1 Department of Pharmacy , Faculty of Medicine , University of Malaya , 50603 Kuala Lumpur , Malaysia . Email: [email protected] ; Email: [email protected] ; ; Tel: +60 3 79674959
2 School of Pharmacy , Ningxia Medical University , Yinchuan , 750004 , P. R. China
3 Department of Pharmacology , Yong Loo Lin School of Medicine , National University of Singapore , 117597 , Singapore
4 Department of Oral Biology and Craniofacial Sciences and Oral Cancer Research and Coordinating Centre , Faculty of Dentistry , University of Malaya , 50603 Kuala Lumpur , Malaysia
5 Penang Medical College , 4 Jalan Sepoy Lines , 10450 George Town , Pulau Pinang , Malaysia
6 Department of Chemistry , Faculty of Science , University of Malaya , 50603 Kuala Lumpur , Malaysia