Research

Under the drug development and discovery programme, two principal areas of research have been identified; addiction science and infectious diseases. With natural products being the most consistent and successful source of drugs, work is being undertaken to source for potential compounds for opiate substitution therapy and infectious diseases. With our research strength in analytical science, isolation chemistry and pharmacology,  potential compounds from natural products will be first subjected to preclinical evaluation. In view of merging the strength of natural products with modern analytical techniques, scientific approaches as well as the establishment of their preclinical and clinical studies, the development of new functional compounds with high therapeutic value could be achieved within a short span of time.

Current Research Project:

• Opioid receptors ligand binding guided approach to evaluate indole alkaloids from Mitragyna speciosa and other Rubiaceae plants for the treatment of pain
• Mitragynine and analogs brain uptake, distribution and elimination kinetics in rats
• Development of a new mitragynine formulation for application in analgesic study
• Design and synthesi s of chemical library focused on opiate and anticancer activities (co-researcher)

People

Current PhD student (as main supervisor)

• Nelson Chear Jeng Yeou

Current MSc students (as main supervisor)

• Sangeeta Vani A/P Alagasamy

Publications

SELECTED PUBLICATIONS (FROM 2010)

1. Damodaran, T., Tan, B.W.L., Liao, P., Ramanathan, S., Keat, L.G., Hassan, Z. (2018) Clitoria ternatea L. root extract ameliorated the cognitive and hippocampal long-term potentiation deficits induced by chronic cerebral hypoperfusion in the rat. J Ethnopharmacol., 224, 381-390.
2. Jagabalan, J.D.Y., Murugaiyah, V., Zainal, H., Mansor, S.M., Ramanathan, S. (2018) Intestinal permeability of mitragynine in rats using in situ absorption model. J Asian Nat Prod Res. 1-13.
3. Singh, D., Narayanan, S., Vicknasingam, B.K., Prozialeck, W.C., Ramanathan, S., Zainal, H., Harun, S.N. (2018) Severity of Pain and Sleep Problems during Kratom (Mitragyna speciosa Korth.) Cessation among regular kratom users. J Psychoactive Drugs., 20, 1.
4. Lee, M.J., Ramanathan, S., Mansor, S.M., Yeong, K.Y., Tan, S.C. (2018) Method validation in quantitative analysis of phase I and phase II metabolites of mitragynine in human urine using liquid chromatography-tandem mass spectrometry. Anal Biochem., 543, 146.
5. Bendran, A.P., Murugaiyah, V., Ramanathan, S. (2016). Review on murine models available for dengue vaccine development. Indian Journal of Natural Products and Resources, 7 (3), 201-2016.
6. Venugopalan, S.K., Shanmugarajan, T.S., Navaratnam, V., Mansor, S.M., Ramanathan, S. (2016). Dexamethasone provoked mitochondrial perturbations in thymus: Possible role of N-acetylglucosamine in restoration of mitochondrial function. Biomed Pharmacother., 83, 1485-1492.
7. Rajan, V.P., Gunasekaran, S., Ramanathan, S., Murugaiyah, V., Samsudin, M.W., Din, L.B. (2016) Biological activities of four Parmotrema species of Malaysian origin and their chemical constituents. Journal of Applied Pharmaceutical Science, 6 (08), 036-043.
8. Gunasekaran, S., Rajan, V.P., Ramanathan, S., Murugaiyah, V., Samsudin, M.W., Din, L.B. (2016) Antibacterial and antioxidant activity of lichens Usnea rubrotincta, Ramalina dumeticola, Cladonia verticillata and their chemical constituents. Malaysian Journal of Analytical Science, 20 (1), 1-13.
9. Perumal, S., Mahmud, R., Ramanathan, S. (2015) Anti-infective potential of caffeic acid and epicatechin 3-gallate isolated from methanol extract of Euphorbia hirta (L.) against Pseudomonas aeruginosa. Nat Prod Res., 29 (18), 1766-1769.
10. Ponnusamy, Y., Chear, N.J.., Ramanathan, S., Lai, C.S. (2015) Polyphenols rich fraction of Dicranopteris linearis promotes fibroblast cell migration and proliferation in vitro. J Ethnopharmacol., 168, 305-314.
11. Ramanathan, S., Parthasarathy, S., Murugaiyah, V., Magosso, E., Tan, S.C., Mansor, S.M. (2015) Understanding the physicochemical properties of mitragynine, a principal alkaloid of Mitragyna speciosa, for preclinical evaluation. Molecules, 20 (3), 4915-4927.
12. Yan-Fen Lee, Nanthini Sridewi, Surash Ramanathan, Kumar Sudesh (2015) The influence of electrospinning parameters and drug loading on polyhydroxyalkanoate (PHA) nanofibers for drug delivery. International Journal of Biotechnology for Wellness Industries 4, 103-113.
13. Lee, M.J., Ramanathan, S., Ismail, R., Mansor, S.M., Ali, M.A., Tan, S.C. (2014) Stability test for the enzyme immunoassay reagents of mitragynine. Asian Pacific Journal of Tropical Disease, 4 (3), 244.
14. Hazim, A.I., Ramanathan, S., Parthasarathy, S., Muzaimi, M., Mansor, S.M. (2014) Anxiolytic-like effects of mitragynine in the open-field and elevated plus-maze tests in rats. J Physiol Sci., 64 (3), 161-169.
15. Annegowda, H.V., Tan, P.Y., Mordi, M.N., Ramanathan, S., Hamdan, M.R., Sulaiman, M.H., Mansor, S.M. (2013) TLC-bioautography-guided Isolation, HPTLC and GC-MS-assisted analysis of bioactives of Piper betle leaf extract obtained from various extraction techniques: In vitro evaluation of phenolic content, antioxidant and antimicrobial activities. Food Analytical Methods, 6 (3), 715-726.
16. Sabetghadam, A., Ramanathan, S., Sasidharan, S., Mansor, S.M. (2013) Subchronic exposure to mitragynine, the principal alkaloid of Mitragyna speciosa, in rats. J Ethnopharmacol., 146 (3), 815-823.
17. Parthasarathy, S., Ramanathan, S., Murugaiyah, V., Hamdan, M.R., Mohd Said, M.I., Lai, C.S., Mansor, S.M. (2013) A simple HPLC-DAD method for the detection and quantification of psychotropic mitragynine in Mitragyna speciosa (ketum) and its products for the application in forensic investigation. Forensic Sci Int., 226 (1-3), 183-187.
18. Aruldass, C.A., Marimuthu, M.M., Ramanathan, S., Mansor, S.M., Murugaiyah, V. (2013) Effects of Mesua ferrea leaf and fruit extracts on growth and morphology of Staphylococcus aureus. Microsc Microanal., 19 (1), 254-260.
19. Rajoo, A., Sasidharan, S., Jothy, S.L.., Ramanathan, S., Mansor, S.M. (2013) Ultrastructural study of Elaeis guineensis (oil palm) leaf and antimicrobial activity of its methanol extract against Staphylococcus aureus. Tropical Journal of Pharmaceutical Research 12 (3), 419-423.
20. Perumal, S., Mahmud, R., Piaru, S.P., Lee, W.C., Ramanathan, S. (2013) Antiradical and cytotoxic activities of varying polarity extracts of the aerial part of Euphorbia hirta L. Journal of Chemistry, Article ID 983253.
21. Annegowda, H.V., Gooi, T.S., Awang, S.H.H., Alias, N.A., Mordi, M.N., Ramanathan, S., Mansor, S.M. (2012) Evaluation of analgesic and antioxidant potency of various extracts of Cinnamomum iners bark. International Journal of Pharmacology 8 (3), 198-203.
22. Annegowda, H.V., Mordi, M.N., Ramanathan, S., Hamdan, M.R., Mansor, S.M. (2012) Effect of extraction techniques on phenolic content, antioxidant and antimicrobial activity of Bauhinia purpurea: HPTLC determination of antioxidants. Food Analytical Methods, 5 (2), 226-233.
23. Nagaya, D., Ramanathan, S., Ravichandran, M., Navaratnam, V. (2012) A118G mu opioid receptor polymorphism among drug addicts in Malaysia. J Integr Neurosci., 11 (1), 117-122.
24. Perumal, S., Mahmud, R., Piaru, S.P., Lee W.C., Ramanathan, S. (2012) Potential antiradical activity and cytotoxicity assessment of Ziziphus mauritiana and Syzygium polyanthum. International Journal of Pharmacology, 8 (6), 535-541.
25. Perumal, S., Pillai, S., Lee W.C., Mahmud, R., Ramanathan, S. (2012) Determination of minimum inhibitory concentration of Euphorbia hirta (L.) extracts by tetrazolium microplate assay. Journal of Natural Products, 5, 68-76.
26. Perumal, S., Mahmud, R., Pillai, S., Lee, C.W., Ramanathan, S. (2012) Antimicrobial activity and cytotoxicity evaluation of Euphorbia hirta (L.) extracts from Malaysia. APCBEE Procedia, 2, 80-85.
27. Kamilla L., Ramanathan S., Sasidharan S., Mansor S.M. Toxicity evaluation of methanol extract of Clitoria ternatea L. Leaf. Malaysian Journal of Medicine and Health Sciences, 8 (2), 33-39.
28. Sahgal, G., Ramanathan, S., Sasidharan, S., Mordi, M.N., Ismail, S., Mansor, S.M. (2011) In vitro and in vivo anticandidal activity of Swietenia mahogani methanolic seed extract. Trop Biomed., 28 (1), 132-137.
29. Krudsood, S., Looareesuwan, S., Wilairatama, P., Leowattana, W., Tangpukdee, N., Chalermrut, K., Ramanathan, S., Navaratnam, V., Olliaro, P., Vaillant, M., Kiechel, J.R., Taylor, W.R.J.  (2011) Effect of artesunate and mefloquine in combination on the Fridericia corrected QT intervals in Plasmodium falciparum infected adults from Thailand. Trop Med Int Health, 16 (4), 458-465.
30. N.I. Mohd Ali, H.V. Annegowda, S.M. Mansor, S. Ismail, S. Ramanathan, M.N. Mordi. (2011) Phytochemical screening, antioxidant and analgesic activities of Croton argyratus ethanolic extracts. Journal of Medicinal Plants Research, 6 (21), 3724-3731.
31. Parthasarathy, S., Ramanathan, S., Ismail, S., Adenan, M.I., Mansor, S.M., Murugaiyah V. (2010) Determination of mitragynine in plasma with solid-phase extraction and rapid HPLC-UV analysis, and its application to a pharmacokinetic study in rat. Anal Bioanal Chem., 397 (5), 2023-2030.
32. Devaraj, S., Esfahani, A.S., Ismail, S., Ramanathan, S., Yam, M.F. (2010) Evaluation of the antinociceptive activity and acute oral toxicity of standardized ethanolic extract of the rhizome of Curcuma xanthorrhiza Roxb. Molecules, 15 (4), 2925-2934.
33. Azizi, J., Ismail, S., Mordi, M.N., Ramanathan, S., Said, M.I., Mansor, S.M. (2010) In vitro and in vivo effects of three different Mitragyna speciosa Korth leaf extracts on phase II drug metabolizing enzymes—glutathione transferases (GSTs). Molecules, 15 (1), 432-442.
34. Mustaffa, F., Indurkar, J., Ismail, S., Mordi, M.N., Ramanathan, S., Mansor, S.M. (2010) Analgesic activity, toxicity study and phytochemical screening of standardized Cinnomomum iners leaves methanolic extract. Pharmacognosy Res., 2 (2), 76-81.
