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  1. Anti-inflammatory and antioxidant activities of the methanol extract of Gynura segetum leaf
    Seow LJ, Beh HK, Umar MI, Sadikun A, Asmawi MZ
    Int Immunopharmacol, 2014 Nov;23(1):186-91.
    PMID: 25194675 DOI: 10.1016/j.intimp.2014.08.020
    Gynura segetum, family Compositae, is a cultivated species and can be found growing in the tropical regions of Indonesia and Malaysia. The plant is known for its use for the treatment of cancer, inflammation, diabetes, hypertension and skin afflictions. In the current study, in vivo anti-inflammatory effect of the methanol extract G. segetum leaf and its antioxidant effect in vitro have been investigated for the first time. The in vitro antioxidant activities of the methanol extract were measured using common methods including total phenolic content; total flavonoid content; scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and β-carotene bleaching assays. The in vivo anti-inflammatory activities were tested using the cotton pellet implanted animal model. The measurement of pro-inflammatory cytokine (TNF-α and IL-1) levels in the blood samples of the rats was carried out by using ELISA kits. The inhibitory activity on cyclooxygenase (COX) enzyme of methanol extract was also evaluated. The methanol extract exhibited good antioxidant activity which is associated with their total phenolic and flavonoid contents. Methanol extract strongly inhibited the granuloma tissue formation in rats and the anti-inflammatory potential was mediated through the inhibition of pro-inflammatory cytokines and COX-2 enzyme activities. Taken together, the present study suggests that G. segetum's leaf is a natural source of antioxidants and has potential therapeutic benefits against chronic inflammation.
  2. 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.
  3. Vasorelaxant and chemical fingerprint studies of Citrus reticulatae pericarpium extracts
    Tan CS, Loh YC, Ch'ng YS, Ng CH, Yeap ZQ, Ahmad M, et al.
    J Ethnopharmacol, 2019 Mar 25;232:135-144.
    PMID: 30543913 DOI: 10.1016/j.jep.2018.12.014
    ETHNOPHARMACOLOGICAL RELEVANCE: Citrus reticulatae Pericarpium (Chen pi) was widely used as an important ingredient in the prescription of TCM to treat phlegm fluid retention type hypertension. Since Chen pi is involved in treatment as antihypertensive TCM formula, we have reasonable expectation in believing that it might possess vasorelaxant activity.

    AIM OF THE STUDY: This study is designed to investigate the vasorelaxant effect of Chen pi and to study its pharmacology effects.

    MATERIALS AND METHODS: The vasorelaxant effect of water extract of Chen pi (CRW) were evaluated on thoracic aortic rings isolated from Sprague Dawley rats. The fingerprint of Chen pi and the extracts were developed with quantification of hesperidin content by HPTLC.

    RESULTS: CRW exhibited the strongest vasorelaxant activity. CRW caused the relaxation of the phenylephrine pre-contracted aortic rings in the presence and absence of endothelium as well as in potassium chloride pre-contracted endothelium-intact aortic ring. The incubation of propranolol (β-adrenergic receptor blocker), atropine (muscarinic receptor blocker), Nω-nitro-L-arginine methyl ester (NO synthase inhibitor), ODQ (sGC inhibitor), indomethacin (COX inhibitor), 4-aminopyridine (KV blocker), barium chloride (Kir blocker), and glibenclamide (KATP blocker) significantly reduced the vasorelaxant effects of CRW. CRW was also found to be active in reducing Ca2+ releases from the sarcoplasmic reticulum and suppressing the voltage-operated calcium channels.

    CONCLUSION: The vasorelaxant effect of CRW on rat aorta involves NO/sGC, calcium and potassium channels, muscarinic and β-adrenergic receptors.

  4. Anti-hypertensive and vasodilatory effects of amended Banxia Baizhu Tianma Tang
    Tan CS, Loh YC, Ng CH, Ch'ng YS, Asmawi MZ, Ahmad M, et al.
    Biomed Pharmacother, 2018 Jan;97:985-994.
    PMID: 29136777 DOI: 10.1016/j.biopha.2017.11.021
    Although Banxia Baizhu Tianma Tang (BBT) has been long administered for hypertensive treatment in Traditional Chinese Medicine (TCM), the ratio of the herbal components that makes up the formulation has not been optimized with respect to the anti-hypertensive effect that it inherently possesses. A newly amended BBT (ABBT) formulation was developed using the evidence-based approach of orthogonal stimulus-response compatibility model. The ABBT showed enhanced therapeutic effect while maintaining its traditional theoretical approach rooted in TCM. This study was designed to investigate the possible mechanism of actions involved in the vasodilatory activity of ABBT-50 by evaluating its vasodilative effect on isolated Sprague Dawley rats in the presence of absence of various antagonists. When pre-contracted with phenylephrine, relaxation was observed in endothelium intact (EC50=0.027±0.003mg/ml, Rmax=109.8±2.12%) and denuded aortic rings (EC50=0.409±0.073mg/ml, Rmax=63.15±1.78%), as well as in endothelium intact aortic rings pre-contracted with potassium chloride (EC50=32.7±12.16mg/ml, Rmax=34.02±3.82%). Significant decrease in the vasodilative effect of ABBT-50 was observed in the presence of Nω-nitro-l-arginine methyl ester (EC50=0.12±0.021mg/ml, Rmax=75.33±3.28%), 1H-[1,2,4] Oxadiazolo[4,3-a]quinoxalin-1-one (EC50=0.463±0.18mg/ml, Rmax=54.48±2.02%), methylene blue (EC50=0.19±0.037mg/ml, Rmax=83.69±3.19%), indomethacin (EC50=0.313±0.046mg/ml, Rmax=71.33±4.12%), atropine (EC50=0.146±0.013mg/ml, Rmax=77.2±3.41%), and 4-aminopyridine (EC50=0.045±0.008mg/ml, Rmax=95.55±2.36%). ABBT-50 was also suppressing Ca2+ release from sarcoplasmic reticulum and inhibiting calcium channels. Vasodilatory effects of ABBT-50 are mediated through NO/sGC/cGMP cascade and PGI2, followed by muscarinic pathways and calcium channels.
  5. Potential immunosuppressive and antiinflammatory activities of Malaysian medicinal plants characterized by reduced cell surface expression of cell adhesion molecules
    Tanaka S, Yoichi S, Ao L, Matumoto M, Morimoto K, Akimoto N, et al.
    Phytother Res, 2001 Dec;15(8):681-6.
    PMID: 11746860
    In the search for agents effective against immune-mediated disorders and inflammation, we have screened Malaysian medicinal plants for the ability to inhibit the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the surface of murine endothelial cells (F-2), and mouse myeloid leukaemia cells (M1), respectively. Of 41 kinds (29 species, 24 genera, 16 families) of Malaysian plants tested, 10 and 19 plant samples significantly downregulated the expression of ICAM-1 and VCAM-1, respectively. Bioassay-directed fractionation of an extract prepared from the bark of Goniothalamus andersonii showed that its ingredients, goniothalamin (1) and goniodiol (2) inhibited the cell surface expression of both ICAM-1 and VCAM-1. The present results suggest that Malaysian medicinal plants may be abundant natural resources for immunosuppressive and antiinflammatory substances.
  6. Underlying mechanism of vasorelaxant effect exerted by 3,5,7,2',4'-pentahydroxyflavone in rats aortic ring
    Tew WY, Tan CS, Asmawi MZ, Yam MF
    Eur J Pharmacol, 2020 Aug 05;880:173123.
    PMID: 32335091 DOI: 10.1016/j.ejphar.2020.173123
    Morin (3,5,7,2',4'-pentahydroxyflavone) is a yellow coloured natural flavonoid found in plants of the Moraceae family. This favonoid is easily sources from readily available fruits, vegetables and eve certain beverages. Among the sources that was identified, it is clear that morin is most abundantly found in almond, old fustic, Indian guava, and Osage orange. Multiple studies have suggested that morin has multiple therapeutic actions and possess potential to be a functional potent drug. Previous studies demonstrated that morin is capable of resolving deoxycorticosterone acetate-salt-induced hypertension and possess strong vasorelaxant properties. However, the exact mechanisms remains unknown. Therefore, this study is designed to investigate the in vitro mechanism of morin-induced vasorelaxant effects. The underlying mechanisms of morin's vasorelaxant activities were evaluated on thoracic aortic rings isolated from Sprague-Dawley rats. Results from the study demonstrated morin causing vasodilatory reaction in phenylephrine and potassium chloride pre-contracted endothelium-intact aortic rings with the effect being significantly affected in endothelium-denuded aortic rings. Pre-incubation of the aortic rings with ODQ (selective cGMP-independent sGC inhibitor), indomethacin (nonselective COX inhibitor), L-NAME (endothelial nitric oxide inhibitor), propranolol (β2-adrenegic receptors blocker), and atropine (muscarinic receptors blocker) significantly reduced the vasorelaxant effect of morin. It was also found to be able to reduce the intracellular calcium level by blocking VOCC and calcium intake from the extracellular environment and the intracellular release of calcium from the sarcoplasmic reticulum. The present study showed that the vasorelaxant effect of morin potentially involves the NO/sGC, muscarinic receptors, β2-adrenegic receptors, and calcium channels.
  7. Multi-constituent synergism is responsible for anti-inflammatory effect of Azadirachta indica leaf extract
    Umar MI, Asmawi MZ, Sadikun A, Abdul Majid AM, Atangwho IJ, Khadeer Ahamed MB, et al.
    Pharm Biol, 2014 Nov;52(11):1411-22.
    PMID: 25026347 DOI: 10.3109/13880209.2014.895017
    Azadirachta indica A. Juss. (Meliaceaes) leaves have been used traditionally to treat swelling and rheumatism in Indian cultures.
  8. Fulltext Bioactivity-guided isolation of ethyl-p-methoxycinnamate, an anti-inflammatory constituent, from Kaempferia galanga L. extracts
    Umar MI, Asmawi MZ, Sadikun A, Atangwho IJ, Yam MF, Altaf R, et al.
    Molecules, 2012 Jul 23;17(7):8720-34.
    PMID: 22825623 DOI: 10.3390/molecules17078720
    This study evaluated the anti-inflammatory effect of Kaempferia galanga (KG) using an activity-guided approach. KG rhizomes were serially extracted with petroleum ether, chloroform, methanol and water. These extracts (2 g/kg each) were tested for their ability to inhibit carrageenan-induced rat paw edema. The chloroform extract was found to exert the highest inhibition (42.9%) compared to control (p < 0.001), hence it was further fractionated by washing serially with hexane, hexane-chloroform (1:1) and chloroform. The chloroform fraction (1 g/kg) showed the highest inhibitory effect (51.9%, (p < 0.001), on carrageenan-induced edema. This chloroform fraction was further fractionated with hexane-chloroform (1:3) and chloroform, and of the two fractions, the hexane-chloroform sub-fraction was the most effective in inhibiting edema (53.7%, p < 0.001). GC-MS analysis of the active sub-fraction identified ethyl-p-methoxycinnamate (EPMC) as the major component, which was re-crystallized. EPMC dose-dependently inhibited carrageenan-induced edema with an MIC of 100 mg/kg. Moreover, in an in vitro study, EPMC non-selectively inhibited the activities of cyclooxygenases 1 and 2, with IC₅₀ values of 1.12 µM and 0.83 µM respectively. These results validate the anti-inflammatory activity of KG which may be exerted by the inhibition of cyclooxygenases 1 and 2. EPMC isolated from this plant may be the active anti-inflammatory agent.
  9. Fulltext The Adipokine Component in the Molecular Regulation of Cancer Cell Survival, Proliferation and Metastasis
    Umar MI, Hassan W, Murtaza G, Buabeid M, Arafa E, Irfan HM, et al.
    Pathol Oncol Res, 2021;27:1609828.
    PMID: 34588926 DOI: 10.3389/pore.2021.1609828
    A hormonal imbalance may disrupt the rigorously monitored cellular microenvironment by hampering the natural homeostatic mechanisms. The most common example of such hormonal glitch could be seen in obesity where the uprise in adipokine levels is in virtue of the expanding bulk of adipose tissue. Such aberrant endocrine signaling disrupts the regulation of cellular fate, rendering the cells to live in a tumor supportive microenvironment. Previously, it was believed that the adipokines support cancer proliferation and metastasis with no direct involvement in neoplastic transformations and tumorigenesis. However, the recent studies have reported discrete mechanisms that establish the direct involvement of adipokine signaling in tumorigenesis. Moreover, the individual adipokine profile of the patients has never been considered in the prognosis and staging of the disease. Hence, the present manuscript has focused on the reported extensive mechanisms that culminate the basis of poor prognosis and diminished survival rate in obese cancer patients.
  10. Fulltext Ethyl-p-methoxycinnamate isolated from Kaempferia galanga inhibits inflammation by suppressing interleukin-1, tumor necrosis factor-α, and angiogenesis by blocking endothelial functions
    Umar MI, Asmawi MZ, Sadikun A, Majid AM, Al-Suede FS, Hassan LE, et al.
    Clinics (Sao Paulo), 2014 Feb;69(2):134-44.
    PMID: 24519205 DOI: 10.6061/clinics/2014(02)10
    The present study aimed to investigate the mechanisms underlying the anti-inflammatory and anti-angiogenic effects of ethyl-p-methoxycinnamate isolated from Kaempferia galanga.
  11. Fulltext Antihyperglycemic Effect of Methanol Extract of Syzygium polyanthum (Wight.) Leaf in Streptozotocin-Induced Diabetic Rats
    Widyawati T, Yusoff NA, Asmawi MZ, Ahmad M
    Nutrients, 2015 Sep;7(9):7764-80.
    PMID: 26389944 DOI: 10.3390/nu7095365
    Syzygium polyanthum (S. polyanthum), a plant belonging to Myrtaceae, is widely used in Indonesian and Malaysian cuisines. Diabetic patients in Indonesia also commonly use it as a traditional medicine. Hence, this study was conducted to investigate the antihyperglycemic effect of the methanol extract (ME) of S. polyanthum leaf and its possible mechanisms of action. To test for hypoglycemic activity, ME was administered orally to normal male Sprague Dawley rats after a 12-h fast. To further test for antihyperglycemic activity, the same treatment was administered to glucose-loaded (intraperitoneal glucose tolerance test, IPGTT) and streptozotocin (STZ)-induced diabetic rats, respectively. Hypoglycemic test in normal rats did not show significant reduction in blood glucose levels (BGLs) by the extract. Furthermore, IPGTT conducted on glucose-loaded normal rats also did not show significant reduction of BGLs. However, repeated administration of metformin and three doses of ME (250, 500 and 1000 mg/kg) for six days caused significant reduction of fasting BGLs in STZ-induced diabetic rats. The possible mechanisms of action of S. polyanthum antihyperglycemic activity were assessed by measurement of intestinal glucose absorption and glucose uptake by isolated rat abdominal muscle. It was found that the extract not only inhibited glucose absorption from the intestine but also significantly increased glucose uptake in muscle tissue. A preliminary phytochemical qualitative analysis of ME indicated the presence of tannins, glycosides, flavonoids, alkaloids and saponins. Additionally, Gas Chromatography-Mass Spectrometry (GC-MS) analysis detected squalene. In conclusion, S. polyanthum methanol leaf extract exerts its antihyperglycemic effect possibly by inhibiting glucose absorption from the intestine and promoting glucose uptake by the muscles.
  12. Fulltext Bioactivity-Guided Fractionation and Identification of Antidiabetic Compound of Syzygium polyanthum (Wight.)'s Leaf Extract in Streptozotocin-Induced Diabetic Rat Model
    Widyawati T, Yusoff NA, Bello I, Asmawi MZ, Ahmad M
    Molecules, 2022 Oct 12;27(20).
    PMID: 36296407 DOI: 10.3390/molecules27206814
    (1) Background: An earlier study on the hypoglycemic activity of S. polyanthum (Wight.) leaf methanol extract identified squalene as the major chemical compound. The present study was conducted to assess the hypoglycemic effect of fractions and subfractions of the methanol extract of S. polyanthum compared to the squalene using a bioassay-guided in vivo study. (2) Methods: The methanol extract was fractionated using the liquid−liquid fractionation method. Streptozotocin-induced type 1 diabetic rat was used to study the hypoglycemic effect. (3) Results: The findings showed that chloroform fraction significantly (p < 0.05) lowered blood glucose levels of diabetic rats as compared to the control. Further fractionation of chloroform fraction yielded subfraction-1 and -2, whereby subfraction-1 exhibited a higher blood-glucose-lowering effect. The lipid profile test showed that the total cholesterol level of subfraction-1 and squalene-treated groups decreased significantly (p < 0.05). An immunohistochemistry study revealed that none of the treatments regenerated pancreatic β-cells. Gas chromatography−mass spectrophotometer analysis identified the presence of squalene in the active methanol extract, chloroform fraction, and subfraction-1. In silico analysis revealed a higher affinity of squalene against protein receptors that control lipid metabolism than metformin. (4) Conclusions: Data obtained from the present work suggested the crude methanol extract exerted the highest hypoglycemic effect compared to fraction, subfraction, and squalene, confirming synergistic effect may be responsible for the hypoglycemic activity of S. polyanthum.
  13. A new sesquiterpenoid from the rhizomes of Homalomena sagittifolia
    Wong KC, Hamid A, Eldeen IM, Asmawi MZ, Baharuddin S, Abdillahi HS, et al.
    Nat Prod Res, 2012;26(9):850-8.
    PMID: 21999629 DOI: 10.1080/14786419.2010.551770
    A new sesquiterpenoid, 1α,4β,7β-eudesmanetriol (1), was isolated together with the known compounds 1β,4β,7β-eudesmanetriol (2) and oplopanone (3) from the rhizomes of Homalomena sagittifolia. The structures of these compounds were determined by extensive spectral analyses. The compounds 1 and 2 inhibited growth of Pseudomonas stutzeri with a MIC value of 117 µM when evaluated for antibacterial activity using the minimum concentration assay. Both these compounds showed remarkable activities against acetylcholinesterase enzyme with IC(50) values ranging between 25 and 26 µM. The isolation of these sesquiterpenoids and their biological activities observed in this study support the reported traditional uses of H. sagittifolia for the treatment of microbial related diseases and central nervous system disorders.
  14. Fulltext Antioxidant and toxicity studies of 50% methanolic extract of Orthosiphon stamineus Benth
    Yam MF, Lim CP, Fung Ang L, Por LY, Wong ST, Asmawi MZ, et al.
    Biomed Res Int, 2013;2013:351602.
    PMID: 24490155 DOI: 10.1155/2013/351602
    The present study evaluated the antioxidant activity and potential toxicity of 50% methanolic extract of Orthosiphon stamineus (Lamiaceae) leaves (MEOS) after acute and subchronic administration in rats. Superoxide radical scavenging, hydroxyl radical scavenging, and ferrous ion chelating methods were used to evaluate the antioxidant properties of the extract. In acute toxicity study, single dose of MEOS, 5000 mg/kg, was administered to rats by oral gavage, and the treated rats were monitored for 14 days. While in the subchronic toxicity study, MEOS was administered orally, at doses of 1250, 2500, and 5000 mg/kg/day for 28 days. From the results, MEOS showed good superoxide radical scavenging, hydroxyl radical scavenging, ferrous ion chelating, and antilipid peroxidation activities. There was no mortality detected or any signs of toxicity in acute and subchronic toxicity studies. Furthermore, there was no significant difference in bodyweight, relative organ weight, and haematological and biochemical parameters between both male and female treated rats in any doses tested. No abnormality of internal organs was observed between treatment and control groups. The oral lethal dose determined was more than 5000 mg/kg and the no-observed-adverse-effect level (NOAEL) of MEOS for both male and female rats is considered to be 5000 mg/kg per day.
  15. Screening of stepping forces in an arthritic rat model using a novel analgesic meter and data acquisition system
    Yam MF, Ahmad M, Por LY, Ang LF, Basir R, Asmawi MZ
    Sensors (Basel), 2012;12(7):9603-12.
    PMID: 23012561
    The stepping forces of normal and Freund Complete Adjuvant (FCA)-induced arthritic rats were studied in vivo using a proposed novel analgesic meter. An infrared charge-coupled device (CCD) camera and a data acquisition system were incorporated into the analgesic meter to determine and measure the weight of loads on the right hind paw before and after induction of arthritis by FCA injection into the paw cavity. FCA injection resulted in a significant reduction in the stepping force of the affected hind paw. The stepping force decreased to the minimum level on day 4 after the injection and then gradually increased up to day 25. Oral administration of prednisolone significantly increased the stepping forces of FCA-induced arthritic rats on days 14 and 21. These results suggest that the novel device is an effective tool for measuring the arthritic pain in in vivo studies even though walking is a dynamic condition.
  16. Fulltext A simple isocratic HPLC method for the simultaneous determination of sinensetin, eupatorin, and 3'-hydroxy-5,6,7,4'-tetramethoxyflavone in Orthosiphon stamineus extracts
    Yam MF, Mohamed EA, Ang LF, Pei L, Darwis Y, Mahmud R, et al.
    J Acupunct Meridian Stud, 2012 Aug;5(4):176-82.
    PMID: 22898066 DOI: 10.1016/j.jams.2012.05.005
    Orthosiphon stamineus extracts contain three flavonoids (3'-hydroxy-5,6,7,4'-tetramethoxyflavone, sinensetin, and eupatorin) as bioactive substances. Previous reported high performance liquid chromatography- ultraviolet (HPLC-UV) methods for the determination of these flavonoids have several disadvantages, including unsatisfactory separation times and not being well validated according to International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) standard guidelines. A rapid, specific reversed-phase HPLC method with isocratic elution of acetonitrile: isopropyl alcohol: 20mM phosphate buffer (NaH(2)PO(4)) (30:15:55, v/v) (pH 3.5) at a flow-rate of 1ml/minute, a column temperature of 25°C, and ultraviolet (UV) detection at 340 nm was developed. The method was validated and applied for quantification of different types of O stamineus extracts and fractions. The method allowed simultaneous determination of 3'-hydroxy-5,6,7,4'-tetramethoxyflavone, sinensetin, and eupatorin in the concentration range of 0.03052-250 μg/ml. The limits of detection and quantification, respectively, were 0.0076 and 0.061 μg/ml for 3'-hydroxy-5,6,7,4'-tetramethoxyflavone, 0.0153 and 0.122 μg/ml for sinensetin and 0.0305 and 0.122 μg/ml for eupatorin. The percent relative standard deviation (% RSD) values for intraday were 0.048-0.368, 0.025-0.135, and 0.05-0.476 for 3'-hydroxy-5,6,7,4'-tetramethoxyflavone, sinensetin, and eupatorin, respectively, and those for intraday precision were 0.333-1.688, 0.722-1.055, and 0.548-1.819, respectively. The accuracy for intraday were 91.25%-103.38%, 94.32%-109.56%, and 92.85%-109.70% for 3'-hydroxy-5,6,7,4'-tetramethoxyflavone, sinensetin, and eupatorin, respectively, and those for interday accuracy were 97.49%-103.92%, 103.58%-104.57%, and 103.9%-105.33%, respectively. The method was found to be simple, accurate and precise and is recommended for routine quality control analysis of O stamineus extract containing the three flavonoids as the principle components in the extract.
  17. Fulltext Development of a stepping force analgesic meter for a rat arthritic model
    Yam MF, Por LY, Peh KK, Ahmad M, Asmawi MZ, Ang LF, et al.
    Sensors (Basel), 2011;11(5):5058-70.
    PMID: 22163890 DOI: 10.3390/s110505058
    Behavioural assessment of experimental pain is an essential method for analysing and measuring pain levels. Rodent models, which are widely used in behavioural tests, are often subject to external forces and stressful manipulations that cause variability of the parameters measured during the experiment. Therefore, these parameters may be inappropriate as indicators of pain. In this article, a stepping-force analgesimeter was designed to investigate the variations in the stepping force of rats in response to pain induction. The proposed apparatus incorporates new features, namely an infrared charge-coupled device (CCD) camera and a data acquisition system. The camera was able to capture the locomotion of the rats and synchronise the stepping force concurrently so that each step could be identified. Inter-day and intra-day precision and accuracy of each channel (there were a total of eight channels in the analgesimeter and each channel was connected to one load cell and one amplifier) were studied using different standard load weights. The validation studies for each channel also showed convincing results whereby intra-day and inter-day precision were less than 1% and accuracy was 99.36-100.36%. Consequently, an in vivo test was carried out using 16 rats (eight females and eight males). The rats were allowed to randomly walk across the sensor tunnel (the area that contained eight channels) and the stepping force and locomotion were recorded. A non-expert, but from a related research domain, was asked to differentiate the peaks of the front and hind paw, respectively. The results showed that of the total movement generated by the rats, 50.27 ± 3.90% in the case of the male rats and 62.20 ± 6.12% in that of the female rats had more than two peaks, a finding which does not substantiate the assumptions made in previous studies. This study also showed that there was a need to use the video display frame to distinguish between the front and hind paws in the case of 48.80 ± 4.01% of the male rats and 66.76 ± 5.35% of the female rats. Evidently the assumption held by current researchers regarding stepping force measurement is not realistic in terms of application, and as this study has shown, the use of a video display frame is essential for the identification of the front and hind paws through the peak signals.
  18. Fulltext Antioxidant and hepatoprotective effects of Murdannia bracteata methanol extract
    Yam MF, Ang LF, Lim CP, Ameer OZ, Salman IM, Ahmad M, et al.
