrate for nitric oxide synthase or glibenclamide, the ATP-sensitive K(+) channel inhibitor, but was enhanced by methylene blue, the non-specific guanylyl cyclase inhibitor. FKB also produced dose-dependent inhibition of licking response caused by intraplantar injection of phorbol 12-myristate 13-acetate, a protein kinase C activator (PKC). Together, these data indicate that the NO/cyclic guanosine monophosphate/PKC/ATP-sensitive K(+) channel pathway possibly participated in the antinociceptive action induced by FKB.
  15. Perimal EK, Akhtar MN, Mohamad AS, Khalid MH, Ming OH, Khalid S, et al.
    Basic Clin Pharmacol Toxicol, 2011 Mar;108(3):155-62.
    PMID: 20955360 DOI: 10.1111/j.1742-7843.2010.00635.x
    This study investigated the antinociceptive effects of zerumbone in chemical behavioural models of nociception in mice. Zerumbone given through intraperitoneal route (i.p.) produced dose-related antinociception when assessed on acetic acid-induced abdominal writhing test in mice. In addition, the i.p. administration of zerumbone exhibited significant inhibition of the neurogenic pain induced by intraplantar (i.pl.) injection of capsaicin and bradykinin. Likewise, zerumbone given by i.p. route reduced the nociception produced by i.pl. injection of glutamate and phorbol myristate acetate (PMA). The antinociception caused by zerumbone in the acetic acid test was significantly attenuated by i.p. pre-treatment of mice with l-arginine (nitric oxide precursor) and glibenclamide (ATP-sensitive K(+) channel inhibitor). However, the antinociception of zerumbone was enhanced by methylene blue (non-specific gyanylyl cyclase inhibitor). Together, these results indicate that zerumbone produces pronounced antinociception against chemical models of nociception in mice. It also strongly suggests that the l-arginine-nitric oxide-cGMP-PKC-K(+) ATP channel pathways, the TRPV1 and kinin B2 receptors play an important role in the zerumbone-induced antinociception.
  16. Ong HM, Mohamad AS, Makhtar N', Khalid MH, Khalid S, Perimal EK, et al.
    J Ethnopharmacol, 2011 Jan 7;133(1):227-33.
    PMID: 20920570 DOI: 10.1016/j.jep.2010.09.030
    Acmella uliginosa (Sw.) Cass. is a medicinal herbaceous plant that is commonly used by the Malay community in Malaysia to relieve pain often associated with mouth ulcers, toothache, sore throat, and stomach ache.
  17. Mohamad AS, Akhtar MN, Zakaria ZA, Perimal EK, Khalid S, Mohd PA, et al.
    Eur J Pharmacol, 2010 Nov 25;647(1-3):103-9.
    PMID: 20826146 DOI: 10.1016/j.ejphar.2010.08.030
    The present study examined the potential antinociceptive activity of flavokawin B (6'-hydroxy-2',4'-dimethoxychalcone), a synthetic chalcone using chemical- and thermal-induced nociception models in mice. It was demonstrated that flavokawin B (FKB; 0.3, 1, 3 and 10 mg/kg) administered via both oral (p.o.) and intraperitoneal (i.p.) routes produced significant and dose-dependent inhibition in the abdominal constrictions induced by acetic acid, with the i.p. route producing antinociception of approximately 7-fold more potent than the p.o. route. It was also demonstrated that FKB produced significant inhibition in the two phases of the formalin-induced paw licking test. In addition, the same treatment of flavokawin B (FKB) exhibited significant inhibition of the neurogenic nociceptive induced by intraplantar injections of glutamate and capsaicin. Likewise, this compound also induced a significant increase in the response latency period to thermal stimuli in the hot plate test and its antinociceptive effect was not related to muscle relaxant or sedative action. Moreover, the antinociception effect of the FKB in the formalin-induced paw licking test and the hot plate test was not affected by pretreatment of non-selective opioid receptor antagonist, naloxone. The present results indicate that FKB produced pronounced antinociception effect against both chemical and thermal models of pain in mice that exhibited both peripheral and central analgesic activity.
  18. Sulaiman MR, Perimal EK, Akhtar MN, Mohamad AS, Khalid MH, Tasrip NA, et al.
    Fitoterapia, 2010 Oct;81(7):855-8.
    PMID: 20546845 DOI: 10.1016/j.fitote.2010.05.009
    The anti-inflammatory activity of zerumbone (1), a natural cyclic sesquiterpene isolated from Zingiber zerumbet Smith was investigated using carrageenan-induced paw edema and cotton pellet-induced granuloma tissue formation test in mice. It was demonstrated that intraperitoneal administration of 1 at a dose of 5, 10, 50 and 100 mg/kg produced significant dose-dependent inhibition of paw edema induced by carrageenan. It was also demonstrated that 1 at similar doses significantly suppressed granulomatous tissue formation in cotton pellet-induced granuloma test.
  19. Harasstani OA, Moin S, Tham CL, Liew CY, Ismail N, Rajajendram R, et al.
    Inflamm Res, 2010 Sep;59(9):711-21.
    PMID: 20221843 DOI: 10.1007/s00011-010-0182-8
    OBJECTIVES: We evaluated several flavonoid combinations for synergy in the inhibition of proinflammatory mediator synthesis in the RAW 264.7 cellular model of inflammation.

    METHODS: The inhibitory effect of chrysin, kaempferol, morin, silibinin, quercetin, diosmin and hesperidin upon nitric oxide (NO), prostaglandin E(2) (PGE(2)) and tumour necrosis factor-alpha (TNF-alpha) secretion from the LPS-induced RAW 264.7 monocytic macrophage was assessed and IC(50) values obtained. Flavonoids that showed reasonable inhibitory effects in at least two out of the three assays were combined in a series of fixed IC(50) ratios and reassessed for inhibition of NO, PGE(2) and TNF-alpha. Dose-response curves were generated and interactions were analysed using isobolographic analysis.

    RESULTS: The experiments showed that only chrysin, kaempferol, morin, and silibinin were potent enough to produce dose-response effects upon at least two out of the three mediators assayed. Combinations of these four flavonoids showed that several combinations afforded highly significant synergistic effects.

    CONCLUSIONS: Some flavonoids are synergistic in their anti-inflammatory effects when combined. In particular chrysin and kaempferol significantly synergised in their inhibitory effect upon NO, PGE(2) and TNF-alpha secretion. These findings open further avenues of research into combinatorial therapeutics of inflammatory-related diseases and the pharmacology of flavonoid synergy.

  20. Liew CY, Tham CL, Lam KW, Mohamad AS, Kim MK, Cheah YK, et al.
    Immunopharmacol Immunotoxicol, 2010 Sep;32(3):495-506.
    PMID: 20109039 DOI: 10.3109/08923970903575708
    HMP [3-(2-hydroxyphenyl)-1-(5-methyl-furan-2-y-l) propenone] was evaluated for its ability to inhibit the synthesis of major proinflammatory mediators and cytokines in interferon-gamma (IFN-gamma)- and lipopolysaccharide (LPS)-induced RAW 264.7 cells and phorbol myristate acetate (PMA)-differentiated/LPS-induced U937 cells. HMP suppressed the production of nitric oxide (NO) with significant inhibitory effects at doses as low as 0.78 microM (P < 0.05). Prostaglandin E2 (PGE2) secretion was also inhibited at doses of 12.5 microM and above (P < 0.01). The secretion of both TNF-alpha and IL-6 were only inhibited at the highest dose used (25 microM; P < 0.001). IL-1beta secretion was also inhibited from 12.5 microM onwards (P < 0.01). This inhibition was demonstrated to be caused by down-regulation of inducible enzymes, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), without direct effect upon iNOS or COX-2 enzyme activity. HMP only inhibited iNOS (P < 0.001) and IL-1beta (P < 0.05) gene expression at the highest tested concentration. HMP did not affect the secretion of chemokines IL-8 and monocyte chemotactic protein-1 (MCP-1) and the anti-inflammatory cytokine IL-10. The most striking effect of HMP was its NO inhibitory activity and therefore we conclude that HMP is a selective inhibitor of iNOS.
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