1. Faculty of Medicine, University of Malaya, Petaling Jaya, Kuala Lumpur 50603, Malaysia
2. Medicinal and Aromatic Plants Institute, National Centre for Research, Khartoum 1111, Sudan
3. Department of Pharmacology, Faculty of Pharmacy, University of Khartoum, Khartoum 1111, Sudan
4. UPM-MAKNA Cancer Research Laboratory, Institute of Biosciences, University of Putra Malaysia, Serdang, Selangor 43400, Malaysia
5. Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia