Parkinson's disease is neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in substantia nigra pars compacta. It is well known that the incidence of Parkinson's disease is lower in women as compared with men. Although the reason for this gender difference is not clear, the level of female steroid hormones or their receptors may be involved in pathogenesis. Neuroprotective effect of estrogen is well recognized but progesterone showed conflicting results regarding neuroprotection. This book emphasizes on role of progesterone in pathogenesis of parkinson's disease. In recent years, there has been renewed interest in plant medicine for the treatment against wide variety of diseases. Herbal medicines are recognized by WHO as an essential building block for primary health care, especially in developing countries like India. This book also accentuates potential of herb Ocimum sanctum against experimentally induced parkinsonism in rodents.