Amyloid beta (A beta) induced toxicity is an invitro neural degeneration model for Alzheimer's disease. Pregnenolone (P), pregnenolone sulphate (PS) are the major steroids produced in the neural tissue and are also called neuroactive steroids because of their behaviors like neurotransmitter. The synthesis of steroids in neural tissue could be changed by ischemia, oxidative stress or neurotoxicity namely induced by A beta, glutamate. The potential roles of P and PS in vital neuronal functions and in A beta peptide toxicity are not clearly identified. This work aims to investigate the effects of P, PS and A beta on the cell viability using two separate cell lines. The effects of conformational changes in A beta were also evaluated.