1. Department of Pharmacology, Faculty of Pharmacy, King Saud University, Riyadh, Saudi Arabia,
2. Pharmacology and Toxicology Department, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt,
3. Anatomy Department, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia, and
4. Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia