RESEARCH ARTICLE Bacopa monniera ameliorates cognitive impairment and neurodegeneration induced by intracerebroventricular- streptozotocin in rat: behavioral, biochemical, immunohistochemical and histopathological evidences M. Badruzzaman Khan & Muzamil Ahmad & Saif Ahmad & Tauheed Ishrat & Kumar Vaibhav & Gulrana Khuwaja & Fakhrul Islam Received: 2 March 2014 /Accepted: 10 July 2014 # Springer Science+Business Media New York 2014 Abstract The standardized extract of Bacopa monniera (BM) is a complex mixture of ingredients with a uniquely wide spectrum of neuropharmacological influences upon the central nervous system including enhanced learning and memory with known antioxidant potential and protection of the brain from oxidative damage. The present study demon- strates the therapeutic efficacy of BM on cognitive impairment and oxidative damage, induced by intracerebroventricular injection of streptozotocin (ICV-STZ) in rat models. Male Wistar rats were pre-treated with BM at a selected dose (30 mg/Kg) given orally for 2 weeks and then were injected bilaterally with ICV-STZ (3 mg/Kg), while sham operated rats were received the same volume of vehicle. Behavioral parameters were subsequently monitored 2 weeks after the surgery using the Morris water maze (MWM) navigation task then were sacrificed for biochemical, immunohistochemical (Cu/Zn-SOD) and histopathological assays. ICV-STZ-infused rats showed significant loss in learning and memory ability, which were significantly improved by BM supplementation. A significant increase in thiobarbituric acid reactive species and a significant decrease in reduced glutathione, antioxidant enzymes in the hippocampus were observed in ICV-STZ rats. Moreover, decrease in Cu/Zn-SOD expression positive cells were observed in the hippocampus of ICV-STZ rats. BM supplementation significantly ameliorated all alterations in- duced by ICV-STZ in rats. The data suggest that ICV-STZ Present Address: T. Ishrat Department of Clinical and Administrative Pharmacy, University of Georgia, Augusta, GA 30912, USA Present Address: K. Vaibhav Department of Medical Laboratory Imaging & Radiologic Sciences, Georgia Regents University, Augusta, GA 30912, USA Present Address: G. Khuwaja I F. Islam Neuroscience and Toxicology Unit, Faculty of Pharmacy, Jazan University, Jazan, Kingdom of Saudi Arabia M. Badruzzaman Khan and Muzamil Ahmad contributed equally to this work. M. B. Khan (*) : M. Ahmad : S. Ahmad : T. Ishrat : K. Vaibhav : G. Khuwaja : F. Islam (*) Neurotoxicology Laboratory, Department of Medical Elementology & Toxicology, Jamia Hamdard (Hamdard University), Hamdard Nagar, New Delhi 110062, India e-mail: mbkhan1@gmail.com e-mail: fislam2001@yahoo.co.in Present Address: M. B. Khan Department of Neurology, Georgia Regents University, 1120 15th Street, CB2614, Augusta, GA 30912, USA Present Address: M. Ahmad Pharmacology Division, Indian Institute of Intergrative Medicine (IIIM), Canal Road, Jammu 180001, India Present Address: S. Ahmad Department of Biological Science, Rabigh College of Science and Arts, King Abdul Aziz University, Rabigh Campus, Jeddah, Saudi Arabia Metab Brain Dis DOI 10.1007/s11011-014-9593-5