phytoestrogens and Nervous-System-Diseases

Genistein (GEN) is a non-steroidal phytoestrogen that belongs to the isoflavone class. It is abundantly found in soy. Soy and its products are used as food components in many countries including India. The present review is focused to address roles of GEN in brain functions in the context of learning and memory as a function of aging and neurological disorders. Memory decline is one of the most disabling features observed during normal aging and age-associated neurodegenerative disorders namely Alzheimer's disease (AD) and Parkinson's disease (PD), etc. Anatomical, physiological, biochemical and molecular changes in the brain with advancement of age and pathological conditions lead to decline of cognitive functions. GEN is chemically comparable to estradiol and binds to estrogen receptors (ERs). GEN acts through ERs and mimics estrogen action. After binding to ERs, GEN regulates a plethora of brain functions including learning and memory; however detailed study still remains elusive. Due to the neuroprotective, anti-oxidative and anti-inflammatory properties, GEN is used to restore or improve memory functions in different animal models and humans. The present review may be helpful to understand roles of GEN in learning and memory during aging and neurological disorders, its direction of research and therapeutic perspectives.

Topics: Aging; Animals; Estradiol; Genistein; Humans; Nervous System Diseases; Phytoestrogens

Menopause jeopardizes the integrity of brain and makes it vulnerable to various diseases, both of psychiatric and degenerative nature. Exogenous estrogen supplementation confers neuroprotection but the results of Women's Health Initiative (WHI), Million Women Study (MWS) and incidence of endometrial cancer, breast cancer and venous thromboembolism reported with estrogen use have engendered doubts over its clinical translation for postmenopausal neurological disorders. Scientific community and general public have started recognizing the protective potential of phytochemicals in climacteric medicine. These phytochemicals are plant-derived, non-steroidal bioactive estrogenic compounds. Emerging preclinical studies have suggested that these phytochemicals display potential benefits in mitigating postmenopausal depression, anxiety, cerebral ischemia and cognitive dysfunction. Thus, the aim of present review is: a) to give an overview of neuroprotective action of estrogen, b) to address the chemical and pharmacological features of various classes of phytoestrogens, and c) to present preclinical and clinical evidence of effect of phytoestrogens on climacteric neurobiology with their possible mechanisms of action.

Topics: Climacteric; Humans; Nervous System Diseases; Neuroprotective Agents; Phytochemicals; Phytoestrogens