    J Acupunct Meridian Stud, 2010 Sep;3(3):197-202.
    PMID: 20869021 DOI: 10.1016/S2005-2901(10)60036-2
    Murdannia bracteata (C. B. Clarke) is a local plant that is widely used in Malaysia as a traditional remedy for various diseases of the kidney and liver, including inflammation and cancer. In the present study, we investigated the antioxidant and hepatoprotective activities of M. bracteata methanol extract (MB). 2,2'-diphenyl-1-picrylhydrazyl radical scavenging activity, lipid peroxidation inhibition and trolox equivalent antioxidant capacity of MB were determined. The hepatoprotective activity of MB was studied using a CCl(4)-induced liver toxicity model in rats. The hepatoprotective effect was assessed by monitoring the plasma malondialdehyde level and serum alanine transaminase and aspartate transaminase activities. Histopathological changes of hepatic tissue were also investigated. The results indicated that MB possessed potential antioxidant, lipid peroxidation inhibition and free radical scavenging activities. Pretreatment of rats with MB (500 mg/kg and 1000 mg/kg per os) before induction of CCl(4)-induced hepatotoxicity showed a dose-dependent reduction in the necrotic changes in hepatic tissue. The increases in plasma malondialdehyde level, serum alanine transaminase and aspartate transaminase activities were also significantly inhibited by MB. The total phenolic content of MB determined using Folin-Ciocalteu assay was found to be 10%. The results of the present study indicated that the hepatoprotective effect of MB is most likely due to its antioxidant and free radical scavenging properties.
  19. Fulltext HPLC and anti-inflammatory studies of the flavonoid rich chloroform extract fraction of Orthosiphon stamineus leaves
    Yam MF, Lim V, Salman IM, Ameer OZ, Ang LF, Rosidah N, et al.
    Molecules, 2010 Jun 21;15(6):4452-66.
    PMID: 20657453 DOI: 10.3390/molecules15064452
    The aim of the present study was to verify the anti-inflammatory activity of Orthosiphon stamineus leaf extracts and to identify the active compound(s) contributing to its anti-inflammatory activity using a developed HPLC method. Active chloroform extract of O. stamineus was fractionated into three fractions using a dry flash column chromatography method. These three fractions were investigated for anti-peritoneal capillary permeability, in vitro nitric oxide scavenging activity, anti-inflammatory and nitric oxide (NO) inhibition using carrageenan-induced hind paw edema method. The flavonoid rich chloroform extract fraction (CF2) [containing sinensetin (2.86% w/w), eupatorin (5.05% w/w) and 3'-hydroxy-5,6,7,4'-tetramethoxyflavone (1.101% w/w)], significantly reduced rat hind paw edema, NO and decreased dye leakage to peritoneal cavity at p < 0.05. IC(50) of in vitro NO scavenging of CF2 was 0.3 mg/mL. These results suggest that the anti-inflammatory properties of these CF2 may possibly be due to the presence of flavonoid compounds capable of affecting the NO pathway.
  20. Fulltext Anti-inflammatory and analgesic effects of Elephantopus tomentosus ethanolic extract
    Yam MF, Ang LF, Ameer OZ, Salman IM, Aziz HA, Asmawi MZ
    J Acupunct Meridian Stud, 2009 Dec;2(4):280-7.
    PMID: 20633503 DOI: 10.1016/S2005-2901(09)60069-8
    Elephantopus tomentosus is widely used in Asia, especially in Malaysia, for the treatment of pain and inflammation. In the present study, the analgesic and anti-inflammatory effects of a 95% ethanol extract of E. tomentosus were investigated in different experimental models. In the anti-inflammation study, 1000 mg/kg of extract significantly reduced carrageenan-induced hind paw edema (p < 0.05) and inhibited abdominal permeability compared with control (p < 0.01). The analgesic activity was assayed in several experimental models in mice: (1) hot plate, (2) tail flick, (3) writhing test; and rats: carrageenan-induced hyperalgesia pain threshold test. However, at the doses tested, no significant activity was found in the hot plate test and the tail flick test. E. tomentosus ethanol extract at 1000 mg/kg significantly (p < 0.05) increased hyperalgesia pain threshold and inhibited writhing activity. The results suggest that E. tomentosus ethanol extract at 1000 mg/kg dose is effective in anti-inflammatory and non-steroidal anti-inflammatory drug type anti-nociception activities.
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