Ninjin-yoeito activates ghrelin-responsive and unresponsive NPY neurons in the arcuate nucleus and counteracts cisplatin-induced anorexia

Reduced appetite or anorexia substantially deteriorates quality of life in various diseases including cancer, depression and heart failure. Furthermore, reduced appetite may stand upstream of sarcopenia and frailty. All these diseases are heavy burdens in the modern medicine and society. Therefore, the means that counteracts reduced appetite has been awaited, however, effective and well evidenced substance is not currently available. Ninjin-yoeito, a Japanese kampo medicine comprising twelve herbs has been used to treat anorexia. However, underlying mechanism is little known. Neuropeptide Y (NPY) and ghrelin are the most potent central and peripheral inducers of appetite, respectively. This study sought to determine whether Ninjin-yoeito influences NPY and/or ghrelin-responsive neurons in the hypothalamic arcuate nucleus (ARC), a feeding center. We isolated single…