35. Sabetghadam, A., Ramanathan, S., Mansor, S.M. (2010) The evaluation of antinociceptive activity of alkaloid, methanolic and aqueous extracts of Malaysia Mitragyna speciosa korth leaves in rats. Pharmacognosy Res., 2 (3), 181-185.
36. Sahgal, G., Ramanathan, S., Sasidharan, S., Mordi, M.N., Ismail, S., Mansor, S.M. (2010) Brine shrimp lethality and acute oral toxicity studies on Swietenia mahagoni (Linn.) Jacq. seed methanolic extract. Pharmacognosy Res., 2 (4), 215-220.
37. Melinda, K.P., Rathinam, X., Marimuthu, K., Diwakar, A., Ramanathan, S., Kathiresan, S., Subramaniam, S. (2010) A comparative study on the antioxidant activity of methanolic leaf extracts of Ficus religiosa L, Chromolaena odorata (L.) King & Rabinson, Cynodon dactylon (L.) Pers. and Tridax procumbens L.. Asian Pacific Journal of Tropical Medicine, 3 (5), 348-350.
38. Krishnan, N., Ramanathan, S., Sasidharan, S., Murugaiyah, V., Mansor, S.M. (2010) Antimicrobial activity evaluation of Cassia spectabilis leaf extracts. International Journal of Pharmacology, 6 (4), 510-514.
39. Krudsood, S., Looareesuwan, S., Tangpukdee, N., Wilairatana, P., Phumratanaprapin, W., Leowattana, W., Chalermrut, K., Ramanathan, S., Navaratnam, V., Olliaro, P., Vaillant, M., Kiechel, J.R., Taylor, W.R.J. (2010) New fixed-dose artesunate-mefloquine formulation against multidrug-resistant Plasmodium falciparum in adults: a comparative phase IIb safety and pharmacokinetic study with standard-dose nonfixed artesunate plus mefloquine. Antimicrob Agents Chemother., 54 (9), 3730-3737.
40. Rajoo, A., Ramanathan, S., Sasidharan, S., Mansor, S.M. (2010) Standardization of Elaeis guineensis with respect to authenticity, assay and chemical constituent analysis. African Journal of Biotechnology, 9 (44), 7544-7549.
41. Torey, A., Sasidharan, S., Latha, L.Y., Sudhakaran, S., Ramanathan, S. (2010) Antioxidant activity and total phenolic content of methanol extracts of Ixora coccinea. Pharm Biol., 48 (10), 1119-1123.
42. Mustaffa, F., Indurkar, J., Ismail, S., Mordi, M.N., Ramanathan, S., Mansor, S.M. (2010) Antioxidant capacity and toxicity screening of Cinnomomum iners standardized leaves methanolic extract. International Journal of Pharmacology, 6 (6), 888-895.
43. Annegowda, H.V., Mordi, M.N., Ramanathan, S., Mansor, S.M. (2010) Analgesic and antioxidant properties of ethanolic extract of Terminalia catappa L. leaves. International Journal of Pharmacology, 6 (6), 910-915.
44. Annegowda, H.V., Nee, C.W., Mordi, M.N., Ramanathan, S., Mansor, S.M. (2010) Evaluation of phenolic content and antioxidant property of hydrolysed extracts of Terminalia catappa L. leaf. Asian Journal of Plant Sciences, 9 (8), 479-485.
45. Annegowda, H., Anwar, L..N., Mordi, M.N., Ramanathan, S., Mansor, S.M. (2010) lnfluence of sonication on the phenolic content and antioxidant activity of Terminalia catappa L. leaves. Pharmacognosy Res., 2 (6), 368-373.
46. Devaraj, S., lsmail, S., Ramanathan, S., Marimuthu, S., Yam M.F. (2010) Evaluation of the hepatoprotective activity of standardized ethanolic extract of Curcuma xanthorrhiza Roxb. Journal of Medicinal Plant Research, 4 (23), 2512-2517.

Published Abstract

1. Pillai Rajan, V., Gunasekaran, S., Ramanathan, S., Murugaiyah, V., Samsudin, M.W., Din, L.B. (2015) Antibacterial activity of extracts of Parmotrema praesorediosum, Parmotrema rampoddense, Parmotrema tinctorum and Parmotrema reticulatum. AIP Conference Proceedings, 1678, 050015-1 - 050015-4 (2015); doi: 10.1063/1.4931294.